不同减氮施肥模式对水稻土壤养分及可培养微生物数量的影响

为了研究不同减氮施肥对水稻土壤养分及可培养微生物数量的影响,设置4个处理,对不同处理土壤养分和可培养微生物数量进行分析,比较不同施肥处理对土壤养分及可培养微生物数量的影响。结果表明：与不施肥(CK)相比,施肥处理土壤有机质、全氮、全磷、碱解氮、有效磷、速效钾含量都有显著性提高。20%氮肥减施(T2)后有机质、pH、全钾、有效磷、速效钾含量都有所上升,30%氮肥+50%有机氮(T3)施肥土壤中全氮、全磷、碱解氮、有效磷、速效钾含量都显著性升高,各处理间土壤全钾含量无显著性差异。在水稻苗期,30%氮肥+50%有机氮(T3)施肥土壤中可培养细菌、真菌、放线菌,芽孢杆菌数量明显提升。在水稻分蘖期,100%氮肥施肥(T1)土壤可培养真菌数量显著性升高。在水稻成熟期,各处理间差异不明显,水稻生长期间可培养木霉菌数量差异都不显著。说明在稻菜轮作土壤中实施合理减氮施肥是减少养分累积、保持土壤养分稳定的重要措施。

Effects of Different Nitrogen Reduction Fertilization Models on Rice Soil Nutrients and the Number of Cultivable Microorganism

To study the effects of different nitrogen reduction fertilization models on rice soil nutrients and cultivable microorganism quantity, four treatments were set up to analyze soil nutrients and cultivable microorganism quantity and compare the effects of different fertilization models. The results showed that compared with CK, the contents of soil organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, available phosphorus and available potassium were significantly increased. The content of organic matter, pH, total potassium, available phosphorus and available potassium all increased after 20% nitrogen fertilizer reduction (T2). 30% nitrogen fertilizer + 50% organic nitrogen (T3) fertilization could significantly increase the content of total nitrogen, total phosphorus, alkali hydrolyzable nitrogen, available phosphorus and available potassium in soil, but there was no significant difference among the treatments. In the rice seedling stage, the number of cultivable bacteria, fungi, actinomycetes and bacillus in the soil fertilized with 30% nitrogen + 50% organic nitrogen (T3) significantly increased. During the tillering stage of rice, the number of fungi that could be cultivated in soil increased significantly under 100% nitrogen fertilizer treatment (T1). In the rice maturity period, the difference between the treatments was not obvious. There was no significant difference in the number of cultivable Trichoderma during rice growth. Therefore, it is an important measure to reduce the accumulation of soil nutrients and maintain their stable content by implementing reasonable nitrogen reduction fertilization in rice vegetable rotation soil.