Trial Location: Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview
Research Coordinator: Dr. Akim Omokanye
From: Peace Country Beef & Forage Association 2015 Annual Report
Soybean plants may be grazed or harvested from the flowering stage to near maturity for use as high-quality hay. Soybeans may also be grown as a silage crop in pure culture or cocktail mixtures. Soybeans are some-times referred to as “short-day plants”, as they flower in response to shortened day length. The beginning of the reproductive period with flowering and the date of maturation are affected by day length more than the actual age of the plant. Varieties differ in their response to day length. Agronomically, soybeans have the ad-vantage of fixing nitrogen when properly inoculated, and do not require a lot of specialized equipment to grow. Crop species choice is one of the important decisions any crop producer makes. The objective of this trial was to test and select soybean varieties for forage yield and quality for livestock use based on local growing conditions.
Methods
Fourteen (14) roundup ready soybean varieties with varied heat units requirement (Table 1) were tested in a small plot field trial at the Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview. Prior to seeding, soil tests were carried out and we cultivated the land. A rlock d(RCBD) with three (3) replications was used. Seeding rate was 55 plants/m2 (5.1 plants/ft2). Seed depth was 0.75-1.00”. Six rows were seeded per plot using plot drill at 9” row spacing on May 22. Seed was inoculated with HiFlo® Spherical Granules at seeding. Fertility was 0 lbs/ac N, 60 lbs/ac P, 28 lbs/ac K, and 18 lbs/ac S (based on soil testing). In crop spraying was done once with Round-up.
Results
Forage dry matter (DM) yield varied from 1275 lbs DM/ac for Mammoth to 4641 lbs DM/ac for TH3303 (Figure 1). Seven of the 14 varieties had > 3000 lbs DM/ac, while the other 7 had <3000 lbs DM/ac.
The forage protein (CP) was generally >16% for all soybean varieties (Table 1). All varieties therefore far ex-ceeded the protein requirements of mature beef cattle as well as growing and finishing calves.
The forage Ca, P, Mg & K of all varieties exceeded the Ca, P, Mg & K requirements by a dry gestating cow.
The forage energy (%TDN) was highest for TH33005 (74% TDN) and lowest for Reston (64% TDN). Generally, all varieties far exceeded the energy requirements of dry gestating cows (55% TDN at the 2nd trimester and 60% TDN at 3rd trimester). For the other forms of energy measured, TH33005 also had higher ME, NEL, DE, NEM and NEG than other varieties. For a mature cow which requires 0.97-1.10 NEM (Mcal/kg) during pregnancy and 1.19-1.28 NEM (Mcal/kg) during lactation, all soybean varieties were well within these values.
Conclusion - The trial site (Fairview) and area in 2015 was dry and so the soybeans did not grow well. But looking at the forage DM yield for Reston and TH3303, which had up to 2.0 tons DM/ac and the ability for all varieties to meet the protein, minerals (except for Na) and energy requirements of a mature, it shows that some soybean varieties have potential in the Peace.