选用多年种植茶园与相邻自然土之间进行物理、化学、微生物特性比较研究。结果表明,随着茶园种植年限的延长,土壤容重、孔隙、水稳性团聚体、水分性能、三相比等物理指标得到明显而持续的改善;同时,土壤持续酸化,CEC增加,pH下降,交换性酸量增大。持续种茶土壤的基础养分较自然土有大幅度增加,有效钾有所减少;钙、镁有效量随种植年限的延长呈持续减少趋势。土壤微量元素Mn、Zn、Cu和重金属元素Cd、Pb、As、Hg、Cr全量未出现积累或减少,但Mn有效性增幅较大,Cu、Zn有效性也有显著增加,Hg有效性则显著下降。茶园土壤中3大类群微生物数量较自然土大幅增多。

The investigation on two tea garden soils (continue planting tea for 30 and 50 years, respectively) and their neighboring natural soil in Yongchuan Experimental Tea Garden were conducted to characterize the effects of continue planting on physical, chemical and microbial changes of the soil properties. Results showed that the physical properties of tea garden soils, including bulk density, porosity, water-stable aggregate, water capacity, moisture and three-phase fraction, improved markedly and continuously along with planting ages of the tea garden. Besides, the cation exchangeable capacities (CEC) enlarged and soil acidification strengthened progressively (soil pH declined, exchangeable acidity increased). Investigation showed that the soil organic matter, available NPK and total NP increased in large scale after 30 years planting. However they had no more increase when planting time lengthened from 30 years to 50 years. Available Ca and Mg decreased steadily with planting years and available K also decreased slightly in the old tea garden soil. Total Mn, Zn, Cu, Cd, Pb, As, Hg, Cr showed no accumulation or reduction in soil after 50 years planting, while available Mn, Cu, Zn increased and available Hg decreased significantly. The amount of bacteria, fungi and actinomyces rised significantly in planting soil of 30 years, but no further rised in planting soil of 50 years.