Research Coordinator: Dr. Akim Omokanye
Location: Fairview Research Farm
From: Peace Country Beef & Forage Association 2019 Annual Report
In crop mixtures, any species utilizing the same combination of resources will be in direct competition. However, based on differences in phenological characteristics of species in mixtures, the interaction among them may lead to an increased capture of a limiting growth resource. Mixtures of winter rye or winter triticale with spring oats can be harvested for silage, with the fall regrowth providing a productive, quality pasture in the fall, when perennial pastures are going into dormancy and decreasing in productivity. One of the most important criteria for the success of mixtures in practice is their yielding ability. The objective of this trial was to determine the forage potential of spring-planted spring/winter cereal mixtures.
Methods
Experimental Site: Fairview Research Farm (NW-5-82-3-W6M) on RR #35, MD of Fairview.
Previous Crop: The previous crop at the site was an alfalfa hay crop for several years until the Fall of 2017. The site remained unseeded (chemical fallow) in 2018.
Land Preparation: In the Fall of 2018, the site was sprayed with Roundup at 1.0 L/acre (to kill the existing alfalfa dominated vegetation) and plowed. The site was disced & harrowed in the spring of 2019.
Soil analysis completed in the Fall of 2018 was from the soil depth of 0-6” showed an organic matter content of 8.2%, pH of 6.2 and an electrical conductivity of 0.21 ds/m. The soil test reports showed 10 lbs N/acre, 14 lbs P/acre and 485 lbs K/acre as well as 9 lb S/acre.
Spring soil moisture at seeding: 12.3% (0-5 cm soil depth) and 13.6% (0-20 cm soil depth).
Spring soil temperature a seeding: 9.48°C (0-5 cm soil depth) and 8.09°C (0-20 cm soil depth).
Experimental Design: Randomized Complete Block Design with 4 replications and 14 treatments (5 cereal monocrops and 9 cereal mixtures) as shown below:
1. Triticale monoculture (Variety: Bunker) seeded at 34.3 plants/ft2 (100% seeding rate)
2. Barley monoculture (Variety: CDC Maverick barley) seeded 27.8 plants/ft2 (100% seeding rate)
3. Oat monoculture (Variety: CDC Haymaker oat) seeded 27.8 plants/ft2 (100% seeding rate)
4. Fall rye monoculture (Variety: Prima) seeded at 24 plants/ft2 (100% seeding rate)
5. Soft white wheat (Paramount) seeded at 34.3 plants/ft2 (100% seeding rate)
6. 75% oat + 75% triticale
7. 75% oat + 75% fall rye
8. 75% barley + 75% triticale
9. 75% barley + 75% fall rye
10. 75% barley + 75% oat
11. 50% barley + 16% oat + 16 triticale + fall rye
12. 25% barley + 25% oat + 25% triticale + 25% fall rye
13. 25% barley + 25% oat + 25% triticale + 25% SWW
14. 33% barley + 33% oats + 33% triticale
Each crop in the mixtures was seeded at the indicated percentage of the monoculture seeding rates and the variety of the monoculture cereal.
Seeding date was on May 23.
Seeding Method: The seeds were sown using a Fabro plot drill equipped with disc-type openers on 9” row spacing. Six rows that were 8 m in length were sown per plot. Seeding depth was 0.75”.
Fertility for an average cereal crop forage yield (actual lbs/acre) was applied at: 89 N + 39 P + 0 K + 13 S. No K was applied as the soil test reports showed optimum levels of K for triticale and soft white wheat production for the year.
Spraying: Pre-emergent herbicide with StartUp (Glyphosate, 540 grams acid equivalent per litre, present as potassium salt) was applied at 0.67 L/acre. StartUp is a water-soluble herbicide for non-selective weed control. In-crop herbicide application was with Prestige A (170 mL/acre) + Prestige B (800 mL/acre).
Harvesting for forage dry matter (DM) yield determination was completed on August 13 when the oat varieties were at the milk stage, barley at the soft dough stage and triticale at the early milk stage. Forage samples were shipped to A & L laboratory, Ontario for forage quality determination. Notes were also taken on plant lodging.
Rainfall received from seeding to forage harvest was 159.9 mm (or 6.30”) and it compared well to 167.2 mm (6.58”) for the long-term average for the same period.
Results and Implications
Forage Dry Matter (DM) yield
The forage DM yield was highest for 75% barley + 75% fall rye (11,100 lbs/acre), followed closely by soft white wheat monoculture (10,251 lbs/acre) and then 75% barley + 75% oat (10,135 lbs/acre) (Table 1).
Of the 5 cereal monocultures, only soft white wheat monoculture conveniently had up to 5 tons forage DM yield/acre. For the cereal mixtures, only 2 mixtures (both 75% barley + 75 triticale and 75% barley + 75% fall rye) produced 5 tons DM/acre or more. Overall, fall rye monoculture produced the lowest forage DM yield with 5,031 lbs DM yield/acre.
There wasn’t any forage yield advantage from mixtures with 3-4 crops over monocultures and two cereal crop mixtures (double intercropping).
The triticale monoculture had 1,231-1,695 lbs/acre more forage DM yield than 75% oat + 75% triticale, 50% barley + 16% oat + 16 triticale + fall rye and 25% barley + 25% oat + 25% triticale + 25% fall rye. The triticale monoculture had less forage yield advantage over other mixtures. The barley monoculture did not have any significant forage yield advantage over those mixtures which had barley. Similar results were obtained for oat and fall rye monocultures and their mixtures.
Forage Quality
The forage CP was highest for fall rye (13.0% CP). Both barley and oats had lower forage CP (10.7% CP) than other cereal monocultures and all mixtures. The beef cattle rule of thumb indicates that a dry beef cow in early to mid-gestation requires 7% of CP in the diet for maintenance which increases to 9% CP in late pregnancy and 11% CP for lactating cows or young (first parity) growing cows. The results obtained in this trial show that most cereal monocultures and all mixtures conveniently met the CP requirements of mature beef cattle.
Fall rye monoculture had the least acid detergent fiber (ADF) and neutral detergent fiber (NDF), followed by 75% barley + 75% fall rye mixture and then triticale monoculture (Table 2). NDF is a predictor of voluntary intake because it provides bulk or fill. In general, low NDF values are desired because NDF increases as forages mature. ADF values are inversely related to digestibility, so forages with low ADF concentrations are usually higher in energy. So, fall rye monoculture, 75% barley + 75% fall rye mixture and triticale monoculture also tended to have some slightly higher forage %TDN than other monocultures and mixtures. With the lower NDF values obtained for fall rye monoculture, 75% barley + 75% fall rye mixture and triticale monoculture, there may be a tendency that when all the monocultures and mixtures are presented side by side to cows in a preference study fall rye monoculture, 75% barley + 75% fall rye mixture and triticale monoculture would likely be preferred and consumed more than others.
The forage TDN was generally 65% or more for the monocultures and mixtures tested here (Table 2). A range of 55-65% TDN and 0.90-1.32 Mcal/kg NEM have been recommended for beef cows. The forage TDN and NEM obtained here all met the TDN and NEM requirements of mature beef cattle.
The forage macro minerals (Ca, P, K, Mg, Na and S) and trace minerals (Cu, Fe, Zn and Mn) are shown in Table 3. The forage Ca varied from 0.31 - 0.44% and from 0.22 - 0.28% for P. Fall rye monoculture had the highest forage K. The required K, S and Na (except for triticale and oat monocultures) by mature beef cattle have been met by all monocultures and mixtures. The forage Ca, P and Mg were only enough for a pregnant cow in mid pregnancy. No monocultures and mixtures tested here was consistently able to meet the trace-mineral requirements of mature beef cows. This shows that mineral supplementation would be required when feeding any of the monocultures and mixtures tested here because of their inability to completely meet mineral requirements.
Conclusion
Of the 5 cereal monocultures, only soft white wheat monoculture conveniently had up to 5 tons forage DM yield/acre. For the cereal mixtures, only 2 mixtures (both 75% barley + 75 triticale and 75% barley + 75% fall rye) produced 5 tons DM/acre or more. There wasn’t any apparent forage yield advantage from mixtures with 3-4 crops over monocultures and two cereal crop mixtures (double intercropping). The results obtained here therefore show that most cereal monocultures and all mixtures conveniently met the CP requirements of mature beef cattle. No monocultures and mixtures tested within this trial were consistently able to meet the trace-mineral requirements of mature beef cows. This shows that mineral supplementation would be required when feeding any of the monocultures and mixtures tested here because of their inability to completely meet the requirements of minerals.