Starter Nitrogen Fertilizer Management for Continuous No-Till Corn Production

摘要

High residue levels provide excellent erosion control but can result in cool, wet seedbeds creating a situation where starter fertilizer may be beneficial. Research was conducted from 1999 to 2001 evaluating N rates in starter containing N, P, K, and sometimes S; and different starter fertilizer placements for continuous no-till corn (Zea mays L.). Placements consisted of direct seed contact, dribble over-the-row, and a subsurface band (5 cm below and 5 cm to the side of the seed row). Nitrogen rates for direct seed and dribble placements were 11, 22, 45, and 56 kg N ha–1; and 34, 67, 101, and 134 kg N ha–1 for the subsurface placement. Nitrogen was balanced at 168 kg ha–1 on all treatments, including a no-starter check using broadcast ammonium nitrate at planting. Addition of S in starter was evaluated with subsurface placement. Starter fertilizer, regardless of placement, often increased early season dry matter production and significantly increased grain yields. Increasing N above 22 kg ha–1 in direct seed contact did not increase yields and significantly reduced stands 2 of 3 yr. Stands were unaffected with higher N rates in dribble over-the-row and subsurface placements; however, applying N above 11 and 34 kg ha–1, respectively, resulted in little added yield benefit. Inclusion of 11 kg S ha–1 in a subsurface starter fertilizer sometimes increased early season dry matter production, grain yield, and nutrient uptake. Results suggest starter fertilizer is an effective, efficient way of stimulating early growth and improving yields of continuous no-till corn in Kansas.