Cover Crop Mixtures (Cocktails) for Forage: Forage Yield & Quality in High Prairie

Project Site: Bill Fevang's Farm - High Prairie

Research Program Manager: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2018 Annual Report

A mixture of two annual crops involving cereal-legume intercrops (e.g. barley & peas) for forage production has widely been tested by applied research associations in Alberta. Such intercrops are used by producers for greenfeed or silage. Growing multi-species annual crop mixtures (e.g. 4, 6 or even greater) may often be considered as a practical application of ecological principles based on biodiversity, plant interactions and other natural regulation mechanisms (Malézieux et al. 2007). Such mixtures could increase forage production (BCRC 2016; Davies et al. 2015; Wortman et al. 2012), improve water and soil quality, nutrient cycling, moisture conservation, and crop productivity when used in crop rotation systems (Chu et al. 2017; Hobbs et al. 2008). A multispecies annual crop mixture can be selected from a diversity of crop groups (e.g. grasses, legumes and brassicas). Each crop species in a mixture may reach maturity at slightly different times, therefore providing green forage continuously through the growing season (BCRC 2016). In 2018, a field trial was done in High Prairie to test annual crop mixtures with 4-8 crops versus monoculture CDC Haymaker oats for forage yield and quality.

Methods

The study site was at Bill Fevang’s farm in High Prairie. The site had canola the year before and it was sprayed with a pre-seed burnoff before seeding the cocktails in 2018. Soil tests from 0-6” showed an organic matter of 10.3%, a pH of 5.9 and an electrical conductivity of 1.0 dS/m. The soil had 27 lbs N/acre, 23 lbs P/ac, 496 lbs K/ac and 19 lbs S/ac. The cover crop treatments tested are provided below in Table 1.

· Seeding date: June 7th

· Legumes were inoculated at seeding

· No fertilizer was applied to any of the treatments including the Haymaker oats

· No in-crop spraying was done on any of the treatments including the Haymaker oats

· Harvest date: August 20th

Results

Forage Yield

The forage dry matter (DM) yield varied greatly between the treatments. CCC #3 had the highest forage DM yield (9468 lbs/acre), followed by CDC Haymaker oats (8185 lbs/acre), CCC #1 (7913 lbs/acre) and then CCC #2 (7044 lbs/acre) (Table 2). Only CCC #3 had a forage yield advantage (16%) over CDC Haymaker oats. Other cocktails had 272-3762 lbs DM/acre less than CDC Haymaker oats. Both pearl millet and sugar beet in CCC #4 as well as mung bean in CCC #7 did not germinate, hence the reason for their lower forage DM yields than most cocktails tested here.

Forage Quality (Tables 2 & 3)

Crude Protein—The forage crude protein (CP) was generally above 13%. CCC #6 had the highest forage CP with about 19% CP. Both CDC Haymaker oats and CCC #3 had lower forage CP than other treatments. Except for straight CDC Haymaker oats (check) and CCC #3, all cocktails exceeded the protein requirements for mature beef cattle as recommended by NRC (2000). Also, except for straight CDC Haymaker oats (check) and CCC #3, all cocktails were well within the recommended 12-14% CP for growing and finishing calves according to NRC (2000).

Only CCC #4 seemed to barely meet the 65% TDN that has been suggested for a lactating beef cow (NRC, 2000). Other cocktails and CDC Haymaker oats were adequate only for a dry gestating beef cow.

Looking at the forage minerals of the different cocktails and CDC Haymaker oats, in most cases, except for Na, cocktails generally had higher forage minerals than CDC Haymaker oats.

Generally, the K, Mg, Na, S, Fe, Zn and Mn requirements of both young and mature beef cattle as recommended by NRC (2000) were met by all cocktails but not CDC Haymaker oats (short of Zn). Only CCC #4, #5, #6 and #7 had adequate Ca for a lactating beef cow. Other treatments fell short of meeting the 0.58% Ca needed by a lactating beef cow. Similarly, only CCC #4, #5 and #7 met and even exceeded the Cu requirements of both young and mature beef cattle (10% Cu). CCC #4, #5, #6 and #7 had higher forage Ca, Mg, Cu, Zn and Mn than other cocktails and CDC Haymaker oats. For a lactating beef cow, all treatments (except for CCC #6) failed to meet the 0.26% P needed.

Conclusion

CCC #3 produced the highest forage DM yield, however, its yield was comparable to CDC Haymaker oats. Pearl millet, mung beans and sugar beet did not do well in cocktails that included them in this study as well as in previous PCBFA trials, so pearl millet, mung beans and sugar beet are not recommended for inclusion in cocktails for now in this area.

Acknowledgments

Thank you to Bill Fevang, Darin Stewart, Jim Campbell (Imperial Seed) and Kevin Elmy (Elmy’s Friendly Acres Seed Farm) for their donations.

References

BCRC (Beef Cattle Research Council), 2016. Cover Crops as Forage for Beef Cattle. http://www.beefresearch.ca/files/pdf/BCRC_Cover_Crops_Fact_Sheet.pdf (accessed 11 September 2018).

Chu, M., Jagadamma, S., Walker, F.R., Eash, N.S., Buschermohle, M.J., Duncan, L.A., 2017. Effect of Multispecies Cover Crop Mixture on Soil Properties & Crop Yield. Agricultural & Environmental Letters, 2(1).

Davis, C., Presley, D., Farney, J. K., Sassenrath, G. F., 2015. Evaluating Multispecies Cover Crops for Forage Production, "Kansas Agricultural Experiment Station Research Reports: Vol. 1: Iss. 4. https://doi.org/10.4148/2378-5977.1058 (accessed 4 August 2018).

Hobbs, P.R., Sayre, K., Gupta. R., 2008. The role of conservation agricul­ture in sustainable agriculture. Philos. Trans. R. Soc. B 363:543–555. doi:10.1098/rstb.2007.2169

Malézieux, E., Crozat, Y., Dupraz, C., Laurans, M., Makowski, D., Ozier-Lafontaine, H., Rapidel, B., de Tourdonnet, S., Valantin-Morison, M., 2009. Mixing plant species in cropping systems: concepts, tools and models: a review. In Sustainable agriculture (pp. 329-353). Springer, Dordrecht.

NRC (National Research Council), 2000. Nutrient Requirements of Beef Cattle (7th ed.). Washington, DC: The National Academies Press.

Wortman, S. E., Francis, C. A., Bernards, M. L., Drijber, R. A., Lindquist, J. L., 2012. Optimizing cover crop benefits with diverse mixtures and an alternative termination method. Agron. J. 104, 1425-1435.