长期不同施肥对稻田土壤有机质和全氮的影响

Effects of Long-Term Fertilization on Soil Organic Matter and Total Nitrogen in Paddy Soil

通过对湖南新化、宁乡、株洲、桃江、武岗5个国家级稻田肥力长期定位试验点18年的田间定位试验,研究了不同施肥方式下0-20 cm土层土壤有机质和全N含量的演变规律。结果显示,中量和高量有机肥与化肥配合处理在提高土壤有机质和全N含量方面效果明显优于单施化肥和秸秆还田处理,且随有机肥用量的增加而增加,表明有机肥与化肥配合施用是提高土壤有机质和N素肥力的重要措施。在不同施肥方式下,稻田土壤有机质总体上呈现出上升或者下降的趋势,但在不同的年份会有波动。

Changes in soil organic matter and total nitrogen in the 0 - 20 cm soil layer of paddy fields under different fertilization treatments were monitored and studied at 5 long-term field experiment sites （1986-2003）. Results indicated that the treatments of chemical fertilizer plus medium- or high- rate of organic manure showed much better effect in increasing soil organic matter and total nitrogen in the soil than the treatments of chemical fertilizer or incorporation of straws into the soil did, and the effect rose with the rate of organic manure applied, suggesting the combined application of manure and chemical fertilizer is the most effective measure to increase soil organic matter and total nitrogen. Soil organic matter content in paddy soils different in fertilization pattern tends to increase or decrease and fluctuates from year to year.