Reference

Field evaluation of urease inhibitors for corn production

Field evaluation of urease inhibitors for corn production. Schlegel, A. J.; Nelson, D. W.; Sommers, L. E. (Agron. Dep., Purdue Univ., West Lafayette, IN 47907, USA). Agron. J., 78(6), 1007-12 (English) 1986. CODEN: AGJOAT. ISSN: 0002-1962. DOCUMENT TYPE: Journal CA Section: 19 (Fertilizers, Soils, and Plant Nutrition) Section cross-reference(s): 5 Phosphoroamide urease [9002-13-5] inhibitors were evaluated for their ability to increase N uptake and grain yield of corn (Zea mays) when added to surface-applied urea fertilizers. Six urease inhibitors [trichloroethyl phosphorodiamidate [94511-51-0], diethyl phosphoric triamide [25316-38-5], dimethyl phosphoric triamide [19316-37-1], N-(diaminophosphinyl)cyclohexylamine [25316-51-2], N-benzyl-N-methyl phosphoric triamide [94317-62-1], and phenylphosphorodiamide (PPD) [7450-69-3]] were evaluated. Urea prills, urea soln., and urea-ammonium nitrate (UAN) soln. were broadcast, and UAN soln. was banded onto the surface of conventional till (CT) Chalmers silty clay loam (Typic Haplaquoll) and no-till (NT) Raub silt loam (Aquic Arquidoll) in 1983. Two urease inhibitors [PPD and N-butyl thiophosphoric triamide (TPT) [94317-64-3]] were broadcast with urea prills and UAN soln. (60, 120, and 180 kg N/ha) onto CT and NT Chalmers and NT Avonburg silt loam (Aeric Fragiaqualf) soils in 1984. With both tillage systems in 1983, urea prills produced greater grain yield and tissue N content than did UAN soln., although no differences between broadcasted and banded UAN or between fertilizers with and without urease inhibitors were obsd. In 1984, urease inhibitors increased grain yield and N uptake of NT corn when applied with urea prills, but not with UAN soln. When conditions existed for substantial NH3 loss, TPT performed as well or better than PPD. Urease inhibitors will be most beneficial when added to urea that is surface-applied to soils with large amts. of residue cover under conditions of adequate moisture to promote urea hydrolysis and NH3 volatilization but without sufficient pptn. to move the urea into the soil.