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分析了“世行贷款国家造林项目”(简称NAP)区内人工林地力衰退的现状和原因 ,阐明了NAP防止地力衰退采取的对策 ,并根据土壤肥力监测结果分析了NAP实施过程中土壤肥力的变化情况 ,提出了防止土壤肥力退化的措施。结果表明 :项目实施 5a来 ,营造了 1 38 5× 1 0 4 hm2 的集约经营人工林 ,由于严格执行了“环保规程” ,有效地防止了土壤肥力的退化 ,土壤肥力不仅没有下降 ,而且略呈增加的趋势。项目区内热带片和亚热带片的速效氮和有机质略有下降外 ,土壤中的全氮、速效磷、速效钾、缓效钾等 7种养分呈上升趋势。项目区华北 -中原、辽东低丘岗地片 ,土壤中的各种养分含量逐渐增加 ,其中速效磷、速效钾和代换钙镁增加的速度最快
This paper analyzes the current status and causes of the decline of plantation productivity in the state of World Bank Loan Afforestation Project (NAP), clarifies the countermeasures adopted by NAP to prevent the decline of soil fertility, and analyzes the soil fertility during NAP implementation based on the monitoring results of soil fertility Changes, put forward to prevent degradation of soil fertility measures. The results showed that the intensive management plantation of 1 38 5 × 104 hm2 was constructed during the project implementation period. Due to strict implementation of “environmental protection regulations”, soil fertility was effectively prevented from deteriorating. Soil fertility not only did not decrease but also slightly Showing an increasing trend. In the project area, the available nitrogen and organic matter in the tropical and subtropical slices slightly decreased. The contents of total nitrogen, available phosphorus, available potassium and slow-acting potassium in the soil showed an upward trend. In the project area, the contents of various nutrients in soil of North China-Central Plains and Liaodong-Shaddock increased gradually, of which the contents of available phosphorus, available potassium and substituted calcium-calcium increased most rapidly