Effects of Alfalfa and Alfalfa-Grass Mixtures on Dry Matter Yield and Nutritive Values.

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Alfalfa (Medicago sativa L.) is an important forage legume grown in Kansas since it is more productive than grasses. However, the data available on the nutritional value of legume-grass mixtures in Kansas as well as rest of Midwest regions in the US is lacking.  Thus, research is needed on mixtures such as alfalfa with smooth brome, alfalfa with tall fescue, and alfalfa with smooth brome and tall fescue.

The objective of this study was to determine the unfertilized and fertilized forage species in alfalfa, smooth bromegrass, tall fescue, and alfalfa-grass mixture for forage yield and nutritive values. An additional objective was to incorporate the traditional methods and remote sensing techniques to identify and evaluate the forage productivity. This study was conducted at Ashland Bottoms, Kansas in a clay loam soil. Soil analysis showed organic matter content of 1.9%, pH of 6.9, P₂O₅ of 54 ppm, K₂O of 285 ppm, and NO₃ of 14 ppm. Three different alfalfa varieties (reduced-lignin alfalfa Hi-GEST 360, RR Tonnica roundup ready, Gunner alfalfa varieties) and two grasses (Smooth Bromegrass and Brarolex endophyte-free Tall Fescue) were planted as a pure crop and mixtures, respectively. Urea was applied at a rate of 56 kg/ha^-1 following planting in 2015, and at green up and after second cutting in 2016. Forage samples were collected to determine dry matter yield and nutritive values such as acid detergent fiber (ADF), neutral detergent fiber (NDF), nitrogen content, crude protein (CP), in-vitro dry matter digestibility (IVDMD), and relative feed volume (RFV) of reduced lignin alfalfa, roundup ready alfalfa, conventional alfalfa, grasses, and alfalfa-grass mixtures.