A vast amount of South Carolina’s land area is devoted to conventional, row crop agriculture methods. Although these practices generate substantial economic benefits, adverse effects have been observed in the form of impacts to water related ecosystem services, including water quality in nearby streams. Therefore, sustainable farming practices are being promoted such as planting of cover crops on idle cropland. This study has two parts, assessing the farmers’ cover crop implementation rates and whether the implementation of cover crops will provide a substantial ecosystem service benefit, particularly in terms of its sediment retention capacity and water holding capacity, in Santee River Basin Network (SRBN) of South Carolina. We used the Sediment Delivery Ratio (SDR) and Water Yield (WY) modules of the Integrated Valuation of Ecosystem Services and Tradeoff (InVEST) model to estimate the amount of sediment being retained and potential water held by landcover. We modified the Cropland Data Layer (CDL) of 2014 to 2018 obtained from United States Department of Agriculture (USDA) by changing the off-season crops per month to idle cropland to account for the seasonality of the crops. We ran the models for two scenarios: with or without cover crops, per month from 2014 to 2018.
Results/Conclusions
Results from the implementation survey show that farmers are interested in implementing cover crops. Additionally, they are often willing to accept federal cost-share payments to plant cover crops. Results from the InVEST model show that cover crops could improve water quality by reducing potential sediments exported to the stream. Cover crops perform better retaining sediments within the landcover as compared to leaving cropland barren. Furthermore the amount of water yield within the landscape also decreases over time as compared to leaving the off-season areas barren due to cover crops. This shows that cover crops decrease further potential runoff which could contribute to flooding events downstream. Using the Auto Regressive Integrated Moving Average (ARIMA) forecasting model, it is expected that water related ecosystem service benefits will increase over time. The sediment retention capacity will continue to increase while potential excess water runoff is projected to decrease if cover crops are implemented. The results of the survey and simulation shows that sustainable farming strategies can improve ecosystem-based landscape management within the SRBN and farmers are overall willing to accept payments to implement these practices. It is evident that cover crops contribute positively to stakeholders’ well-being and help maintain soil and environmental health.