Location: Plant Science Research
Title: Crop–livestock systems in temperate-humid regions of North and South America: Mitigation and adaptation Author
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 30, 2013
Publication Date: June 1, 2014
Citation: Franzluebbers, A.J. 2014. Crop–livestock systems in temperate-humid regions of North and South America: Mitigation and adaptation. In: Fuhrer, J., Gregory, P. (Editors), Climate Change Impact and Adaptation in Agricultural Systems, CAB International, Wallingford, UK. p. 124-139. Interpretive Summary: Integrated crop-livestock systems represent a diversity of agricultural approaches used for various reasons, but which can be characterized as mixing crop production aspects with animal production aspects. An ARS scientist at the Plant Science Research Unit in Raleigh North Carolina reviewed and synthesized the scientific literature on how integrated crop-livestock systems in humid regions can help mitigate climate change and be used to adapt to climate changes. Grasslands and agricultural cropping are capable of coexistence in ecologically-oriented approaches, e.g. long-term sod-based rotations, short-term cover crops, temporally dynamic inter-cropping or relay-cropping, and spatially dynamic strip-cropping, alley-cropping, or silvo-pastoral systems. Forages have extensive, fibrous root systems that explore large volumes of soil, mostly in the surface foot of soil, but also penetrating deep into the profile. Perennial forages also extend the growing season compared with annual cash crops, thereby photosynthesizing, depositing rhizosphere carbon inputs, and drying soil during longer periods of time than annual crops. A transformation of agriculture is needed to increase production, mitigate past environmental damage, protect biological diversity, reduce dependence on fossil fuels, provide healthier foods, and increase economic and cultural opportunities in rural America. When incorporated into diverse agricultural systems that include livestock, perennial grasses and legumes and a wide variety of annual forages offer enhanced agro-ecosystem resilience in the face of uncertain climate and market conditions.
Technical Abstract: Climate change can affect integrated crop-livestock systems similar to that of specialized agricultural systems, but mixed production systems offer some alternatives to both mitigate and adapt to climate change, resulting in potentially less severe devastating effects on farm- and national-scale agricultural production outcomes. Some reasons for designing and implementing integrated crop-livestock systems are based on production concerns of (a) farms operating on marginal profit, (b) economic vulnerability with specialized production, (c) high cost of fuel and nutrients, (d) pests greater with monocultures, and (e) yield decline could be overcome with rotation. Some environmental incentives for integrated crop-livestock systems are (a) nutrient recycling could be improved in both crop and livestock systems and (b) conservation of soil and water are more easily possible with sod-based management systems. Integrated crop-livestock systems rely on forages as part of a diversity of crop choices. These forages provide large benefit towards the balance of C in soil. The effect of integrated crop-livestock systems on greenhouse gas emissions (CO2, CH4, and N2O) is largely unknown. There is large spatial and temporal complexity of integrated crop-livestock system designs, which make projections of greenhouse gas emissions uncertain. Forage and grazing lands have historically provided a sustainable and resilient land cover, rooted by a variety of vigorous grasses and forbs and serving as key biospheric engineering components mediating a plethora of essential ecosystem services, notably water cycling, nutrient cycling, gas exchange with the atmosphere, climate regulation, food and feed production, and aesthetic experience.