不同施肥结构下稻田产量及土壤有机质和氮素营养的变化

通过野外调查采样和室内测定．研究了湖南省土肥站1986年冬季在全省各地建立的、持续了18年的6个土壤肥力与施肥效益，监测长期定位试验点中不同施肥处理对稻田土壤有机质、氮素肥力及水稻产量的影响。结果表明：与不施肥处理相比．长期有机肥与无机肥配施能全面提高土壤全氮、碱解氮和有机质的含量；NP、NK、NPK各化肥处理的全氮、碱解氮和有机质含量处于同一水平，施用有机肥是增加土壤有机质古量的最有效途径，有机质与全氮含量具有极显著的正相关性（r=0．959＊＊）。各施肥区的产量比CK处理显著增加，OM60和OM30处理平均比CK处理增产106．2％和108．5％，且两处理间差异不明显。宁乡、临澧两试验点习惯施肥处理的平均产量分别比NPK处理还低1．5％和3．5％，说明当地农民的施肥配比有待改进。

Effect of Different Fertilizer Application Systems on Soil Fertility Quality and Rice Yield

Base on 18 years' fertilizer experiments,the study analyses the characters of the N nutrient and organic matter in paddy soil and rice yield after application of different fertilizers.The results show that: comparing with treatment no fertilizer,applying organic manure combined with chemical fertilizers can increase the quantity of organic matter,available and total N,and it is the most remarkable in the several treatments,and the content was keep at an identical horizontal in all the chemical fertilizer treatments.The contents of soil organic matter was correlated with the contents of soil total nitrogen(r1=0.959**).Applying either the chemical fertilizer or the organic fertilizer could lead to the remarkable increase of rice yield.There were 106.2% and 108.5% increase of yield in the treatments OM30 and OM60 compared to CK treatment.and there was no difference in the two treatments.The rice yield of treatment CD in Ningxiang and Linli were 1.5% and 3.5% lower than that of NPK treatment,it was showed that the farmers at the two regions should improve the proportion of the applying fertilizer.