Effects of Conservation Management Practices on Soil Health and Crop Yields in Eastern South Dakota

Conservation management practice adoption on agricultural land has increased in recent years due to increasing public and private investment. The anticipated impact of increasing conservation management practice adoption are reduced greenhouse gas emissions and improved soil, water, and air quality. Understanding how these conservation management practices affect agricultural producers economically is vital to properly incentivize these practices. The existing literature on how conservation management practices affect soil health and crop yields is mixed and generally has been conducted on experimental research stations. These studies may not fully account for the on-farm effects of conservation management practices. The objectives of this study are to 1) analyze the effect of conservation management practices on soil health, 2) identify the determinants of soil health, 3) estimate the economic value of soil organic matter, and 4) analyze the effect of conservation management practices on crop yields. To do this, I gathered data from producers in eastern South Dakota. Producers enrolled fields in the study, completed a survey, and shared actual production history for the fields. Soil samples from participating farmers’ fields were collected in the springs of 2019 and 2021. These samples were submitted to the Cornell University Soil Laboratory for a Comprehensive Assessment of Soil Health (CASH) test. Using this data, I performed Ordinary Least Squares and Least Absolute Shrinkage and Selection Operator regressions to estimate the effects of conservation management practices have on soil health and crop yields. Results show that conservation management practice adopting producers significantly improved soil health, but decreased soybean yields. For individual conservation management practices, cover crops and diverse crop rotations improved soil health, and cover crops and conservation till increased crop yields. Unexpectedly, diverse crop rotations and conservation tillage were found to have hindered soil health, and diverse crop rotation adopters were found to have decreased yields. The negative results for diverse crop rotations may be due to our focus only on corn and soybean crop yields and our relatively few conventional producers