Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/11/2011
Publication Date: 10/16/2011
Citation: Wilson, J.D., Kaufman, R.C., Bean, S., Presley, D. 2011. The effect of cover cropping systems and nitrogen fertilization on sorghum grain characteristics. Meeting Abstract. Cereal Foods World. 56:A70.
Technical Abstract: No-till farming has become an increasing popular cropping practice, due to increased water and soil conservation. Recently, cover cropping has been added to the system to aid in weed prevention and also increase soil fertility. The objective of this study was to determine the effect of cropping system as well as nitrogen fertilization on sorghum grain. The experimental design was a 3x4 factorial with three cover crop treatments (none, soybean, and Sunn hemp) crossed with four nitrogen rates (0, 33.6, 67.2, and 100.8 kg/ha) in plots following the harvest of wheat. A sorghum hybrid was then planted the following spring in each plot. Grain was harvested and cleaned for analysis including kernel, protein and starch characteristics. The hardness and size of kernels was measured by the Single Kernel Characterization System (SKCS). The average kernel hardness across all nitrogen rates was 74.7, 74.6, and 69.7 for soybean, Sunn hemp, and none, respectively. The kernel weight and diameter was also significantly larger for the cover crop treatments compared to no cover crop. The soybean cover crop had the highest protein content at 9.2% followed by Sunn hemp at 8.8% and no cover crop at 8.2%. The 0 and 33.6 kg/ha nitrogen rates had significantly lower hardness values (68.7 and 70.0) than the 67.2 and 100.8 kg/ha (76.2 and 77.3) treatments. The protein content of the grains ranged from 8.1% in the 0 kg/ha rate to 9.5% in the 100.8 kg/ha rate. Protein digestibility values and starch granule size distributions were not affected by nitrogen level or cover cropping treatments. The utilization of cover crops appears to increase the protein content without causing a deleterious effect on protein digestibility. The end-product quality is not hampered by the use of beneficial cropping systems necessary for sustainable agriculture.