不同有机无机肥配合施用对土壤活性有机质含量及pH值的影响

Effect of Combined Organic and Inorganic Fertilizer on Labile Organic Matter and Acidity of Soil

通过连续3年在大田进行的不同有机无机肥配合施用试验,研究不同有机无机肥配合比例对土壤活性有机质含量及土壤酸化状况的影响,并探讨了土壤活性有机质及总有机质与作物产量及土壤性质之间的相关性。结果表明:①适量无机肥施用增加了土壤活性有机质含量,提高了土壤碳库管理指数;有机无机肥配合施用对提高土壤活性有机碳含量的作用大于单独施用无机肥,在75%有机肥的处理中活性有机质含量和碳库管理指数最大,分别为无机肥处理的1.37和1.39倍,不施肥对照的1.68和1.84倍。②不同施肥处理土壤pH值、阳离子代换量及交换性盐基离子含量随无机肥比例的上升而显著下降,交换性A l3+含量随无机肥比例的上升而增加,交换性H+含量变化趋势则不明显;配合施用有机肥处理的pH均高于不施肥对照,各处理pH值随着无机肥施用比例的提高显著下降,降幅与无机肥比例呈极显著线性相关,R2=0.998(P<0.01)。③水稻产量仅与中活性有机质、活性有机质、碳库管理指数显著相关,相关系数分别为0.902、0.811、0.820,而与水稻土总有机质含量无显著相关;总有机质含量与各盐基离子含量、阳离子代换量、pH值都显著相关,而活性有机质含量和碳库管理指数仅与交换性K+、Na+含量及pH值相关。

Through three consecutive year fertilization experiment carried out in paddy soil in the Taihu Lake District, the labile organic matter（LOM） and acidity of soil applied with combined organic and inorganic fertilizers were detected, and the relationships between labile organic matter, total organic matter（ TOM）, rice yield and soil properties were analyzed. Appropriate amount of inorganic fertilizer increased LOM and raised carbon pool management index（CP-MI）. Combined application of organic and inorganic fertilizers had a greater effect on soil LOM increase than inorganic fertilizers did, and the maximums of CPMI and LOM which occurred in the treatment of 75% organic fertilizer plus 25% inorganic fertilizer were 1.37 and 1.39 times as much as those in the treatment of 100% inorganic fertilizer and 1.68 and 1.84 times as much as CK （no fertilization）, respectively. Soil pH value,cation exchangeable capacity（CEC） and exchangeable bases were decreased whereas exchangeable aluminum content was increased with the rising proprtion of inorganie fertilizers. Exchangeable hydrogen was not remarkably affected, pH values of soil applied with organic fertilizers were higher than that in CK,and declined linearly（P 〈 0. 05） with the rising proportion of inorganic fertilizer. Rice yield correlated significantly with mid-labile matter, LOM, and CPMI, with the correlation coefficients of 0. 902,0. 800 and 0. 820, respectively. TOM showed significant positive correlations with the CEC, exchangeable bases and pH value,however, LOM and CMPI were found only closely related to exchangeable potassium and sodium and soil pH.