When applying anhydrous ammonia or ammonia-laden manure, waiting until soil temperatures drop below 50 degrees maximizes nitrogen availability and minimizes its loss.
Check out two articles in the latest Manure Scoop blog, from Iowa Manure Management Action Group’s (IMMAG) update. One features the science behind 50 and cooling. The other highlights how manure application timing affected yields, effectiveness and nitrate-nitrogen losses through tile lines for four corn-soybean rotations.
Check Iowa State University Extension and Outreach’s real-time soil temperature data map at http://mesonet.agron.iastate.edu/data/soilt_day1.png.