Fertilizer value of poultry litter applied by subsurface band vs. surface broadcast in corn production

Optimal yield of corn fertilized with poultry litter (PL) may be achieved with less PL if applied by subsurface banding (LSS). The objective of this study was to determine, using economic analysis, if profit maximizing PL rate can be reduced if applied by LSS relative to the conventional surface broadcast (LBC) in corn production. Corn was grown with six PL rates ranging from 4.4 to 27.0 Mg ha(-1) applied by LSS or LBC and with seven synthetic N (sN) rates ranging from 0 to 292 kg ha(-1). Rates of PL or sN that maximized yield or profit were determined from yield response curves. The results showed that yield maximizing PL was greater than profit maximizing PL by as much as 25% regardless of the application method showing that targeting maximum yield is wasteful and may reduce profit. Both yield and profit maximizing PL rates were less if applied by LSS than by LBC while the respective yields did not differ greatly. As much as 17% more grain was produced by 1 Mg ha(-1) profit maximizing PL if applied by LSS than by LBC. Availability of N from PL was 40% if applied by LSS. These results show that applying PL by subsurface banding conserves N, leads to greater grain yield per 1 Mg PL, and thus the same corn yield may be obtained with less PL if applied by banding than by surface broadcasting.