Manuresheds: Redesigning crop-livestock agriculture for sustainable intensification

TitleManuresheds: Redesigning crop-livestock agriculture for sustainable intensification
Publication TypeConference Paper
Year of Publication2019
AuthorsSpiegal S., Kleinman PJA, Bryant R, Endale D, Dell C, Yang Q, Flynn CK, Gowda P, Duncan E, Carter J, Browning DM
Conference Name2019 Annual Meeting of the US Regional Association of the ​International Association for Landscape Ecology
Date Published04/2019
Conference LocationFort Collins, CO
ARIS Log Number362179

Meeting the dietary demands of humans while protecting Earth's ecosystems is among the greatest challenges of the Anthropocene. Sustainable intensification is expanding as a response to this grand challenge, but success will require an improved understanding of regional, national, and international agricultural systems, including spatial relationships among system components, land use changes that influence the spatial relationships, and optimal approaches to distributing resources. Agricultural specialization and intensification of the 19th and 20th centuries are central considerations, as these advancements led to monumental increases in production and efficiency, but also resulted in uneven geographic distribution of agriculture types and an uncoupling of nutrient biogeochemical cycles. Now, concentrations of animals in certain regions produce manure nutrient accumulations that contribute to air and water pollution, while concentrations of crops in other regions result in nutrient deficits typically filled by intensive fertilizer use. Great potential exists to create new nutrient cycles through strategic consideration of manure sources and crop requirements. This recoupling requires creative solutions. To that end, the Long-Term Agroecosystem Research (LTAR) network is exploring the concept of the “manureshed,” the manure-spreadable land in the geographic, environmental, and social radius of a confined livestock operation. To better understand opportunities for expanding manuresheds in the United States, we identified the nationwide, county-level pattern of livestock distribution, manure excess, and crop assimilation of manure nutrients. Manure phosphorus and nitrogen leftover after crop removal were calculated assuming all manure produced in the county was applied to all croplands in the county. We then classified counties with manure in excess of cropland assimilative capacity into types distinguished by barriers to, and possibilities for, expanding manuresheds within and between counties. We expect that manureshed research can guide the redesign of crop-livestock agriculture to advance sustainable intensification in the United States and other nations.