Influence of Cover Crop and Tillage Systems on Optimal Nitrogen Rate for Tennessee Cotton Considering Risk

Abstract

Upland cotton fields have minimal amounts of crop residue after harvest to cover the soil surface, which exposes the soil and increases the risk of soil erosion. This is especially challenging in the Mid-South U.S. where cotton is commonly grown on sandy or silty soils that are naturally prone to soil erosion. Winter cover crops and no-till planting are two practices that can mitigate soil erosion by increasing soil surface biomass. However, there is uncertainty on how these practices can impact producers’ profits and risk. We determine the influence of four winter cover crops and two tillage systems on the optimal nitrogen rates, cotton yields, and net returns for risk-neutral to risk-averse cotton producers. Data came from a long-term nitrogen (N), tillage, and cover crop experiment in Tennessee. A flexible moment model was used to estimate the impact of risk on the decision to plant cover crops and tillage system. Planting cover crops on till planted cotton decreased optimal N fertilizer rate as well as optimal yields. However, the impact of cover crops on optimal N rate, yields, net returns for no-till planting depends on the cover crop species. A risk-neutral producer would select a till and no cover crop system, but as risk aversion increases, no-till planting with no cover crop system was optimal. Results improve the understanding into the profitability and risk of using cover crops and no-till, which will assist producers in making optimal production systems.