Photosynthetic Diurnal Changes of Bothriochloa ischaemum Mixed Sowing with Lespedeza davurica in Loess Hilly-gully Region Study on Lotononis bainesii Mixed Sowing Respectively with Three Kinds of Perennial Forage Grasses A comprehensive evaluation of the productive performance of legume-grass mixtures under different mixed sowing patterns Grasslands Growth Characteristics of Sowing Alfalfa Mixed with Fescue Dynamics of Interspecific Competition of Legume-Grass Mixture under Different Mixed Sowing Patterns