Organic Researcher Spotlight: Dr. Ajay Nair
Integrating poultry, cover crops & vegetable production can reduce purchased inputs while increasing yields
Written by Brian Geier
Dr. Ajay Nair, Department of Horticulture Chair, Iowa State University
Organic farmers with successful Integrated Crop-Livestock Systems (ICLS) report benefits ranging from increased farm productivity and reduced inputs to improvements in soil fertility and increased nutrient density in food products. Additionally, organic farmers report site-specific benefits, for instance livestock grazing that provides unique options for crop pest control or decreases the need for mechanical cultivation (learn more about these specific benefits to organic farmers in OFRF’s Crop-Livestock Integration resources).
While these benefits are becoming better understood, researchers at Iowa State University, led by Dr. Ajay Nair, wanted to look more closely at a specific crop-livestock integration scenario: poultry and diversified organic vegetable production systems. “Commonly researched and implemented methods of crop-livestock integration in the United States,” they write, “include grazing livestock on cover crops, rotational grazing of permanent pasture, and grazing livestock on crop residues such as corn or wheat. Several reviews on crop-livestock integration discuss its benefits, such as increased soil organic carbon, aggregate stability, enhanced nutrient cycling, and increased soil nitrogen (N). There is, however, limited research on the integration of animals in vegetable production.” Now, with funding from USDA’s Organic Agriculture Research & Education Initiative (OREI), Dr. Nair and a team of researchers across the country are evaluating poultry, cover crop and vegetable integration.
Pastured Poultry: a unique fit for diversified vegetable production
Organic vegetable production systems are often highly diversified, requiring intensive management techniques and quick turnaround times between crops. Poultry, which require less space and are easier to move than other livestock could prove to be a unique fit for organic vegetable farmers. Add to that the relatively low capital investment and many growers and researchers wonder if integrating poultry with vegetables could be profitable while still meeting food safety and National Organic Program requirements. “‘How will I integrate poultry? Where? When?’ That was the number one question our growers had,” explains project lead, Dr. Nair.
Above, left: the three rotations in the study are: 1) vegetable > vegetable > cover crop (V-CC), 2) vegetable > cover crop > poultry (V-CC-P), and 3) vegetable > poultry > cover crop (V-P-CC). Above, right: a floorless coop moves around a cover crop in a plot where treatment 2 (V-CC-P) is being evaluated.
The research evaluates the effects of pasturing poultry in movable, floorless coops through vegetable and cover crop rotations. The multi-state project, which involves research in Iowa, Kentucky and California won’t conclude until August of 2024, but it already has several key findings:
- Poultry and cover crops can successfully be integrated with vegetable production systems.
- Where poultry are integrated with vegetable production systems, nitrogen inputs can be reduced while vegetable yields are increased.
- In field tests at Iowa State University, over time, more weeds accumulated in systems where poultry were integrated with vegetables than in systems without poultry.
- Birds in this study are more efficient at converting food to meat. The Feed Conversion Ratio (FCR) of birds in this study is almost double that of conventionally raised broilers.
The impact of USDA funding for organic research & farmers
Dr. Nair, a professor at the Department of Horticulture at Iowa State’s College of Agriculture and Life Science who in July of this year became the Department Chair, credits the USDA/NIFA’s Organic Research and Extension Initiative for making projects like his possible all over the country.
“OREI is the foundation for several of the organic projects that happen across the country, and we are very thankful for NIFA for having such a dedicated program for organic growers. It serves as a good platform for us to reach out to organic growers and for organic growers to reach out to us.” -Dr. Ajay Nair
You can learn more about this project and the importance of OREI in this video excerpt from OFRF’s interview with Dr. Nair in early 2024:
This research is funded by the USDA/NIFA’s Organic Research and Extension Initiative. To learn more about OFRF’s advocacy work to protect and increase this type of funding, and how you can help become an advocate for organic farming with us, see our Advocacy page.
The project builds on a previous OREI grant that helped to identify varieties that worked well in organic crop rotations with sorghum. These varieties are now being evaluated to identify those with higher protein and sugar content, and better protein quality (measured both by digestibility and consumer preference). Dr. Thavarajah calls her approach “participatory breeding” that includes both consumers and farmers in the process. Interestingly, 
