Resumo

SOZZI, Antonio  e  CENTENO, Ángel. Covering alternatives in sorghum planted under direct sowing system. Bioagro [online]. 2006, vol.18, n.2, pp.129-135. ISSN 1316-3361.

The effect of different alternatives of natural mulching management on the growth and yield of sorghum under direct sowing system was evaluated. A field trial using a complete randomized design with arrangement of big plots was carried out. Treatments consisted in a conventional tilled plot and four non-tillage plots with different covering management (one rotary hoeing pass or one field roller pass, completed 1 or 15 days before sowing). The four non-tillage treatments received application of herbicide (Glifosate) at 1,440 g·ha^-1 one day before sowing. The evaluation included covering (covered soil area and cover dry weight), soil (bulk density and moisture content), and crop (plant height, final plant number, and yield). Statistical analysis showed that under direct sowing the cover lasted longer time and soil water was better conserved as compared to conventional tillage, and the effect was greater in the field roller than in the rotary hoeing treatment. The crop growth and yield was higher in the conventional tillage system, and it was attributed to the better soil physical pre-conditioning, especially the attaining of lower bulk density.

Palavras-chave : Sorghum bicolor; direct sowing; tillage; mulching.