稻田植茶后土壤团聚体水稳性变化特征及影响因素分析

Research on the Water Stability and the Driving Forces of Soil Aggregate After Paddy Field Switched to Tea Garden

采用野外调查与室内分析相结合的方法,研究名山地区稻田植茶后土壤团聚体水稳性变化特征及其影响因素。结果表明:稻田及植茶后的土壤水稳性团聚体含量在各粒径及土层间表现不同,稻田、茶园5年和10年土壤水稳性团聚体含量总体上随着粒径的减小呈先降低后上升的趋势,茶园15年水稳性团聚体含量则随着粒径的减小逐渐增加。从不同土层来看,在0—20,20—40cm土层中,随着稻田植茶年限的增加,土壤团聚体含量以>2mm粒径团聚体为主转变为以<0.25mm粒径团聚体为主,而在40—60cm土层中,总体上<0.25mm粒径团聚体占据着主要地位;在0—20cm和20—40cm土层,稻田植茶后土壤团聚体水稳性逐年下降,由大到小依次为水稻田>茶园5年>茶园10年>茶园15年,而在40—60cm土层,土壤团聚体水稳性由大到小依次为茶园5年>茶园10年>水稻田>茶园15年,不同土层中团聚体的水稳性与>0.25mm粒径团聚体含量呈正相关关系。稻田及稻田植茶后的土壤团聚体水稳性受土壤的理化性质影响,其中受>0.25mm粒径团聚体含量、土壤容重、总孔隙度的影响较显著。就所测养分而言,稻田土壤团聚体的水稳性影响因素为有机质和游离氧化铁,茶园5年的影响因素为有机质和阳离子交换量(CEC),茶园10年的影响因素为有机质、CEC和有效磷含量,而茶园15年的影响因素主要是CEC含量。

Adopting field investigation and indoor analysis,the changes of soil water-stable aggregates distribution and the driving forces in the conversion of paddy field to tea garden were examined.The results showed that soil water-stable aggregate in the paddy field and tea garden was different among different size class and soil layer.With the decrease of the particle size,the water-stable aggregate firstly decreased and then increased in paddy soil and tea plantation with 5years,10 years.In the 15 years tea garden,water-stable aggregate was increased with the decrease of the particle size.With the increasing years of tea planation,water-stable aggregate was given priority to〉 2 mm turn into〈 0.25 mm both in 0—20cm and 20—40cm soil layer,while〈0.25 mm water-stable aggregate was the predominant contributor in 40—60cm soil layer.The water stability of soil aggregate decreased with the increasing years both in 0—20cm and 20—40cm soil layer,whereas the ranking from high to low in 40—60cm soil layer was：tea plantation 5year〉stea plantation 10years〉paddy field〉tea plantation 15 years.The stability water of soil aggregate was positively correlated with the content of〉0.25 mm water-stable aggregate.The water stability of soil aggregates was positively correlated with the soil chemical properties,and the main driving factors were 〉0.25 mm aggregates,soil bulk density and total porosity.In terms of nutrients,the driving forces of water stability in paddy field,tea garden 5years,10 years and 15 years were organic matter,organic matter and CEC,organic matter,CEC and effective phosphorus content,content of CEC,respectively.