Posted on Dec 01, 2009
Nitrogen fertilizer costs have fluctuated wildly in the past few years. Sorghum silage is an attractive crop because it requires less fertilizer than corn silage. However, fertilizer guidelines are not available for forage sorghum production in the desert southwest. In order develop these guidelines, we propose to conduct a nitrogen fertilizer rate study in Maricopa, AZ. Nitrogen fertilizer will be applied to forage sorghum at 6 rates varying from 0 to 300 lbs N/acre in split applications during the season. The lower portion of the stem will be sampled six times during the season and analyzed for nitrate. Preliminary post-plant nitrogen fertilizer guidelines based on lower stem nitrate will be developed. Publishable guidelines can only be established with 2 or more years of data.