pH和肥料对茶园土壤基础呼吸的影响

Effect of pH and Fertilizers on Basic Respiration in Tea Garden Soils

对茶园土壤添加不同用量石灰处理形成三种不同pH值的土壤,采用室内培养法,通过添加菜籽饼和硫酸铵,研究了pH及碳氮互作对茶园土壤基础呼吸速率的影响。结果表明:在培养的28天中,土壤基础呼吸速率表现出先高后低的趋势,不同pH值的茶园土壤以pH 4.05的土壤最高,显著高于其它2个土壤,pH 4.22土壤次之,pH 3.60土壤最低;添加菜籽饼可以显著增加土壤的呼吸速率,加氮对土壤基础呼吸速率的影响不明显;同时添加菜籽饼和氮肥在pH 4.22的土壤呼吸有协同增效作用,但在pH 3.60和pH 4.05的土壤不明显。试验还表明,土壤基础呼吸与土壤微生物量碳呈极显著正相关,但与土壤水溶性有机碳含量相关性不明显。

Three different pH values of tea garden soil were adjusted with adding different amounts of lime, and then rape seed cake and ammonium sulphate were applied into this soil. By using laboratory incubation method, this research determined the effect of pH and interaction of carbon and nitrogen on soil basal respiration. The results showed that during 28 days of incubation, the basal respiration rate in tea garden soils showed a downward trend or increased at first and then decreased subsequently. The basal respiration in soil with pH value of 4.05 was the highest, next in soil with pH value of 4.22, and the lowest in soil with pH value of 3.60. Soil respiration significantly increased after adding rape seed cake, but had little change after adding ammonium sulphate to soil. And it showed a synergistic effect in soil with pH value of 4.22 after adding rape seed cake together with ammonium sulphate to soil. No such results were found in soils with pH values of 4.05 and 3.60. The experiment also showed that soil respiration had significant and positive correlation with soil microbial biomass carbon, but not with soil water soluble organic carbon.