Diversifying soybean production risk using maturity group and planting date choices

While soybean [Glycine max (L.) Merr.] production risk is typically managed by planting a range of maturity groups (MGs) across a few diff erent planting dates (PDs), there have been no reports that have quantified changes in risk and profitability using this diversification strategy. Th ree years of field-trial data from eight locations in six states were analyzed to determine risk–return tradeoff s across MG and PD. Producer revenue expectations were adjusted by soybean harvest date, assessing oil and meal premiums or discounts, and diff erential irrigation requirements by MG and PD, whereas costs for seed, fuel, fertilizer, equipment, and chemicals were held constant. Using portfolio theory, an efficient frontier— maximizing net returns for a given level of risk or minimizing risk for a given level of net return—was estimated by location. Cultivars from MG III and MG IV had higher expected net returns than MG V and VI at all locations. Early-season planting combinations were found to be riskier than the three successive planting dates but led to oil, protein, and seasonal sale price premiums. Across diff erent environments, selecting two to six MG×PD combinations was sufficient to lower risk by 29 to 40% when compared to the single, profit-maximizing MG×PD choice. Depending on location, this risk reduction decreased net returns between 2 and 22% when compared to the profit-maximizing MG×PD choice.