The results of this study should not be extrapolated to all times, placements, and rates of manure application or to other types of manure. Research during the past decade has shown that manure often is an unreliable source of N for crop production. The critical problem for improving N management is to learn which practices provide reliable sources of N and which do not. General rules of thumb do not provide this information. Perhaps the most important finding during the past decade of N research is that precision farming technologies empower farmers to evaluate their N management practices on their fields.
Trials can be simple and inexpensive.
Coordinated groups of farmers working with researchers can rapidly distinguish manure management practices that provide reliable sources of N from those that do not. Such information could be especially valuable to farmers where phosphorus-based guidelines force decreases in rate of manure application. We are looking for groups of farmers who have combines equipped with yield monitors and GPS receivers and would like to work with us to improve N management on manured cornfields this year. 148.2 2.5 Hancock 190 14.7 161.4 160.5 0.9 Hancock 190 13.0 162.4 159.0 3.4 Floyd 85 27.0 174. This information subject to a usage policy .