Field Evaluation of Urease Inhibitors for Corn Production1
- A. J. Schlegel,
- D. W. Nelson and
- L. E. Sommers2
Phosphoroamide urease inhibitors were evaluated for their ability to increase N uptake and grain yield of corn (Zea mays L.) when added to surface-applied urea fertilizers. Six urease inhibitors [trichloroethyl phosphorodiamidate, diethyl phosphoric triamide, dimethyl phosphoric triamide, N-(diaminophosphiny1)-cyclohexylamine, N-benzyl-N-methyl phosphoric triamide, and phenylphosphorodiamide (PPD)] were evaluated. Urea prills, urea solution, and urea-ammonium nitrate (UAN) solution were broadcast, and UAN solution was banded onto the surface of conventional till (CT) Chalmers silty clay loam (Typic Haplaquoll) and no-till (NT) Raub silt loam (Aquic Argiudoll) in 1983. Two urease inhibitors [PPD and N-(n-butyl)-thiophosphoric triamide (TPT)] were broadcast with urea prills and UAN solution (60, 120, and 180 kg N ha−1) 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 solution, although no differences between broadcasted and banded UAN or between fertilizers with and without urease inhibitors were observed. In 1984, urease inhibitors increased grain yield and N uptake of NT corn when applied with urea prills, but not with UAN solution. 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 amounts of residue cover under conditions of adequate moisture to promote urea hydrolysis and ammonia volatilization but without sufficient precipitation to move the urea into the soil.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .