Written by: Buthaina Al-Maqtari & Akim Omokanye,
Location: Bill Fevang's Farm - High Prairie
From: Peace Country Beef & Forage Association 2019 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.
The study site was at Bill Fevang’s farm in High Prairie. The site had canola in 2018 and it was sprayed with a pre-seed burnoff before seeding in 2019.
The plots were replicated 4 times in a randomized complete block design. The following broadleaf forbs and flax were seeded:
1. Plantain - seeded at 3.5 lbs/acre
2. Phacelia - seeded at 5 lbs/acre
3. Buckwheat - seeded at 48 lbs/acre
4. Flax - seeded at 50 lbs/acre
Seeding date was on June 7. The seeds were sown using a Fabro plot drill equipped with disc-type openers on 9” row spacing. Six rows that were 8 m long were sown per plot. Seeding depth was 0.75”.
No fertilizer was applied to any of the broadleaf crops.
No in-crop spraying was done. Instead, the plots were hand-weeded two times throughout the growing season.
Harvesting for forage dry matter (DM) yield determination and quality analysis was completed on August 28. Forage samples were sent to A & L Laboratory in Ontario for quality determination.
Forage Quality (Table 1)
Energy, expressed as total digestible nutrients (TDN), is a key value to consider when determining energy supplementation needs for beef cattle feed. It is important to provide cattle with adequate amounts of energy for an optimal animal performance. Among the crops tested here, Plantain produced a significantly higher forage TDN% than others. Plantain also exceeded the %TDN recommendations for both young (65-70% TDN) and mature lactating beef cattle (65% TDN) (Table 1). All other crops tested here fell short of the 65 TDN% required for young calves and lactating cows.
The forage crude protein (CP) was significantly higher in Plantain with 17.4 CP%, followed by Phacelia (15.6 CP%). Buckwheat and Flax respectively had forage CP of 10.8% and 11.4%.
Phacelia had higher forage Ca, Mg and Na values than other crops (Table 1). All crops tested here exceeded the levels of Ca, P, K, Mg and S required for mature and young beef cattle. Only Buckwheat and Phacelia did not meet the Na requirements for mature and young beef cattle.
Looking at Table 1, both forage Cu and Zn were similar for all crops. However, flax seemed to have the tendency to improve forage Cu and Zn when comparted to the other crops tested. Plantain had significantly higher Fe than other crops, while Buckwheat showed significantly higher Mn level than the other crops.
The ADF and NDF levels were the lowest in Plantain, which is positively correlated to a better digestibility and forage energy. The forage NEM and NEG was the highest in Plantain and lowest in Phacelia. All broadleaf crops exceeded the NEM and NEG recommended levels for young and mature cattle.