Selective Cropping As A Soil Conservation Practice: A Benefits Evaluation

While policies that take land out of production provide a quick fix to erosion, the sustainability of such approaches has been questioned, particularly with the increasing demand for arable land. Policies that reconcile the needs for food, feed, fuel, and healthy ecosystems provide a more sustainable alternative approach to soil erosion management in agricultural lands. This study evaluates the impacts of such a policy that prioritizes the implementation of cropping systems with relatively high environmental benefits. The effectiveness of three field cropping systems and three grassland systems in reducing soil erosion is examined on a 6.6 ha field plot in central Texas over a 20-year period. Soil loss rates under each system are estimated using the Agricultural Policy/Environmental eXtender (APEX) model. A relational comparison of the simulated soil losses and water budget components is undertaken to determine the impact of alternative cropping and grassland systems on the landscape's hydrologic and erosion processes. The results revealed that replacing a winter wheat system and a corn cropping system with a spring wheat system improved soil retention by 19% and 25%, respectively. Growing switchgrass for bioenergy production instead of forage hay improved soil retention considerably (by 40%). Irrespective of the grassland system adopted (restoration to native prairie or growing switchgrass for hay or bioenergy), the replacement of corn or wheat cropping systems with grassland systems increased soil retention by over 70%. This study shows that there is an opportunity to alleviate concerns about conservation programs that take cropland out of production and those that use food crops as fuel and feedstocks, while considerably reducing soil loss from agricultural lands. Incorporating the merits and demerits of cropping systems and why one system should be preferred over another during on-farm and policy decision-making may go a long way toward ensuring food, feed, and energy security and environmental sustainability.