The efficacy of nitrification inhibitors depends on soil properties and environmental conditions. The nitrification inhibitor 3.4-dimethylpyrazole phosphate （DMPP） was investigated in a sandy loam and a loamy soil t...The efficacy of nitrification inhibitors depends on soil properties and environmental conditions. The nitrification inhibitor 3.4-dimethylpyrazole phosphate （DMPP） was investigated in a sandy loam and a loamy soil to study its effectiveness as influenced by inhibitor concentration, application form, and soil matric potential. DMPP was applied with concentrations up to 34.6 mg DMPP kg^-1 soil as solution or as ammonium-sulfate/ammonium-nitrate granules formulated with DMPP. DMPP inhibited the oxidation of ammonium in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. When applied as solution, increasing DMPP concentrations up to 7 mg DMPP kg^-1 soil had no influence on the inhibition. The effectiveness of DMPP formulated as fertilizer granules was superior to the liquid application of DMPP and NH4^＋, particularly in the loamy soil. Without DMPP, a decline in soil matric potential down to -600 kPa decreased nitrification in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. DMPP was most effective in the sandy loam particularly under conditions of higher soil moisture, i.e., under conditions favorable for nitrate leaching.展开更多
We investigated the effect of small amounts of ammonium sulfate （NH4）2SO4 on compound fertilizer granulation. We examined the following raw materials： humic acid, ammonium chloride, urea, potassium chloride, and mo...We investigated the effect of small amounts of ammonium sulfate （NH4）2SO4 on compound fertilizer granulation. We examined the following raw materials： humic acid, ammonium chloride, urea, potassium chloride, and monoammonium phosphate. The mass ratio of organic matter, nitrogen, phosphorus, and potassium was typically 22：17：7：2. In the absence of （NH4）2SO4, the granulation rate of the compound fertilizer was low, and increased significantly following the addition of 1–2% （NH4）2SO4. We suggested the following physical and chemical processes as potential mechanisms： （NH4）2SO4 promoted the conversion of yellow flue gas desulfurization gypsum into gypsum whiskers; （NH4）2SO4 interacted with humic acid and urea to generate a new complex; urea sulfate was formed under acidic conditions. The combined effect of the above physical and chemical processes was an increase both in the rate of interactions between the materials and in system viscosity, which has the end result of increasing the granulation rate.展开更多
基金the Federal Ministry of Education and Research, Bonn, Germany (No423-40003-0339812)BASF, Ludwigshafen, Germany
文摘The efficacy of nitrification inhibitors depends on soil properties and environmental conditions. The nitrification inhibitor 3.4-dimethylpyrazole phosphate （DMPP） was investigated in a sandy loam and a loamy soil to study its effectiveness as influenced by inhibitor concentration, application form, and soil matric potential. DMPP was applied with concentrations up to 34.6 mg DMPP kg^-1 soil as solution or as ammonium-sulfate/ammonium-nitrate granules formulated with DMPP. DMPP inhibited the oxidation of ammonium in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. When applied as solution, increasing DMPP concentrations up to 7 mg DMPP kg^-1 soil had no influence on the inhibition. The effectiveness of DMPP formulated as fertilizer granules was superior to the liquid application of DMPP and NH4^＋, particularly in the loamy soil. Without DMPP, a decline in soil matric potential down to -600 kPa decreased nitrification in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. DMPP was most effective in the sandy loam particularly under conditions of higher soil moisture, i.e., under conditions favorable for nitrate leaching.
基金This work was supported by The Natural Science Foundation of Shanxi Province （Grant No. 2012011009-3）.
文摘We investigated the effect of small amounts of ammonium sulfate （NH4）2SO4 on compound fertilizer granulation. We examined the following raw materials： humic acid, ammonium chloride, urea, potassium chloride, and monoammonium phosphate. The mass ratio of organic matter, nitrogen, phosphorus, and potassium was typically 22：17：7：2. In the absence of （NH4）2SO4, the granulation rate of the compound fertilizer was low, and increased significantly following the addition of 1–2% （NH4）2SO4. We suggested the following physical and chemical processes as potential mechanisms： （NH4）2SO4 promoted the conversion of yellow flue gas desulfurization gypsum into gypsum whiskers; （NH4）2SO4 interacted with humic acid and urea to generate a new complex; urea sulfate was formed under acidic conditions. The combined effect of the above physical and chemical processes was an increase both in the rate of interactions between the materials and in system viscosity, which has the end result of increasing the granulation rate.
