Row spacing on both sorghum and maize dry matter yield and quality.

摘要

The purpose of the present study was to compare dry matter yield and nutritive value of conventional hybrid grain sorghum [(Sorghum bicolor (L.))] as influenced by row spacing, with conventional hybrid maize (Zea mays L.). Sorghum hybrid var. Solarius was planted at two distances between rows, 75 and 20 cm, and maize var. Anjou 387 at 75 cm (conventional planting). Dry matter yield (DMY) in both species decreased over the years, being this fall greater in maize. DMY fell by 20.7, 6.5 and 5 t ha-1 in 2009 when compared to 2007 for maize, sorghum 75 and 20 cm, respectively, indicating that DMY in sorghum 20-cm was less affected by a drop in rainfall than in the other treatments. When averaged over the years, sorghum 20-cm showed the higher protein concentration, 104.1 g kg-1 MS vs 89.4 and 70.5 g kg-1 DM for sorghum 75-cm and maize, respectively. Digestibility in maize was higher than in the average of the two sorghum treatments, 692 vs 636 g kg-1 DM, respectively. Lignin concentration in maize was 18 vs 28.8 g kg-1 DM for the average of the two sorghum treatments. However, digestibility in both sorghum treatments increased by 77.2 g kg-1 MS from 2007 to 2009. Maize was more sensitive to environmental variations. Sorghum planted at 20 cm between rows shows both greater DMY and protein concentration than maize in dry matter yield when rainfall is a limiting factor.