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

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.