长期施用含硫含氯化肥稻田土壤化学性质的演变特征

Evolution of the Soil Chemical Properties in Paddy Field Under Long-term Application of Sulfur-Containing and Chloride-Containing Fertilizers

【目的】探讨长期施用含硫和含氯化肥土壤化学性质的演变,为稻田土壤的合理施肥及持续利用提供理论依据。【方法】对持续33年施用含硫和含氯化肥的定位试验历年土壤样品化学性质进行系统测定,统计分析其变化特征。【结果】长期施用SO42-、Cl-+SO42-和Cl-肥料的土壤pH均表现下降趋势,施用SO42-肥料的土壤pH随年份极显著下降,年均下降0.028个pH单位。各处理(SO42-、Cl-+SO42-和Cl-处理)土壤有机质、全氮、全磷及Olsen-P含量都有增加趋势,SO42-、Cl-+SO42-和Cl-处理土壤有机质年均增加分别为0.31、0.17、0.15 g.kg-1,全氮年均增加分别为10.6、3.0、11.2 mg.kg-1,全磷年均增加分别为22.9、21.0、4.8 mg.kg-1,Olsen-P年均增加分别为1.42、1.14、0.58 mg.kg-1。各处理土壤全钾和交换性钾含量基本保持平衡,无明显增加或下降趋势。【结论】长期施用含硫化肥有利于土壤有机质和全磷积累,以及土壤有效磷活化。因此在南方红壤丘陵地区,应重视含硫肥料的施用并注意防止其酸化。

【 Objective 】 Evolution of the soil chemical properties in paddy field under long-term application of sulfur-containing and chloride-containing fertilizers was investigated.Its purpose was to provide a theoretical basis for fertilization and sustainable use of soil.【Method】 Historical soil samples from 33 years long-term field experiment were analyzed.【Result】 The results showed that the soil pH all decreased with years in all treatments of SO42-,Cl-＋SO42-and Cl-.The annual decreasing rate of the soil pH reached 0.028 under the treatment of SO42-and that decreased with years significantly.The contents of soil organic matter,total nitrogen,total phosphorus and Olsen-P all increased with years.The annual increasing rates were 0.31,0.17 and 0.15 g.kg-1 for soil organic matter,10.6,3.0 and 11.2 mg.kg-1 for total nitrogen,22.9,21.0 and 4.8 mg.kg-1 for total phosphorus,and 1.42,1.14 and 0.58 mg.kg-1 for Olsen-P in the treatments of SO42-,Cl-＋SO42-and Cl-,respectively.Total potassium and exchangeable potassium content in the soil were kept balance under different treatments.【Conclusion】 A clear advantage in accumulation of the soil organic matter and total phosphorus,and in activation of the soil Olsen-P was observed under long-term application of sulfur-containing fertilizers.Therefore,sulfur-containing fertilizers should be paid more attention to prevent soil acidification in the hilly area of southern China.