Research Program Manager: Dr. Akim Omokanye
From: Peace Country Beef & Forage Association 2018 Annual Report
Intercropping systems involving cereals with legumes have been observed to provide several major advantages, such as higher total yield, better land use efficiency, yield stability, better utilization of light, water, and nutrients, improved soil conservation, and maintenance of soil fertility. Peas are usually included in mixes to improve quality of the feed. To increase utilization of annual cereal and legume forages as hay, greenfeed, or silage, and to develop supplementation programs for forage-based nutrition, it is important to know how the nutritional values of different forages match up with beef cow needs. The objective of this study was to compare the intercrops of spring oats, barley, and triticale with 2 pea varieties to respective cereal monocrops for forage yield and feed quality. This was part of the regional silage variety trials in Alberta. In addition to the report presented here, results from this site and other parts of the province for the pea-cereal mixtures will also be reported in the Alberta Seed Guide (www.seed.ab.ca).
Methods
The study site was at the Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview. The site had been in alfalfa hay for more than 15 years. The site was sprayed with Roundup and plowed in the fall before. This was later disced and harrowed in the spring before seeding. Soil tests at 0-6” showed an organic matter of 7.6%, a pH of 6.9, and an electrical conductivity of 0.2 dS/m.
Experimental Design: Randomized complete block design in 4 replications.
Treatments: 3 cereals (1 barley, 1 oat & 1 spring triticale) & 2 pea varieties (CDC Meadow & CDC Leroy) were used in the following pea-cereal mixtures:
1. AAC Austenson barley (monocrop)
2. Taza triticale (monocrop)
3. CDC Baler oat (monocrop)
4. CDC Austenson barley/CDC Leroy pea
5. CDC Austenson barley/CDC Meadow pea
6. Taza triticale/CDC Leroy pea
7. Taza triticale/CDC Meadow pea
8. CDC Baler oat/CDC Leroy pea
9. CDC Baler oat/CDC Meadow pea
Seeding Date & Rate: seeding was done on May 25 at the following rates:
1. CDC Austenson barley- 300 plants/m2 (27.8 plants/ft2)
2. CDC Baler oat - 300 plants/m2 (27.8 plants/ft2)
3. Taza triticale - 370 plants/m2 (34.3 plants/ft2)
4. Pea-cereal mixtures - 75% of pea seeding rate + 50% of cereal seeding rate
Seeding Method: 6-row Fabro plot drill with 9” row spacing
Fertility (actual lbs/acre): 60 lbs/acre of 11-52-0
Roundup was used for burn off. In-crop spraying was done on June 19 with 0.17 L/acre Prestige XC A+ 0.80 L/ acre Prestige XC B. Hand weeding was done once on July 4th.
Harvesting for forage dry matter (DM) yield determination and quality analysis was done on August 10 for pea-barley mixes and barley monocrop (soft-dough stage), August 14 at the milk stage of oats for pea-oat mixes and oat monocrop, and August 15 for pea-triticale mixes and triticale monocrop (late milk stage). Two composite forage samples were sent to A & L laboratory in Ontario for quality determination.
Results
Forage Dry Matter (DM) Yield
Both CDC Baler oats/CDC Meadow pea mixture and CDC Baler monocrop had significantly higher forage DM yield than other mixtures and monocrops. A forage DM yield of greater than 4.0 tons/acre was produced by CDC Baler oats/CDC Meadow pea mixture and CDC Baler monocrop, while others had less than 4.0 tons/acre forage DM yield (Table 1). Two of the monocrops (CDC Baler oats and Taza triticale) were in the top 3 forage yielders. There appeared not to be any forage DM yield advantage from mixing peas with cereals. The only extra forage DM yield came from CDC Baler oat/CDC Meadow peas over CDC Baler oat monocrop with 485 lbs DM yield/acre.
Forage Quality
Crude protein (CP): The forage CP was not statistically different for the mixes and cereal monocrops (Table 1). All mixes and cereal monocrops seemed to have adequate CP for dry gestating and lactating beef cows.
The forage energy as determined by total digestible nutrients (TDN) was significantly different between cropping treatments, with CDC Baler oats recording the highest forage TDN (71.3%) (Table 1). Only CDC Baler oats had >70% TDN. Others had <70% TDN. Both CDC Austenson barley and CDC Austenson/CDC Leroy peas had far lower forage TDN than other mixtures and cereal monocrops, and they were the only ones that did not have adequate TDN for a dry gestating beef cow. In most cases, other mixtures and cereal monocrops were able to meet the 55% TDN needed by a dry gestating beef cow in mid-pregnancy and 60% TDN required in late-pregnancy, while only CDC Baler oats and CDC Baler/CDC Meadow peas met and exceeded the 65% TDN needed by a lactating beef cow.
The forage minerals were mostly different for the cropping treatments tested, but forage P, Mg, Cu, and Zn had similar values for the cropping treatments. CDC Austenson barley/CDC Leroy peas had the highest forage Ca, K, Mg, S and Zn (Table 2).
All mixtures and cereal monocrops were able to meet the recommended levels of Ca, P, K, Mg, Na (except CDC Baler oats monocrop, CDC Baler oats/CDC Meadow peas, and Taza triticale), S, Fe, Zn, and Mn for a dry gestating beef cow. For a lactating beef cow, except on a few occasions, the cropping treatments were mostly short of Ca and P. Generally, the forage Cu did not meet the requirements of any categories of beef cattle.
