Research Coordinator: Dr. Akim Omokanye
Collaborating producer: John Prinse (MD of Big Lakes)
From: Peace Country Beef & Forage Association 2014 Annual Report
Cereals can provide high energy feed for livestock within a short period of time. They can be harvested at the milk to soft dough stage for stored feed, or they can be swathed and left for late season swath grazing. Millets, though a warm season annual cereal crop, are a good option for harvested green feed and for swath grazing. Also, winter cereals are an option for producers wishing to graze the stand during the summer and late into the fall period; fall rye can be used for this option. Spring seeding a spring and winter cereal together is a good option for providing a season long forage option. We can harvest the spring cereal as silage and use the winter cereal below for mid to late season grazing. Intercropping maximizes the number of plants per acre and nutrient. In this study, we used a winter cereal (fall rye) in mixtures with crown millet (red proso millet) and sweet clover to improve forage yield and quality. If planting sweet clover as livestock feed, use low coumarin varieties. Coumarin is a substance present in varying amounts in all sweet clover species. Two varieties of sweet clover, Norgold yellow sweet clover and Polara white sweet clover have very low coumarin content and do not pose a problem when feeding livestock. By including fall rye in the mixtures, we also want-ed to see how much fall rye would be available for late fall or early spring grazing following a late summer grazing.
The study took place at John Prinse’s farm at Enilda, near High Prairie, MD of Big Lakes. The site had been used for swath grazing for a few years prior to the present study. Demonstration strip design was used on a 12.6-acre piece of land. Spring soil sample taken from 0-6 inches soil depth and analyzed by Exova laboratory in Edmonton showed 13.9% OM and a pH of 6.6. The soil had marginal N, optimum P & S, and excess K required for crop growth. The soil was not tilled before seeding.
We used 2 cereals (fall rye (FR) and red proso millet (M) and a forage legume (sweet clover (SC)) for this trial. Proso millet is a variety of crown millet. The crop treatments consisted of the following:
Treatment 1 - Crown millet (15 lb/ac) + fall rye (0.5 bus/ac) + yellow blossom sweet clover (3 lbs/acre);
Treatment 2 - Crown millet (15 lb/ac) + fall rye (1.5 bus/ac) + yellow blossom sweet clover (3 lbs/acre) and
Treatment 3 - Monoculture crown millet @ 20 lbs/acre
Seeding was done on June 15 with a John Deere 752 no till disk drill with 24 rows @ 7.5” row spacing. The seed drill had multiple boxes for seeds and fertilizers. We put fall rye in one box, mixed millet + sweet clover seeds in another box and the fertilizer blend in the fertilizer box. We applied 80 lbs/acre blend of 46-0-0 (50 lbs/acre ) + 11-52-0 (30 lbs/acre) at seeding. Sweet clover was treated with Nitragin Gold pre-inoculant before seeding. Spraying for pre-emergence weed control on June 17 with 0.6 L Roundup® + 0.6 MCPA® to control horsetail and other weeds.
Harvesting of the plots for estimation of forage DM yield and quality was done on August 28, when the millet was at the mid dough stage. And then the millet plot (treatment 3) was swathed for swath grazing, while both treatments 1 and 3 ( fall rye, sweet clover and millet mixtures) were grazed with cow-calf pairs.
Forage Dry Matter (DM) Yield
Monoculture millet (Treatment 3) had the most forage DM yield (5685 lbs/acre), followed by Treatment 1 (a mixture with 0.5 bushel/acre fall rye) with 2649 lbs/acre and then Treatment 2 (a mixture with 1.5 bushels/acre fall rye) with 1529 lbs/acre (Figure 1). Monoculture millet had 3000-4000 lbs/acre more DM than both crop mixtures tested (Treatments 1 and 2). Increasing the seeding rate from 0.5 to 1.5 bushels/acre for fall rye had significant effect on forage DM obtained among the 2 mixtures with fall rye.
Both crop mixtures (Treatments 1 & 2) had higher protein (crude protein, CP) than monoculture millet (Treatment 3) (Figure 2). Both treatments 1 & 2 had sufficient CP that is needed by a mature beef cow (7-11% CP). Monoculture millet was only able to barely meet the 7% CP requirement of a cow in mid pregnancy.
The forage energy (total digestible nutrients, TDN) was higher for Treatment 2 (a mixture with 1.5 bushes/acre fall rye) than Treatment 1 (a mixture with 0.5 bushels/acre fall rye) and monoculture millet (Treatment 3). Generally, all treatments had >60% TDN. Both crop mixtures (Treatments 1 and 2) as well as monoculture millet (Treatment 3) had adequate TDN needed by a mature beef cow (55-60-65% TDN). But monoculture millet (Treatment 3) slightly fell short of the 65% TDN required by a nursing cow.
Forage Ca, Mg, ADF and other forms of energy (ME, NEL, DE, NEM and NEG) were higher with higher fall rye seeding rate (Treatment 2) (Table 1). The forage Ca varied from 0.22% Ca for monoculture millet to 1.49% Ca for Treatment 2. The forage P, Mg and K contents respectively varied from 0.23 to 0.29% P, 0.13 to 0.28% Mg and 1.91 to 2.85% K. The requirements for Ca, P, Mg and K by a dry gestating cow were met by all the treatments. All treatments fell short of 0.06-0.08% Na needed by this category of beef cow. For a nursing cow, which requires 0.42% Ca, 0.26% P, 0.20% Mg, 0.70% K and 0.10% Na, Treatments 1 & 2 had sufficient Ca, Treatments 1 & 3 had adequate P, only Treatment 2 had enough Mg. Also for a nursing cow, all treatments exceeded K requirement and all the treatments fell short of Na requirement by this category of cow.
Some Notes on Millets and Sweet Clover
There are several different types of millet, but the three most commonly grown in Western Canada are Crown (proso), Siberian (foxtail) and German (foxtail). Millets are small seeded species, therefore shallow seeding (½" to 1") is recommended. Proso millets are generally larger seeded than foxtail millets, therefore recommended seeding rates are higher. For forage production, proso millet seeding rates range from 20 to 25 pounds per acre and foxtail millets from 15 to 20 pounds per acre.
The cost of the adding clover seed is off-set by the nitrogen produced for next year's crop. The amount of nitrogen contributed by red clover can range from 30 to 50 pounds per acre and for sweet clover from 50 to 100 pounds per acre by full bloom, depending on the density of the stand, moisture availability, soil type and the length of the growing season.
Sweetclover, like other legumes, can capture and fix some of its own nitrogen. Legumes require a special kind of nitrogen-fixing bacteria to manufacture nitrogen from the air. The kind of bacteria required depends on the kind of legume being planted. Sweetclover and alfalfa require the same bacteria to induce formation of effective nodules on the roots.
Sweetclover seed always should be inoculated before planting. Use the proper strain of nitrogen-fixing bacteria. This will help ensure the formation of effective nodules or “nitrogen factories” to fix atmospheric nitrogen into a form the plant can use. The seed serves only as a carrier to place the proper bacterial strain in the soil to facilitate nodule formation on root hairs.
Companion crops often are used with new seedings of sweetclover for economic reasons. Use an early maturing companion crop if it is to be harvested as grain or remove late-maturing companion crops as hay or silage. When removing the companion crop, leave a minimum 6-inch stubble height to encourage adequate fall sweetclover growth and a buildup of root reserve to maintain a vigorous stand.
A major benefit of sweetclover in the crop rotation is its ability to fix atmospheric nitrogen into a form that’s useable to plants. In addition, its deep penetrating, widely branched root system improves soil drain-age, aeration and the soil’s general physical condition. Sweetclover plowed under as green manure the year following establishment adds considerable organic matter to the soil, improving soil tilth and the ease of tilling soils. Sweetclover often is grown on saline-seep contributing areas to use deep soil moisture, reducing the lateral flow of water that forms the seep area in crop-fallow rotations.