茶园土壤酸化过程的碳氮循环耦合机制研究

茶树是多年生植物，随着植茶时间的延长，土壤酸度会不断提高。近年来所采用的多种措施都没能明显延缓茶园土壤酸化的进程，其关键在于对茶园土壤酸化的内部机制不明。本研究在前期工作基础上，将茶树、土壤及微生物作为一个系统，以茶苗为供试作物，应用盆栽试验结合同位素（14C和15N标记）示踪技术研究碳氮在茶树-土壤-微生物系统中的分配，量化茶树生长期间碳氮循环对土壤各组分及酸化的贡献；应用色谱分析技术研究碳氮在土壤中的化学组分和结构特征，阐明其在土壤中的化学转化机理；采用模拟培养试验，探讨种植收获后碳氮在土壤中的残留形态及氮在土壤中的硝化和矿化动态，以揭示茶树生长输入的"新氮"在土壤中的分解规律及根际的碳源对土壤酸化的贡献。从不同角度揭示碳氮循环在茶树-土壤-微生物系统内的分配转化及其耦合机制，进一步探明茶园土壤碳氮循环的过程和特征，完善茶园土壤酸化机理，为土壤酸化的有效调控提供理论依据。

Tea (Camellia sinensis(L.) Kuntze)is an unusual and perennial plant because the soil becomes strongly acidified following the planting of tea, and soil pH generally continues to decrease with the increase of stand age. In recent years many measures can not obviously delay the process of garden soil acidification. The key to internal mechanism of soil acidification in tea garden is unknown.This study based on the previous work, as tea tree seedlings for the experimental crops, is to make tea tree, soil and microbial as a system, with the application of the pot experiment isotopes (14C and 15N labeling) tracer technology, the distribution of carbon and nitrogen in the system of the tea tree-soil- microorganism will be researched. And it will quantify the effect of components of soil acidification of growth of tea tree with carbon and nitrogen cycles. Application chromatographic analysis technique to research the chemical composition and structure characteristics of carbon and nitrogen in the soil,is of clarifing chemical transformation mechanism in the soil.Using simulated training experiments, this study discusses the residue form of carbon and nitration and mineralization dynamic of nitrogen in the soil after harvest,in order to reveal the decomposition rules of input "new nitrogen" and contribution of soil acidification of carbon sources on the rhizosphere with tea tree growth. From different angle,the study will reveal distribution transformation and coupling mechanism of carbon and nitrogen cycles in the system of tea tree-soil microorganism, further prove the process and characteristics of carbon and nitrogen in tea garden soil and improve the acidification mechanism of tea garden soil.And the study will provide the effective theory basis to control the soil acidification .