Influence of Tillage Practices on Lint Yield, Water Quality of Surface Runoff and Soil 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 ac^-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.