Harvest Date Effect on Forage Yield, Botanical Composition, and Nutritive Value of Novel Legume-Grass Mixtures

The potential for novel forage mixtures to address reduced herbage for late season grazing was investigated. Forage legumes, sainfoin (Onobrychis viciifolia Scop.) (SF) cvs. AC Mountainview, Shoshone, and Nova (MountainSF, ShoshoneSF, and NovaSF), cicer milkvetch (Astragalus cicer L.) cv. AC Veldt (CMV), Canadian milkvetch (Astragalus canadensis L.) cv. Great Plains (CaMV), and alfalfa (Medicago sativa L.) cv. AC Yellowhead (ALF) were evaluated in binary mixtures with meadow bromegrass (Bromus riparius Rehm.) cv. Admiral (MBG), hybrid bromegrass (B. riparius × B. inermis Leyss.) cv. AC Success (HBG) and Russian wildrye [Psathyrostachys junceus (Fisch.) Nevski.] cv. Tom (RWR) for yield, botanical composition, and nutritive value on July and September harvest dates at Saskatoon and Swift Current, Saskatchewan, Canada from 2016 to 2018. Hybrid bromegrass-legume mixture produced 16–38% greater forage compared to RWR-legume (7.5 vs. 5.6 Mg ha−1 in July and 6.1 vs. 5.1 Mg ha−1 in September at Saskatoon, and 3.2 vs. 2.0 Mg ha−1 in July at Swift Current). MountainSF and ALF had the greatest legume contribution to total yield at July harvest at Swift Current (67.7 ± 3.2%) and Saskatoon (62.1 ± 2.1%), respectively, while CaMV had lowest composition at Swift Current (20.2 ± 2.5%) and Saskatoon (12.6 ± 3.5%). The CMV and ALF-grass mixtures at Saskatoon and legume-RWR mixtures at both sites in July had greatest CP content. The July harvest had greatest yield, legume content and nutritive value compared to the September harvest at both sites. Study results suggest if yield is the objective, then either ALF or CMV with HBG may be considered. If nutritive value is the goal, any legume with RWR is an option. Finally, ALF or CMV in mixture with either HBG or RWR could be summer or fall stockpile forage in the Northern Great Plains of western Canada.

Establishment and productivity of cicer milkvetch (Astragalus cicer L.) in alfalfa (Medicago sativa L.) or alfalfa- hybrid bromegrass mixtures

Cicer milkvetch (Astragalus cicer L.) (CMV) is a non-bloating, perennial legume that has shown persistence under grazing. Limited information is available on its seedling establishment and subsequent forage yield and nutritive value in alfalfa (Medicago sativa L.) mixtures. Field plots were seeded in May 2013 at Melfort, SK, Canada to evaluate ‘Oxley II’ cicer milkvetch performance in ‘AC Grazeland’ alfalfa or alfalfa and ‘AC Success’ hybrid bromegrass (Bromus riparius × B. inermis) mixtures from 2014 to 2017. Two controlled environment tests were also conducted by treating seeds of CMV using alfalfa root aqueous extract. Seed germination and seedling height of CMV were significantly reduced in aqueous extract. In field, establishment of CMV in a mixture containing alfalfa was reduced, and CMV dry matter proportion in the mixture increased only 3.5% over three years. Increasing CMV seeding rate did not increase its DM percent in the mixtures, indicating a high allelopathic effect of alfalfa. Forage DM yield of all mixtures was linearly correlated to the proportion of alfalfa, and adding hybrid brome did not increase the DM yield. Forage DM yield was higher for the three-cut than the two-cut treatments for CMV-alfalfa mixtures, but there was no difference between the cutting frequency for CMV-alfalfa- hybrid brome mixtures. Fiber concentrations decreased linearly with increased CMV seeding rate in the mixtures. This study showed CMV establishment in alfalfa mixtures was reduced in a same row seeding, and the allelopathic effect was not reduced by lower alfalfa seeding rates or adding a grass.

Prospects for growing Astragalus chickpea (Astragalus cicer L.) as a fodder culture

The article discusses the feeding qualities of the Astragalus cicer L. in different agroecological and agroclimatic conditions.

USE OF LEGUMES FOR ECOLOGICAL RECLAMATION OF STEPPE DEGRADED PASTURES OF KULUNDA

Intensive development of the steppe communities of Kulunda, located in the southern part of the West Siberian lowland in the XX century led to a significant anthropogenic transformation of all steppe ecosystems. Representatives of the legume family, which is the most important component of steppe grasses, have almost disappeared from the grasslands. The research was conducted on the territory of the Mikhailovsky district of the Altai territory, on the lands of LLC KKH «Partner» in the environs of Poluyamki village scince 2013-till present days climatic conditions of dry steppe zone of Western Kulunda. The aim of the work was to evaluate representatives of the legume family for ecological reclamation of Kulunda steppe pastures. The experiment was performed on 2 degraded fenced steppe areas (10 x 10 m) corresponding to the third stage of pasture digression. Winter sowing of legumes was carried out: cicer milk vetch (Astragalus cicer L.), sainfoin milk vetch (A. onobrychis L.), furrowed milk vetch (A. sulcatus L.), bird’s foot trefoil (Lotus corniculatus L.), sickle alfalfa (Medicago falcata L.), hop alfalfa (M. lupulina L.) and late spring sowing: cicer milk vetch and sainfoin, bird’s foot trefoil by tapping into the sod. Monthly growth dynamics of sown plants (number of shoots per m2, height, phenology) was recorded, and the feed value of aboveground biomass was established. It was found that the drought-resistant species of alfalfa sickle has a significant biomass, is short-lived in the grass stand and requires re-sowing every 4 years. Hop alfalfa is recommended for improving degraded pastures, but due to its short ontogeny, it needs to be re-sown every three years. Among milk vetches, sainfoil milk vetch is the most promising – a long-rooted, rod-rooted polycarpic that increases its area due to numerous underground rhizomes. The greatest nutritional and energy value was possessed by the phytomass of bird’s foot trefoil and sickle alfalfa.

Nitrogen Fixation and Resource Partitioning in Alfalfa (Medicago sativa L.), Cicer Milkvetch (Astragalus cicer L.) and Sainfoin (Onobrychis viciifolia Scop.) Using 15N Enrichment under Controlled Environment Conditions

Availability of nitrogen (N) limits pasture production. Inclusion of legumes into grass pastures can provide an alternative N source through biological N2 fixation (BNF), and enhance retention and cycling of soil C and N. Despite the use of alfalfa (Medicago sativa L.), cicer milkvetch (Astragalus cicer L.) and sainfoin (Onobrychis viciifolia Scop.) in grass-legume pastures to improve forage quality, relative BNF potentials and resource partitioning are unknown. We quantified BNF using 15N isotope dilution and estimated resource partitioning in alfalfa, two cultivars of cicer milkvetch and two cultivars of sainfoin under controlled conditions. Percentage of nitrogen derived from atmosphere followed the order alfalfa (92%) > cicer milkvetch (87%) > sainfoin (81%); corresponding to estimated N contributions of 200, 128 and 65 kg N ha−1 yr−1, respectively, based on total herbage. Root dry matter was 24% to 36% greater than shoot dry matter in all of the legumes, providing substantial below-ground C and N. Cultivars of the same species did not differ in any measured parameter (p > 0.05). Despite the lower BNF in cicer milkvetch and sainfoin compared to alfalfa, their use may not negatively affect stand productivity and C storage.

Evaluation of Cicer Milkvetch and Alfalfa Cultivars for Nutritive Value, Anti-Quality Factors and Animal Preference

Cicer milkvetch (CMV; Astragalus cicer L.) is an alternative non-bloat legume to managing alfalfa. A 2-yr study was conducted to compare three CMV cultivars (Oxley II, Oxley, and Veldt) to AC Grazeland alfalfa (ALF; check forage) for nutritive value and animal preference. Each yr, replicate samples (n = 4) of each forage type were harvested late summer and analyzed for nutrient profile. Oxley II had lower (p < 0.05) fiber content than AC Grazeland, while Oxley and Veldt were similar (p = 0.48) to AC Grazeland for neutral detergent fibre (NDF), acid detergent fibre (ADF) and starch. In contrast, Oxley II had higher (p < 0.05) net energy for gain (NEg) than AC Grazeland, and Oxley and Veldt were similar (p > 0.05) to AC Grazeland for NEg. All three CMV varieties had similar levels of total digestible nutrients (TDN) (63.6 ± 0.6%; p > 0.05), but had higher (p = 0.01) energy content than AC Grazeland alfalfa (54.9 ± 1.4% TDN). Selenium (Se) concentrations were similar (p > 0.05) among CVM cultivars and less than 1 mg/kg DM, and no swainsonine or nitrotoxins were detected in the CMV cultivars. The Oxley II CMV tended (p = 0.06) to have a higher (139) relative feed value (RFV) compared to AC Grazeland (94), while Oxley and Veldt had moderate RFV values (128). Dry matter intake of Oxley II, Veldt, and Oxley CMV was 4, 18, and 28% greater than AC Grazeland, respectively. Based on the relative preference index (ratio of forage DMI to AC Grazeland alfalfa DMI), forage types are ranked as follows: AC Grazeland (1.0) < Veldt (1.2) < Oxley (1.4) < Oxley II (1.7). Study results suggest that CMV cultivars harvested late summer, maintained higher forage quality with greater preference compared to alfalfa.