Closing nutrient cycles for animal production - current and future agroecological and socio-economic issues

Authors: Kronberg, Scott; PROVENZA, FREDERICK - Utah State University; VAN VLIET, STEPHAN - Duke University; YOUNG, SIERRA - North Carolina State University

Submitted to: Animal-The International Journal of Animal Biosciences
Publication Type: Review Article
Publication Acceptance Date: 4/12/2021
Publication Date: 7/24/2021
Citation: Kronberg, S.L., Provenza, F.D., Van Vliet, S., Young, S.N. 2021. Closing nutrient cycles for animal production - current and future agroecological and socio-economic issues. Animal-The International Journal of Animal Biosciences. 15.Article 100285. https://doi.org/10.1016/j.animal.2021.100285.
DOI: https://doi.org/10.1016/j.animal.2021.100285

Interpretive Summary:

Technical Abstract: We face an urgent and complex challenge of producing large amounts of healthful animal and plant foods for millions of people while maintaining essential ecosystem services. To compound this challenge, we must do so while not further degrading our environment and conserving essential nutrients such as copper, magnesium, phosphorus, selenium and zinc that are believed to be in limited supply for fertilizer. Much good research has been done, but to meet this challenge, we need to greatly increase on-farm and watershed-scale research that includes on-farm evaluations and demonstrations of the putative best combinations of stewardship techniques over multiple years in real-world settings, which are backed by data on nutrient inputs, soil, air, and water chemistry (fluxes) and water discharge. We also need to work with farmers, specialists, and generalists in highly creative interdisciplinary teams that resist forming silos and that use combinations of techniques linked to agroecology and industrial ecology in combination with state-of-the-art engineering. Some of these research and demonstrations farms need to be in catchments prone to pollution of aquatic and terrestrial ecosystems with nitrogen, phosphorus and other nutrients. Some of the most promising approaches include mixed crop-livestock systems although these alone may not be productive enough to meet the dietary needs of an estimated 10 billion people by 2050. Others approaches could be state-of-the-art multi-trophic production systems, which include several species of plants integrated in production with vertebrates (e.g., ruminants, pigs, poultry) and invertebrates (e.g., insects, earthworms) and fish and/or shrimp or crayfish such that these systems include species that utilize wasted feed and excreta and recycle nutrients back to the animals (via plants or invertebrates) in the systems. To cut costs and increase desirable outputs we must recycle nutrients much better within our food production systems and produce more animal-based products as nutrients cycle through the systems.