不同培肥方式对西藏中部退化土壤的影响

对西藏中部土壤复退过程中土壤物理、化学 (养分 )、生物变化及其效应进行了探讨 ,初步结果表明 ,在西藏高原生态条件下 ,有机肥 ,特别是有机—无机肥配合施用在短期内对降低土壤容重 ,提高土壤孔度 ,增加 1～ 3 mm水稳性团聚体数量 ,提高土壤养分和有机质含量 ,促进土壤生物繁殖具有显著作用 ,并呈随有机肥投入量递增而显著增加的趋势 ,化肥 (包括化肥平衡施用 )的综合效应则相对较低。大幅度提高土壤有机质含量及供钾水平是退化土壤肥力恢复过程中面临的重要问题。不同培肥方式的土壤微生物数量构成中细菌均占绝对优势 ,对作物营养具较大贡献 ;化肥、有机—无机肥配合施用不利于土壤真菌、放线菌数量的提高

Effect of Different Methods of Application on Degenerated Soil in Middle Part of Tibet

Effects of different methods of application on physical, chemical (soil nutrient) and biological property of degenerated soil were studied in middle part of Tibet. Preliminary results showed that there was marked effect of apply organic manure, especially the organo mineral fertilizer could reduce the bulk density, and improve the porosity, 1~3mm waterstable aggregate, soil nutrient contents, organic matter contents, amount of earthworm under the ecological conditions of the Tibet plateau in a short time, and these increased significantly by the increase of the amount of organic manure. But comprehensive effect of chemical fertilizer (consist of balance manuring) was lower relatively. The organic matter and available potassium increased by a big margin will were vital question in the course of the fertility restoration of degenerated soil. The amount of bacterium account for overwhelming majority of the soil microbes under the different methods of application, and it made a greater contribution to crop nutrition. Soil fungus and actinomyces was relatively less under the applied inorganic fertilizer and organo mineral fertilizer.