Integration of Poultry Litter and Mineral N on Growth and Yield of Winter Canola.

Canola (Brassica napins (L.)) has the potential for being used in a double-cropping system as a winter crop in the Southeastern US, but little information is known about its nitrogen management in this region, especially when using poultry litter (PL) as a nutrient source. Therefore, the objective of this study was to evaluate canola growth and yield response to poultry litter fertilization compared to inorganic N fertilization. This study was conducted from 2016 to 2017 at two locations (Shorter, AL – on a Compass loamy sand and Prattville, AL – on a Lucedale fine sandy loam) using a randomized complete block design with four replications. Fertility treatments consisted of an unfertilized control (P₀U₀), inorganic N fertilizer urea at 180 kg N ha^-1 (P₀U₁₈₀), PL at 68 kg N ha^-1 plus 112 kg N ha^-1 urea (P₆₈U₁₁₂), PL at 112 kg N ha^-1 plus 68 kg N ha^-1 urea (P₁₁₂U₆₈), and PL at 180 kg N ha^-1 (P₁₈₀U₀). Integration of PL and urea application significantly increased canola growth (plant height and aboveground biomass) and grain yield, while no differences in leaf greenness was observed when compared to a single PL application or the control. The P₆₈U₁₁₂ treatment resulted in an equivalent or slightly greater aboveground biomass, grain yield, and N uptake compared to the recommended urea treatment. Therefore, a combination of PL and inorganic N could potentially reduce the usage of chemical fertilizer without decreasing winter canola yield.