nitrogen is formed when small organisms in the soil change organic nitrogen to ammonia-nitrogen and then to nitrate-nitrogen.
When more manure nitrogen is applied than the plant needs or at times when the plant does not need it, extra nitrate- nitrogen can build up in the soil. When heavy rains occur or there is too much irrigation, the nitrate-nitrogen can be “washed” past the plant roots through the soil to ground- water. As a result, plants may lose nutrients and wells used for drinking may have higher levels of nitrate-nitrogen.
It is important to apply manure at rates that support plant growth. If too much manure is applied, the nutrients can wash into surface water. Bacteria in the water breaks down the nutrients. In the process, the bacteria uses some of the dissolved oxygen that fish and other aquatic life need. In addition, bacteria from the manure may wash into nearby water, increasing bacteria levels. Higher bacteria levels in water can be a problem in drinking water sources as well