长期不同施肥对茶园土壤碳氮磷构成的影响

Effects of Long-term Different Fertilization on Carbon, Nitrogen and Phosphorus Pools in Tea Garden Soils

从浙西茶区采集了34个茶园表层土壤,按施肥模式分为施用有机肥+化肥、单施化肥和不施肥等3组茶园,用化学分析方法研究了长期不同施肥下茶园土壤碳、氮、磷库的变化特点。结果表明,3组施肥模式之间的茶园土壤p H和有机碳含量差异不明显;单施化肥或有机肥+化肥的茶园土壤全磷、全氮和有效磷含量明显高于不施肥茶园;全磷与全碳的比例(P/C)和全氮与全碳的比例(N/C):化肥>有机肥+化肥>不施肥;施用有机肥+化肥土壤的有机质结合态磷比例明显高于单施化肥和不施肥土壤,单施化肥土壤的钙结合态磷的比例明显高于施有机肥+化肥和不施肥土壤,不施肥土壤的闭蓄态磷的比例高于施有机肥+化肥和单施化肥土壤;单施化肥土壤具有较高的NO3--N/NH4+-N比和无机氮含量;施用有机肥+化肥土壤有较高比例的颗粒态有机碳、活性有机碳和微生物生物量碳。基于19项分析指标应用主成分分析方法对研究的34个土壤进行聚类的结果也表明,土壤之间碳、氮、磷库组成的差异主要与施肥模式有关。施用有机肥+化肥的茶园土壤养分较为协调。

Thirty-four soil samples we re collected from 34 individual tea gardens in the western part of Zhejiang Province, and divided into three tea garden groups with different fertilization types, including combined application of chemical and organic fertilizers, application of chemical fertilizers, and no fertilizer. The soil samples were characterized by means of chemical analysis to explore the effects of long-term different fertilization on carbon,nitrogen and phosphorus pools in tea garden soils. The results showed that there were no significant differences in soil p H and content of organic carbon among three tea garden groups. The tea garden soils with application of chemical fertilizers or combined application of chemical and organic fertilizers had higher concentrations of total P, total N, and available P than those without application of fertilizers. The ratios of P/C and N/C of the soils decreased in the sequence of application of chemical fertilizers > combined application of chemical and organic fertilizers > no fertilizers. The proportion of organic P in total P in the soils with combined application of chemical and organic fertilizers was significantly higher than those of soils with application chemical fertilizers, and no fertilizers. The proportion of Ca-P in inorganic P in the soils with application chemical fertilizers was significantly higher than those of soils with combined application of chemical and organic fertilizers, and no fertilizers. However, the proportion of occluded P in inorganic P in the soils with no fertilizers was significantly higher than those of soils with combined application of chemical and organic fertilizers, and application chemical fertilizers. The soils with application of chemical fertilizers had higher NO3--N/NH4+-N and available inorganic N. Combined application of chemical and organic fertilizers could increase concentrations of particulate organic carbon, active organic carbon and microbial carbon in the soils. Principal component analysis showed that different fertilization modes had resulted into differentiation of carbon, nitrogen, and phosphorus pools in tea garden soils. The clustering results of 34 soil samples by principal component analysis based on 19 indices of C, N, P in soils showed that the differences in compositions of carbon, nitrogen, phosphorus among the soils were mainly related with fertilization types. The soils with combined application of chemical and inorganic fertilizers had optimum carbon, nitrogen and phosphorus.