Estimating Yield Potential by Planting Date Utilizing Observed Data From the Soybean Research Verification Program.

The Soybean Research Verification Program (SRVP) was created in 1983 and represents a public demonstration of the implementation of research-based recommendations in actual field-scale farming environments. The objectives of the SRVP are to: 1) educate producers on the benefits of utilizing University of Arkansas recommendations to improve yields and/or net returns, 2) to conduct on-farm field trials to verify research based recommendations, 3) to aid researchers in identifying areas of production that require further study, 4) to improve or refine existing recommendations which contribute to more profitable production, and 5) to incorporate data from SRVP into Extension educational programs at the county and state level. The specific goals of the Soybean Research Verification Program are: 1) to demonstrate to producers that University of Arkansas soybean management recommendations developed from small-plot research are applicable to large-scale field applications and provide optimum yields and economic returns, 2) to evaluate the current University of Arkansas soybean management recommendations for completeness and determine where weaknesses in knowledge or information exists and further research is warranted, and 3) to train new County Extension Agents in soybean production and provide experiences that will benefit the agent in his overall county programming with respect to soybean production. The SRVP has been conducted on 444 commercial rice fields in 39 counties in Arkansas.

Until recently, data from the SRVP have only been subjected to analyses based upon the current year results.  This study uses the entire dataset in a panel-context with cross-sectional and time-series attributes to evaluate long-term trends for use in a whole-farm decision making model. Observed data from 1983 to 2007 were analyzed to estimate the yield potential by planting date and to determine whether Arkansas farmers are planting earlier over time. The shape of the functional form was evaluated by goodness of fit metrics and estimation results reveal the expected yield potential based on planting dates measured as ‘weeks of year’.