By Glen Arnold, CCA, Ohio State University Extension
Wheat fields will begin to firm up in Ohio and the topdressing with nitrogen fertilizer will soon start. There is usually a window of time, typically around the last week of March or the first week of April, when wheat fields are firm enough to support manure application equipment. By this date, wheat fields have broken dormancy and are actively pulling moisture and nutrients from the soil. With the limited fall and winter opportunities to apply manure to fields, many livestock farms have more manure than usual for this time of year.
The key to applying the correct amount of manure to fertilize wheat is to know the manure’s nitrogen content. Most manure tests reveal total nitrogen, ammonia nitrogen and organic nitrogen amounts. The ammonia nitrogen portion is readily available for plant growth. The organic nitrogen portion takes considerably longer to mineralize and generally will not be available when wheat uptakes the majority of its nitrogen in the months of April and May.