藏东南大型国营农场———米林农场土壤养分含量明显下降 ,有机质、碱解氮、有效磷、有效钾分别较 1992年降低49 4% ;49.3 % ;47.8% ;72 .5 %。下降的主要原因是施肥水平低 ,化肥利用率不高 ,种植结构单一。因此 ,大量施用有机肥 ,合理施用化肥 ,调整种植结构 ,扩种绿肥是培肥该农场土壤的主要措施 The soil nutrient content of the large-scale state-owned farms in southeastern Tibet - Milin farms decreased significantly. The contents of organic matter, available nitrogen, available phosphorus and available potassium decreased by 49.4%, 49.3%, 47.8% and 72.5% respectively as compared with those in 1992. The main reason for the decline is the low fertilization level and the low utilization of chemical fertilizers, with a single planting structure. Therefore, the large-scale application of organic fertilizers, rational use of fertilizers, adjustment of planting structure and expansion of green manures are the main measures to fertilize the farm soil