Sorghum Grain Quality as Affected by Different Nitrogen Fertilizer Sources, Cultivar and Field Condition

Abstract

The source of nitrogen fertilizer applied in the soil during the development of sorghum can affect the grain quality. The objective of this study was to determine the quality of sorghum grains as influenced by different nitrogen fertilizer sources and field conditions. The experiment used incorporated a 2x5x2 factorial arranged in a split-split plot design that was fitted into a randomized complete block design. Sorghum grain samples were analyzed for ash, fiber, fat, protein, and starch contents in percentages by using a Near-infrared spectroscopy machine. Nitrogen fertilizer source and had a significant effect on sorghum crude protein content during the 2018/19 planting season. The study indicated that nitrogen fertilizer sources such as limestone ammonium nitrate and urea are suitable for improving the quality of the sorghum grain. For example, limestone ammonium nitrate significantly improved the quality of the sorghum grain since it affected protein and starch content. Urea was also found to play a significant role in the grain quality as it affected the fiber and starch content of the grain. Field conditions had a significant effect on sorghum crude fiber and protein during the 2019/20 planting season. The increase in crude fiber under dryland field conditions proves that the quality of sorghum can be increased under no supplementary irrigation. This study, therefore, indicates that sorghum grain quality is influenced by the type of cultivar, the nitrogen fertilizer source, and the field conditions.