Evaluating Cover Crop Cocktails for Forage Production in the Peace Region of Alberta

Interest in the potential for a multispecies cover crop (CC) blend (cocktails) for silage, swath grazing, greenfeed and pastures has been growing amongst beef cattle producers in the Peace Country (PC) region of Alberta, Canada. The idea of CC cocktails is new in the region, indicating that the concept of a CC cocktail mix is an area where local research for local producers is needed. The objective of this study was to test several cocktails to identify those with superior forage production (yield and nutritional value) for beef cattle production. Twelve (12) cocktails (treatments) consisting of 2-9 cover crops and an oat (Avena sativa) mono-crop as check were arranged in a randomized complete block design in 3 replications in 2016 cropping season. The CC species used were from cereal grains/grasses, legumes and brassicas. From forage DM yield and nutritional value obtained in this study for all cocktails and check (CDC Haymaker oat), all cocktails generally had higher DM yield as well as better nutritional value than check. Six (6) of the 12 cocktails produced more DM yields (109-137%) than check. Overall, cocktail #1 (peas, oats, hairy vetch, tillage radish, purple top turnips and crimson clover) produced the most forage DM yield (10 t ha^-1) than other cocktails and check. The forage crude protein (CP), total digestible nutrients (TDN) and net energy for maintenance (NE_M) respectively varied significantly (P<0.05) from 8.87-23.7%, 60.1-70.1 and 1.46-1.75 MCal kg^-1, with check recording the least values in each range. All cocktails were able to meet the protein requirements of mature beef cattle, and in most cases, cocktails were well within the CP requirements for growing and finishing beef calves. The cocktails in most cases had enough %TDN for mature beef cattle, while the check was only able to meet the %CP and %TDN requirements of a gestating beef cow. The benefits of cocktails were obvious with higher forage macro- and trace-minerals than check. Four of the 12 cocktails seemed to have greater potential for forage production in the PC region of Alberta. Field notes taken show that the following crops in the cocktails did not germinate and where they did germinate, their growth was not impressive: Persian clover (Trifolium resupinatum L.), BMR hybrid sorghum (Sorghum spp.), berseem clover (Trifolium alexandrinum) and teff grass (Eragrostis tef).