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  • 1
    facet.materialart.
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    Springer
    In:  Heidelberg, Springer, vol. 113, no. XVI:, pp. 1-14, (ISBN 1-56670-263-3)
    Publication Date: 1999
    Keywords: Handbook of geophysics ; Seismology ; Seismics (controlled source seismology) ; Early warning systems (earthquakes, volcanic eruptions, tsunamis etc.) ; Earthquake hazard ; KTB ; ICDP ; IOcean Drilling Program ; climate ; Antarctica ; Nuclear explosion ; Volcanology ; GeodesyY ; satellites ; remote ; sensing ; gas ; hydrates ; Geothermics ; Energy (of earthquakes) ; potable ; water ; waste ; soils ; evolution ; Geol. aspects ; geotechnics ; Engineering geophys. ; ores
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  • 2
    Electronic Resource
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    Entomologia experimentalis et applicata 57 (1990), S. 143-150 
    ISSN: 1570-7458
    Keywords: Bruchidae ; Callosobruchus maculatus ; competition ; development ; evolution ; fecundity ; growth rates ; host preferences ; life tables ; mortality ; natural selection ; net reproductive rate ; oviposition traits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le taux partiel de reproduction nette (R inf0 sup* ) dépend de l'espèce de la plante sur laquelle les œufs sont pondus et du nombre de larves entrant dans la graine. La survie larvaire est réduite par 1/(le nombre de larves par graine) parce qu'une seule larve se développe dans une graine. La fécondité n'est pas modifiée par la compétition subie par les larves, la mortalité larvaire a l'effet le plus important sur R inf0 sup* . Les femelles éliminent ou réduisent la compétition larvaire en dispersant leurs œufs uniformément et font si peu d'erreurs avec une hyperdispersion que l'évolution d'un comportement plus précis n'accroîtrait R inf0 sup* que de 4% au maximum. Des femelles retournant à une distribution des œufs au hasard provoqueraient une réduction de R inf0 sup* de 25% au moins. Les légumineuses généralement cultivées dans l'Inde du Sud sont des hôtes acceptables quand elles sont présentées seules. Le choix des femelles entre 2 hôtes élève R inf0 sup* de 30% ou plus par rapport à une distribution au hasard. Les préférences les plus nettes concernent des combinaisons présentant la plus grande différence de R inf0 sup* . Les femelles qui hyperdispersent leurs œufs, choisissent leurs hôtes et évitent les pertes par compétition en empêchant que les œufs ne donnent plus de descendants que ne le ferait une ponte au hasard. Les particularités de la ponte sont variables et héritables. Les lignées se sélectionnent bien, en fonction de la dispersion de leurs œufs sur les graines, de la discrimination des plantes hôtes, et de la modulation de leur taux de ponte. La sélection naturelle maintient ces particularités du comportement d'une façon sédentaire.
    Notes: Abstract The deposition of eggs by this strain of Callosobruchus maculatus (Fab.) (Bruchidae: Coleoptera) departs from randomness in three ways; eggs are uniformly dispersed, oviposition rates drop when beans begin to carry 2 or more eggs, and there are sharp host preferences. Using random egg placement for the unspecialized condition, these traits are evaluated for their effect on a female's contributions of offspring to the next generation (R0, the net reproductive rate). The major increases in R0 result from females dispersing eggs so uniformly that larval competition is either reduced or eliminated. Females reduce their oviposition rate when the larva from an egg added to a bean is almost certain to die in competitive encounters. Host preferences and larval survival in a host are positively associated with the abundance of the host in South India. The three oviposition traits act together to give and R0 that is 25–50% than that of eggs placed at random. These traits are known to be variable and heritable, hence, the conditions necessary for natural selection are statisfied.
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  • 3
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    Entomologia experimentalis et applicata 80 (1996), S. 163-165 
    ISSN: 1570-7458
    Keywords: olfaction ; EAG ; sensory physiology ; antennal sensitivity ; interspecies hybrids ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 4
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    Entomologia experimentalis et applicata 91 (1999), S. 359-368 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ssp. arcuata ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; host plant range ; near-isogenic ; Y-linkage ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Y-linked gene (R-gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near-isogenic flea beetle lines were developed. The YE-line contained the Y-linked R-gene, and male larvae from this line survived on B. vulgaris. The ST-line did not contain the gene and did not survive on the plant. The YE-line had been developed through 8–9 generations of backcrosses (YE-males with ST-females) and the two lines were considered to be isogenic except for genes located on the Y-chromosome. A single copy of the Y-linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R-genes. The Y-linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y-linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade-offs of the Y-linked gene were discovered. The results suggest that the occurrence of the Y-linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
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  • 5
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    Entomologia experimentalis et applicata 86 (1998), S. 175-182 
    ISSN: 1570-7458
    Keywords: Aleyrodidae ; greenhouse whitefly ; nitrogen ; host selection ; oviposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tomato plants, Lycopersicon esculentum Miller cv 'Tres Cantos', were supplied with high (308 ppm), medium (140 ppm) and low (84 ppm) nitrogen doses in order to determine the influence of nitrogen fertilization on feeding and oviposition site selection by greenhouse whitefly adults, T. vaporariorum (Westwood). The nitrogen and water content was higher in plants supplied with 308 N ppm than in plants with medium or low nitrogen doses and no differences were found in soluble sugar content. The leaves of the upper plant stratum (leaves 1–5) had the greatest nitrogen and water content, independent of the nitrogen dose applied. The plants were exposed to T. vaporariorum adults into a greenhouse under two current (late autumn-winter and spring-early summer) situations of the tomato crop in the Mediterranean area. The distribution of whitefly adults on the plants was affected by the nitrogen dose in both experimental conditions, the number of adults was higher on the plants supplied with high nitrogen dose. Within plants, adult distribution was affected by leaf position, the upper plant stratum being preferred for feeding. Whitefly females selected for oviposition and laid more eggs on plants and leaves of plants with higher nitrogen and water contents. We conclude that whitefly host selection for feeding and ovipositing are related to differences in nitrogen and water content of the host plant.
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  • 6
    ISSN: 1570-7458
    Keywords: fecundity ; host plant quality ; Pistia stratiotes ; Spodoptera pectinicornis ; nitrogen ; trichomes ; oviposition ; biological control of weeds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We determined the influence of larval host quality of the floating aquatic weed Pistia stratiotes L. (Araceae) on the fecundity and egg distribution of the biological control agent Spodoptera pectinicornis (Hampson) (Lepidoptera: Noctuidae). Different nutritional levels were produced by growing plants with relatively low and high levels of nitrogen, phosphorus and potassium fertilizer. Female and male pupal biomass were significantly greater when the larvae were fed leaves from the high fertilizer plants. Although the fertilizer treatments did not significantly influence total fecundity, there was an indirect effect as adults from larger pupae were more fecund. Regardless of treatment, ovipositing females formed a depression in the leaf surface by removing trichomes into which they deposited the egg masses. Most of the egg masses were laid on the lower leaf surface, on leaf positions 5–8 (counting from the young inner to the outer leaves) and during days 1–2 post-eclosion. Most of the eggs were laid in masses but about 12% were solitary. Females fed the low fertilizer treatment laid a greater proportion (mean ± s.e.) of their eggs as solitary eggs (17.3 ± 3.4% of total eggs) than did females fed the high fertilizer treatment (8.3 ± 2.3% of total eggs). The increased percentage of solitary eggs laid by the females from the low quality larval diet may be an adaptive response to decrease competition among the progeny.
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  • 7
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    Acta biotheoretica 46 (1998), S. 141-156 
    ISSN: 1572-8358
    Keywords: locomotion ; Squamata ; lizards ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In lower quadrupedal vertebrates locomotor efficiency seems to result from the associate movements of the axial and appendicular systems, which are totally independent in structure and embryological origin. The curvature of the trunk, produced by a standing wave, magnifies the propulsive action of the limbs. In intermediate forms, the association of an elongate trunk with limbs reduced in size brings about functional consequences which may be noticeably diverse according to the degree of trunk elongation and limb reduction. According to environmental constraints, animals search for better locomotor efficiency, which implies the maintenance or breakage of this association of both locomotor systems. In some cases, limb action on the ground is added to the axial wave action through a perfect mutual adjustment of rhythmic activity, until mechanical inefficiency of the limbs is reached by possible loss of contact with the ground. In other cases, the limbs dragged on the ground during the stance phase act against the axial action or, on the contrary, are inhibited by the axial system. A review of available data tries to contribute to an understanding of the respective roles of both systems in the transition to limblessness.
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  • 8
    ISSN: 1570-7458
    Keywords: Bemisia argentifolii ; Encarsia formosa ; poinsettia ; parasitoids ; nitrogen ; tri-trophic level interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract More wasps of Encarsia formosa Gahan (Hymenoptera: Aphelinidae) were found on fertilized poinsettias, Euphorbia pulcherrima (Willd.) (Euphorbiaceae), than on non-fertilized plants. Parasitization of Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae) by E. formosa was higher on plants treated with calcium nitrate than with ammonium nitrate or on control plants. In a no-choice test, host feeding by E. formosa was higher when hosts were on fertilized plants than when hosts were on control plants. The nitrogen content of whitefly pupae reared on plants treated with ammonium nitrate was higher than those on calcium nitrate-treated plants. Variability in the parasitization of B. argentifolii by E. formosa appears to be due to host plant-mediated differences in the whiteflies. E. formosa may be influenced by the nutritional suitability of the host, which influences whether wasps continue to oviposit, feed, or disperse.
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  • 9
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    Entomologia experimentalis et applicata 80 (1996), S. 7-13 
    ISSN: 1570-7458
    Keywords: host-plant selection ; sensory physiology ; neural coding ; deterrents ; peripheral interactions ; receptor sites ; genetics of insects ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent advances in our understanding of the relationship between chemosensory and behavioural responses to phytochemicals come from a number of studies on ovipositional and food selection behaviour of flies, butterflies, moths and beetles. Establishing input-output relationships has provided insight into the way in which the activity of chemoreceptors is translated into host-plant selection behaviour. This was achieved for both the qualitative contrast acceptance/rejection and for quantifiable preference hierarchies. By now it is clear that the subtlety of coding the complex phytochemical profiles offered by potential host plants relies on across-fibre patterns or ensemblefiring of taste neurons. Progress along these lines depends on unravelling processing pathways in the central nervous system, still a largely unexplored area in herbivorous insects. Increased interest can be noted for the mechanisms operating during the most peripheral events of chemoreception: the interaction of phytochemical and chemoreceptor, determining the specificity of recognition. Evidence for ‘peripheral integration’ has accumulated. Deterrent receptors have an especially puzzling nature. Although such cells respond to a wide array of structurally diverse secondary plant metabolites, their sensitivity profile differs between closely related species. To what extent membrane-bound receptor molecules are involved and what degree of specificity is conferred by these, is largely unknown. Sensitivity to a certain group or class of compounds is determined by single genes in several cases. This allows for a scenario in which single gene mutations affect stimulus-receptor interactions, which might concurrently affect host-plant selection behaviour.
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  • 10
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    Entomologia experimentalis et applicata 80 (1996), S. 320-324 
    ISSN: 1570-7458
    Keywords: multitrophic interactions ; phylogeny ; evolution ; fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 11
    ISSN: 1570-7458
    Keywords: Brassica rapa ; B. juncea ; consumption rate ; glucosinolates ; growth rate ; indolyl ; isothiocyanate ; Mamestra configurata ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mamestra configurata (Walker) (Lep., Noctuidae) larvae were fed excisedBrassica juncea (commercial brown mustard) orB. rapa cv. Tobin (Canola) foliage of three plant growth stages-rosette (stage 2), stem elongation (stage 3) and flowering (stage 4). Relative consumption rates (RCRi) were not significantly different between the plant species. Within theB. juncea treatments, there were no significant growth stage differences in RCRi. However, withinB. rapa, RCRi increased with advancing plant growth stage. Larvae fedB. juncea foliage had significantly reduced relative growth rates (RGRi) compared to larvae fedB. rapa foliage. Within theB. juncea treatments, RGRi decreased with advancing plant growth stage. There were no significant growth stage differences in RGRi in theB. rapa treatments. RGRi was inversely proportional to the levels of isothiocyanate-releasing glucosinolates in theB. juncea treatments. RCRi was inversely proportional to the levels of indolyl glucosinolates in theB. rapa treatments. Levels of total phenols and catechols inB. juncea did not show any trend which could be related to growth stage effects in the insect nutritional indices. InB. rapa, levels of phenols and catechols in stage 3 and 4 foliage were lower than that of stage 2 foliage. Analyses of total nitrogen in field-grown plants showed reductions in percent nitrogen from rosette to flowering stage foliage. The response ofM. configurata to different growth stages of its host plants are discussed in relation to changing levels of allelochemicals and nitrogen.
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  • 12
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    Entomologia experimentalis et applicata 92 (1999), S. 205-216 
    ISSN: 1570-7458
    Keywords: Samea multiplicalis ; Spodoptera pectinicornis ; Pistia stratiotes ; waterlettuce ; nitrogen utilization efficiency ; compensatory feeding ; nitrogen ; biological control of weeds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Compensatory responses of caterpillars fed low quality food include increased consumption and utilization of essential nutrients. Information about an insect's responses to nutritional challenges from their host plants could benefit weed biological control efforts in the selection and establishment of new agents. The target weed, Pistia stratiotes L. (Araceae) is a floating aquatic plant that has relatively low nitrogen levels which are further diluted with high water content. Efforts to establish the insect Spodoptera pectinicornis (Hampson) (Lepidoptera: Noctuidae) for biological control of P. stratiotes could benefit by examining the nutritional responses of a similar widely established lepidopteran species, Samea multiplicalis (Guenèe) (Lepidoptera: Pyralidae). Larvae of this species were fed leaves of P. stratiotes plants that had been fertilized (NPK) at high and low rates. The leaves of the fertilized plants had a 4.3-fold increase in nitrogen (dry weight) and a 1.6-fold increase in water content. The results suggest that no compensatory increases occurred in larvae fed leaves from the low fertilized plants as no changes were found in fresh mass consumption or nitrogen utilization efficiency. Consequently, development time from second-third instars to pupation was delayed about 3 days compared with larvae fed the high nitrogen leaves. Furthermore, consumption of nitrogen was only 30% and its accumulation into larval tissues was only 60% compared with the larvae fed the high fertilized leaves. The resulting larvae had both a final biomass and a growth rate that were reduced by 40%. Regardless of plant fertilizer level, the larvae fed at a rate 5–10 times greater than that of similar lepidopteran species consuming either low or high quality diets, suggesting that the S. multiplicalis larvae may be functioning at their biological limit for ingesting food.
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  • 13
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    Entomologia experimentalis et applicata 91 (1999), S. 29-35 
    ISSN: 1570-7458
    Keywords: chemoreception ; deterrents ; Pieris ; Brassicaceae ; cardenolides ; host-plant selection ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
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  • 14
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    Acta biotheoretica 47 (1999), S. 29-40 
    ISSN: 1572-8358
    Keywords: Sexual selection ; mate selection ; gamete selection ; evolution ; ploidy ; asssortative mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for 'good genes' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the most successful mate selection strategies are those based on assortative mating or on advantageous genes.
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  • 15
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    Entomologia experimentalis et applicata 60 (1991), S. 173-182 
    ISSN: 1570-7458
    Keywords: Genetics ; evolution ; host adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When populations are exposed to different environments, evolutionary processes can lead either to genetically differentiated strains or to the appearance of increased generalism at the individual level. For evolution to occur, genetic variability in performance in different environments is required. Here, intraspecific genetic variation across environments was estimated in the flour beetle Tribolium castaneum (Herbst) by comparing the responses of two strains of T. castaneum to different flour types. Replicated groups from each strain were allowed to develop on either the standard whole wheat medium or on one of four novel flours (wheat, rice, corn and oat). In several of the novel flours, clear differences in mean development time or population size of one or both strains were seen relative to performance in the standard medium. Moreover, the strains differed significantly in their phenotypic responses to the flours. One strain did particularly poorly on oat flour. Reduced oviposition, reduced larval survivorship and increased larval cannibalism were examined as possible causes of the low productivity on oat flour. These three factors accounted for about 70% of the reduction in population size when this strain oviposited and developed in oat flour. The difference between these two outbred strains in response to these five flours suggests that genetic variation in resource use is present within T. castaneum and may also be present within strains and natural populations in grain storage facilities. Such variation would permit an evolutionary response to selection in multiple environments (flours). This process has agricultural implications when several types of grain are stored in a single location because it could eventually lead to the evolution of highly generalized populations of T. castaneum, an important pest of stored products.
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  • 16
    ISSN: 1570-7458
    Keywords: Coleoptera ; bruchidae ; anesthesia ; carbon dioxide ; nitrogen ; cold ; oviposition and mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of anesthetizing with carbon dioxide, nitrogen, or low temperature on the reproductive behavior and fecundity of Callosobruchus subinnotatus was investigated. Males and females anesthetized with N2 as virgins had shorter recovery time, copulated earlier, and had shorter mating time than those subjected to CO2 or low temperature. Exposure of males and females to 2.0±0.5 °C for 10 min had the most profound effect on the recovery periods, copulation time, and duration of mating. Adults anesthetized with CO2 and low temperature laid fewer eggs than those anesthetized with N2. Females were more affected than males by the treatments, except when males were chilled for 10 min, and this prolonged the time for commencement of mating. The mode of anesthesia could affect egg production because vitellogenesis and choriogenesis take place in the imago stage of bruchids.
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  • 17
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    Entomologia experimentalis et applicata 64 (1992), S. 225-238 
    ISSN: 1570-7458
    Keywords: Lymantria dispar (L.) ; diet switching ; nitrogen ; specialization ; plant-animal interactions ; insect behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gypsy moth (Lymantria dispar (L.) (Lepidoptera: Lymantriidae)) larvae were reared from hatch on 1.25% N or 3.5% N artificial diet (previous diet) and switched reciprocally to the other diet (current diet) after molting into the second, third, fourth, or fifth instar. The nitrogen concentration of food consumed during previous instars had a strong residual effect on the growth rate in subsequent instars when a diet switch was made during instars two through four, but did not affect growth rate of fifth-instar larvae despite effects on food consumption and utilization. In early instars, larvae reared on 1.25% N artificial diet and then switched to 3.75% N diet had lower mass-adjusted growth rates than larvae continuously reared on 3.75% N diet. Conversely, larvae reared on 3.75% N diet and switched to 1.25% N had higher mass-adjusted growth rates than larvae reared continuously on 1.25% N diet. Relative to larvae previously reared on 1.25% N diet, fifth-instar male larvae previously reared on 3.75% N diet had slightly lower consumption rates, higher net growth efficiency (ECD), and higher gross growth efficiency (ECI). Larvae previously reared on 3.75% N diet tended to have lower food assimilation efficiency (AD) and lower nitrogen assimilation efficiency (AD(N)). Although both previous and current diet nitrogen concentration strongly affected larval growth and food utilization, the interaction term between these was not significant for any response variables except ECD and ECI. Because the interaction term reflects the effect of switching per se, the results indicate that there was a metabolic cost associated with switching, but no inherent net cost or benefit of diet-switching to growth.
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  • 18
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    Entomologia experimentalis et applicata 61 (1991), S. 7-16 
    ISSN: 1570-7458
    Keywords: Plutella xylostella ; Trichoplusia ni ; Hellula phidilealis ; Artogeia rapae ; nitrogen ; population growth ; cabbage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of different nitrogen (N) fertilization rates (0, 45, 90, and 168 kg N/ha), plant nitrogen concentration, and plant biomass on abundance and population growth of diamondback moth, Plutella xylostella (L.), cabbage looper, Trichoplusia ni (Hübner), cabbage budworm, Hellula phidilealis (Walker), imported cabbageworm, Artogeia rapae (L.), and cross-striped cabbageworm, Evergestis rimosalis (Guenée), were investigated in Homestead and Sanford, Florida in 1987. The effects of these factors on the parasitization of P. xylostella were also examined. In Homestead, abundance of most insect pests and parasitized P. xylostella increased with an increase in the level of N applied and with an increase in plant biomass. Similar results were found in Sanford, although results were not consistently significant. Abundance of most insect pests was significantly positively correlated with plant N concentration. Multiple regression analyses indicated that foliar biomass was significantly more important than N fertilization rate and subsequent plant N concentration at predicting abundance of insect pests and parasitized P. xylostella on cabbage.
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  • 19
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    Entomologia experimentalis et applicata 82 (1997), S. 37-44 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; genetics ; sex-linkage ; X- and Y-chromosome ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A polymorphism in host plant exploitation has been discovered in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) where one resistant population is able to use Barbarea vulgaris R.Br. ssp. arcuata (Opiz.) Simkovics (Brassicaceae) as a host plant while a susceptible population is not. Crosses (F1, F2, and backcrosses) between the two flea beetle populations were made, and survival of the progeny on B. v. ssp. arcuata was measured. The ability of P. nemorum larvae to survive in this plant species depended on the presence of major, dominant genes (R-genes). The two most abundant R-genes in the resistant flea beetle population were X- and Y-linked, respectively. The use of B. v. ssp. arcuata as a natural host plant by the resistant population of P. nemorum seems to be an extension of the host plant range of the species. The role of sex-linked genes in the evolution of host range is discussed.
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  • 20
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    Entomologia experimentalis et applicata 82 (1997), S. 25-35 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; resistance ; host plant ; variation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several sorts of variation in the interaction between the insect, Phyllotreta nemorum L. (Coleoptera:Chrysomelidae:Alticinae), and the plant, Barbarea vulgaris R.Br. (Brassicaceae), have been discovered: 1) genetic differences in the levels of defences in the plant, 2) genetic differences in the ability of insects to cope with the plant defences, 3) seasonal variation in levels of defences in the plant, and 4) differences between leaf types in levels of defences. Two plant accessions were suitable for larval development throughout the season while the remaining nine accessions were more or less unsuitable for larvae from the ‘susceptible’ T-population at least at certain times of the year. All accessions were suitable for the ‘resistant’ E-population throughout the year. There was a seasonal variation in levels of defences in some accessions which were unsuitable for the T-population during the summer period when beetles were present, but not during autumn and spring when the beetle were hibernating. Upper (younger) cauline leaves of these accessions had higher levels of defences than lower (older) cauline leaves. The resistant E-population used B. vulgaris as a natural host plant while the susceptible T-population did not. The use of B. vulgaris as a natural host plant by the E-population of P. nemorum seems to be an extension of the host plant range of the species. Variation in plant defences may have facilitated the switch in host plant use by the resistant flea beetle population.
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    Entomologia experimentalis et applicata 77 (1995), S. 205-210 
    ISSN: 1570-7458
    Keywords: nitrogen ; maize ; lepidopterous stem and cob borers ; Sesamia calamistis ; Eldana saccharina ; Mussidia nigrivenella ; Cryptophlebia leucotreta ; dead hearts ; stem tunneling ; yields
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    Topics: Biology
    Notes: Abstract The influence of four nitrogen levels (0, 60, 90 and 120 kg N/ha) on growth of maize and development of lepidopterous pests was investigatdd in a field trial. Nitrogen had a positive effect on both plant growth variables (plant height, stem diameter and yield), and development and survival ofSesamia calamistis andEldana saccharina, and thereby increased the incidence of dead hearts and stem tunneling. However, the percent yield loss due to artificial infestation decreased with increasing N application rate from 20% to 11% in the in the 0kg/ha and 120kg/ha treatment, respectively. Using a multiple regression analysis, plant height, plant diameter and stem tunneling were found to be the most important variables explaining the variability in maize yield.
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    Entomologia experimentalis et applicata 92 (1999), S. 165-177 
    ISSN: 1570-7458
    Keywords: Chrysomelidae ; herbivory ; Asteraceae ; life history ; nitrogen ; plant quality ; season
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    Topics: Biology
    Notes: Abstract Phytophagous insects which feed on the leaves of herbaceous host plants have to adapt their life histories to the fact that protein nitrogen is usually highest in growing tissues in spring. We monitored field populations of larvae and adults of three chrysomelid species (Galeruca tanaceti (L.) (main host Achillea millefolium (L.) Yarrow), Cassida rubiginosa (Mueller) (main host Cirsium arvense (L.) Scop.) and Oreina luctuosa (Suffrian) (host Centaurea scabiosa (L.)) together with the amount of protein nitrogen of their food resources and host plant biomass. As expected, the development of host quality, measured as concentration of protein nitrogen, and host plant biomass showed inverse trends during the season. The euryphagous G. tanaceti attacks Achillea early and profits from high nitrogen concentrations in the leaves. Occasional overexploitations of local populations of Achillea are compensated by the capacity to move to other host species. In C. rubiginosa, a species with a host range restricted to the Cardueae, the main larval feeding activity is postponed to a period when the nitrogen content of the host leaves had dropped to 50% of its initial value, but when host plant biomass had increased by 30%. In the monophagous O. luctuosa the larval development is synchronized with a still later phase of host phenology, at which the nitrogen content is below 50% but plant biomass has reached its maximum. There seem to be selection factors, which oppose the use of high quality food in spring and which force the latter two species to postpone their larval development to a later time in the year. This could be caused by numerous factors like, for example, mean daytime temperature. Later in the season the larvae have to cope with the low quality of their host plants. They have, however, the advantage of large quantities of food available. A laboratory study with adults and mature larvae of O. luctuosa shows that this species can overcome low levels of protein nitrogen either by selecting younger leaves with higher nitrogen concentrations or by increasing the daily food consumption rate (RCR) on leaves with a low level of nitrogen and by a prolongation of the feeding period. In this way the larvae compensate the effect of lower daily growth rates (RGR) and a lower food conversion index (ECI) on poor food quality: Regardless of the level of protein nitrogen there was no statistically significant difference in total gain of weight during the third-instar feeding period and in the weight at the end of the third larval stage. The three investigated chrysomelids show that there exists a broad spectrum of adaptations to overcome the dilemma of variable food quality.
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    Journal of insect behavior 6 (1993), S. 715-735 
    ISSN: 1572-8889
    Keywords: Aphrodisiac ; cockroach ; evolution ; mating behavior ; sex pheromone ; sternal glands ; tergal glands
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    Topics: Biology
    Notes: Abstract Two chemical signals are essential in all cockroach sexual behavioral sequences: the sex pheromone released by one partner, generally the female (for long distance attraction), and an aphrodisiac sex pheromone produced exclusively by male tergal glands (for female mounting and tergal contact or “feeding” behavior). Unlike the other cockroach groups, the males of the Oxyhaloinae species produce both chemical signals: the pheromone and the aphrodisiac. The occurrence of three patterns of mating behavior (A, B, and C), the production of male sex pheromones, and the existence in the male of developed sternal and tergal glands in seven related Oxyhaloinae species, make these cockroaches a useful model for studying the evolution of mating behavior patterns. The various types of mating behavior were not classified in the previous studies by Roth and Barth. In this report, they have been named type A (female in upper position), B (male in upper position), and C (male and female end to end). In type A mating, the male tergal glands, which are licked by the females, are well developed, whereas in types B and C, there is no licking of the male's tergal secretion by the females and the tergal glands are much less developed; the aphrodisiacs secreted by the tergal glands may no longer act in this case through contact chemoreception, but through an olfactory process involving volatile components. One common sex pheromone component seems to be acetoin. I suggest that the mating behavior tends from A toward B and C during the evolutionary process with a concomitant regression of the tergal glands and changes in the aphrodisiac emission levels. The mating behavioral sequences of cockroaches (Dictyoptera) and crickets (Orthoptera) show a striking degree of similarity and are probably examples of convergent evolution.
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  • 24
    ISSN: 1572-8927
    Keywords: Supersaturation ; nitrogen ; cosolvent ; cetyltrimethylammonium bromide
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    Topics: Chemistry and Pharmacology
    Notes: Abstract The decomposition of ammonium nitrite in water creates a supersaturated solution of nitrogen. The same process occurs in water-organic solvent mixtures. Acetone, dioxane, dimethylsulfoxide (DMSO) and dimethylformamide (DMF) are the cosolvents used in this study. The limits of supersaturation of nitrogen (C SL /mol L−1) were determined in all of these solvent mixtures by releasing the dissolved gas sonicationally and measuring the volume of released gas. C SL was generally increased in the presence of cosolvents. The effectiveness sequence of organic solvents was found to be as DMF〈DMSO〈Dioxanet≅Acetone. Transportation period of small bubbles formed during sonication is changed by compositions of solvent mixtures. These periods may depend on the viscosity of the solution. Effects of the presence of cetyltrimethylammonium bromide were also studied. It was concluded that there may be a relation between the strength of the watercosolvent H-bonds and C SL and all of the measured quantities of this study were generally affected by micelle formation.
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  • 25
    ISSN: 1572-8889
    Keywords: Belostomatidae ; giant water bugs ; paternal care ; eggs ; reproduction ; behavior ; brooding ; evolution
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    Topics: Biology
    Notes: Abstract Males of the giant water bug Lethocerus medius(Guerin) typify their monobasic subfamily, the Lethocerinae, in that they do not brood eggs attached to their backs as do males of all members of the subfamily Belostomatinae. Exclusive male parental investment as expressed in the Belostomatinae is extremely rare behavior among animals, and evolution of the trait is obscure. Lethocerus mediusmales apparently remain with their mates through oviposition and are consistently found in attendance of eggs after the female has departed. This behavior may enhance paternity assurance at no cost in opportunity for polygyny. Two double clutches of eggs were found, from which we infer the potential for polygynous matings and shared parental investment. Male L. mediusbrood attended egg clutches above the surface of the water, where they may moisten them, shade them, and defend them against predation. Egg attendance/brooding by L. mediusand other Lethocerusspecies may represent a plesiomorphic state from which paternal back- brooding evolved in the Belostomatinae.
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    Journal of insect behavior 11 (1998), S. 179-189 
    ISSN: 1572-8889
    Keywords: open-air foraging ; caste ; polyethism ; litter feeder ; nitrogen ; termite
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    Topics: Biology
    Notes: Abstract The Southeast Asian nasute termite Longipeditermes longipes forages on the open ground on leaf litter. Its monomorphic workers carry back food balls in their mandibles while dimorphic soldiers defensively surround the marching columns and the foraging patches. When mechanically disturbed, workers hide under the litter, whereas antennating soldiers face as closely as possible the source of disturbance. Foragers prefer the lower, nitrogen-rich layer of the litter. Soldier behavior and column organization (returning workers in the center lanes, outgoing workers in the two flanking lanes) are similar to those in the related genera Hospitalitermes and Lacessititermes, which, however, tend to forage above ground.
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    Catalysis letters 13 (1992), S. 45-53 
    ISSN: 1572-879X
    Keywords: Ammonia ; synthesis ; nitrogen ; rate-determining step ; potassium promotion
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    Topics: Chemistry and Pharmacology
    Notes: Abstract The simple concept of a single rate-determining step, the dissociation of N2(a), in ammonia synthesis is inconsistent with experimental results. It is proposed that three reaction steps, N2(a) → 2N(a) (1) N(a) + H(a)→NH(a) (2) NH3(a)→NH3(g) (3) are dominant in determining the rate of synthesis. Under industrial conditions reactions (2) and (3) are more important than (1). The role of K+ as promoter in these reactions is discussed, especially as an “anchor” for adsorbed oxygen.
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    Catalysis letters 16 (1992), S. 159-164 
    ISSN: 1572-879X
    Keywords: Chemisorption ; nitrogen ; carbon dioxide ; platinum ; water gas shift reaction
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    Topics: Chemistry and Pharmacology
    Notes: Abstract The relationship between sites responsible for nitrogen chemisorption and sites responsible for stronger adsorption of carbon dioxide on platinum black is reported. A 2 to 1 ratio has been found between molecules of more strongly adsorbed carbon dioxide and molecules of nitrogen chemisorbed on individual samples. This relationship has allowed us to deduce the structure of chemisorbed carbon dioxide. Carbon dioxide is relatively weakly chemisorbed on platinum. Reasons for the weakness of this chemisorption are discussed.
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    Catalysis letters 37 (1996), S. 163-165 
    ISSN: 1572-879X
    Keywords: nitrogen ; Rh(111) ; thermal desorption ; Arrhenius parameters ; lateral interactions ; NO decomposition
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Associative desorption of N atoms from the Rh(111) surface is simulated in the framework of the lattice-gas model. The Arrhenius parameters and nearest-neighbour lateral interaction employed to describe the measured thermal desorption spectra are as follows:v=1013 s−1,E d=40 kcal/mol, and ε1=1.7 kcal/mol. The results obtained are used to clarify the role of nitrogen desorption in the NO + CO reaction on Rh(111) atT=400–700 K andP NO≈P CO≈0.01 atm.
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    Aquatic sciences 53 (1991), S. 263-272 
    ISSN: 1420-9055
    Keywords: Lake ecosystem ; chl-a ; phosphorus ; nitrogen ; river flow ; thermocline ; simulation model ; multiple regression
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    Topics: Biology
    Notes: Abstract The management variables which primarily affect phytoplankton biomass (as chl-a) in Lake Mjøsa, Norway, are total phosphorus loading (TP) and the timing and volume of water through flow (by active storage reservoirs). The response of the lake to changes in these factors is studied using a simulation model of the lake ecosystem. Chl-a responses from both observed data and the simulated results are extracted by multiple regression. Results show that decreasing TP load decreases chl-a, but less at low TP levels (〈 10 mg TP · m−3). There is also a certain time period for peak river flow which gives the least yield of chl-a per unit TP. This time period occurs in early summer (i.e., around June 10) if the total phosphorus load is low, and later if the load is high. Both observations and simulation results show that a high water flow increases chl-a at low epilimnion depths (〈 15 m), but that the same high water flow decreases chl-a when epilmnion is deep.
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    Cellular and molecular life sciences 50 (1994), S. 521-523 
    ISSN: 1420-9071
    Keywords: Ancient DNA ; evolution ; conservation ; biology ; anthropology ; plant biology ; PCR (polymerase chain reaction)
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    Cellular and molecular life sciences 52 (1996), S. 14-24 
    ISSN: 1420-9071
    Keywords: Lycaenidae ; Formicidae ; symbiosis ; mutualism ; parasitism ; communication ; ecology ; evolution
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    Topics: Biology , Medicine
    Notes: Abstract Associations with ants, termed myrmecophily, are widespread in the butterfly family Lycaenidae and range from mere co-existence to more or less specific mutualistic or even parasitic interactions. Secretions of specialized epidermal glands are crucial for mediating the interactions. Transfer of nutrients (carbohydrates, amino acids) from butterfly larvae to ants plays a major role, but manipulative communication with the help of odour signals is also involved. By means of myrmecophily, lycaenid butterflies largely escape ant predation, and certain species gain protection through attendant ants or achieve developmental benefits from ant-attendance. Benefits to the ants range from minimal to substantial food rewards. While most lycaenid species maintain facultative relationships with a variety of ant genera, highly specific and obligatory associations have convergently evolved in a number of butterfly lineages. As a corollary, communication systems are largely unspecific in the former, but may be highly specialized in the latter. The sophisticated communication between obligate myrmecophiles and their host ants is tightly connected with the evolutionary rise of specialized life-cycles and thus is a source of augmenting diversity within the butterflies.
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  • 33
    ISSN: 1420-9071
    Keywords: Insect ; behaviour ; high-speed cinematography ; jumping ; electrophysiology ; evolution
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    Notes: Abstract The Indian antHarpegnathos saltator may be unique among insects in using its jumping capacity not only as an escape mechanism but also as a normal means of locomotion, and for catching its prey in flight. High-speed cinematography used to analyse the various phases of the jump suggests thatHarpegnathos employs a novel jumping mechanism to mediate these behaviours: namely the synchronous activation of its middle and hindlegs. Electrophysiological recordings from muscles or nerves in pairs of middle and hindlegs show remarkably synchronous activity during fictive jumping, supporting the synchronous activation hypothesis.Harpegnathos is not the only ant to jump, and a cladistic analysis suggests that jumping behaviour evolved independently three times during ant evolutionary history.
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    Cellular and molecular life sciences 46 (1990), S. 1106-1117 
    ISSN: 1420-9071
    Keywords: Genetic code ; eucaryotic cell ; evolution ; code ambiguity ; code universality ; convergence
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    Topics: Biology , Medicine
    Notes: Summary This article is a review of the rules used by eucaryotic cells to translate a nuclear messenger RNA into a polypeptide chain. The recent observation that these rules are not identical in two species of a same phylum indicates that they have changed during the course of evolution. Possible scenarios for such changes are presented.
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    Cellular and molecular life sciences 49 (1993), S. 1027-1036 
    ISSN: 1420-9071
    Keywords: Archaea (archaebacteria) ; extreme halophiles ; archaeol phospholipids ; archaeol glycolipids ; membrane function ; evolution
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    Notes: Abstract Archaebacteria (archaea) are comprised of three groups of prokaryotes: extreme halophiles, methanogens and thermoacidophiles (extreme thermophiles). Their membrane phospholipids and glycolipids are derived entirely from a saturated, isopranoid glycerol diether,sn-2,3-diphytanylglycerol (‘archaeol’) and/or its dimer, dibiphytanyldiglyceroltetraether (‘caldarchaeol’). In extreme halophiles, the major phospholipid is the archaeol analogue of phosphatidylglycerolmethylphosphate (PGP-Me); the glycolipids are sulfated and/or unsulfated glycosyl archaeols with diverse carbohydrate structure characteristic of taxons on the generic level. Biosynthesis of these archaeol-derived polar lipids occurs in a multienzyme, membrane-bound system that is absolutely dependent on high salt concentration (4 M). The highly complex biosynthetic pathways involve intermediates containing glycerol ether-linked C20-isoprenyl groups which are reduced to phytanyl groups to give the final saturated polar lipids. In methanogens, polar lipids are derived both from archaeol and caldarchaeol, and thermoacidophiles contain essentially only caldarchaeol-derived polar lipids. The function of these membrane polar lipids in maintaining the stability, fluidity and ionic properties of the cell membrane of extreme halophiles, as well as the evolutionary implications of the archaeol and caldarchaeol-derived structures will be discussed.
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    Cellular and molecular life sciences 48 (1992), S. 729-731 
    ISSN: 1420-9071
    Keywords: Urea cycle ; leech ; botryoidal tissue ; hirudineans ; evolution
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    Topics: Biology , Medicine
    Notes: Abstract Ornithine carbamoyltransferase (OCT) and arginase, but not arginine synthetase (AS), were detected in the body wall and gut tissues of the leech. The activities of these enzymes were not altered by starvation. The high activity of arginase in body wall is probably due to the association of the latter with botryoidal tissue. Hirudineans, which evolved from oligochaete ancestors, appear to have lost the citrulline-arginine segment of the urea cycle due to their ammonotelic mode of nitrogen excretion.
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    Cellular and molecular life sciences 50 (1994), S. 987-1001 
    ISSN: 1420-9071
    Keywords: Hsp70 ; evolution ; gene duplication ; gene homology
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    Topics: Biology , Medicine
    Notes: Abstract The family of genes encoding heat shock proteins of about 70 kDa (hsp70) in vertebrates is reviewed under genetic aspects. After a detailed description of the various hsp70 genes more general characteristics of the organization and evolution of the multigene family are discussed.
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    Cellular and molecular life sciences 49 (1993), S. 317-319 
    ISSN: 1420-9071
    Keywords: Chitin ; cuticle ; evolution ; vertebrates ; bony fish ; Blenniidae ; Paralipophrys trigoides
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    Topics: Biology , Medicine
    Notes: Abstract Lectin binding, endo-chitinase binding and enzymatic degradation studies show that the epidermal cuticle of the bony fishParalipophrys trigloides (Blenniidae) is chitinous. This is the first evidence that a vertebrate species possesses a chitinous tissue. Recently aXenopus gene has been identified which has significant sequence similarity to the catalytic domain of yeast chitin synthase III, a chitin producing enzyme1,2. Taken together these two findings imply that chitin synthesis capability may be a basic vertebrate feature.
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    Cellular and molecular life sciences 50 (1994), S. 429-437 
    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
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    Cellular and molecular life sciences 51 (1995), S. 454-464 
    ISSN: 1420-9071
    Keywords: Quantitative genetics ; life history ; evolution ; cladocera ; heritability ; Daphnia ; zooplankton
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    Topics: Biology , Medicine
    Notes: Abstract Quantitative genetic techniques are powerful tools for use in understanding the microevolutionary process. Because of their size, lifespan, and ease of culture, many zooplankton species are ideal for quantitative genetic approaches. As model systems, studies of zooplankton life histories are becoming increasingly used for examination of the central paradigms of evolutionary theory. Two of the fundamental empirical questions that zooplankton quantitative genetics studies can answer are: 1) How much genetic variance exists in natural populations for life history traits? 2) What is the empirical evidence for trade-offs that permeate life history theory based on optimality approaches? A review of existing data onDaphnia indicates substantial genetic variance for body size, clutch size, and age at first reproduction. Average broad-sense heritabilities for these three characters across 19 populations of 6 species are 0.31, 0.31, and 0.34, respectively. Although there is some discrepancy between the two pertinent studies that were designed to decompose the total genetic variance into its additive and non-additive components, a crude average seems to suggest that approximately 60% of the total genetic variance has an additive basis. The existing data are somewhat inconsistent with respect to presence/absence of trade-offs (negative genetic correlations) among life history traits. A composite of the existing data seems to argue against the existence of strong trade-offs between offspring size and offspring number, between present and future reproduction, and between developmental rate and fecundity. However, there is some evidence for a shift toward more negative (less positive) covariances in more stressful environments (e.g., low food). Zooplankton will prove to be very useful in future study in several important areas of research, including the genetics and physiology of aging, the importance of genotype-environment interaction for life history traits, and the evolution of phenotypic plasticity.
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    Cellular and molecular life sciences 52 (1996), S. 503-510 
    ISSN: 1420-9071
    Keywords: Drosophila ; accessory gland ; reproduction ; sexual behavior ; sperm displacement ; evolution
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    Topics: Biology , Medicine
    Notes: Abstract Recent results from biochemical and molecular genetic studies of the accessory gland proteins in maleDrosophila are reviewed. The most prominent feature is the species-specific variability. However, the analysis of the sex peptide inD. melanogaster shows that there is a strong homology in the molecular structure to the closely related sibling species, and that divergence increases with increasing phylogenetic distance. For this reason the sex peptide, after being transferred to the female genital tract during copulation, reduces receptivity and increases oviposition only in virgin females belonging to the same species group and subgroup. Even though studies were hitherto limited to a small number of the secretory components, it is evident that the accessory gland proteins play a key role in reproductive success of the fruit fly by changing female sexual behavior, supporting sperm transfer, storage and displacement. Thus, genes encoding the accessory gland proteins are apparently under strong evolutionary selection.
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    BioMetals 11 (1998), S. 277-295 
    ISSN: 1572-8773
    Keywords: evolution ; classification ; EF-hand ; domain ; homology ; chimera ; congruence ; gene duplication ; gene fusion ; eukaryote ; dendrogram ; calmodulin ; troponin C ; light chain of myosin ; S100 ; parvalbumin ; calcineurin ; recoverin ; calpain ; sorcin ; diacylglycerol ; calbindin ; aequorin ; phospholipase C ; BM-40
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Forty-five distinct subfamilies of EF-hand proteins have been identified. They contain from two to eight EF-hands that are recognizable by amino acid sequence as being statistically similar to other EF-hand domains. All proteins within one subfamily are congruent to one another, i.e. the dendrogram computed from one of the EF-hand domains is similar, within statistical error, to the dendrogram computed from another(s) domain. Thirteen subfamilies - including Calmodulin, Troponin C, Essential light chain, Regulatory light chain - referred to collectively as CTER, are congruent with one another. They appear to have evolved from a single ur-domain by two cycles of gene duplication and fusion. The subfamilies of CTER subsequently evolved by gene duplications and speciations. The remaining 32 subfamilies do not show such general patterns of congruence; however, some - such as S100, intestinal calcium binding protein (calbindin 9kd), and trichohylin - do not form congruent clusters of subfamilies. Nearly all of the domains 1, 3, 5, and 7 are most similar to other ODD domains. Correspondingly the EVEN numbered domains of all 45 subfamilies most closely resemble EVEN domains of other subfamilies. Many sequence and chem-ical characteristics do not show systemic trends by subfamily or species of host organisms; such homoplasy is widespread. Eighteen of the subfamilies are heterochimeric; in addition to multiple EF-hands they contain domains of other evolutionary origins.© Kluwer Academic Publishers
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  • 43
    ISSN: 1572-879X
    Keywords: adsorption ; adsorption isotherms ; dinitrogen ; FTIR spectroscopy ; geminal species ; NaY ; nitrogen ; zeolites
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Adsorption of N2 on NaY zeolites at 85 K and equilibrium pressures higher than 1 kPa results in the formation of geminal dinitrogen complexes characterized by an IR band at 2333.5 cm−1 (2255.4 cm−1 after adsorption of 15N2). With decreasing equilibrium pressure the complexes tend to loose one N2 ligand, thus forming linear species characterized by an IR band at 2336.8 cm−1 (2258.7 cm−1 after adsorption of 15N2). All species disappear completely after evacuation. Co-adsorption of N2 and CO revealed that the dinitrogen complexes are formed on Na+ cations. The changes in the concentrations of the linear and geminal N2 species with the changes in the equilibrium pressure are excellently described by equations of adsorption isotherms proposed earlier for mono- and di-carbonyls.
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    Minds and machines 6 (1996), S. 463-480 
    ISSN: 1572-8641
    Keywords: Human reasoning ; evolution ; deontic reasoning ; transitive reasoning ; non-human primates ; neocortical ratio ; dominance hierarchy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract Research from ethology and evolutionary biology indicates the following about the evolution of reasoning capacity. First, solving problems of social competition and cooperation have direct impact on survival rates and reproductive success. Second, the social structure that evolved from this pressure is the dominance hierarchy. Third, primates that live in large groups with complex dominance hierarchies also show greater neocortical development, and concomitantly greater cognitive capacity. These facts suggest that the necessity of reasoning effectively about dominance hierarchies left an indelible mark on primate reasoning architectures, including that of humans. In order to survive in a dominance hierarchy, an individual must be capable of (a) making rank discriminations, (b) recognizing what is forbidden and what is permitted based one's rank, and (c) deciding whether to engage in or refriin from activities that will allow one to move up in rank. The first problem is closely tied to the capacity for transitive reasoning, while the second and third are intimately related to the capacity for deontic reasoning. I argue that the human capacity for these types of reasoning have evolutionary roots that reach deeper into our ancestral past than the emergence of the hominid line, and the operation of these evolutionarily primitive reasoning systems can be seen in the development of human reasoning and domain-specific effects in adult reasoning.
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    Minds and machines 9 (1999), S. 309-346 
    ISSN: 1572-8641
    Keywords: language ; grammar ; syntax ; semantics ; evolution ; emergence ; brain size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract It is commonly argued that the rules of language, as distinct from its semantic features, are the characteristics which most clearly distinguish language from the communication systems of other species. A number of linguists (e.g., Chomsky 1972, 1980; Pinker 1994) have suggested that the universal features of grammar (UG) are unique human adaptations showing no evolutionary continuities with any other species. However, recent summaries of the substantive features of UG are quite remarkable in the very general nature of the features proposed. While the syntax of any given language can be quite complex, the specific rules vary so much between languages that the truly universal (i.e. innate) aspects of grammar are not complex at all. In fact, these features most closely resemble a set of general descriptions of our richly complex semantic cognition, and not a list of specific rules. General principles of the evolutionary process suggest that syntax is more properly understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution. It is argued that grammatical rules used in given languages are likely to be simply conventionalized, invented features of language, and not the result of an innate, grammar-specific module. The grammatical and syntactic regularities that are found across languages occur simply because all languages attempt to communicate the same sorts of semantic information.
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  • 46
    ISSN: 1572-8757
    Keywords: kinetics ; isotope-exchange ; nitrogen ; adsorption ; methane ; zeolite ; equilibria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Isotope Exchange Technique (IET) was used to simultaneously measure pure and binary gas adsorption equilibria and kinetics (self-diffusivities) of CH4 and N2 on pelletized 4A zeolite. The experiment was carried out isothermally without disturbing the adsorbed phase. CH4 was selectively adsorbed over N2 by the zeolite because of its higher polarizability. The multi-site Langmuir model described the pure gas and binary adsorption equilibria fairly well at three different temperatures. The selectivity of adsorption of CH4 over N2 increased with increasing pressure at constant gas phase composition and temperature. This curious behavior was caused by the differences in the sizes of the adsorbates. The diffusion of CH4 and N2 into the zeolite was an activated process and the Fickian diffusion model described the uptake of both pure gases and their mixtures. The self-diffusivity of N2 was an order of magnitude larger than that for CH4. The pure gas self-diffusivities for both components were constants over a large range of surface coverages (0 〈 θ 〈 0.5). The self-diffusivities of CH4 and N2 from their binary mixtures were not affected by the presence of each other, compared to their pure gas self-diffusivities at identical surface coverages.
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  • 47
    ISSN: 1572-879X
    Keywords: platinum ; rhodium ; alloy ; surface composition ; nitrogen ; oxygen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two kinds of adsorbed N atoms exist on a Pt0.25Rh0.75(100) surface. One desorbs at 490 K and the other desorbs at 650 K. The former reacts with H2 at 400 K, but the latter does not. It is supposed that the adsorption of these two N atoms is responsible of the surface composition, ratio of Pt and Rh.
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    Journal for general philosophy of science 21 (1990), S. 231-257 
    ISSN: 1572-8587
    Keywords: basic rules ; change ; discipline-neutral ; evolution ; analogy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A small step is made in the direction of defining some general basic rules which can serve as a framework for research in several fields of the social sciences. The method of working with analogies asks for a more accurate approach. Starting from the concept of evolution in the form of a basic rule another basic rule is formulated. This rule shows what are the most important factors in long term developments and what types of development one can expect.
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  • 49
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    Journal for general philosophy of science 22 (1991), S. 133-141 
    ISSN: 1572-8587
    Keywords: evolution ; teleology ; chance ; purpose ; anthropomorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary Revaluation of the problem of natural teleology seems an important precondition for elucidating our environmental crisis and for formulating an ‘ecological ethics’, because it calls for a recognition of an intrinsic value in nature and organisms. Therefore, it is necessary to show that the concept of natural teleology is not in contradiction with scientific theories, in particular not with the theory of evolution. In this paper I shall argue that there is a fundamental misunderstanding about the concepts of teleology and chance in modern thinking. This as a result of a radical transformation of the Aristotelian concept of teleology by Christian theologians during the Middle Ages. This confusion resulted in the rejection of teleology from evolution and in an exaggeration of the role of chance. However, not a solution for the problem of teleology is given here, but only an attempt to prove that neither the fossil-record, nor the role of chance in evolution can give adequate arguments for the negation of teleology in evolution. That is not to say that, therefore there exists teleology in evolution, but the problem of teleology in nature cannot, be solved by the scientific theory of evolution, but only be elucidated by philosophical analysis. At the end of the paper it is argued that teleology must be rather presupposed in evolution.
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    Journal for general philosophy of science 23 (1992), S. 85-103 
    ISSN: 1572-8587
    Keywords: life ; teleology ; evolution ; reality ; representation ; experience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A comprehensive definition of the phenomenon called “life” led to the addition of many dimensions to the natural sciences, and especially the conscious mental dimension. Historical attention is paid not only to those employing the natural philosophical paradigms, but also to evolutionary theories and to the Kantian teleological philosophy. The belief that science can solve the riddle of life is a category of purposal thinking. A revised version of critical teleology is essential for comprehension of life.
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    Entomologia experimentalis et applicata 62 (1992), S. 29-36 
    ISSN: 1570-7458
    Keywords: Alkaloids ; cinnabar moth ; insect genetics ; larval performance ; Lepidoptera ; nutritional ecology ; nitrogen ; sugar ; Tyria jacobaeae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In a laboratory experiment using full-sibs, 60% of the variation in pupal weight of the monophage Tyria jacobaeae L. (Lepidoptera, Arctiidae) could be explained by variation in the nitrogen concentration of the food plant, Senecio jacobaea L. and only 4% by variation in sugar concentration. Larval weight and growth rates of young and old larvae were also positively correlated with nitrogen and sugar concentration. Developmental time was negatively correlated with nitrogen concentration. In a second experiment full-sib families differed significantly in larval weight at day 7, mortality, growth rate and developmental time. Pupal weight did not differ significantly among families, but was positively correlated with nitrogen concentration of Senecio. Larval performance was not significantly influenced by concentrations of sugars or alkaloids. We conclude that larval performance of Tyria during most of the larval period is mainly determined by genetic factors, but pupal weights are primarily determined by nitrogen concentration of the food plant.
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    Entomologia experimentalis et applicata 66 (1993), S. 3-12 
    ISSN: 1570-7458
    Keywords: evolution ; coevolution ; selection ; insect attack ; plant defense ; competition ; enemy free space ; chemoreception ; specialization ; plant recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Most hypotheses concerning the evolution of insect-plant relationships are based on the assumptions that, (1) phytophagous insects reduce plant fitness, and that (2) insect-plant relationships are the result of unconstrained selection. It can be shown, however, that there is little evidence to support these assumptions. As an alternative, it is proposed that the evolution of insect-plant relationships results primarily from autonomous evolutionary events; namely from heritable functional changes within the insects' nervous system that determine plant recognition and ultimately host plant specificity. These changes cannot be evoked by selective ecological agents. They originate from intrinsic changes (mutationssensu lato) within the insect genome. Ecological factors play a secondary role: by either supporting or preventing the establishment of the new genotype with the novel food preference.
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  • 53
    ISSN: 1570-7458
    Keywords: Cryptomyzus ; aphid ; hybridization ; host plant preference ; reproductive performance ; host-alternation ; speciation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé C. galeopsidis Kaltenbach contient plusieurs formes qui ont différentes relations avec des plantes hôtes et des cycles distincts. Des croisements ont permis d'élucider la taxonomie de ces formes et d'étudier l'hérédité de préférences d'hôtes, des performances reproductives et de l'alternance d'hôtes. Une des formes apparaît comme une espèce distincte par suite de la valeur adaptative réduite des hybrides. Les autres formes avec alternance ou non des hôtes sont considérées comme conspécifiques et représentant deux stratégies vitales différentes. Les performances reproductives sont probablement polygéniques puisque les hybrides ont des performances intermédiaires. Les préférences d'hôtes des hybrides montrent certains degrés de dominance et semblent déterminées par quelques gènes seulement. L'alternance des hôtes est envisagée comme ayant une hérédité monofactorielle. Les conséquences sur la spéciation sont discutées.
    Notes: Abstract The aphid species Cryptomyzus galeopsidis (Kaltenbach) includes several distinct forms which have different host plant relationships and life cycles. Cross breeding was used to elucidate the taxonomic status of these forms and to investigate the inheritance of host preference, reproductive performance and host-alternation. One of the forms appeared to be a distinct species because of the reduced fitness of the hybrids. Other host-alternating and non host-alternating forms are considered conspecific and represent two life cycle strategies. Reproductive performance is probably controlled polygenically, since hybrids show an intermediate performance. Host preference in hybrids showed some degree of dominance and seemed to be determined by only a few genes. Host-alternation is presumed to be inherited monofactorially. The implications for speciation are discussed.
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    Journal for general philosophy of science 30 (1999), S. 37-58 
    ISSN: 1572-8587
    Keywords: protein ; experimentation ; conceptual variation and selection ; evolution ; Mulder ; Liebig ; Pflüger ; Nägeli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract A philosophically comprehended account is given of the genesis and evolution of the concept of protein. Characteristic of this development were not shifts in theory in response to new experimental data, but shifts in the range of questions that the available experimental resources were fit to cope with effectively. Apart from explanatory success with regard to its own range of questions, various other selecting factors acted on a conceptual variant, some stemming from a competing set of research questions, others from an altogether different field of inquiry, and still others from the external environment. These results are best explained on, hence support, an evolutionary model of the progress of experimental investigation, whose outlines are briefly discussed.
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    Minds and machines 6 (1996), S. 481-505 
    ISSN: 1572-8641
    Keywords: Neuroscience ; evolutionary psychology ; interfield theory ; evolution ; teleology ; function ; functionalism ; brain mapping ; language processing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract The idea of integrating evolutionary biology and psychology has great promise, but one that will be compromised if psychological functions are conceived too abstractly and neuroscience is not allowed to play a contructive role. We argue that the proper integration of neuroscience, psychology, and evolutionary biology requires a telelogical as opposed to a merely componential analysis of function. A teleological analysis is required in neuroscience itself; we point to traditional and curent research methods in neuroscience, which make critical use of distinctly teleological functional considerations in brain cartography. Only by invoking teleological criteria can researchers distinguish the fruitful ways of identifying brain components from the myriad of possible ways. One likely reason for reluctance to turn to neuroscience is fear of reduction, but we argue that, in the context of a teleological perspective on function, this concern is misplaced. Adducing such theoretical considerations as top-down and bottom-up constraints on neuroscientific and psychological models, as well as existing cases of productive, multidisciplinary cooperation, we argue that integration of neuroscience into psychology and evolutionary biology is likely to be mutually beneficial. We also show how it can be accommodated methodologically within the framework of an interfield theory.
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  • 56
    ISSN: 1432-0789
    Keywords: Key words Microbial biomass C ; Water-soluble organic carbon ; Light fraction organic carbon ; Fertilizer ; nitrogen ; 13C nuclear magnetic resonance ; Infrared spectrophotometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Soil samples taken from four experimental sites that had been cropped to continuous corn for 3–11 years in Ontario and Quebec were analyzed to evaluate changes in quantity and quality of labile soil organic carbon under different nitrogen (N) fertility and tillage treatments. Addition of fertilizer N above soil test recommendations tended to decrease amounts of water-soluble organic carbon (WSOC) and microbial biomass carbon (MBC). The quality of the WSOC was characterized by 13C nuclear magnetic resonance and infrared spectrophotometry and the results indicated that carbohydrates, long-chain aliphatics and proteins were the major components of all extracts. Similar types of C were present in all of the soils, but an influence of management was evident. The quantity of soil MBC was positively related to the quantities of WSOC, carbohydrate C, and organic C, and negatively related to quantities of long-chain aliphatic C in the soil. The quantity of WSOC was positively related to the quantities of protein C, carbohydrate C, and negatively related to the quantity of carboxylic C. The quantity of soil MBC was not only related to quantities of soil WSOC but also to the quality of soil WSOC.
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    Biology and fertility of soils 26 (1998), S. 169-172 
    ISSN: 1432-0789
    Keywords: Key words Urea ; Coated fertilizers ; Ammonium ; nitrogen ; Nitrate nitrogen ; Nitrogen uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Understanding the fate of different forms of nitrogen (N) fertilizers applied to soils is an important step in enhancing N use efficiency and minimizing N losses. The growth and N uptake of two citrus rootstocks, Swingle citrumelo (SC), and Cleopatra mandarin (CM), seedlings were evaluated in a pot experiment using a Candler fine sand (hyperthermic, uncoated, Typic Quartzipsamments) without N application or with 400 mg N kg–1 applied as urea or controlled-release fertilizers (CRF; either as Meister, Osmocote, or Poly-S). Meister and Osmocote are polyolefin resin-coated urea with longevity of N release for 270 days (at 25°C). Poly-S is a polymer and sulfur-coated urea with release duration considerably shorter than that of either Meister or Osmocote. The concentrations of 2 M KCl extractable nitrate nitrogen (NO3 –-N) and ammonium nitrogen (NH4 +-N) in the soil sampled 180 days and 300 days after planting were greater in the soil with SC than with CM rootstock seedlings. In most cases, the extractable NH4 + and NO3 – concentrations were greater for the Osmocote treatment compared to the other N sources. For the SC rootstock seedlings, dry weight was greater with Meister or Poly-S compared with either Osmocote or urea. At the end of the experiment, ranking of the various N sources, with respect to total N uptake by the seedlings, was: Meister = Osmocote 〉 Poly-S 〉 Urea 〉 no N for CM rootstock, and Meister = Poly-S = Osmocote 〉 Urea 〉 no N for SC rootstock. The study demonstrated that for a given rate of N application the total N uptake by seedlings was greater for the CRF compared to urea treatment. This suggests that various N losses were lower from the CRF source as compared to those from soluble fertilizers.
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    Biology and fertility of soils 26 (1997), S. 31-34 
    ISSN: 1432-0789
    Keywords: Key words Microbial biomass ; Air-drying ; Extractable ; nitrogen ; Extractable phosphorus ; Tropical soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The microbial contribution to extractable N and P after the air-drying of eight Indian dry tropical Ultisols was quantified. Air-drying of the soils decreased microbial biomass C by 25–53% but increased extractable N and P by 14–34% and 24–121%, respectively. This increase in the extractable N and P was accounted for, to some extent, by microbial biomass killed due to air-drying. Microbial biomass contributes 17–36% and 19–82% to the extractable N and P, respectively, possibly due to air-drying of the soils. I conclude that due to contamination of microbial biomass with the available nutrients in air-dried soils, measurements of extractable nutrients should be made on field-moist soils.
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  • 59
    ISSN: 1436-5073
    Keywords: AES ; laser ; iron ; nitrogen ; oxygen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The laser induced modification of iron surfaces with atmospheric species was investigated by means of Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). Different laser systems were used for irradiating iron samples in a wide range of the laser processing parameters up to small foci and ultra short pulses. A nitriding of iron connected with an oxidation of the near surface region was observed in the wavelength range between 193 nm and 10.6 μm using large foci (∼0.1 cm2) and short pulses (10...1400ns). In case of small foci (∼7·10−6cm2) with ns-pulses (50 ns) an enrichment of the iron melt with nitrogen and an advanced oxidation of the surrounding area of the laser spot were detected. When using shorter pulses (200 fs, 40 ps) no indications for a nitriding were found.
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  • 60
    ISSN: 1573-0417
    Keywords: Great Basin ; climatic variations ; productivity ; organic matter ; nitrogen ; phosphorus ; hardwater lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Sediment cores from the shallow and deep basins of Pyramid Lake, Nevada, revealed variations in composition with depth reflecting changes in lake level, river inflow, and lake productivity. Recent sediments from the period of historical record indicate: (1) CaCO3 and organic content of sediment in the shallow basin decrease at lower lake level, (2) CaCO3 content of deep basin sediments increases when lake level decreases rapidly, and (3) the inorganic P content of sediments increases with decreasing lake volume. Variations in sediment composition also indicate several periods for which productivity in Pyramid Lake may have been elevated over the past 1000 years. Our data provide strong evidence for increased productivity during the first half of the 20th Century, although the typical pattern for cultural eutrophication was not observed. The organic content of sediments also suggests periods of increased productivity in the lake prior to the discovery and development of the region by white settlers. Indeed, a broad peak in organic fractions during the 1800's originates as an increase starting around 1600. However, periods of changing organic content of sediments also correspond to periods when inflow to the lake was probably at extremes (e.g. drought or flood) indicating that fluctuations in river inflow may be an important factor affecting sediment composition in Pyramid Lake.
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  • 61
    ISSN: 1573-0417
    Keywords: colonization ; evolution ; lakes ; Norway ; deglaciation ; land uplift ; invertebrates ; Chironomidae ; Porifera ; Bryozoa ; diatoms ; Charophyta ; tsunami
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Invertebrate colonization of lakes following the uplift of land from the sea was studied in four lakes, currently situated between 39 and 24 m a.s.l., on the central Norwegian coast. The lakes were isolated from the sea between 9500 and 7700 years B.P. Animal and algal remains picked from core samples showed that the first colonizers preserved as fossils were usually members of the Chironomidae, Daphnidae/Chydoridae, Acarina, Porifera (Ephydatia mülleri and Spongilla lacustris), Bryozoa (Cristatella mucedo and Plumatella spp.) and Charophyta (Chara sp.). Of the chironomids, the genus Chironomus was present in the oldest lacustrine layers of all four lakes, but other genera recorded at the marine/lacustrine boundary were Dicrotendipes, Procladius (?), Einfeldia, Microtendipes, and Glyptotendipes. Remains of the caddis fly family Limnephilidae were also present in the earliest lacustrine sediments in Kvennavatnet and Kvernavatnet. The oldest invertebrate fauna is typical for mesotrophic lakes. However, chironomids and mites have been present in this area from at least about 10 500 years B.P. A diverse chironomid community was established between 300 and 800 years after isolation from the sea at Kvernavatnet on the island of Hitra, while only between 80 and 120 years passed before a comparably diverse community developed at Kvennavatnet on the mainland coast. A similar development of the invertebrate fauna occurred in Kvennavatnet, Kvernavatnet and Storkuvatnet. However, Litjvatnet deviates greatly from the ‘normal’ pattern because a tsunami disturbed the bottom sediments and fauna. The tsunami, a gigantic sea wave, was caused by a submarine slide from the Norwegian continental slope. It reached Litjvatnet, today located 24 m a.s.l., but was not traced in Storkuvatnet at 30 m a.s.l. This event happened about 7200 years B.P.
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    Journal of paleolimnology 10 (1994), S. 43-52 
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Charophyta are common algae in limnic waters from many regions and are an interesting group from an evolutionary point-of-view, as they are believed to be related to the Chlorophyceae and land plants. Paleontological-botanical systematics are discussed, taking into consideration some new advances. Charophytes live in all types of inland waters and are sensitive to ecological change, and so they are very useful paleolimnological markers. Gaps concerning gyrogonite morphology in extant taxa and their responses to different environmental conditions must be described. This paper discusses data concerning ecological factors affecting the distribution of Argentinian Charophyta (principally distributed between 30°S and 40°S), gyrogonite morphology related to different ecological conditions, and the way that Charophyta can modify the environment.
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    Journal of paleolimnology 4 (1990), S. 1-22 
    ISSN: 1573-0417
    Keywords: sulfate ; carbon ; nitrogen ; hydrogen ; organic matter ; enrichment factor ; lake sediments ; paleolimnology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract This paper discusses the use of S as a paleolimnological tracer of limnetic sulfate concentration. A positive relationship (p〈0.05) was found between limnetic sulfate and sediment S concentrations for the Great Lakes, English Lakes, and lakes from the Adirondack and Northern New England regions. There is a positive correlation (p〈0.05) between C and S concentration in sediment across all regions studied. The importance of C in affecting S content in sediment was also examined by a series of cores taken at different water depths in Big Moose Lake (Adirondacks). There was a strong relationship between C and S among cores with sediment from deeper water having higher C and S concentrations (r 2=0.99). Sulfur from the shallower cores had greater concentrations of chromium-reducible S (pyrite), while cores from deeper waters had a greater proportion of organic S fractions including C-bonded S and ester sulfates. For assessing historical changes in S accumulation in sediments, enrichment factors were calculated for the PIRLA lakes. Pre-1900 net sediment accumulation rates of S were very similar across all regions. Sulfur enrichment was greatest in Adirondack sediment which had total post-1900 S accumulation of 1.1 to 7.4 times pre-1900 S accumulation. Sediment from Northern New England (NNE) generally had lower S concentration than Adirondack sediments and S enrichment factors ranged from 1.2 to 2.1. Sediment from the Northern Great Lakes States region had similar S concentration and distribution with depth to NNE sediment. In two Northern Florida lakes, sediment showed little variation in S concentration with depth, but in two other lakes from the same region, there was higher S concentration in deeper layers. Lakes which had the greatest enrichment factors also exhibited the most marked changes in C:S ratios. Ratios of C:N showed little variation (10.6 to 26.1) among the PIRLA lakes. A first order model indicated slow decomposition within these organic rich sediments. Elemental concentrations and ratios of sediment from a variety of lakes and reservoirs were complied. Maximum and minimum elemental ratios for all the data were 28 to 8.1 for C:N, 0.81 to 0.11 for C:H, and 675 to 12.5 for C:S, respectively. For the C:S ratios in all regions except the Great Lakes, the maximum ratio was less than 231. Both the maximum and minimum amount of N and H concentration of organic matter is related to biotic processes. The minimum concentration of S is regulated not only by nutrient demands but also by non-assimilatory processes. Sulfur incorporation into sediments is a function of a complex of factors, but limnetic sulfate concentration and organic matter content play a major role in regulating the S content of sediment. Further quantification of S incorporation pathways will aid in the paleolimnological interpretation of sediment S profiles. Such information is also important in assessing how S sediment pools will respond to decreases in limnetic sulfate concentration which may occur with decreases in inputs from acidic deposition.
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    Journal of paleolimnology 10 (1994), S. 53-58 
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The Pleistocene charophytes from Arroyo Perucho Verna, Province of Entre Ríos, were analyzed.Chara contraria Br. ex Kütz.,C. contraria var.longilinea Cáceres,C. globularis Thuill. andTolypella intricata (Trent. ex Roth.) Leonh. var.apiculata (A. Br.) Wood were described and illustrated with scanning electron microscope. The assemblage indicates fresh alkaline to slightly saline waters, not very deep, in a lentic or sometimes lotic environment. Extant assemblages provide data for this paleoecological reconstruction.
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    Nutrient cycling in agroecosystems 38 (1994), S. 53-59 
    ISSN: 1573-0867
    Keywords: controlled-release fertilizer ; gel ; iron ; manganese ; nitrogen ; polyacrylamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Using diverse technological approaches, many types of delivery devices have been used to supply plant nutrients at a controlled rate in the soil. One new approach is the use of hydrophilic polymers as carriers of plant nutrients. These polymers may be generally classified as 1) natural polymers derived from polysaccharides, 2) semi-synthetic polymers (primarily cellulose derivatives), and 3) synthetic polymers. By controlling the reaction conditions when forming the polymers, various degrees of cross-linking, anionic charge, and cationic charge can be added, thereby changing their effectiveness as fertilizer carriers. When fertilizer-containing solutions are mixed with hydrophilic polymers to form a “gel” prior to application in the soil, the release of soluble nutrients can be substantially delayed compared with soluble fertilizer alone. The effectiveness of a specific controlled-release polymeric system is determined in part by its specific chemical and physical properties, its biodegradation rate, and the fertilizer source used. Addition of some polymers with nutrients has been shown to reduce N and K leaching from well-drained soils and to increase the plant recovery of added N, P, Fe, and Mn in some circumstances
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    Nutrient cycling in agroecosystems 27 (1991), S. 189-198 
    ISSN: 1573-0867
    Keywords: Winter wheat ; nitrogen ; uptake ; simulation ; model ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Simulation of the nitrogen behavior in the soil and the nitrogen uptake by winter wheat was performed using the model ANIMO. As input for the model ANIMO simulations of the hydrological conditions in the soil crop ecosystem were executed with the model SWATRE. Compared with measured data the simulation of nitrogen uptake by the crop was satisfactory. The simulation of mineral nitrogen in the soil agreed reasonably well with measured data for one of the experiments used for the analysis. The agreement was less for experiments with additional fertilizer applications in May and June.
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    Nutrient cycling in agroecosystems 27 (1991), S. 129-140 
    ISSN: 1573-0867
    Keywords: Douglas-fir ; nitrogen ; mineral cycling ; growth and yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Forest managers in the Pacific Northwest (PNW) use fertilization as a means to increase timber yields in managed stands. Information on the biological basis for nutrient amendments and stand growth responses to fertilization is required to effectively use fertilization as a silvicultural tool, and research programs in mineral cycling and forest nutrition have been underway in the region for about four decades. Most PNW Douglas-fir forest sites are nitrogen deficient. Mineral cycling research has shown high C/N ratios and low nitrification rates for soils in the region. Research and development projects in the Pacific Northwest have produced an information base that is used to select sites and stands for fertilization and to forecast growth after treatment. Much of the basis for operational fertilization programs in western Oregon and Washington comes from cooperative research programs; current activities for these programs are directed toward improving site-specific response information. Forest fertilization in the Pacific Northwest has become a silvicultural practice of major significance over the past two decades. Forest industry and government organizations managing forest lands in western Oregon and Washington apply nitrogen fertilizer to Douglas-fir stands over a range of soil and stand types (operational fertilization of other species is minor). About 50,000 to 55,000 ha are fertilized each year, and future programs will likely be of similar magnitude. Most current plans for management regimes including fertilization call for multiple applications.
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    Nutrient cycling in agroecosystems 40 (1994), S. 165-173 
    ISSN: 1573-0867
    Keywords: Animal manure ; eutrophication ; ground water ; nitrogen ; phosphorus ; surface runoff
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract With the rapid growth of the poultry industry in Oklahoma, U.S.A., more litter is applied to farm land. Thus, information is required on the impact of applications on regional soil and water resources. The effect of soil and poultry litter management on nitrogen (N) and phosphorus (P) loss in runoff and subsurface flow from four 16 m2 plots (Ruston fine sandy loam, 6 to 8% slope) was investigated under natural rainfall. Plots under Bermudagrass (Cynodon dactylon) received 11 Mg litter ha−1, which amounts to contributions of approximately 410 kg N and 140 kg P ha−1 yr−1. In spring, litter was broadcast on 3 of the plots; the upper half of one and total area of the other two. One of the total-area broadcast plots was tilled to 6 cm, the other remained as no till. The fourth plot served as a control. Relative to the control, litter application increased mean concentrations of total N and total P in runoff during the 16-week study for no-till (15.4 and 5.8 mg L−1) and tilled treatments (16.7 and 6.1 mg L−1). However, values for the half-area application (5.6 and 2.0 mg L−1) were similar to the control (5.7 and 1.3 mg L−1). Interflow (subsurface lateral flow at 70 cm depth) P was not affected by litter application; however, nitrate-N concentrations increased from 0.6 (control) to 2.9 mg L−1 (no till). In all cases, 〈 2 % litter N and P was lost in runoff and interflow, maintaining acceptable water quality concentrations. Although litter increased grass yield (8518 kg ha−1) compared to the control (3501 kg ha−1), yields were not affected by litter management. An 8-fold increase in the plant available P content of surface soil indicates long-term litter management and application rates will be critical to the environmentally sound use of this nutrient resource.
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    Nutrient cycling in agroecosystems 42 (1995), S. 1-11 
    ISSN: 1573-0867
    Keywords: nitrogen ; 15N humic substances ; acid hydrolysis ; analytical pyrolysis ; NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Most of the N in surface soils occurs in organic forms. The organic N in soil plays a key role in plant nutrition and soil fertility through its effects on microbial activity and nutrient availability. Typically, about one-third of the fertilizer N applied to temperate-zone soils is immobilized and retained in organic forms at the end of the growing season. A significant portion of this newly immobilized N is no more available to microorganisms and plants than the native humus N. Stabilization processes, probably involving polymerization of amino compounds and polyphenols, result in incorporation of N into humic substances with a concurrent reduction in N availability. This paper presents an account of the forms and nature of organic N in soil, emphasizing possible formation pathways, chemical characterization of humic substances through conventional and solid-state techniques, and the fate and composition of newly immobilized N in soil.
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    Nutrient cycling in agroecosystems 42 (1995), S. 139-148 
    ISSN: 1573-0867
    Keywords: denitrification ; methods ; 15N ; nitrate ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper attempts to answer the question: is denitrification a major route of N loss from tropical agro-ecosystems? This question turns out to be very difficult to answer due to a severe shortage of data on this process for tropical agro-ecosystems other than rice. Given this lack of data, I approach this question by analyzing data on denitrification and nitrous oxide flux in tropical native forest and pasture soils and attempt to make some conclusions and pose some hypotheses about the significance of denitrification in tropical agricultural soils. I also briefly review methods for measuring denitrification. The data analysis suggests that denitrification in tropical forest soils is strongly influenced by the nature and amount of soil C and N turnover. Studies to examine differences in denitrification in different tropical agricultural systems should focus on the effects of system management on C and N turnover. The data analysis also suggests that, just as in temperate regions, denitrification may not be a significant route of N loss from most tropical agricultural systems. However, field studies are necessary to determine if this is actually the case.
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  • 71
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    Keywords: Wheat ; nitrogen ; grain protein content ; grain filling ; urea spraying
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The objective of this work was to determine the effect of foliar urea spraying during or after anthesis, on dry matter and nitrogen accumulation in the wheat grain of two cultivars, differing in grain protein content. The experiment was carried out in the field, and 20 kg N ha−1 as urea (46-0-0) was sprayed at anthesis, 7 or 14 days after anthesis. Dry weight, N content and N percentage of the grain were determined at several stages of its development. Neither the rate nor the duration of dry matter accumulation in the grain was significantly modified by N sprayings at anthesis or later and, consequently, not its final weight. Nitrogen sprayings at anthesis or later increased the grain N content and N percentage at ripeness in both cultivars, but to a greater extent in the low grain protein cultivar. Greater N content in the grain was attributed to a rapid uptake of the N applied and not to a longer duration of the period of N accumulation. The different responses of the cultivars to N sprayings can be related to differences in N demand, and is probably associated, also, to a genetic ability to accumulate N in the grain.
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    Nutrient cycling in agroecosystems 37 (1994), S. 107-113 
    ISSN: 1573-0867
    Keywords: Ensete ventricosum ; fertilizer response ; nitrogen ; phosphorus ; potassium ; sulphur ; starch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ensete (Ensete ventricosum W. Cheesm.) is a root crop which stores starch in the root and in the lower part of the stem. It is grown in the southwest of Ethiopia and due to its drought resistance, it is of outstanding importance for the supply of food to the local population. Until now virtually nothing is known about the response of Ensete to fertilizer application. Field trials carried out on three representative soils in Ethiopia showed that Ensete biomass yields were increased significantly on all three soils by nitrogen and phosphorus application. Potassium had only marginal effect on biomass growth but favourably influenced starch production. Sulfate application had no major impact on growth and starch yield. The yield response was well related to the level of available nutrients in the soil, as determined by electroultrafiltration (EUF). Leaf analysis provided preliminary evidence that optimum levels of N, P, and K may be 3.8%, 0.3%, and 4.8%, respectively.
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    Nutrient cycling in agroecosystems 32 (1992), S. 55-59 
    ISSN: 1573-0867
    Keywords: 15N ; nitrogen ; rice ; soil N ; N fertilizer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In the southern U.S. rice belt it is recommended that rice (Oryza sativa L.) grown in the dry-seeded, delayed flood cultural system have the preflood N fertilizer applied and the field flooded at the fourth to fifth leaf stage of plant development. The objective of this field study was to determine if delaying the flood and preflood N application past the fifth leaf stage was detrimental to rice total N and fertilizer15N uptake, total dry matter, and grain yield. This study was conducted on a Crowley silt loam (Typic Albaqualfs) and a Perry clay (Vertic Haplaquepts). The preflood N fertilizer and flood were delayed 0, 7, 14, or 21 d past the fourth to fifth leaf stage, after which time a permanent flood was established and maintained until maturity. All treatments received 20.5 g N m−2 as15N-labeled urea in three topdress applications. All plant and soil samples were taken at maturity. Harvest index increased as the preflood N and flood were delayed past the 4 to 5 leaf stage. Total N in the grain + straw either decreased or showed a decreasing trend as the N and flood were delayed. Similarly, uptake of native soil N decreased as flood was delayed. Conversely, percent recovery of fertilizer N in the rice plant and the plant-soil system increased as the preflood N and flood were delayed. Rice grain yield was not significantly affected by delaying the preflood N and flood up to 21 d.
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    Nutrient cycling in agroecosystems 37 (1994), S. 227-234 
    ISSN: 1573-0867
    Keywords: catch crop ; mineralization ; nitrogen ; plant species ; residual effects ; soil depletion ; winter hardiness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ten widely different plant species were compared for their ability to reduce soil mineral nitrogen levels in the autumn and their ability to improve the nitrogen nutrition of the succeeding crop. The species included monocots and dicots, crops that survived the winter (persistent) or were winter killed (non-persistent) as well as legumes and non legumes. Their ability to reduce soil mineral nitrogen content was dependent on both root depth and persistency of the crops in the autumn. For non-persistent catch crops most of the mineralization of plant nitrogen occurred during the winter, and for some of these so early as to allow leaching of some mineralized nitrogen. For persistent crops most of the mineralization occurred shortly after incorporation in the spring. The effect of the catch crops on nitrogen uptake by the succeeding barley crop varied from 13 to 66 kg N ha−1 and the differences between the crops could not be related to any single character, but to a combination of root depth, persistency, plant nitrate accumulation, and depletion of the soil mineral nitrogen pool in spring.
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    Nutrient cycling in agroecosystems 45 (1995), S. 221-233 
    ISSN: 1573-0867
    Keywords: fertilizer recovery ; modelling ; nitrogen ; nutrient efficiency ; nutrient surplus ; phosphorus ; Poland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Research on nutrient losses from agricultural systems should try to relate these losses to farm characteristics. This was done for private farms in two districts in Poland. Using data from a farm survey, nutrient surpluses and Nutrient Use Efficiency (NUE, defined as the ratio of outgoing and incoming nutrients) were calculated for nitrogen and phosphorus. Both nutrient surplus and NUE are relatively high. A model was developed to estimate surpluses and NUE from farm characteristics like location, farm size, fertilizer application level, animal density, grass production and sugar beet or potato area. The results of the model are satisfying for nutrient surplus (R2=0.9) and nitrogen NUE (R2=0.4). Estimation of phosphorus NUE was not satisfactory. High surpluses are associated with high fertilizer applications, high animal density and high grass production while an increasing share of sugar beets leads to lower surpluses. A high nitrogen NUE is associated with low fertilizer applications, low animal density and little grass production, and with a high sugar beet area share. Results suggest that, with exception of sugar beet, fertilizer recovery in Poland is very low. Sugar beet, however, combines high fertilizer applications with low surpluses and high NUE. The outcome of the model can be used in the design of environmental policies. The paper ends with some remarks on the type of measures that can be taken, and the effects these will have on private farms in Poland.
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    Nutrient cycling in agroecosystems 46 (1996), S. 81-90 
    ISSN: 1573-0867
    Keywords: elemental sulfur ; granule size ; nitrogen ; phosphorus ; potassium ; S oxidation ; sulfur fertilizers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments were undertaken to determine the effect of granule size and nutrients in granulated compound fertilizers fortified with finely divided elemental sulfur (So) on the rate of So oxidation. In one experiment, So was banded together with or apart from triple superphosphate (TSP) while in two others, So was granulated with nutrient and inert carriers. A fourth experiment examined response to S in an So-fortified TSP from a range of granule sizes. Response and, in some cases, So recovery (using 35S labels) by test crops (maize, wheat, upland rice) was measured. In all experiments, P mixed with So increased plant growth and S recovery above treatments in which P and So were physically separated. There was however, no effect of distance of separation on S recovery. In one experiment, N as urea and N and P as diammonium phosphate (DAP) were also found to enhance response to So although to a lesser degree than P alone. These observations were attributed to a nutritional requirement of So-oxidizing microorganisms for P and N. Granulation of So with carriers also influenced oxidation rate, as inferred from the fertilizer S recovery. For a given So concentration, the effect was inversely proportional to the mean diameter of granules. It is shown that this relationship can be explained if one assumes that So particles in granules collapse into a fixed number of aggregates per granule irrespective of granule size when the soluble nutrient carrier dissolves and diffuses away from the point of application.
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    Nutrient cycling in agroecosystems 46 (1996), S. 53-70 
    ISSN: 1573-0867
    Keywords: crop ; emission ; fertilizer ; nitrogen ; nitrous oxide ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This analysis is based on published measurements of nitrous oxide (N2O) emission from fertilized and unfertilized fields. Data was selected in order to evaluate the importance of factors that regulate N2O production, including soil conditions, type of crop, nitrogen (N) fertilizer type and soil and crop management. Reported N2O losses from anhydrous ammonia and organic N fertilizers or combinations of organic and synthetic N fertilizers are higher than those for other types of N fertilizer. However, the range of management and environmental conditions represented by the data set is inadequate for use in estimating emission factors for each fertilizer type. The data are appropriate for estimating the order of magnitude of emissions. The longer the period over which measurements are made, the higher the fertilizer-induced emission. Therefore, a simple equation to relate the total annual direct N2O−N emission (E) from fertilized fields to the N fertilizer applied (F), was based on the measurements covering periods of one year: E=1+1.25×F, with E and F in kg N ha-1 yr-1. This relationship is independent of the type of fertilizer. Although the above regression equation includes considerable uncertainty, it may be appropriate for global estimates.
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    Nutrient cycling in agroecosystems 46 (1996), S. 179-187 
    ISSN: 1573-0867
    Keywords: electrical conductivity ; leaching ; nitrogen ; pH ; phosphorus ; potassium ; release pattern ; slow-release fertilizers ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the effect of temperature on the release of N, P, and K from slow-release fertilizers (SRF). The study was conducted in micro-lysimeters filled with moist peat medium. Increasing the temperature from 4 to 12°C slightly increased N release from three different slow-release N (SRN) carriers with different particle sizes and coating thicknesses. At 21°C the rate of release was significantly different than the other two temperatures. Urea formaldehyde (UF), sulphur coated urea (SCU) and coated calcium nitrate (CCN), incubated in sphagnum moss peat, released between 3 and 20% of the applied N in six weeks. For eight synthetic and organic NPK carriers, the release pattern was similar to UF and SCU. However, the leaching losses of N from the NPK fertilizers were up to twenty times more than for the SRN products. Except for Osmocote® and Duna, which released 30–40% of the applied N as mineral-N within six weeks, all other slow-release and slowly mineralized NPK carriers acted like readily water-soluble compound NPK. Temperature did not affect the nutrient release from NPK fertilizers.
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    Nutrient cycling in agroecosystems 50 (1998), S. 271-276 
    ISSN: 1573-0867
    Keywords: nitrogen ; monitoring ; dairy farming ; simulation models ; risk assessment ; soil variability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract At the ‘De Marke’ experimental farm a dairy farm was set up with the aim of meeting environmental and economic goals. The farm management with respect to nitrogen emphasized reduction of fertilization and a cattle grazing system that should result in nitrate concentrations in the groundwater below the EC-directive level of 11.3 mg l-1 nitrate-N. At six sites in six different fields of ‘De Marke’, these concentrations were monitored for 4 years. A direct comparison with the chosen limit was possible for these sites, but an evaluation of the environmental achievements of the farming system at farm level was also required. This was achieved by using simulation models and additional information about soils and field management. Based on multiple soil profile descriptions, frequency distributions of model output were generated, allowing a risk assessment for the total farm. The probability of exceeding the chosen threshold value of 11.3 mg l-1 nitrate-N during the period of summer 1991- spring 1995 was 63% for the whole farm, with marked differences between years, crops and hydrological conditions.
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    Nutrient cycling in agroecosystems 50 (1998), S. 321-324 
    ISSN: 1573-0867
    Keywords: nutrient modelling ; leaching ; nitrogen ; phosphorus ; schematization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In context of preparing the Fourth National Policy Document on Water Management in the Netherlands effects of different scenarios of fertilizer management on nitrogen (N) and phosphorus (P) leaching from rural areas into Dutch surface waters were analyzed. The manuscript offers insight into the model instrument that is used to simulate the different scenarios. Main parts of the modelinstrument are: a procedure to schematize the Netherlands in horizontal areal units, field scale mechanistic models for water and nutrient behaviour in the soil and an empirical model for fertilizer additions.
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    Nutrient cycling in agroecosystems 52 (1998), S. 277-287 
    ISSN: 1573-0867
    Keywords: dairy farming ; efficiency ; nitrogen ; organic ; pig farming ; surplus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study is in two parts. In the first part, nitrogen (N) losses per unit of milk and meat in Danish conventional and organic pig and dairy farming were compared on the basis of farm data. In the second part, organic and conventional dairy farming were compared in detail, using modelling. N-surpluses at different livestock densities, fodder intensities, and soil types were simulated. Finally, simulated N-surpluses were used in national scenarios for conversion to organic dairy farming in Denmark. In Part one, pig farming was found to have a higher N-efficiency than dairy farming. Organic pig production had a lower N-efficiency and a higher N-surplus per kg meat than conventional pig production. The possibilities to reduce N-loss by conversion to organic pig production therefore appear to be poor. Organic dairy farming had a higher N-efficiency and a lower N-surplus per kg milk than conventional dairy farming. Conversion from conventional to organic dairy farming may therefore reduce N-losses. In Part two, a positive correlation between livestock density and N-surplus ha-1 was found for dairy farming. For all simulated livestock densities, fodder feeding intensities and soil types, organic systems showed a lower N-surplus per unit of milk produced than conventional systems. National scenarios for dairy farming showed that the present Danish milk production could be achieved with a 24% lower total N-surplus if converted from intensive conventional farming to extensive organic farming. At the same time, N-surplus ha-1 and N-surplus (t milk)-1 would be lowered by 50% and 25% respectively. Changing from intensive to extensive conventional dairy farming with a livestock density equal to that in the organic scenario resulted in a reduction in N-surplus ha-1 of 15%. It was concluded that a reduction in total N-loss from agriculture is possible by converting from conventional to organic dairy farming but at the cost of either lower production on the present dairy farm area, or the current production on a substantially larger area.
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    Nutrient cycling in agroecosystems 52 (1998), S. 289-301 
    ISSN: 1573-0867
    Keywords: food production and consumption ; mitigation strategies ; nitrogen ; nitrogen emission ; nitrous oxide ; sustainability of human N cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract During the past four decades the authors perceive that an increasing non-sustainability (Disintegration) within the agriculture , human nutrition, waste management complex has occurred both in Germany and the European Union. Compared to the basic needs of the population for nutritive energy, fat and protein, we estimate that the production and consumption of food and feed is more than 50% higher than necessary. Using nitrogen (N) input into German agriculture in 1991/92 as an example, we estimated that the N input of 191 kg ha-1 was 2 to 3 times too high. This high N input resulted in the net biomass production of 45 kg ha-1, a 25% efficiency. This inefficiency causes emissions of reactive N and other nutrient compounds into the hydrosphere and atmosphere that were 2 to 8 times too high. For example the contributions of agriculture to the total annual N2O–N emissions of Germany (during 1990–1992), Europe (1990) and of the world (1989) were 110, 691 Gg and 6.7 Tg or 52, 62 and 41%, respectively. The authors demonstrate that emissions of N and P from Germany and EU waste water management systems are also higher than necessary because nutrient recycling is not practiced extensively. Excessive food production and consumption has made the agriculture/human nutrition/waste and waste water complex, like the energy/transportation complex, a main cause of new transboundary environmental damage such as soil and water acidification, hypertrophication of near-natural terrestrial and aquatic ecosystems and climate change. We propose that a sustainable food production/consumption system can be developed that is based both on need-oriented production and consumption with no net exports and on recovery, recycling and more efficient use of nutrients. Using N as an example, the authors show which short and long term action aims must be set and realized by the year 2015, to meet environmental, economical and social sustainability requisites. The suggested, assumed sustainable N balance for German agriculture is characterized by a critical annual input and surplus maximum of 80 and 45 kg N ha-1 respectively, which should almost double biomass production efficiency for N utilization. This estimate is based on reducing animal stocking rates to 0.5 gross weight unit ha-1 to attain no net mineralization or immobilization of N in the soil.
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    Nutrient cycling in agroecosystems 52 (1998), S. 171-178 
    ISSN: 1573-0867
    Keywords: atmospheric deposition ; boreal forests ; critical loads ; forest growth ; gas losses ; leaching ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nitrogen is brought into natural ecosystems from the atmosphere through N-fixation and deposition of NH 4 + and NO 3 - as wet and dry deposition. N is lost from terrestrial ecosystems unaffected by human activities by leaching or as gas, but the losses from different forest-and vegetation types are poorly quantified. The leaching is hampered by uptake in the vegetation and by immobilisation by soil organisms. The gas loss of N in the form of N2O and N2 appears to be rather small, but the loss of NO is unknown. Human activities such as those leading to the increased atmospheric dry and wet deposition of N, may affect the N-losses, but the increase in losses are likely to be very dependent on the amounts of N deposited. The present paper discusses the fate of the N deposited under the existing pollution climate in Norway where N deposition above the natural background has taken place for at least 50 years. The deposition today varies from about 15–20 kg N ha-1 yr-1 in the southernmost parts of the country to background values of about 2 kg ha-1 yr-1 in the north. Even in areas with the highest loads there are no clear indications that N-leaching in forest ecosystems has increased to ‘unacceptable’ levels. The main reason for this appears to be that most of the N deposited are immobilised in forest soils and utilised by forest trees and ground cover vegetation to increased biomass production. At present therefore, no clear signs of N-saturation can be found. This is in relatively good accordance with estimates of critical loads for N in Norwegian coniferous forests. Estimates of immobilisation, gas losses, net uptake in vegetation, biological fixation as well as a figure for ‘acceptable’ leaching, indicate that the long-term critical load of N might be of the order 10 to 30 kg N ha-1 yr-1. Most of the N deposited from the atmosphere appears therefore so far to be retained in the forests and only a small proportion seems to be lost to ground-and surface waters.
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    Nutrient cycling in agroecosystems 53 (1999), S. 209-218 
    ISSN: 1573-0867
    Keywords: cattle slurry ; fertilizer splitting ; nitrogen ; recovery ; residual nitrogen ; Zea mays L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The recovery of soil mineral nitrogen (N) by crops, and its subsequent utilisation for dry matter (DM) production may be increased when the application of N is postponed until after crop emergence. The significance of this strategy for silage maize was studied in nine field experiments on Dutch sandy soils from 1983 to 1988. In five experiments the effect of slurry applied before planting at a rate of circa 66 m3 ha-1, was compared to the effect of a similar rate of which half was applied before planting and half at the 4–6 leaf stage. In the 4-6 leaf stage slurry was either injected or banded. In four other experiments the effect of mineral fertilizer-N splitting was studied. In these experiments, 30 m3 ha-1 cattle slurry, applied before planting, was supplemented with mineral fertilizer-N at rates ranging from 40 to 160 kg ha-1, either fully applied before crop emergence or split. When split, 40 kg ha-1 of the mineral fertilizer-N rate was banded at the 4–6 leaf stage. According to balance sheet calculations, substantial losses of slurry N and mineral fertilizer-N occurred during the growing season. Losses were compensated for, however, by apparent mineralization, ranging from 0.34 to 0.77 kg N ha-1 day-1. Split applications of cattle slurry had a significant positive effect on the DM yield in two out of five experiments compared to the conventional non-split application, but only when the post-emergence slurry application was banded which is no longer in accordance with present legislation. Split applications of mineral fertilizer-N had a significant positive effect in one experiment where rainfall was excessive but not in the others. The results provide insufficient evidence to recommend farmers to split applications. Soil mineral N sampling at the 4–6 leaf stage should hence be considered a control on the appropriateness of early N applications after exceptional weather conditions rather than a routine observation on which the post-emergence N dressing is to be based in a deliberate splitting strategy. Our data suggest that the financial return of a 40 kg ha-1 supplementation with mineral fertilizer-N, was questionable when more than 175 kg N ha-1 were found in the upper 0.6 m soil layer at the 4–6 leaf stage.
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    Nutrient cycling in agroecosystems 53 (1999), S. 259-267 
    ISSN: 1573-0867
    Keywords: farming systems ; nitrogen ; nitrogen budgets ; sustainability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three approaches to nitrogen budgeting were developed and their ability to quantitatively describe nitrogen cycling in a fertilizer based and a grass–clover based beef system tested. Budgets ranged in complexity from the Economic Input:Output (EIO) budget, which accounted simply for purchases and sales of nitrogen over the farmgate, through the Biological Input:Output (BIO) budget, which included estimates of biological nitrogen fixation and attempted to partition losses into leaching and gaseous forms, to the Transfer:Recycle:Input:Output (TRIO) budget, which also accounted for key soil processes. Nitrogen unaccounted for in the fertilized system decreased with increasing budget complexity (285, 212 and 188 kg ha-1 yr-1 unaccounted for by the EIO, BIO and TRIO budgets, respectively). In the legume based grass–clover system, the EIO budget did not accurately describe total nitrogen inputs as it did not include 146 kg ha-1 yr-1 from symbiotic nitrogen fixation. In the grass–clover system, nitrogen unaccounted for was again greater using the BIO than the TRIO budget (103 and 79 kg ha-1 yr-1, respectively). In conclusion, the most complex budgeting approach (TRIO) was able to account for the fate of a greater proportion of nitrogen inputs than the simpler approaches. However, the perceived success of the different approaches was strongly dependent on the precise objective.
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    Nutrient cycling in agroecosystems 55 (1999), S. 1-6 
    ISSN: 1573-0867
    Keywords: chlorophyll meter ; irrigation ; LAI ; nitrogen ; Spring Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A Spring Wheat crop was grown using three irrigation levels and nitrogen rate applications to evaluate chlorophyll meter measurements as a possible nitrogen nutrition index for modelling. These measurements yielded the most reliable indications at Zadoks GS45. The lower limit indicating severe nitrogen deficiency in the leaves was approximately 35 SPAD units while the upper limit of 45 SPAD units, indicated an excess consumption.
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  • 87
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    Nutrient cycling in agroecosystems 55 (1999), S. 89-94 
    ISSN: 1573-0867
    Keywords: algae ; flooded soils ; N cycling ; nitrogen ; 15N ; rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Algal N labelled with 15N added to a flooded soil in laboratory columns without plants was studied to determine the changes over time in the fate of N assimilated by algae and to study how its fate is affected by (a) exclusion of light simulating complete closure of the rice canopy, and (b) addition of fertilizer-NH4 *. In the light but with no added fertilizer-N there was little net mineralization of the added algal N during the first 4 weeks, but after 8 weeks 42% had been mineralized, of which 95% was denitrified. Exclusion of light caused net mineralization to proceed more rapidly in the first 4 weeks due to the death of algal cells and lowered reassimilation. After 8 weeks 51% had been mineralized, of which 54% was denitrified, 16% volatilized and 30% was present as KCl exchangeable NH4 +-N. Application of fertilizer-NH4 + apparently caused mineralization of 25% of the algal N within one week but the results were probably affected by pool substitution in which labelled N mineralized to NH4 +-N was diluted with fertilizer – NH+ 4 and then immobilized leaving more labelled NH4–N in the mineral pool. After 8 weeks, 42% of algal N had been mineralized, of which 69% was estimated to have been denitrified, 19% lost through NH3 volatilization and 12% remained as extracted NH4 ++NO- 3. Uptake of N by a rice crop would reduce the gaseous losses. Algal N was mineralized quickly enough to be available during the growing season of a rice crop and, depending on field conditions, algae may have a role in assimilating N and protecting it from loss as well as being a major driving force for NH3 volatilization through diurnal increases in pH.
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  • 88
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    Nutrient cycling in agroecosystems 35 (1993), S. 217-226 
    ISSN: 1573-0867
    Keywords: calcium ; dry matter distribution ; fertilizer ; harvest index ; magnesium ; manure ; millet ; nitrogen ; nutrient uptake ; phosphorus ; potassium ; Senegal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a fertilizer and manure experiment, millet was grown under four treatments (no fertilizer or manure, farmyard manure, chemical fertilizer, and both). Grain yield and total aboveground biomass production of the unfertilized plot were relatively high. The observed differences in total dry matter production must be attributed to differences in nutrient availability, as amount of rainfall and its distribution were favourable. Results show only small differences in distribution of dry matter among the various plant organs between the best and the non-fertilized treatments. Nutrient supply from natural sources, defined as crop content of N, P, and K at maturity without fertilizer application, amounted to 104, 16 and 103 kg ha−1, respectively, which are very high values. Total uptake of calcium and magnesium is related to that of potassium, as the combined content of these three elements is linearly related to total aboveground biomass production. Minimum removal of nitrogen and phosphorus per ton grain dry matter amounts to 29 and 4kg, respectively, and 9 kg potassium per ton total aboveground dry matter. A possible double function of phosphorus as element of structural biomass and for maintenance of electro-neutrality is discussed.
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  • 89
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    Nutrient cycling in agroecosystems 21 (1990), S. 167-170 
    ISSN: 1573-0867
    Keywords: Mo ; interaction ; soybean ; deficiency ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Recent on-farm liming experiments showed that Mo deficiency in soybean [Glycine max (L.) Merr.] is widespread in northern Alabama. In contrast, a long-term, fertility-rotation experiment in the same area showed no response to Mo during 33 yr when Mo was added bienially to corn [Zea mays L.] in the rotation; however, soybean foliage had the chlorotic appearance of Mo deficiency. The objective of this study was to determine if Mo deficiency was being missed by comparing only two fertilizer treatments. Each rotation-fertilizer treatment plot was split into two, with one-half receiving MO at a 100 g ha−1 foliar rate after seedling emergence, while the other half received none. Yields were increased by Mo in 13 to 16 fertilizer treatments in 1985 and 15 out of 16 in 1986. Leaf-N concentrations and seed weight had comparable increased amounts by the Mo supplement. Without the Mo supplement, there was a response to lime but not to P, K, or a Mo-containing micronutrient mixture; with the Mo supplement, there was no response to liming, but a definite response to P and K (in addition to Mo). The lack of response to Mo when applied to corn in a 2-yr rotation over 33 yr led to the erroneous conclusion that these soils were not Mo deficient for soybean.
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  • 90
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    Nutrient cycling in agroecosystems 22 (1990), S. 71-78 
    ISSN: 1573-0867
    Keywords: Boron ; critical level ; grain ; nitrogen ; nodulation ; nutrition ; toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A two year field study on the effect of nitrogen N and boron B fertilization on the nodulation, mineral nutrition and grain yield of cowpea was carried out in the Nigerian savanna where fairly widespread B deficiency has been reported. Treatments consisted of four levels of N (0, 15, 30 and 60 kg/ha in 1986 and 0, 15, 30 and 45 kg/ha in 1987) and three levels of B (0, 1.5 and 3.0 kg/ha). Cowpea responded positively though nonsignificantly to N fertilization up to 30 kg N/ha. However, N had no effect on the N, P, K and B content of index leaves. Boron application consistently reduced grain yield. Like N, applied B had no effect on the N, P, K concentration of index leaves but increased B concentration highly significantly (P 〈 0.001). The critical level of B toxicity in index leaves was approximated to be 21pm under field condition. Application of N and B depressed nodulation.
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  • 91
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    Nutrient cycling in agroecosystems 23 (1990), S. 97-103 
    ISSN: 1573-0867
    Keywords: Carbon ; mineralization ; nitrogen ; organic fertilizer ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The C and N mineralization characteristics of two organic N fertilizers were determined in a soil-less incubation system at three temperature regimes. Protox (derived from activated sewage sludge) initially degraded more rapidly by microbial action compared with dried blood. However, dried blood released more CO2-C and inorganic N towards the end of the incubation periods. The rate of microbial degradation increased with temperature. Mineralization characteristics of protein-based N sources are discussed in relation to organic N nutrition of vegetable crops.
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  • 92
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    Nutrient cycling in agroecosystems 23 (1990), S. 105-112 
    ISSN: 1573-0867
    Keywords: Ammonium ; fertigation ; nitrate ; nitrogen ; trickle irrigation ; urea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The movement and transformations of ammonium-, urea- and nitrate-N in the wetted volume of soil below the trickle emitter was studied in a field experiment following the fertigation of N as ammonium sulphate, urea and calcium nitrate. Effects on soil pH in the wetted volume were also investigated. During a fertigation cycle (emitter rate 2lh−1) applied ammonium was concentrated in the surface 10 cm of soil immediately below the emitter and little lateral movement occurred. In contrast, because of their greater mobility in the soil, fertigated urea and nitrate were more evenly distributed down the soil profile below the emitter and had moved laterally in the profile to 15 cm radius from the emitter. The conversion of applied N to nitrate-N was more rapid when urea rather than ammonium-N was applied suggesting that the accumulation of large amounts of ammonium below the emitter in the ammonium sulphate treatment probably retarded nitrification. Following their conversion to nitrate-N, both fertigated ammonium sulphate and urea caused acidification in the wetted soil volume. Acidification was confined to the surface 20 cm of soil in the ammonium sulphate treatment, however because of its greater mobility, fertigation with urea (2lh−1) resulted in acidification occurring down to a depth of 40 cm. Such subsoil acidity is likely to be very difficult to ameliorate. Increasing the trickle discharge rate from 2lh−1 to 4lh−1 reduced the downward movement of urea and encouraged its lateral spread in the surface soil. As a consequence, acidification was confined to the surface (0–20 cm) soil.
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  • 93
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    Nutrient cycling in agroecosystems 39 (1994), S. 223-228 
    ISSN: 1573-0867
    Keywords: drip-fertigation ; efficiency ; nitrogen ; sugar cane ; uptake ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nitrogen (N) fertilizer use efficiency by sugar cane in Mauritius rarely exceeds 40%. Since drip-irrigation delivers water uniformly and directly to the root zone with little run-off, application of N via the drip-irrigation system could therefore provide a means of enhancing fertilizer N use by sugar cane. A study was initiated in Mauritius to determine what benefits would accrue from applying urea (120 kg N per ha) to sugar cane through the drip-irrigation network. The data obtained showed that the efficiency of fertilizer N when measured at harvest was nearly doubled by supplying the N daily over 10 to 20 weeks by fertigation. Increased yields of sugar or cane did not, however, accompany the improved N use efficiency. Furthermore, when N was applied through the drip-irrigation network, recovery of N at harvest did not accurately reflect N use efficiency.
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  • 94
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    Nutrient cycling in agroecosystems 29 (1991), S. 133-138 
    ISSN: 1573-0867
    Keywords: Phaseolus vulgaris L. ; nitrogen fixation ; nitrogen ; yield components ; side-dress ; selection criteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract There is usually a positive yield response when N is applied to common bean plants grown on N-poor soils. Recommendations include application of some or all of the N at planting, but growth and yield responses to later applications are not well documented. From 50 to 60kg N ha−1 was applied at different growth stages to three bean lines during three years. All N treatments increased yield compared to the unfertilized control. Nitrogen applied during the vegetative stage produced higher seed yields than N applied at planting, flowering, during podfill or a split application. N applied at planting or during vegetative growth increased pod-set, while application at the vegetative and reproductive stages increased seed weight. Even though N application during the vegetative stage showed a negative effect on nodulation, there was a large shoot growth response. The lower yield from N applied at planting may have been caused by less shoot growth response as well as inhibited nodulation. Based on these results the best management system using N fertilizer was an application during vegetative growth. Further studies are needed to identify bean lines capable of high N2 fixation in the presence of N and to determine optimum amounts and timing of N application to maximize biological and economic yields.
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  • 95
    ISSN: 1573-0867
    Keywords: Canola ; irrigation ; nitrogen ; nitrogen efficiency ; yield ; oil content ; water use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Effects of N application and water supply on yield, oil content and N accumulation by canola, cultivar Marnoo, grown on a heavy clay soil in the Goulburn Murray Irrigation Region were investigated. Treatments were rainfed (Rf) or watered at a deficit of 50 mm (40–60 mm, I50) beginning in the spring. N treatments were 0, 50, 100 or 200 kg N ha−1 at sowing or as split applications of 20/80, and 50/50 kg N ha−1 at sowing and rosette, respectively. Yield (Yg) ranged from 170 to 520 g m−2. Irrigation and N increased yield in both years. Grain yields were increased by N application on the irrigated treatments when 100 or 200 kg N ha−1 was applied. Oil concentrations ranged from a maximum of 46.4% in treatment N0 to a minimum of 40.6% in treatment N200 and was inversely related to seed N concentration. Although fertilizer N decreased oil concentration, it increased the yield of oil. Nitrogen accumulation (Nb) limited yield of all treatments and was described by the equation, Yg = 806[1-EXP(−0.039*Nb)]. This implied a decrease in yield per unit of Nb at the higher rates of fertilizer addition with consequent increases in grain N concentration. The efficiency of water use in the production of grain (WUEg) and biomass (WUEb) were 7.5 and 23 kg ha−1 mm−1 respectively. Nitrogen additions increased WUEg and WUEb in both seasons. Maximum values of 8.9 (WUEg 1986) and 26.8 (WUEb 1987) were measured from treatment N200. These data suggest that the crops made efficient use of the applied water.
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    Nutrient cycling in agroecosystems 42 (1995), S. 185-192 
    ISSN: 1573-0867
    Keywords: 15N ; nitrogen ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The use of15N as a tracer in soil/plant research is examined. The limitations of the so-called Ndff approach are discussed to show the need to consider not just the fate of the added label but also the path that was followed and the rate of the transformation. The development of15N isotope dilution techniques to determine gross rates of nitrogen transformation in soil is reviewed with some indications as to the further development of the approach.
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  • 97
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    Nutrient cycling in agroecosystems 34 (1993), S. 121-126 
    ISSN: 1573-0867
    Keywords: Controlled release fertilizers ; electroultrafiltration ; nitrogen ; ryegrass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The efficiency of different nitrogenous fertilizers under forced leaching conditions was determined in pot experiments using ryegrass as an indicator plant in a sandy loam soil. Treatments were: ON (unfertilized), AN (ammonium nitrate), U (urea), DAP (diammonium phosphate), T (Triabon), FK (Floranid Komplett) and CDU (crotonylidendiurea). N source effects on N uptake, and N leached (as % of N applied) were evaluated. Results show that the fertilizers which behaved best with regard to N uptake were FK followed by Triabon and AN. The most soluble fertilizers, AN and urea, gave the highest N leaching losses. Significant correlations between EUF-NI (rapidly soluble fraction) and leaching, as well as between EUF-N (I + II) and N uptake by the plant (where EUF-N II relates to the slowly soluble fraction) were obtained.
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  • 98
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    Nutrient cycling in agroecosystems 47 (1996), S. 243-250 
    ISSN: 1573-0867
    Keywords: fertilizer value ; nitrogen ; phosphorus ; poultry manure ; urea ; wetland rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Poultry manure applied alone or in combination with urea at different N levels was evaluated as a N source for wetland rice grown in a Fatehpur loamy sand soil. Residual effects were studied on wheat which followed rice every year during the three cropping cycles. In the first year, poultry manure did not perform better than urea but by the third year, when applied in quantities sufficient to supply 120 and 180 kg N ha−1, it produced significantly more rice grain yield than the same rates of N as urea. Poultry manure sustained the grain yield of rice during the three years while the yield decreased with urea. Apparent N recovery by rice decreased from 45 to 28% during 1987 to 1989 in the case of urea, but it remained almost the same (35, 33 and 37%) for poultry manure. Thus, urea N values of poultry manure calculated from yield or N uptake data following two different approaches averaged 80, 112 and 127% in 1987, 1988 and 1989, respectively. Poultry manure and urea applied in 1:1 ratio on N basis produced yields in between the yields from the two sources applied alone. After three cycles of rice-wheat rotation, the organic matter in the soil increased with the amount of manure applied to a plot. Olsen available P increased in soils amended with poultry manure. A residual effect of poultry manure applied to rice to supply 120 or 180 kg N ha−1 was observed in the wheat which followed rice and it was equivalent to 40 kg N ha−1 plus some P applied directly to wheat.
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    Nutrient cycling in agroecosystems 48 (1997), S. 241-246 
    ISSN: 1573-0867
    Keywords: barley ; denitrification ; fertilizerefficiency ; mineralization ; nitrogen ; sludge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Enhanced microbial activity following sewage sludge land application may affect soil N cycling and, therefore, plant available N. We studied the effect of anaerobically treated sewage sludge on N-fertilizer efficiency and on some aspects of the soil N cycling. Field plots (3 m × 9 m) sown with barley (Hordeum vulgare L.) in November were amended with a) sludge (80 mg ha-1) and ammonium nitrate (150 kg N ha-1), b) ammonium nitrate (150 kg ha-1) only, c) or left unamended. Monthly soil samples were taken from 0 to 20-and 20 to 50-cm depths to determine soil inorganic N (NH4 +, NO3-). Denitrification in the upper 20-cm horizon was estimated by measuring N2O+N2 emission from undisturbed soil samples by the acetylene-inhibition technique. Crop yield parameters were analysed before harvesting, and grain production was recorded. With respect to the control, the yield increase for the N-fertilizer treatment was 85% and 45% for the sludge + N-fertilizer treatment. The decrease of N-fertilizer efficiency in sludge amended plots was presumably due to a decrease in spring plant available N. Presumably, microbial immobilisation and denitrification in organic amended treatments were responsible for the decrease in N-fertilizer efficiency.
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  • 100
    ISSN: 1573-0867
    Keywords: Phosphorus ; nitrogen ; iron ; VAM ; Rhizobium ; faba-bean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of rhizobial inoculation, vesicular arbuscular mycorrhizal (VAM) fungi on the growth, P, N and Fe uptake by faba-bean plants (Vicia faba L.V. Giza 2) grown in virgin sandy soil, treated with super or rock-P were studied under green-house conditions. The earthern pots received a half of the recommended rate of P either as single super phosphate or rock-P in the rate of 20 mg P/kg soil, and calcium ammonium nitrate was added in the rate of 10 mg N/kg soil. Iron was applied in two levels 0 and 5 mg Fe/kg soil, in the form of iron sulphate (FeSO4·7H2O). Dry matter yield, as well as P, N and Fe-uptake were determined. Nodule numbers and their dry weights, spore numbers and mycorrhizal root infection were determined. Results indicated that, fungal infection and rhizobial inoculation either alone or in combination increased dry matter yield as compared to uninoculated plants, whereas the percentages increase in dry matter were 34, 26 and 57% in case of super-P application, while they were 56, 47 and 89% in case of rock-P when inoculated withRhizobium, VAM and dual inoculation respectively. Also P, N and Fe uptake were significantly increased due to inoculation, and dual inoculation resulted the highest effect. Generally, inoculation withRhizobium and/or mycorrhizae can remove the deficient effect of P and Fe on N2-fixation and plant growth in the soil of low nutrients content.
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