渭北苹果园土壤有机碳库变异特征

土壤碳库是陆地生态系统中最大且最活跃的碳库之一,是全球碳循环的核心内容.土壤有机碳的固定和矿化不仅对全球大气CO2浓度起着重要的调节作用1],而且影响着土壤肥力及作物产量2-3],指示着植被演替的结果和演化的趋势,倍受学术界广泛关注.

Variation of soil organic carbon pool in apple orchards in Weibei

Distribution of soil organic carbon content and density in soil profiles were studied to explore the evolution trend of soil quality in apple orchards in Weibei, the orchards were devided into three groups of <10a, 10~15a and >15 years, soil samples of 0-100cm layers were collected layer by layer . Results show that the SOC average contents were between 6.79 g/kg and 7.54 g/kg, and the highest SOC content in >15a orchards, the second in 10~15a orchards, the lowest in <10a orchards. The SOC content in more than 15a orchards were significant difference. The SOC content were decreased with soil depth, where increased in 0-10 cm and 20-40 cm soil layers with orchard age. The variation range of SOC density in 0-100cm layers were between 0.95 kg/m2 and 1.95 kg/m2, the significant differences were similar to the SOC content. The total SOC density mostly concentrated on topsoil 0-20cm ,which were all higher than 21.90%. With the orchards age increased directional difference in SOC density was not distinct in different soil profiles. Based on our experiment , the SOC content is accumulated slowly in apple orchards in Weibei, the time-space evolution of SOC stock is both depended on the organic matter and the root activities. The promotion of soil organic matter in orchards is the main task of constructing the bases of high quality fruit-producing in Weibei area.