ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Using hydrophilic polymers to control nutrient release (1994)

Mikkelsen, Robert L.

Springer

Nutrient cycling in agroecosystems 38 (1994), S. 53-59

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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

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00750062

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2

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Land application of poultry litter and water quality in Oklahoma, U.S.A. (1994)

Heathman, G. C. ; Sharpley, A. N. ; Smith, S. J. ; [et al.]

Springer

Nutrient cycling in agroecosystems 40 (1994), S. 165-173

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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.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00750462

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3

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Response of ensete (Ensete ventricosum W.) to mineral fertilizers in southwest Ethiopia (1994)

Uloro, Y. ; Mengel, K.

Springer

Nutrient cycling in agroecosystems 37 (1994), S. 107-113

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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.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00748551

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4

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The effect of nitrogen catch crop species on the nitrogen nutrition of succeeding crops (1994)

Thorup-Kristensen, K.

Springer

Nutrient cycling in agroecosystems 37 (1994), S. 227-234

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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.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00748941

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5

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Application of15N-labelled urea to sugar cane through a drip-irrigation system in Mauritius (1994)

Ng Kee Kwong, K. F. ; Deville, J.

Springer

Nutrient cycling in agroecosystems 39 (1994), S. 223-228

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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.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00750250

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6

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Urea management for lowland transplanted rice as affected by application of farmyard manure (1994)

Son, Tran Thuc ; Buresh, R. J.

Springer

Nutrient cycling in agroecosystems 39 (1994), S. 199-203

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ISSN: 1573-0867

Keywords: farmyard manure ; floodwater ; nitrogen ; Oryza sativa L. ; partial pressure of ammonia ; urea ; Vietnam

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Farmyard manure (FYM) applied to rice-growing soils can substitute for industrial fertilizers, but little is known about the influence of FYM on the effectiveness and optimal management for industrial N fertilizers. A field experiment was conducted in northern Vietnam on a degraded soil in the spring season (February to June) and summer season (July to November) to determine the effect of FYM on optimal timing for the first application of urea. The experimental design was a randomized complete block with two rates of basal incorporated FYM (0 or 6 Mg ha−1) in factorial combination with two timings of the first application of 30 kg urea-N ha−1 (basal incorporated before transplanting or delayed until 14 to 16 d after transplanting). The FYM was formed by composting pig manure with rice straw for 3 months. Basal incorporation of FYM, containing 23 kg N ha−1, increased rice grain yield in both seasons. The yield increase cannot be attributed to reduced ammonia loss of applied urea-N, because FYM did not reduce partial pressure of ammonia (pNH3) following urea application in either season. Basal and delayed applications of urea were equally effective in the absence of FYM, but when FYM was applied rice yields in both seasons were higher for delayed (mean = 3.2 Mg ha−1) than basal (mean = 2.9 Mg ha−1) application of urea. Results suggest that recommendations for urea timing in irrigated lowland rice should consider whether farmers apply FYM.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00750247

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7

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Growth and elemental content of several sagebrush-steppe species in unburned and post-wildfire soil and plant effects on soil attributes (1994)

Blank, Robert R. ; Allen, Fay ; Young, James A.

Springer

Plant and soil 164 (1994), S. 35-41

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ISSN: 1573-5036

Keywords: nitrogen ; phosphorus ; revegetation ; silica ; succession ; shrubland

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Fire is the principal means of stand renewal in big sagebrush-steppe communities of western North America. Plant growth following fire may be influenced by heat-induced changes in the nutrient status of the soil. Moreover, post-wildfire pioneer plant species may alter soil properties, and thereby, impact subsequent plant recruitment. Our study compared the growth and elemental content of big sagebrush (Artemisia tridentata), squirreltail (Elymus elymoides), cheatgrass (Bromus tectorum), and Indian ricegrass (Achnatherum hymenoides), grown under greenhouse conditions in post-wildfire and similar unburned soil. We also examined soil attributes following plant growth. Cheatgrass and squirreltail, grown in post-wildfire soil, had significantly (p≤0.05) greater aboveground mass than plants grown in unburned soil. As compared with unburned soil, post-wildfire soil engendered the following significant (p≤0.05) differences in leaf elemental content: 1) big sagebrush had higher levels of P and lower levels of Mn; 2) squirreltail accumulated more P and N; and 3) all grass species had higher SiO2 content. Following harvest of plants, post-wildfire soil generally contained significantly (p≤0.05) more KCl-extractable ortho-P, NH inf4 + , and SO 4 − , than unburned soil. Plant growth in both burned and unburned soils fostered a significant (p≤0.05) increase in the bicarbonate-extractable pool of P as compared with unplanted controls. Soil Kjeldahl-N was significantly (p≤0.05) greater after plant growth in burned treatments as compared with the control. This study demonstrates that post-wildfire soil can have a stimulatory effect on plant growth for some species. Squirreltail deserves consideration as a post-wildfire revegetation species. Furthermore, pioneer plant growth following wildfires can attenuate soil properties and therefore influence plant succession.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00010108

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8

Electronic Resource

Comparison between a chemical and a biological method to determine the N mineralization potential of temperate-humid region soils (1994)

González-Prieto, S. J. ; Villar, M. C. ; Carballas, M. ; [et al.]

Springer

Plant and soil 162 (1994), S. 147-150

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ISSN: 1573-5036

Keywords: biological method ; chemical method ; mineralization potential ; nitrogen ; soil incubation ; temperate humid-zone

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract The potentially mineralizable organic N of 33 different soils was estimated by a chemical test (hot extraction with 2N KCl) and the values compared with those previously obtained by a biological method (aerobic incubation in the laboratory). On average, the organic N solubilized by the chemical procedure was significantly lower than that mineralized by a two weeks aerobic incubation for all the soils as a whole. The same was true for soils developed over acid rocks and over sediments. However, the values obtained for the soils developed over limestone and basic rocks were similar by both methods. The values obtained by both methods were not significantly correlated neither when considering all soils together nor when considering different groups according to soil management or parent material. Significant correlations between both methods were only found when the soils were separated into two groups according to their organic N content: soils with less than 400 mg N 100 g−1 soil and soils with more than 400 mg N 100 g−1 soil. The organic N solubilized by the chemical procedure was significantly correlated with the hexosamine-N content; however, it was not correlated with the factors that control the biological mineralization of the organic N, except with the soluble Al content. Therefore, the chemical extraction did not seem to address the biologically active N pool in a selective way.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01416100

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9

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A simple model for estimating the contribution of nitrogen mineralization to the nitrogen supply of crops from a stabilized pool of soil organic matter and recent organic input (1994)

Matus, F. J. ; Rodríguez, J.

Springer

Plant and soil 162 (1994), S. 259-271

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ISSN: 1573-5036

Keywords: mineralization rate ; nitrogen ; stabilized organic matter ; crop rotation

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract A simple model was developed to estimate the contribution of nitrogen (N) mineralization to the N supply of crops. In this model the soil organic matter is divided into active and passive pools. Annual soil mineralization of N is derived from the active pool. The active pool comprises stabilized and labile soil organic N. The stabilized N is built up from accumulated inputs of fresh organic N during a crop rotation but the labile N is a fraction of total N added, which mineralizes faster than the stabilized N. The passive pool is considered to have no participation in the mineralization process. Mineralization rates of labile and stabilized soil organic N from different crop residues decomposing in soil were derived from the literature and were described by the first-order rate equation dN/dt =-K*N, where N is the mineralizable organic N from crop residues andK is a constant. The data were groupedK 1 by short-term (0–1 year) andK 2 by long-term (0–10 years) incubation. Because the range of variation inK 2 was smaller than inK 1 we felt justified in using an average value to derive N mineralization from the stabilized pool. The use of a constant rate ofK 1 was avoided so net N mineralization during the first year after addition is derived directly from the labile N in the crop residues. The model was applied to four Chilean agro-ecosystems, using daily averages of soil temperature and moisture. The N losses by leaching were also calculated. The N mineralization varied between 30 and 130 kg N ha−1 yr−1 depending on organic N inputs. Nitrogen losses by leaching in a poorly structured soil were estimated to be about 10% of total N mineralized. The model could explain the large differences in N- mineralization as measured by the potential N mineralization at the four sites studied. However, when grassland was present in the crop rotation, the model underestimated the results obtained from potential mineralization.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01347713

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10

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Root architectural responses of Betula lenta to spatially heterogeneous ammonium and nitrate (1994)

Crabtree, R. C. ; Bernston, G. M.

Springer

Plant and soil 158 (1994), S. 129-134

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ISSN: 1573-5036

Keywords: Betula lenta L. ; black birch ; nitrogen ; root architecture ; soil heterogeneity

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Inorganic soil nitrogen is often heterogeneously distributed, both spatially and in form (ammonium versus nitrate). Here we present information on the architecture of black birch (Betula lenta L.) root systems exposed to homogeneous and heterogeneous nitrogen environments. The major effects on root architecture were at the whole root system level in response to heterogeneity of nitrogen form rather than the effect of local of local nitrate or ammonium supply on local root growth. In the heterogeneous treatment, plant root systems had greater link lengths and more simple branching patterns. Root architectural responses to heterogeneous nitrogen, independent of localized responses to patches, suggest that in a seedling of B. lenta whole plant integration of its environment may override local control of root growth.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00007925

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