北京京郊果园施用不同农肥的土壤呼吸特征研究

Soil respiration characteristics of different fertilization types in peach farms in Beijing suburb

为准确揭示北京京郊不同施肥类型果园的土壤呼吸差异,利用LI-8100开路式土壤碳通量测量系统,测定并分析平谷桃园单施化肥、有机肥和化肥混施、单施有机肥3种典型施肥类型的夏季土壤呼吸昼夜变化状况.结果显示:桃园不同施肥类型的土壤呼吸速率昼夜变化都表现为单峰曲线;有机肥施用小区的土壤日呼吸速率、日碳通量、月碳通量及生长期碳通量均最高.各样地的土壤5cm温度、近地面大气气压、湿度和CO2浓度等环境因子以及土壤有机碳含量、土壤微生物数量、土壤微生物量碳、土壤水分等土壤因子都对土壤呼吸速率具有明显的影响.对不同施肥类型土壤呼吸的分析结果表明,研究地有机肥与化肥配合施用既可以提高土壤有机碳含量,土壤全天CO2释放量也最低;化肥施用小区土壤全天CO2释放量高于有机肥和化肥混施的土壤,但其土壤有机碳、微生物数量及微生物量碳较低;有机肥施用小区的有机碳、微生物数量和微生物量碳最高,但也有着旺盛的土壤呼吸.说明有机肥和化肥混施有助于降低桃园土壤CO2的释放量.

For exploring accurately the difference of various fertilization types in peach land of Beijing, soil carbon flux diurnal variation of three typical fertilization types in peach farm of Pinggu in Beijing were measured continuously in summer with LI-8100 automated soil COz flux system. The results show that the diurnal curves of soil respiration rate under different fertilization types had a simple peak value. The soil respiration rate, soil CO2 flux during a day, soil CO2 flux during a month and soil CO2 flux during the peach growing season of organic manure plot were the highest, those of half organic manure plus half fertilizer were the lowest. Soil CO2 flux of fertilizer plot, half organic manure plus half fertilizer and organic manure during the peach growing season were 448.51, 332.35, 570.34 g CO2 ·m^-2, respectively. The relationships between soil respiration rate and environmental factors, soil factors were extremely prominent, as well as the relationship between soil respiration rate and soil organic carbon,microbial number, microbial biomass carbon and soil water content. The fertilization type of half organic manure plus half fertilizer would be helpful in reducing soil CO2 flux.