Determining the Effect of Planting Date and Land Preparation Method on Seedling Emergence, Forage Mass, and Forage Nutritive Value of Forage Brassica

Abstract

Forage brassicas are used as a forage in monoculture and multispecies mixtures, yet research defining best management practices is limited. Two studies were conducted to evaluate the effects of land preparation method and planting date on establishment, forage mass, and quality of two Brassica species, ‘Inspiration’ canola (Brassica napus L.) and ‘T-Raptor’ hybrid turnip (B. rapa subsp. rapa × B. rapa L.). Each experiment was a randomized complete block design evaluating four land preparation methods: (conventional till (CT), no-till after burning (NB), no-till after mowing (NM), and no-till without residue removal (NR)), and four planting dates: (1 September (S1), 15 September (S15), 1 October (O1), and 15 October (O15)). Significant differences were observed for the canola seedling emergence, but are not of biological significance. Hybrid turnip seedling emergence was the greatest for the CT treatment and consistently greater than NM and NR treatments. Forage mass in the canola study was greatest for the CT and NB. Hybrid turnip forage mass demonstrated similar trends to the canola. CT had the greatest mass and the NR and NM treatments tended to provide the lowest forage mass. Across both studies, earlier planting dates (S1 and S15) resulted in greater overall forage mass than the later planting dates (O1 and O15). Forage nutritive value overall was lower in earlier planted brassica; however, forage nutritive value was not reduced enough to negatively impact livestock.