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.

Core Ideas Annual application of foliar fungicide in continuous soybean increased yields. Breakeven soybean price for applying a foliar fungicide ranged from US$0.13 to $0.27kg−1. Results suggest a high likelihood that foliar fungicide application is profitable. With the expansion in soybean (Glycine max L.) land area in the Southeast, producers are wondering how to profitably manage the disease frogeye leaf spot (FLS) (Cercospora sojina); however, little is known about the profitability of using foliar fungicide on soybean infected with FLS. We determined the effect of total water applied, growing degree days, and foliar fungicide treatment on FLS severity and yield of soybean in maturity group (MG) III, IV, and V. A two‐stage severity/treatment outcome model was estimated and results were used to calculate the breakeven price of soybean for applying a foliar fungicide by MG. Data came from an 11‐yr soybean fungicide (quinone) experiment in Tennessee. Applying a foliar fungicide to soybean in a high disease pressure location reduced FLS severity and increased yields for each MG. Annual application of foliar fungicide in continuous soybean was found to increase yields by 475 kg ha−1 for MG III, 321 kg ha−1 for MG IV, and 408 kg ha−1 for MG V. The breakeven price of soybean, for applying a foliar fungicide, ranged from US$0.13 to $0.27 kg−1 for all MGs, depending on the application cost. A profit‐maximizing producer would apply a foliar fungicide as part of the annual production practices to manage FLS since the soybean price has historically been above the breakeven price. Results from this study will inform Tennessee and southeastern producers on the profitability of spraying soybean with a foliar fungicide to manage FLS.

Little research exists on the optimal temporal frequency between soil tests, given empirical data on potassium (K) carryover and its interaction with cotton yield. We evaluate how decreasing the temporal frequency between obtaining K soil test information affects the net present value (NPV) of cotton production. Monte Carlo simulation was used to determine NPV for cotton production using five soil test schedules ranging from soil testing annually to every fifth year. NPV of returns to K was maximized at $7,580/ac. when producers updated soil testing information every 2 years, which was $2/ac. per year greater than annual soil testing.

Recent research has shown that stochastic yield response functions fit data better than deterministic yield response functions; however, little research exists comparing profit-maximizing fertilizer rates for upland cotton (Gossypium hirsutum L.) using stochastic and deterministic yield response functions. The objective of this research was to determine the most appropriate yield response functional form from which to determine the profit-maximizing potassium (K) rate for cotton in Tennessee. Data were used from a nine-year K fertilizer experiment in Jackson, Tennessee. Quadratic, quadratic-plus-plateau, linear response plateau, and linear response stochastic plateau response functions were estimated to determine the yield response function that best fit the data. The linear response stochastic plateau function was the most suitable yield response function for the data. The profit-maximizing K rate ranged from 65.2 to 74.3kg K ha(-1). Misspecification of the yield response function recommended over-application of K fertilizer and decreased the producer's short-term profits.

We determined the value of soil test information for potassium (K) in upland cotton production using the linear response plateau (LRP) and linear response stochastic plateau (LRSP) functions. A stochastic dynamic programming model was used to determine the net present value to K fertilizer when optimal K was applied with knowledge about K carryover. Using K carryover information for K application decisions increased net present value and helped maintain steady levels of soil K. The LRSP function fit the data better than the LRP, and the value of soil testing was $27 ha(-1) lower over ten years using the LRSP.

Little is known about the profitability of treating soybean infected with frogeye leaf spot (FLS) with a foliar fungicide. We determine the economic effect of total water applied, growing degree days, and foliar fungicide treatment on FLS severity and yield of soybean MG III, IV, and V with a two-stage severity/treatment outcome model. Data were collected from an 11-year soybean fungicide experiment in Tennessee under high, natural disease pressure. The marginal value product and the breakeven price of soybean for applying a foliar fungicide to treat FLS were estimated for each MG. Applying foliar fungicide reduced FLS severity and increased yields for each MG. The results suggest a profit-maximizing producer would apply a foliar fungicide each year to manage FLS.