Several livestock producers have inquired about applying liquid dairy or swine manure to newly planted wheat fields using a drag hose. The thought process is that the fields are firm (dry), there is very little rain in the nearby forecast, and the wheat crop could take advantage of the manure nutrients, especially the nitrogen portion, to promote growth and fall tillering.
The manure nutrients would essentially replace the commercial fertilizer normally applied in advance of planting wheat. The application of fall-applied livestock manure to growing crop can reduce nutrient losses compared to fall-applied manure without a growing crop.
If the wheat is planted at its typical one-inch depth and swine or dairy manure is surface applied there should be no problem applying 4,000 or 5,000 gallons per acre of manure. If the wheat is emerging when manure is being applied, there is the possibility of some burn to the wheat from swine manure. If the wheat is fully emerged, there is little concern for burning.
OSU Extension has conducted research studies involving incorporating manure ahead of planting wheat in October. While the results were good, yields were not as high as expected due to the delay in getting the manure applied and waiting for suitable conditions to plant the wheat crop. Both years of the research trial the delay ended up being over two weeks due to rain and this did not allow the wheat crop to become well established and tiller before cold weather arrived.
If incorporating manure ahead of planting wheat, try to place the manure deep enough (at least three inches) so the manure does not impact the germination and emergence of the wheat crop.