TY - JOUR
T1 - Optimizing nitrogen and irrigation inputs for corn based on nitrate leaching and yield on a coarse-textured soil
AU - Sexton, B. T.
AU - Moncrief, J. F.
AU - Rosen, C. J.
AU - Gupta, S. C.
AU - Cheng, H. H.
PY - 1996
Y1 - 1996
N2 - A study was conducted on a Verndale sandy loam soil (coarse loamy over sandy, mixed, frigid Udic Argiboroll) during 1991 and 1992 at Staples, MN, to asses the influence of irrigation scheduling and N source and rate on corn (Zea mays L.) yield and nitrate leaching. Nitrogen sources were urea and turkey manure. Soils were irrigated to field capacity (i) at a fixed trigger deficit throughout the season, or (ii) at a variable trigger deficit based on crop growth stage. Leaching losses were calculated from measured daily fluxes of water percolation and soil water NO3-N concentrations and from a seasonal N mass balance. Based on yield response curves, maximum corn grain yields were obtained at 202 and 234 kg N ha-1 urea in 1991 and 1992, respectively. This resulted in growing season leaching losses of 72 and 55 kg N ha-1 in 1991 and 1992, respectively. The rate at 95% of the maximum crop yield is suggested to substantially reduce nitrate leaching past the root zone. Using this guideline, nitrate leaching would be reduced by 35% compared with nitrate leaching at the maximum yield. When a variable available water deficit was used to schedule irrigation compared with a fixed deficit schedule (at 95% of maximum yield N rate), nitrate leaching was reduced 46%. At equivalent N rates, turkey manure produced equal or greater crop yields as that from urea applications; however, nitrate leaching was equal to or less than urea.
AB - A study was conducted on a Verndale sandy loam soil (coarse loamy over sandy, mixed, frigid Udic Argiboroll) during 1991 and 1992 at Staples, MN, to asses the influence of irrigation scheduling and N source and rate on corn (Zea mays L.) yield and nitrate leaching. Nitrogen sources were urea and turkey manure. Soils were irrigated to field capacity (i) at a fixed trigger deficit throughout the season, or (ii) at a variable trigger deficit based on crop growth stage. Leaching losses were calculated from measured daily fluxes of water percolation and soil water NO3-N concentrations and from a seasonal N mass balance. Based on yield response curves, maximum corn grain yields were obtained at 202 and 234 kg N ha-1 urea in 1991 and 1992, respectively. This resulted in growing season leaching losses of 72 and 55 kg N ha-1 in 1991 and 1992, respectively. The rate at 95% of the maximum crop yield is suggested to substantially reduce nitrate leaching past the root zone. Using this guideline, nitrate leaching would be reduced by 35% compared with nitrate leaching at the maximum yield. When a variable available water deficit was used to schedule irrigation compared with a fixed deficit schedule (at 95% of maximum yield N rate), nitrate leaching was reduced 46%. At equivalent N rates, turkey manure produced equal or greater crop yields as that from urea applications; however, nitrate leaching was equal to or less than urea.
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U2 - 10.2134/jeq1996.00472425002500050008x
DO - 10.2134/jeq1996.00472425002500050008x
M3 - Article
AN - SCOPUS:0030248271
SN - 0047-2425
VL - 25
SP - 982
EP - 992
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 5
ER -