林地转变为茶园对土壤理化性质的影响

Effect of Converting Forestland to Tea Plantation on Physiochemical Properties of Soil

为揭示林地转变为茶园过程中土壤理化性质的变化规律,在福建省周宁县和政和县两地选择不同植茶年限的茶园,分层采集0～20cm和20～40cm的混合土壤样品。结果表明:林地转变为茶园土壤过程中,土壤理化性质发生明显的变化。林地转变为茶园后,土壤pH值明显降低,土壤酸化严重;与林地土壤相比,茶园土壤田间持水量、含水率、土壤总孔隙度、毛管孔隙度、土壤有机质及速效钾均明显降低,随着植茶年限增加均有所恢复;与林地土壤相比,新垦3年茶园土壤碱解氮和有效铁含量均显著降低,而植茶30年茶园土壤却显著增加;与林地土壤相比,茶园土壤有效磷含量均显著增加,且随着植茶年限增长而增加。三因素方差分析表明,样点、土层深度和样地类型均对土壤理化性质产生明显影响,其中样地类型的影响明显大于样点和土层深度。从土壤理化性质的演变趋势来看,茶园的施肥管理中应适当增加有机肥用量,从而提高土壤肥力和pH值,起到缓解土壤酸化并改善土壤孔隙结构的作用。

Physiochemical properties of the soil in response to the changed land use from forestry to tea plantation were studied in Zhouning and Zhenghe counties,Fujian,China.Samples of soil from 0-20 and 20-40cm depths at the plantations with varied utilization histories were collected for the study.The soil properties were found to vary significantly due to the conversion.The pH decreased significantly and seriously acidified the soil.The water-retention capacity,moisture content,total and capillary porosities,organic matters,and available potassium in the soil decreased significantly as well.However,these conditions improved with time.For instance,in 3 years after the conversion the alkali-hydrolyzable nitrogen and available iron decreased in the soil,but those at a 30-year-old tea plantation recovered and significantly increased.Similarly,the available phosphorus also increased continuously as the years gone by.The analysis of variance indicated that the location,depth and type of soil affected the physiochemical properties significantly,particularly the soil type.The observations suggested that tea farmers of a newly established plantation should increase the utilization of organic fertilizers to help enhance the soil fertility and structure while maintain an appropriate pH.