Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2012
Publication Date: 4/24/2013
Citation: Sanderson, M.A., Archer, D.W., Hendrickson, J.R., Kronberg, S.L., Liebig, M.A., Nichols, K.A., Schmer, M.R., Tanaka, D.L., Aguilar, J.P. 2013. Diversification and ecosystem services for conservation agriculture: Outcomes from pastures and integrated crop-livestock systems. Renewable Agriculture and Food Systems. 28(2):129-144.
Interpretive Summary: Conservation agricultural systems rely on three principles to enhance ecosystem services: 1) minimizing soil disturbance, 2) maximizing soil surface cover, and 3) stimulating biological activity. We suggest that diversity is a key concept common to these three principles. In this paper, we explore the concept of diversity and its role in maximizing ecosystem services from managed grasslands and integrated agricultural systems (i.e., integrated crop-livestock-forage systems). Managing for multiple ecosystem services in complex ecosystems (e.g., agroecosystems) requires a high degree of biodiversity in plant communities and cropping systems distributed across the landscape. In managed grasslands, tools are needed to aid the selection of specific mixtures for managed grasslands and to guide the spatial distribution or arrangement of species and mixtures across the various site-types on a farm to achieve specific functions. An environmental tradeoff exists between maximizing diversity within plant communities grown for bioenergy purposes and having meaningful biomass supplies to meet societal energy demands but it should be recognized that native, perennial monocultures or simple polycultures systems provide more ecosystem services such as C sequestration, wildlife habitat, landscape heterogeneity and nutrient regulation than existing annual cropping systems.
Technical Abstract: Greater demands for agriculture to provide food, feed, fiber, and fuel place increased pressure on farmers to intensify their production practices. Increased use of external inputs and converting marginal land for cropping can compromise the ecosystem services obtained from agriculture, especially conservation, soil health, and biodiversity. An alternative is to develop conservation agricultural systems that exploit synergies of crop diversity to improve ecosystem services. As outlined by Franzluebbers, conservation agricultural systems rely on three principles to enhance ecosystem services: 1) minimizing soil disturbance, 2) maximizing soil surface cover, and 3) stimulating biological activity. We suggest that diversity is the key concept that encompasses these three principles. In this paper, we explore the concept of diversity and its role in maximizing ecosystem services from managed grasslands and integrated agricultural systems (i.e., integrated crop-livestock systems). We also examine tradeoffs involved in realizing greater ecosystem services. Previous research has shown improvements in herbage productivity with increased forage diversity but little response in terms of animal production, which suggests significant tradeoffs. Fulfilling the multiple ecosystem functions needed to maintain a healthy pasture and grazing will entail a multi-scale approach with different forages and combinations of forage species distributed across a farm according to site suitability and the goals of the producer. The concept of dynamic cropping systems incorporates a long-term strategy of annual crop sequencing that optimizes crop and soil use options to attain production, economic, and resource conservation goals by using sound ecological management principles. Integrating dynamic cropping systems with livestock production increases the complexity of management but also creates synergies among the system components that improve resilience and sustainability.