Short-term rotation systems of winter forage mixtures with rice in low mountainous and hilly areas of subtropical zone of China

The experiments were carried out in Lushan county of Sichuan province during the period of 1991 to 1994.The results showed that the three kinds of rotation systems of mixtures of grasses and legumes with rice:Lolium multiflorum+Astragalus sinicus→rice,Loilum multiflorum+Medicago hispida→rice and Lolium multiflorum+Trifolium repens→rice,produced higher forage values and higher rice yield than the controlled plots.The utilization efficiency of cropland niche in those three rotation systems was increased through the improvement of soil structure and nutrition condition and the full utilization of symbiosis and mutual supplemental effects of winter grasses and lugumes.Thus the field gross productivity in the rotation systems were increased.