Comprehensive evaluation of nutrition of grasslands under different mixed sowing patterns

A variety of nutrition indices including crude protein (CP), crude fat (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF), calcium (Ca), phosphorus (P), crude ash and grasslands yield of 15 different mixture modes were analyzed. The grey relational degree method was applied to comprehensively evaluate nutrition. The variation of the contents of CP, CF, ADF, NDF, Ca, P and crude ash was 15%~18%, 1.5%~1.8%, 25%~30%, 30%~50%, 0.4%~1.8%, 0.1%~0.3% and nearly 10%, respectively. Three mixture modes including Leymus chinensis+Setaria italic+Medicago varia (3∶1∶1), Bromus inermis+M.varia(2∶1) and Elymus nutans+M.varia (3∶2) were the best among all of the mixture modes. Two mixture modes including perennial grasses+M.varia (1∶1) and perennial grasses+Avena sativa+M.varia (3∶1∶1) were not suitable. The other 10 mixture modes were better. These results were consistent with mixture mode applied in some regions in Hulunbeir which had the important theoretical value to the entire region.