Quantifying the Potential of 100 bu ac-1 Yield Soybean and Its Profitability for Environmental Conditions in Kentucky

Yields from soybean contests can offer an estimate of the yield potential of current cultivars in a region. Since record soybean yields were obtained by a farmer in Missouri (139 to 161 bu ac-1 in 2006, 2007, and 2010), several other states in the U.S. have crossed the 100 bu ac-1 threshold. In Kentucky, maximum contest yields have increased on average since 2002, but the highest yield reported is still below 100 bu ac-1 (98.4 bu ac-1 in 2015). Understanding what are the main limiting factors for soybean production in KY, and quantifying the environmental potential of current soybean cultivars, is critical for developing management recommendations that can increase both maximum and average yields in the state. Research suggests that water availability might be the greatest limitation for soybean production in KY. There is little information available of the yield response of different soybean maturity groups (MG) grown in Kentucky under irrigated conditions. Provided there is no water limitations, sufficient nitrogen availability to support a high rate of nitrogen demand could help close further the gap between actual and potential yields. The adoption of these high input practices has the potential to increase soybean yield but may not increase net economic returns for producers in KY. Moreover, production practices that minimize direct costs might be a better strategy to ensure high net economic returns in the long term as water and fertilizer prices change in future scenarios. The objectives of this project are: i) to quantify the yield potential of soybean grown in Kentucky under no water limitation for different MG cultivars; ii) to quantify the yield advantage of N fertilizer applications in situations of high yield potential and N demand; and iii) to estimate net economic returns for different combination of MG x N fertilizer x Irrigation management options, and considering different direct costs scenarios.