Corn Yield and Phosphorous Uptake with Banded Urea and Phosphate Mixtures

Abstract

AbstractLow fertilizer P use efficiency is a problem in crop production on acid soils, but efficiency can be affected by methods of fertilizer application. A field experiment was conducted on two eastern Canadian soils (fine‐silty to fine, mixed, frigid Typic Humaquepts) with different pH (5.0 and 6.0 initially) to evaluate the effect of banding different rates of urea with acidic P fertilizers on corn (Zea mays L.) yield and fertilizer use efficiency. Three rates of urea (0, 30, and 60 kg N ha−1) banded with two sources of P (triple superphosphate [TSP] and monoammonium phosphate [MAP] at 38.7 kg P ha−1) or alone without P fertilizer, as control, were studied in 1990. In 1991, three rates of TSP (0, 19.4, and 38.7 kg P ha−1) were used in combination with the same three rates of urea to determine the effect of banding ratio of urea‐N/TSP‐P. The residual fertilizer effects of the 1990 treatment were investigated in 1991. Banding urea with TSP or MAP increased soil extractable P (Mehlich III). At the six‐leaf stage, plant P concentrations and dry matter yield increased linearly with both banded N and P in the Ste. Rosalie soil, and quadratically in the Ormstown soil. Total N and P uptake by corn increased in both years by banding urea with TSP or MAP, and fertilizer P use efficiency increased by 40 to 80%. Urea banded with P increased grain yield in both soils. No interactions were found between banded N rates and P sources in 1990, and between banded N rates and P rates in 1991. Greater residual effects of P fertilizer were found on grain yields and P uptake where P was banded with urea compared with no urea.