Influence of tillage practices on lint yield, water quality, and soil exchangeable N in cotton production.
Objectives of a 2017 field trial were to quantify how different tillage and N fertilization practices affect cotton productivity and nutrient management in a furrow-irrigated cotton production systems. Lint yield, soil N and runoff water quality metrics were measured after using either a conventional sweep plow or conservation tillage plow to clear water furrows combined with either broadcast urea or 32% urea ammonium nitrate (UAN) sidedressed at 90 lb acre-1. Seasonal NO3-N and P were the largest nutrient in runoff and associated with the intensity of irrigation and rainfall. Lint yields ranged from 550 to 1143 lb acre-1 and were unaffected by tillage and fertilizer-N treatments. There was no downward movement of soil NO3-N in the deeper depths across tillage and N fertilizer treatments. Water quality metrics such as pH, electrical conductivity, hardness, total suspended solids (TSS) and soil sediment concentrations (SSC) were within acceptable ranges and expected to have minimal impacts on surrounding waterbodies.