Matter Production and Resources Use Efficiency of Double-Cropping Silage Maize System Research Progress of Natural Resource Utilization in Agroforestry System in China Effects of severity of water stress on gas exchange characteristics of Caragana intermedia seedlings Effects of Different Water Stresses on Eco-physiological Characteristics of Hippophae rhamnoides Seedlings Response of Nitrogen Use Efficiency to Plant Density and Nitrogen Application Rate for Maize Hybrids from Different Eras in Heilongjiang Province Comparison of Yield and Light-temperature Resource Use Efficiency between Wheat-Maize and Maize-Maize Cropping Systems Physiological and growth responses of Sabina vulgaris to disturbance of leaf removal Comparison of Yield and Resource Utilization Efficiency among Different Maize and Rice Cropping Systems in Middle Reaches of Yangtze River Responses of Plant Productivity and Nitrogen Use Efficiency to Nitrogen Fertilization Rate among Rice Varieties Released from Different Years in Liaoning Province