From Compost Carryover to Compost Legacy: Intercropping and Compost Effects on Yield, Quality, and Soil Health in Organic Dryland Wheat
Project Director
Jennifer R. Reeve
Year Funded
2019
Award Number
2019-51300-30476
Funded Institution
Utah State University
Grant Program
OREI (Organic Agriculture Research and Extension Initiative)
USDA NIFA Report (alternate)
Project Overview
Poor soil quality, weeds, limited moisture, and increasingly intense heat, drought, and erratic weather related to climate change create tremendous barriers to dryland organic wheat production in the semiarid interior West. Initial trials indicated that a single heavy application of composted steer manure (22 tons/ac) can substantially improve soil organic matter and wheat yields for 15-28 years after application. This project amplified these findings through trials at multiple sites to assess effects of compost use rates, legume interplanting, and cultivar on wheat yield, weeds, soil nutrient levels, and soil health. Market research was conducted to support organic wheat enterprises in the region.
Farmer Takeaways
(1) A one-time application of well-composted cattle manure (11-22 t/ac) can enhance soil organic matter, fertility, drought resilience, and wheat yields for up to 24 years.
(2) Manure compost at 22 t/ac provides both nutrients and other long-term benefits (e.g. moisture retention) benefits, and supports wheat yield better than synthetic N.
(3) Soil P responses to compost vary with soil type and should be monitored.
(4) Legume intercrops offer soil health and weed management benefits but may fail or entail yield tradeoffs in drier years.
(5) Utah State University Extension bulletins offer practical guidance on marketing of specialty grains.
Project Outputs
Organic Wheat Product Marketing | Utah State University Extension
Atoloye, I. A., Jacobson, A. R., Creech, J. E., & Reeve, J. R. (2022). Soil organic carbon pools and soil quality indicators 3 and 24 years after a one-time compost application in organic dryland wheat systems. Soil and Tillage Research, 224, 105503.
Adeleke, K. A., Atoloye, I. A., Creech, J. E., Dai, X., & Reeve, J. R. (2021). Nutritive and non-nutritive effects of compost on organic dryland wheat in Utah. Agronomy Journal, 113(4), 3518–3531.
Atoloye, I. A., Jacobson, A., Creech, E., & Reeve, J. (2021). Variable impact of compost on phosphorus dynamics in organic dryland soils following a one-time application. Soil Science Society of America Journal, 85(4), 1122–1138.
Carr, P. M., Volkman, M. M., Fordyce, S. I., Crookston, B. S., Yost, M. A., & Reeve, J. R. (2025). Cattle manure impacts on organic wheat production in the northern Great Plains. Canadian Journal of Plant Science, 105, 1–13.
Rodgers, H., Norton, J., Norton, U., & van Diepen, L. T. A. (2024). Sustaining vulnerable agroecosystems with compost: Lasting benefits to soil health and carbon storage in semiarid winter wheat (Triticum aestivum, L.). Applied Soil Ecology, 204, 105716.