Abstract:

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.

Key words: Rice, Nitrogen Reduction Fertilization, Soil, Soil Nutrient Content, Soil Microorganisms