3 Reduce N rate by 25 percent when grazing. On trees less than 5 feet tall, N will stimulate undergrowth competition. The biological conversion of organic matter to nitrate is an acid-forming process that will continue to reduce soil pH unless you follow an adequate sampling and liming program. To help you determine land application rates, a worksheet is provided at the end of this publication. In addition to carefully calculating the application rate, you must also minimize the delay between applying the manure and planting the crop.
Precise timing increases the amount of nitrogen used by the crop and thus reduces leaching.
The risk of surface water and groundwater contamination is greater in areas of high rainfall and where manures are applied in the fall or winter for spring crops. Exercise caution when applying lagoon liquid through irrigation onto standing crops that are undergoing stresses. Whenever samples of manure or lagoon liquid are available for analysis, the specific results should be used to determine application rates and acreage requirements. However, when you are planning new facilities, average values can help determine the approximate acreage requirements for a given size swine operation. Table 6 can be used to determine the minimum acreage a new unit will need for manure use.