Relative Efficiency of Broadcast Versus Banded Phosphorus for Corn¹

Abstract

Abstract Experiments were conducted on Zanesville, Elliott, and Muscatine soils to determine the relative efficiency, with respect to corn yields, of broadcast P as compared to banded P. The 16 fertilizer treatments consisted of 4 rates of banded P and 4 rates of broadcast P in factorial combinations. Yields from each of the 3 soils were used to calculate a multiple regression equation for each soil. The equation is of a quadratic form, and it expresses the relation between yield and rates of banded and broadcast P. The regression equations account for 77 to 88% of the variation in yield. The largest yield increases from added P were 1287, 1474, and 873 pounds of corn per acre for the Zanesville, Elliott, and Muscatine soils, respectively. With all the P either banded or broadcast, the relative efficiency of broadcast P ranged from 0.49 to 1.23 for the 3 soils For a given soil, the relative efficiency of broadcast P varied with rate. At 35.2 pounds of P added per acre, higher yields were obtained on Zanesville and Elliott soils if a combination of banded and broadcast application were used than if all the P was added either banded or broadcast. Banding all the P gave higher yields than the other application methods if 17.6 and 8.8 pounds of P per acre were added. Yields from the Muscatine soil were not dependent on whether all the P was drilled, broadcast, or applied by a combination of both methods.