Ammonia volatilization and control mechanisms in the piedmont of North China Plain Comprehensive evaluation of eco-economic benefits of multi-crop rotation in paddy field systems Reduction of nitrogen fertilizer application under different crop rotation systems in paddy fields of Taihu Area Effect of continuous cropping on Angelica sinensis diurnal photosynthetic dynamics Nitrogen balance in paddy fields under different rotation systems in the Taihu Lake Region Crop yield and soil biochemical properties under different nitrogenfertilization and irrigation management schemes