Abstract: Taking a 2-year old tea garden in Qingdao of Shandong Province as test object, this paper studied the effects of different mulching modes on the soil water and nutrient dynamics and tea plant growth. Four treatments were installed, i.e., no mulching (CK), straw mulching (T₁), plastic film mulching (T₂), and straw plus plastic film mulching (T₃). Comparing with CK, mulching could keep the soil water content at a higher level, and enhance the water use efficiency. In treatments T₁ and T₃, the tea growth water use efficiency and yield water use efficiency increased by 43%-48% and 7%-13%, respectively, compared with CK. Also in treatments T₁ and T₃,the contents of soil organic matter, available-N, nitrate-N, and ammonium-N increased significantly, with the soil fertility improved, and the leaf nitrate-N content and nitrate reductase activity increased, which promoted the tea growth and yield (12%-13% higher than CK) and made the peak period of bud growth appeared earlier. Considering the tea growth and yield, water and nutrient use efficiency, environment safety and economic benefit,  straw mulching could be an effective ground surface mulching mode for young tea garden.

Key words: tea plant, water use efficiency, nitrate-N, ammonium-N, nitrate reductase activity