FERTILIZER NITROGEN SOURCE AND PLACEMENT, AND AGROTAIN~(R) EFFECTS ON NO-TILL COTTON N-USE-EFFICIENCY

摘要

Due to declining supply of ammonium nitrate (AN), alternate sources of fertilizer N such as urea are being explored. Although, urea has commonly been used worldwide, there are still concerns about the loss of N through NH3 volatilization. The additionof a urease inhibitor could reduce this type of loss. The objective of this study was to measure the effects of fertilizer N source and placement, and effects of a urease inhibitor on N-use-efficiency of no-till cotton. A field experiment evaluating fertilizer N source and placement, and Agrotain~(R) effects on no-till cotton N-use-efficiency was conducted. Fertilizer N treatments were applied at total a rate of 120 lb N/acre with 50 % applied at planting and 50 % at early square. Treatments included AN broadcast, urea broadcast, urea ammonium nitrate (UAN 32% N) subsurface banded, UAN surface dribbled, urea treated with Agrotain~(R) broadcast, UAN treated with Agrotain~(R) surface dribbled, and a zero rate of N. The addition of Agrotain~(R) increasedN-use-efficiency of broadcast urea, and performed comparably to AN. However, the addition of Agrotain~(R) to UAN treatments only increased total N uptake. The results suggest a reduction in N loss through NH3 volatilization from urea sources treated with Agrotain~(R) in surface applications.