长期定位施肥小麦-玉米轮作制度下土壤有机质质量演变规律

通过8年长期定位试验,研究了不同施肥方式下褐土有机质质量演变规律.结果表明,长期不施肥或施用常量NPK化肥,使土壤易氧化有机质含量明显下降,氧化稳定系数(Kos)升高,土壤腐殖质组成及其性质均有所恶化,土壤供肥能力降低;连续施用增量NPK化肥,可使土壤有机质数量及质量保持稳定,但投入成本较高;长期施用有机肥(物)料配施常量NPK化肥,可明显提高土壤易氧化有机质含量和有机质总量,降低其Kos值,提高土壤可浸提腐殖酸含量及HA/FA比值,使胡敏酸得到活化和更新,土壤有机质质量提高,土壤对养分的供、贮能力增强,肥力提高.

THE EVOLVEMENT RULE OF SOIL'S ORGANIC MATTERQUALITY UNDER THE CONDITION OF LONG-TERM AND ORIENTED FERTILIZATION OF WHEAT-CORN ROTATION SYSTEM

An eight-year long-term experiment was conducted to investigate the impact of fertilizer application with different methods on the evolvement rule of soil's organic matter quality. The results showed that content of oxidizable organic matter decreased if there was no fertilization or constant NPK chemical fertilizer for a long-term, Kos increased, the composition and characteristics of humus in cinnamon soil worsened and the soil fertility declined. Continuously applying NPK chemical fertilizer could stabilize the quantity and quality of soil organic matter, but the invested capital was high. Long-term organic manure application with constant NPK fertilizer could increase significantly the content of oxidizable organic matter and total organic matter of soil, decrease Kos value, raise the content of extractive humus acid of soil and the rate of HA/FA, activate and renew HA, improve the quality of organic matter, strengthen the ability of reserves and supply of soil nutrient and improve soil fertilizing ability.