Forage brassicas intercropped with oats and peas for late fall grazing.

Context Brassica, grass, and legume mixtures can produce high-quality forage but management remains unclear due to the variation amongst brassica cultivars. Aim This experiment assessed the nutritive value and herbage accumulation of fall-grown brassica, oat (Avena sativa L.), and pea (Pisum sativum L.) mixtures. Methods A two-year, four-replicate RCBD field experiment was conducted with six brassica cultivars planted with oats and peas. Each combination ofMixes with each brassica cultivar , oats, and peas was were planted at five seeding rates. Forage was harvested twice: approximately two and three months after planting. Key results Turnips (Brassica rapa L.), colza (Brassica napus L.), radish (Raphanus sativus L.), and interspecies forage hybrid (Brassica rapa x napus) remained at vegetative growth stage throughout the experiment, and had relatively small differences in nutritive value. When these brassicas were seeded at 1.7-3.4 kg ha–1 with 50-75 kg ha–1 oats and 34-50 kg ha–1 peas they produced an average of 2620 kg dry matter ha–1 with crude protein (CP) of 22.6%, total digestible nutrients (TDN) 64.3%, and neutral detergent fiber (NDF) of 36.2%. Conversely, flowering mustard (Brassica juncea (L.) Czern.) saw declines in nutritive value at the later harvest and performed best when seeded at 5.0 kg ha–1 in mixtures (herbage accumulation: 3654 kg dry matter ha–1, CP: 19.7%, TDN: 63.0%, NDF: 39.5%). Conclusions Growth habit of brassicas has a large effects on how cultivars should be managed in forage mixtures. Implications Brassica seeding rates in mixtures should be based on variety growth habit and harvest timing.