Effects of Mixture Sowing on Forage Yield and Interspecific Competition of Alfalfa and Orchard Grass

[ Objective] To explore the mixture sowing effects and optimal mixture ratio of alfalfa and orchard grass. [ Method] The alfalfa and orchard grass were sowed at different ratios （1 ： 0, 3： 1, 1 ： 1, 1 ： 3 and 0：1 ）. They were grouped and named as CK1, A1, A2, A3 and CK2., respectively. The forage yield, relative yield total （RYT） and the competition rate （CR） of alfalfa and orchard grass in each group were determined, respectively. [ Result] In the A3 treatment group, the total forage yield was the highest （4 827.67 kg/hm2） and significantly different from that of other treatment groups （ P 〈 0.01 ）. In every treatment group, the RYT was higher than 1, and the alfalfa was more competitive than the orchard grass in the mixed-seeding pasture. [ Conclusion] Our studies may provide a basis for the establishment of high yield and high quality artificial mixture pasture.

Forage production and persistence characteristics of grazed native warm-season grass mixtures with or without nitrogen fertilizer

Background:Native warm-season grass(NWSG)mixtures may provide a lownitrogen(N)-input summer perennial forage option to extensively managed forage-livestock systems.Methods:Mixed pastures of big bluestem(Andropogon gerardii Vitman),little bluestem(Schizachyrium scoparium Michx.),and indiangrass(Sorghastrum nutans L.)fertilized with 0 or 67 kgNha−1 were continuously stocked with beef heifers and cows.Forage mass,nutritive value,and canopy heights were determined every 2 weeks during the grazing season.Stand persistence measures included the canopy cover and leaf area index(LAI)and plant crown density at spring emergence following 3 years of grazing management.Results:Forage mass,canopy height,and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study.Forage NWSG fertilized with N had a greater decrease in LAI during the growing season(51%decrease)than unfertilized NWSG.Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.Conclusions:Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage-livestock systems.

Combining Ability in Mixtures of Prairie Grass and Clovers

Our objective was to evaluate the combining ability among cultivars of forage species, commonly sown in temperate regions of Argentina using a short rotation system. Three genetically diverse cultivars of prairie brome grass (Bromus catharticus, cv Copetona, cv ?andú and cv Tango), a white clover cultivar (Trifolium repens, cv Lucero) and a red clover cultivar (T. pratense, cv Tropero) were evaluated. A randomized complete block design experiment was established in 2005. The treatments included five monocultures and ten binary mixtures. The experiment was harvested 6 times over an 18-month period. Cumulative dry matter yield (kg?ha–1) was calculated as the sum of the six individual harvests. Diallel analysis provided estimates of the general combining ability (GCA) and specific combining ability (SCA). Red clover in monoculture and mixtures produced the highest yields, with significant positive GCA effects (P P P P < 0.01). Given the short-term nature of this study, we must limit our inference to short-term pastures (<2 years). Under these conditions, red clover had the best combination with prairie brome grass.