以江西进贤红壤性水稻土长期试验为基础,运用模糊数学及统计学方法进行土壤肥力综合评价及其效应研究,以期达到土壤培肥的目的.结果表明,有机质、速效氮、速效磷、速效钾、物理性粘粒、团聚度和团聚体稳定率为研究区土壤肥力评价最小数据集,由其所得评价结果具有高度代表性和科学性.NPKM的SFI值最大且与其他处理均呈显著差异.NPKM、2NPK、NPK各处理SFI值分别高出对照(CK) 31.3％、13.0％和10.1％.SFI值的时间演变为NPKM处理先增后降,临界年限在第12年,N和CK处理缓降,其它处理缓增.一定范围内,二次曲线较直线更能揭示作物产量与SFI的关系,进一步拟合发现,SFI和作物相对产量间符合“S”型波尔兹曼生长曲线,SFI增至0.60时,相对产量增幅趋零,NPKM处理(SFI=0.688)已属于此；模拟可知,作物产量趋稳时相应施肥年限表现为NPKM (2a) ＜2NPK (8a) ＜NPK (9a) ＜NP (11a) ＜K、NK (13a)＜P(14a)处理.综上,长期平衡施肥(NPKM、2NPK和NPK)明显提高土壤综合肥力,NPKM更为显著,但其现状对作物增产已无效,应减施或不施若干年；长期偏施肥对土壤肥力贡献不力,尤其是长期单施氮反使土壤肥力下降.%Based on the data of long-term fertilization experiment in red paddy soil at Jinxian county, Jiangxi province. Integrated soil fertility was evaluated and its effects were analyzed by fuzzy mathematics and statistics methods. The results showed that organic matter, available N, available P, available K, physical clay, aggregate ratio and aggregate stability were proposed a minimum data set( MDS) for soil fertility assessment and the evaluation results produced by MDS had good representativeness and scientificalness. Among all treatments, SFI for NPKM was maximum and had a significant difference with SFI for other treatments. Compared to the control, the SFI of NPKM, 2NPK and NPK treatments was about 31. 3% , 13. 0% and 10. 1% higher respectively. As time went on, the SFI for NPKM treatment increased firstly and decreased subsequently and the critical time was 12th year after cultivated, the SFI for N and CK treatments slowly decreased and that of other treatments slowly increased over time. Within a certain range, the quadratic curve fitting could better reveal the relationship between total yield and SFI than that of the linear fitting. Further fitting found that the relationship of SFI and relative yield accorded with "S" shape Boltzmann growth model, from this a conclusion could be drawn that when SFI increased to 0. 60, the increment of relative yield was close to zero, and NPKM treatment ( SFI = 0. 688 ) had demonstrated the obvious similar effect. When relative yield closed to stable, corresponding fertilization age was the years of 2 (NPKM) , 8 (2NPK), 9(NPK), 11 (NP), 13 ( K and NK) and 14 (P), respectively. In summary, long-term balanced fertilization (NPKM, 2NPK and NPK) had improved obviously integrated soil fertility, especially NPKM treatment, but its present situation had no effect on increasing crop yield and fertilizer application should be reduced or prohibited for several years. Long-term partial fertilization could slightly increase SFI, but long-term single N application made SFI decrease.
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