Effects of Low Lignin Alfalfa and Alfalfa-Grass Mixtures on Yield and Nutritive Values.

Alfalfa is an important forage legume grown in our region and is usually more productive than grasses, and may be more productive in mixtures with grasses. A pasture of mixed low lignin alfalfa, smooth brome grass and tall fescue has a big advantage, since this combination can limit the problem of bloating and short grazing seasons that come with alfalfa, and causes better animal performance than a pasture of pure smooth brome or tall fescue. However, the data available on the nutritional value of legume grass mixtures is lacking, so research is needed on alfalfa-grass mixtures. The objective of this study is to identify the best performing low lignin alfalfa-grass mixtures as compared to mono-culture of low lignin alfalfa, roundup ready and conventional alfalfa varieties. An additional objective is to determine the unfertilized and fertilized forage species in legume grass mixtures for dry matter yield and forage quality. Three different alfalfa varieties were planted (low lignin alfalfa, roundup ready and conventional alfalfa varieties), and two grasses (Smooth Brome and Tall Fescue) as a pure crop and in the grass mixture. Urea was applied at a rate of 56 kg ha^-1 after planting 2015 and at the green up and after second cutting in 2016. The experimental design was split plot in RCBD with four replications. Each plot size was 1x6 m, for a total of 112 plots. Forage samples were collected to determine forage quality by Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), Crude Protein (CP), and Relative Feed Value (RFV) of low lignin alfalfa, roundup ready, conventional alfalfa and legume mixtures. Results indicated that dry matter yield in mono-culture reduced-lignin alfalfa and reduced-lignin alfalfa with a combination of smooth bromegrass and tall fescue mixture was significantly higher than alfalfa and smooth bromegrass mixtures. Also, reduced-lignin alfalfa had significantly higher nutritive values than conventional alfalfa and roundup ready alfalfa varieties. There was no statistical difference in fertilizer treatment in either year.