The Performance of Some Broadleaf Cover Crops in High Prairie

Research Coordinator: Dr. Akim Omokanye

Location: Bill Fevang's Farm - High Prairie

From: Peace Country Beef & Forage Association 2018 Annual Report

Typically, annual cover crops (including broadleaf types) are sown as monocultures within annual crop rotations to protect soil from erosion or give other agroecosystem services, such as building soil fertility and organic matter, retaining nutrients, or suppressing weeds during periods when cash crops are not actively growing. This report looks at the forage production potential of 4 broadleaf crops for beef cattle production.

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 broadleaf crops 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 following 4 broadleaf crops were tested:

1. Plantain seeded at 3.5 lbs/acre

2. Chicory at 5 lbs/acre

3. Phacelia at 5 lbs/acre

4. Buckwheat at 48 lbs/acre

These were replicated 4 times in a randomized complete block design.

· Seeding date: June 7

· No fertilizer was applied to any of the broadleaf crops

· No in-crop spraying was done. Instead the plots were hand weeded twice.

· The broadleaf crops were harvested on August 20 for forage dry matter (DM) yield determination and quality analysis. Two composite forage samples were sent to A & L laboratory in Ontario for quality determination.

Results

Forage Dry Matter (DM) Yield

The forage DM yield was significantly different between crops. Buckwheat and phacelia had significantly higher forage DM yield than plantain and chicory. Overall, both buck wheat and phacelia had impressively greater forage DM yield in this study. Buckwheat had forage DM yield of 8480 lbs/acre, followed by phacelia with 7802 lbs/acre, plantain with 3040 lbs/acre and then chicory with 2131 lbs/acre.

Forage Quality

Energy, expressed by total digestible nutrients (TDN), is one of the most crucial nutrients for beef cattle in cold climates. Chicory and plantain produced significantly higher forage TDN, with 69.2% and 68.6% respectively, when compared to buckwheat and phacelia with 54-57% TDN . Phacelia and buckwheat produced forage TDN levels that are lower than the recommended forage TDN for a dry beef cow in late pregnancy and after calving. On the other hand, with forage TDN content of about 70%, both chicory and plantain had enough TDN for all categories of both young and mature beef cattle.

The forage CP was lowest for buckwheat (13% CP) and highest for chicory (about 25% CP). The forage CP of all broadleaf crops was generally enough to meet the CP requirements for mature and young cattle. Chicory, in particular, when included in cocktail mixtures would be able to improve the forage CP value of the cocktail.

Minerals

In most cases, the forage macro minerals tested here (Ca, P, K, Mg, Na, and S) were significantly and consistently higher for chicory than other broadleaf crops. Phacelia produced by far the highest forage Ca of all broadleaf crops tested. All crops in the present study exceeded the K, Mg, and Ca levels recommended for both mature and young beef cattle.

For the forage trace minerals (Cu, Fe, Zn, Mn), chicory also produced high forage minerals than all other broadleaf crops. All broadleaf crops in this study generally produced high levels of trace minerals, and all exceeded the trace minerals required for young and mature beef cattle. The only exception was plantain, which did not meet the 40 ppm of Mn required for mature beef cattle, though it did have enough for young beef cattle.

Conclusion

The study showed that both phacelia and buckwheat produced significantly higher forage DM yield than plantain and chicory, but overall, chicory produced better forage quality than the other broadleaf crops . Depending on the seeding rate, when added to a cover crop cocktail mixture, phacelia and buckwheat could contribute some significant forage DM to the total forage production, while chicory would greatly improve forage quality for beef cattle production.