香蕉种植方式和环境因子对土壤热导率的影响

Effects of banana cultivation patterns and environmental factors on soil thermal conductivity

【目的】探究香蕉种植方式和环境因子对土壤热导率的影响,为广西调整香蕉合理种植模式及有效利用喀斯特地区土壤水热资源提供参考依据。【方法】以广西地区水田起畦(DT处理)与旱地开沟(ST处理)种植的香蕉为研究对象,利用田间定位监测系统对研究区域环境因子及5、20和40 cm深度土层的土壤含水量进行连续观测,计算土壤热导率,并结合土壤的基本理化性质,分析2种种植方式下土壤热导率的变化规律。【结果】DT处理的土壤砂粒和黏粒含量均高于ST处理,且在20和40 cm土层处差异显著(P<0.05,下同);土壤容重显著高于ST处理。随着土壤深度的增加,DT处理土壤的有机质含量分别比ST处理增加56.0%、35.8%和48.0%。在各土层中,DT处理的土壤热导率平均值均显著大于ST处理,其中DT处理20 cm土层的土壤热导率平均值高于ST处理26.2%。降雨和环境温度是影响土壤热导率的主要因素,其中,环境温度与2种种植方式下5和20 cm土层的土壤热导率呈负相关;降水量与2种种植方式下5和20 cm土层的土壤热导率呈显著或极显著(P<0.01,下同)正相关;在40 cm土层,降水量仅与DT处理的土壤热导率呈极显著正相关。除雨型Ⅰ外,DT处理的土壤热导率平均值均大于ST处理;雨型Ⅳ和Ⅵ发生时,DT处理在各土层对降雨的响应程度均大于ST处理。【结论】降雨和环境温度因子改变对广西地区种植香蕉的土壤热导率动态变化具有重要影响。降雨发生时,水田起畦种植香蕉方式对土壤热导率的提高效果更佳,更有利于广西地区调整香蕉合理种植模式和高效利用喀斯特地区水热资源。

【Objective】The effects of banana cultivation patterns and environmental factors on soil thermal conductivity were discussed to provide a theoretical basis for scientific and rational planting of bananas in Guangxi and the effective utilization of soil water and heat resources in karst area.【Method】Two treatments including converting paddy fields to dry land through paddy field furrowing(DT treatment)and dry land trenching(ST treatment)were set up to measure soil moisture at 5,20 and 40 cm depth using a field positioning monitoring system,which were calculated soil thermal conductivity.The above data combined with measured basic physical and chemical properties,and continuously observed the environmental factors in this area were used to analyze the variation law of soil thermal conductivity under the two planting methods.【Result】The content of sand and clay in DT treatment was higher than that in ST treatment,which only showed the significant difference at the 20 and 40 cm soil layers(P0.05,the same as below).The soil bulk density of DT treatment was significantly greater than that of ST treatment.The organic matter content of DT treatment under different depth soil layers was higher than that of ST treatment,which increased by 56.0%,35.8%and 48.0%through the soil profile,respectively.The average soil thermal conductivity of DT treatment in each soil layer was significantly greater than that of ST treatment,especially for the 20 cm soil layer,in which the average soil thermal conductivity of DT treatment was 26.2%higher than that of ST treatment.Rainfall and ambient temperature were the main factors that affected soil thermal conductivity in this experimental area,of which the ambient temperature was negatively correlated with soil thermal conductivity at 5 and 20 cm soil layers under two planting methods.Precipitation had a significant or extremely significant positive correlation(P0.01,the same as below)with soil thermal conductivity at 5 and 20 cm soil layers under the two planting methods.At 40 cm soil layer,precipitation had only a extremely significant positive correlation with soil thermal conductivity under DT treatment.Except for rain typeⅠ,the soil thermal conductivity of DT treatment was higher than that of ST treatment.When rain patternsⅣandⅥoccurred,the response degree of DT treatment to rainfall in all soil layers was greater than that of ST treatment.【Conclusion】The occurrence of rainfall and the change of ambient temperature have a great influence on the dynamic change of banana soil thermal conductivity in Guangxi.When rainfall occurs,paddy field furrow planting method has better effect on improving soil thermal conductivity.Planting bananas in paddy field was more conducive to the adjustment of rational banana planting pattern in Guangxi and the efficient utilization of water and heat resources in karst area.