Effects of different nitrogen additions on the yield, quality and nutrient absorption of forage maize Effects of nitrogen on agronomic traits and dry matter yield and their relationship in sweet sorghum Effect of Different Zn2+ Activities on the Growth and Some Physiological Characteristics of Leaf and Root among Rice Genotypes Yield characteristics and genetic diversity of main alfalfa varieties in China Evaluation the Potential of Sweet Sorghum Grown for Silage Crop Effects of Nitrogen Application on the Forage Dry Matter Yield and Quality of Alfalfa with Seasonal Cultivation Effect of cutting time on the biomass production and forage quality of Lolium multiflorum