Project Site: Mack Erno's Farm - Teepee Creek
Research Program Manager: Dr. Akim Omokanye From: Peace Country Beef & Forage Association 2018 Annual Report
There is still growing interest in the potential for a multispecies cover crop mixtures (cocktails) for forage-based livestock production. A cocktail mixture is a number of cover crop species mixed together to take advantage of each of its species' unique offering to the soil. Mixtures of cover crop species can be planted to optimize the benefits associated with cover crop use. The three major categories of commonly grown cover crops are grasses, legumes, and brassicas. Legumes in the mixtures can contribute N through symbiotic dinitrogen (N2) fixation, which can benefit non-legumes growing in the mixtures, through the transfer of N by the roots. Better forage quality, increased soil organic matter, and improved overall soil health are some of the benefits seen by producers who have seeded cover crops. Several annual forage legumes have been tested in parts of the Peace Country. Some have done well, while some have performed poorly in those trials and demonstrations. The objective of this trial was to assess the performance of some of the introduced annual forage legumes at Teepee Creek.
Methods
The study site was at Mack Erno’s farm in Teepee Creek. The site had canola the year before and it was sprayed with a pre-seed burnoff of Express + Roundup before seeding in 2018.
Soil tests from 0-6” showed an organic matter of 5.2%, a pH of 5.5, and an electrical conductivity of 0.37 dS/m. The soil had 73 lbs N/acre, 29 lbs P/ac, 398 lbs K/ac and 25 lbs S/ac.
We used randomized complete block design with 4 replicates.
The following annual forage legumes were tested:
1. Chickling vetch seeded at 50 lbs/acre
2. H.O. crimson clover seeded at 20 lbs/acre
3. Hairy vetch seeded at 20 lbs/acre
4. Frosty berseem clover seeded at 15 lbs/acre
5. Crimson clover seeded at 20 lbs/acre
6. Serradella seeded at 3 lbs/acre
· The legumes were inoculated at seeding on May 31.
· Small plots measuring 1.8 m x 8 m were used.
· The legumes received 50 lbs/acre of 11-52-0 fertilizer only.
· No in-crop spraying was done during crop growth.
· Harvest date: August 23
Results
Forage Dry Matter (DM) Yield
The forage DM yield varied significantly between some of the legumes tested. Chickling vetch produced the highest forage DM yield (3916 lbs/acre), while Serradella had the least forage DM yield (1623 lbs/acre) (Figure 1). At harvest, with the exception of frosty berseem clover, all legumes had flowered. The chickling vetch had several pods on it as well. No pods were observed on the hairy vetch.
Forage Quality
The forage crude protein (CP) was generally above 14% for the legumes tested (Table 1). This indicates that the legumes far exceeded the 11% CP needed by a lactating beef cow. Hairy vetch had the most forage CP.
Both crimson clover and H.O. crimson clover were more mature at harvest than the other legumes, hence the reason for the lower forage CP, and higher ADF and NDF values obtained for both. (Table 1).
All legumes tested had adequate TDN for a dry gestating beef cow, which is 55% in mid pregnancy and 60% in late pregnancy. Other than H.O. crimson clover, which fell short of meeting the 65% TDN needed by a lactating beef cow, all legumes had enough %TDN for lactating beef cow. Chickling vetch in particular had far more %TDN than the other legumes.
The forage Ca was higher for the legumes tested here. The forage Ca varied from 0.72% for Chickling vetch to 1.26% for Serradella. A mature beef cow requires 0.18% Ca during pregnancy and 0.58% Ca during lactation. This shows that all legumes would be capable of supplying the required amount of Ca when used as a greenfeed or silage. The legumes could also help improve the forage Ca content when included in cocktail mixtures. However, caution would need to be taken when feeding monocrop crimson clover or H.O. crimson clover as greenfeed or silage to beef cattle because of their ability to cause bloat.
Hairy vetch had the highest levels of forage P, K, S, and Cu (Table 2).
All legumes would be able to supply the required K, Mg, Na, S, Fe, Zn, and Mn for mature beef cattle. Only hairy vetch seemed to have adequate P for a lactating beef cow. Other legumes were only able to supply
Conclusion
Both vetches had higher forage DM yield than the other annual forage legumes tested here. All legumes far exceeded the protein requirements of mature beef cattle. The legumes were mostly sufficient in the amount of TDN that is needed by a cow. This trial shows that all legumes tested would be capable of supplying the required amount of Ca when used as a greenfeed or silage. The legumes could also help improve the forage Ca content of other crop species with low Ca content when included in cocktail mixtures.