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Effect of ammonium fertilizer on NH3 loss and Ca, Mg, ammonium and nitrate content in a calcareous soil solution (1987)

Fenn, L. B. ; Wu, E.

Springer

Biology and fertility of soils 5 (1987), S. 171-174

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ISSN: 1432-0789

Keywords: Ca precipitation ; Calcium sulfate formation ; Ammonium carbonate ; Ammonium hydroxide ; Ammonium phosphate ; Ammonium sulfate ; Ammonia loss

Source: Springer Online Journal Archives 1860-2000

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

Notes: Summary This study examined the effects of NH inf4 + fertilizers [(NH4)2SO4, (NH4)2HPO4, CO(NH2)2, NH4OH, and NH4NO3] on NH3 loss and the quantity of Ca + Mg, NH inf4 + and NO inf3 sup− in the solution of a calcareous soil (Harkey sicl, Typic Torrifluvent). Various NH4 fertilizers applied at a depth of 5 cm in the soil produced differing NH3 loss characteristics. Applying (NH4)2SO4 (AS) resulted in high volatile NH3 losses as compared with NH4OH (AH) and (NH4)2CO3 (AC). The AS treatment formed an equal molar amount of CaSO4, which increased the mobility of ammonium, while AH and AC treatments caused Ca precipitation and decreased ammonium mobility. Leaching the AS system before NH3 loss could occur resulted in the most rapid nitrification rate. Lower nitrification rates were found with AH and AC than AS under the same conditions. Surface placement of NH4 fertilizers resulted in variable leachate contents of Ca + Mg. Ammonium sulfate reacted with CaCO3 either to solubilize some Ca + Mg or simply to replace exchangeable Ca + Mg with NH4, while AH, AC, and (NH4)2HPO4 (DAP) precipitated essentially an equivalent molar amount of soluble and adsorbed Ca + Mg. Use of NH4NO3, which does not form an insoluble calcium precipitate, resulted in the leaching of an equivalent molar amount of exchangeable Ca + Mg from the Harkey soil.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00257654

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2

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Guayule seedling response to nitrogen fertilizers (1987)

Fenn, L B ; Miyamoto, S ; Gobran, G

Springer

Nutrient cycling in agroecosystems 11 (1987), S. 113-121

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ISSN: 1573-0867

Keywords: ammonium sulfate ; urea ; calcium nitrate ; nitrogen-calcium interaction ; leaching ; subirrigation ; calcium

Source: Springer Online Journal Archives 1860-2000

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

Notes: Abstract Slow growth and high seedling mortality limit direct seeding establishment of guayule (Parthenium argentatum G.). This study was conducted to assess seedling growth enhancement by the addition of different rates and forms of N fertilizers and Ca salts. Experiments were conducted in a greenhouse with cultivar 593 under both surface and subirrigated conditions using water low in salts (salinity of 0.8 dSm−1, SAR of 5.0 and 10 mg Ca L−1). Under surface-irrigated conditions, seedling height and fresh plant weight increased with N application to the irrigation water to 70 mg L−1. The best seedling growth was observed when (NH4)2SO4 was added in combination with CaCl2 or CaSO4. Progressively less growth was observed by addition of (NH4)2SO4 alone, CO(NH2)2 plus CaSO4, CO(NH2)2 alone and Ca(NO3)2. When seedlings were subirrigated, however, the best growth was observed with Ca(NO3)2. Intermediate growth was obtained with (NH4)2SO4 plus CaSO4 and lowest growth rates with (NH4)2SO4 alone. These differential responses may be explained by the differences in leaching and volatile characteristics of the N forms. Growth enhancement from N and Ca additions increased with time with significant increases 45 days after seeding. Nitrogen application with Ca may be effective amendment in promoting subsequent growth of direct seeded guayule.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01051055

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3

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Ammonia losses from surface-applied urea as related to urea application rates, plant residue and calcium chloride addition (1987)

Fenn, L. B. ; Malstrom, H. L. ; Wu, E.

Springer

Nutrient cycling in agroecosystems 12 (1987), S. 219-227

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ISSN: 1573-0867

Keywords: soil organic matter ; urea hydrolysis rates ; microbial activity ; NH3 volatilization

Source: Springer Online Journal Archives 1860-2000

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

Notes: Abstract Volatile losses of NH3 from surface-applied urea are known to decrease in the presence of soluble Ca-salts or with a decrease in easily decomposable organic matter content (EDOM), both of which influence urease activity. How these factors interact to affect NH3 losses is not fully understood. Studies were conducted to determine the effect CaCl2 in sand with varying rates of EDOM on NH3 losses from surface applied urea. The same effects were examined on agricultural soils containing partially decomposed native organic matter (NOM). Determinations were made in the laboratory on field soils, sand free of organic matter and sand with known amounts of grass clippings (GC, EDOM). Low levels of GC in sand with low amounts of added urea resulted in little NH3 loss. Ammonia loss increased as more N was applied at the low levels of GC. The loss was independent of urea application rates at high levels of GC. Ammonia losses were reduced more effectively at low EDOM and NOM in the presence of Ca. Incubation of sand with GC at low rates prior to urea addition increased NH3 losses relative to high levels of non-incubated GC. For the above situation incubation for as high as 24 days resulted in equivalent NH3 losses. The amount and state of decomposition of existing organic matter affected the degree of NH3 loss from surface placed urea and its control by added Ca-salts. Microbial decomposition of EDOM, such as might occur in the spring prior to urea addition, led to greater NH3 losses. Greater loss of NH3 from urea might be an indication of a larger ureolytic microbial population leading to increased urease production.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01315106

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4

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Effects of initial soil calcium content on ammonia losses from surface-applied urea and calcium-urea (1988)

Fenn, L. B.

Springer

Nutrient cycling in agroecosystems 16 (1988), S. 207-216

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ISSN: 1573-0867

Keywords: Acid soil ; calcareous soil ; nitrogen fertilization ; ammonia volatilization ; urea

Source: Springer Online Journal Archives 1860-2000

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

Notes: Abstract Ammonia loss from surface-applied urea occurs because urea hydrolysis increases the pH of the placement site microenvironment. Addition of Ca-salts with urea will control or reduce the microsite pH, thus reducing NH3 losses. The degree of Ca-saturation of the cation exchange sites may influence the ratio of calcium:urea required to control ammonia loss. A laboratory study was conducted to determine if adsorbed Ca or CaCO3 additions (acid soils only) had a measureable impact on Ca control of NH3 loss from surface applied urea at various Ca:urea ratios. With urea alone applied to the soil surface varying the adsorbed Ca content of the treatment soil did not influence NH3 loss. The addition of CaCl2 with urea on the same pretreated soils generally resulted in NH3 losses reflecting the initial pH of the soil. The Ca-saturated acid soils and those acid soils receiving CaCO3 had higher NH3 losses than untreated soils in the presence of urea with soluble CaCl2. It was noted that increasing the calcium:urea ratios progressively depressed the NH3 loss from all soils. Increasing the percent Na-saturation of the calcareous Harkey soil to 25 and 50% (ESP) reduced Ca control of NH3 loss due to Ca being exchanged for Na on the cation exchange sites. Inclusion of CaCl2 with the urea mixture on the surface of the pretreated acid soils resulted in stepwise differences in NH3 loss concuring with the increases in pretreatment soil pH values (differing exchangeable Ca content). Other parameters that influence the amount of NH3 loss, such as acidic buffer capacity and CEC, appeared more important than anticipated for control of NH3 loss with the calcium:urea mixture. On Ca enriched soils the calcium:urea mixture was only slightly less effective in its ability to control NH3 losses than on untreated soils.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01051371

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5

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Ammonia losses from surface-placed mixtures of urea-calcium-potassium salts in the presence of phosphorus (1990)

Fenn, L. B. ; Tatum, G. ; Horst, G.

Springer

Nutrient cycling in agroecosystems 21 (1990), S. 125-131

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ISSN: 1573-0867

Keywords: NH3 volatilization ; Ca precipitation ; phosphorus compounds ; calcium-potassium salts ; urea

Source: Springer Online Journal Archives 1860-2000

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

Notes: Abstract Phosphorus compounds frequently are mixed with urea containing materials for economy in fertilizer operations. There is little published information on NH3 losses from surface application of these mixtures. However, there is evidence that P can react and precipitate with adsorbed and added Ca and increase the potential for NH3 loss. This paper compares NH3 losses from surface applied urea plus KCl or CaCl2 in the presence of 5 common P sources. The N, with Ca, K, and P salts, was surface-applied to a calcareous (Harkey) and an acid soil (Cuthbert) in a laboratory and the NH3 losses determined by passage of the exhaust air through a 2% boric acid solution. Ammonia losses were increased with (in the presence of KCl or CaCl2) KH2PO4 (KP) (calcareous soil only) and K2HPO4 (K2P), unaffected by Na5P3O10 (PP) but decreased with Ca(H2PO4)2 (CaP) and H3PO4 (HP) (No HP or PP applied to the acid soil). Urea which hydrolyses in environments with lower soluble and desorbable Ca levels is susceptible to higher NH3 losses. The effectiveness of KCl for control of NH3 loss depended on the existence of desorbable Ca to react with the decomposing urea. Therefore the deleterious impact of P on NH3 loss was greater with KCl than with CaCl2. Adding Ca directly with the urea made additional Ca available for reaction with P and urea. Monocalcium phosphate (CaP) alone with urea, in a calcareous soil, did not reduce NH3 loss; however, NH3 loss was reduced in the acid soil. The addition of CaCl2 with urea + CaP reduced NH3 loss more than CaCl2 with urea. The HP reaction with CaCO3 was more rapid and complete than occurred with the acidic CaP. Sodium tripolyphosphate (PP) with urea had little impact on NH3 loss over that produced by the KCl or CaCl2 salts alone. The HP and CaP chemicals did not appear to function strictly as acid sources (calcareous soil). The Harkey soil has 8% CaCO3 which would appear adequate to neutralize any acidity introduced by the P fertilizers. The explanation may lie in double salt formation between the Ca-urea-P materials.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01087421

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6

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Nutrition response of Norway spruce and willow to varying levels of calcium and aluminium (1993)

Gobran, G. R. ; Fenn, L. B. ; Persson, H. ; [et al.]

Springer

Nutrient cycling in agroecosystems 34 (1993), S. 181-189

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ISSN: 1573-0867

Keywords: Acid forest soils ; calcium-aluminum balance ; calcium-ammonium absorption ; willow trees ; Norway spruce trees

Source: Springer Online Journal Archives 1860-2000

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

Notes: Abstract Decreased forest tree growth has often been attributed to increasing soil acidification, especially from high concentrations of soluble Al3+ and low base saturation. The growth of willow cuttings (Salix viminalis L. 78183) and Norway spruce seedlings (Picea abies L. Karst) were measured in a greenhouse in the presence of variable Ca2+ at uniform NH 4 + concentrations. Sets of willows were grown in sand culture, one watered with Ingestad's nutrient solution (INS, pH 5.4) and the other watered with acidified Ingestad's nutrient solution (NSA, pH 3.8). Three levels of Ca2+ and Al3+ concentrations (in NSA only) were established for all nutrient solutions. Sets of Norway spruce seedlings were grown in calcareous sand and watered with INS, one of pH 5.4 and the other of pH 2.1 (resulting in two Ca2+ concentrations after acid neutralization by CaCO3). In the field, observations were made on the correlation of naturally occurring soil solution Al3+ and Ca2+ to spruce needle Al, Ca2+ and N concentrations. In the willow studies, both the above- and below-ground biomass were negatively influenced by the presence of Al3+. Aluminium decreased the growth of rooted cuttings (more in roots than shoots), reduced the uptake of N, Ca2+, Mg2+ and P, significantly lowered the weight of fine roots, and caused overall reductions of tissue nutrient concentrations. As Al3+ concentrations increased, increased concentrations of Ca2+ were needed by the willow to help ameliorate the effects of Al3+. In field samples of spruce needles and soil, CAB (CAB = Log10 Ca2+ /Al3+) was positively correlated with N concentration. From a combination of greenhouse and field studies the mechanisms for Ca2+ amelioration of Al3+ toxicity in trees appear to be i) the effect of Ca2+ on reduced absorption of Mn2+ and Al3+, ii) the effects of Ca2+ on NH 4 + and P absorption, iii) and the stimulation of tree growth.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00750113

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7

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Urease activity in two cultivated and non-cultivated arid soils (1992)

Fenn, L. B. ; Tipton, J. L. ; Tatum, G.

Springer

Biology and fertility of soils 13 (1992), S. 152-154

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ISSN: 1432-0789

Keywords: Urea fertilization ; Urease ; Soil depth ; Soil organic matter ; Arid soils ; Pre-incubation

Source: Springer Online Journal Archives 1860-2000

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

Notes: Summary Since urease activity in soil is believed to be relatively constant, the present study was designed to examine the effects of incubation, soil depth and the effect of cultivation on the persistence of urease activity in arid soils. Two soils were used, a Harkey (coarse, silty, mixed, calcareous, thermic, Typic Torrifluvent) and a Saneli (Clayey over sandy skeletal, montmorillonitic, calcareous, Vertic Torrifluvent), each consisting of a cultivated field and a non-cultivated roadbed site. Urease activity was much lower and more varable in the roadbed soils (40 years without cultivation) than in the cultivated field soils. Pre-incubation for 24 h with urea (with toluene) and without urea (without toluene) greatly reduced the total urease activity in all cases in relation to “cell free” urease activity (with toluene). Urease activity in the two field soils decreased slightly with profile depth but the decrease was greatest below the plow depth (33 cm). Protease activity or some inactivation processes must have lowered the urease content since there was substantially reduced urease activity after most pre-incubations. The extent of the urease activity decrease was so great that the addition of urea would have been required to increase the production of urease enzyme.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00336271

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