Forage yield and chemical composition of canola (Brassica napus L.) as affected by sowing methods

摘要

The sowing method of spring-type canola (Brassica napus L. var. oleifera) for forage has a major influence on its productivity and agronomic management. A field experiment was conducted in Matamoros, Coahuila, Mexico, during two growing seasons (2008-2009 and 2009-2010) to determine dry matter (DM), crude protein (CP) and net energy for lactation (NEL) yields, as well as canola forage chemical composition as a function of six sowing methods. The treatments assessed were broadcast sowing and five different row spacings: 019, 038, 057, 076 and 095m (double row, 020m apart). In the first year, with a mean growing season temperature of 172 degrees C, sowing methods did not affect DM yield, but CP and NEL content and yield were higher in 019-m row spacing. The mean temperature in the second year (135 degrees C) was slightly lower than the long-term mean (148 degrees C) in the region, resulting in the highest DM (8840kgha(-1)), CP (2486kgha(-1)) and NEL yields (51103MJha(-1)) with 019-m row spacing. In row-sowing methods with over 019-m row spacing, DM, CP and NEL yields decreased by 193-397, 204-421 and 212-427% respectively. Results indicate that sowing methods significantly affected canola forage productivity.