Enhancing agroecosystem performance and resilience through increased diversification of landscapes and cropping systems

The development of modern, industrial agriculture has been characterized by large reductions in biological diversity, both across landscapes and within farming systems. Loss of biodiversity is particularly evident in the U.S. Corn Belt. Simplification of crop and non-crop vegetation in the Corn Belt has resulted in huge amounts of crop and livestock products, but is also concomitant with multiple challenges, including soil erosion, water quality degradation, greater prevalence of pesticide-resistant in pest populations, new crop diseases, loss of knowledge and infrastructure to support diverse markets, declines in rural community vitality, and strong susceptibility to variations in weather conditions, production costs, and crop prices. This presentation will review data from two field experiments in Iowa addressing the impacts of cropping system diversification. Results indicate that (1) conversion of small amounts of cropland to strips of reconstructed prairie can provide disproportionately large improvements in soil conservation, nutrient retention, and densities of native plants and birds; and (2) diversification of the dominant corn-soybean rotation with small grain and forage crops can lead to substantial reductions in agrichemical and fossil hydrocarbon use, lower herbicide-related aquatic toxicity, decreased crop damage by certain pathogens, and improved soil retention and soil quality, without compromising profitability. These patterns indicate that increasing biodiversity can be a viable strategy for improving agroecosystem health and resilience in the U.S. Corn Belt.