Nitrogen fertility effects of alfalfa, pea green manure, and poultry manure on organic wheat productivity in a semiarid climate

ABSTRACT

Maintaining soil available nitrogen levels in organic systems is a particularly large challenge in the semiarid inland Pacific Northwest. This study compared the nitrogen fertility effects of alfalfa forage, winter pea green manure, and poultry manure for organic wheat production. Soil inorganic nitrogen and wheat yields were the greatest following poultry manure application and the least following winter pea green manure and alfalfa forage, but winter pea biomass production was positively correlated with wheat yields. Soil total nitrogen (TN) was the greatest following alfalfa, but more research is needed to identify practices that increase the release of nitrogen from legume residues in semiarid organic systems.

KEYWORDS:

• Green manure
• nitrogen
• organic
• semiarid
• wheat

Acknowledgments

Thanks to Dennis Pittmann, Louise Lorent, and Margaret Davies for their invaluable expertise in the field and the lab. Thanks also to Les and Pat Boyd, for sharing their land with public researchers with the common goal of advancing knowledge about organic wheat production in the inland PNW.

Funding

This work was supported by the U.S. Department of Agriculture [2009-51300-05578]. Funding for the project was provided by USDA-NIFA Organic Agricultural Research and Extension Initiative (OREI) grant 2009-51300-05578.

Additional information

Funding

This work was supported by the U.S. Department of Agriculture [2009-51300-05578]. Funding for the project was provided by USDA-NIFA Organic Agricultural Research and Extension Initiative (OREI) grant 2009-51300-05578.