节水灌溉条件下乌龙茶需水规律及灌溉定额研究

目的]探讨乌龙茶节水灌溉的需水规律及其水分利用效率。方法]以2年生铁观音茶树为试验材料,研究微喷灌节水灌溉方式下乌龙茶的需水规律、灌溉水量、有效降雨量以及节水灌溉定额。结果]5月、7～10月是乌龙茶的需水量高峰期,占全年需水量的59.15%。1983～2009年乌龙茶节水灌溉定额为551.4 mm,降雨有效利用率33%;其中大雨、中雨和小雨的有效利用率分别为17%、50%和77%。随着降雨量的增加,乌龙茶需水量下降,降雨有效利用量增加,而降雨有效利用率下降。结论]乌龙茶的最佳灌溉量是40～50 cm土层的土壤湿度达到75%时的田间持水量。乌龙茶生长需水关键期7～10月,适宜的灌水定额21.0 mm,灌水次数10～15次,灌水周期8～12 d。

Water-demand Regulations and Irrigation Program of Olong Tea under Condition of Water-saving Irrigation System

Objective] The aim was to investigate water-demand regulations and water use efficiencies under different irrigation systems of oolong tea.Method] Taking 2 years old Tie Guanyin tea(Camellia sinensis(L.) O.Kuntze) as test materials,water-demand regulations of the oolong tea,irrigation water amount,effective rainfall and the scale of water-saving irrigation under the method of micro-irrigation were studied.Result] The results showed that May,July to October were the peak water demand of Oolong tea,accounting for annual water demand of 59.15%.Under controlling irrigation system,the irrigation quota was 551.4 mm,and the total rainfall utilization efficiency was 33% from 1983 to 2009.The rainfall utilization efficiency of heavy,middle and light rain were 17%,50% and 77% respectively.With the increasing of rainfall,the water-demand amount was decreasing,the rainfall utilization amount was increasing,but the rainfall utilization efficiency was decreasing.Conclusion] Oolong tea optimum irrigation amount was the field capacity while the soil moisture of 40-50 cm soil layer reached 75%.The critical period of growing water demand was from July to October,the appropriate irrigating water quota was 21.0 mm,irrigation frequency was 10 to 15 times,and irrigation cycle was 8-12 d.