元谋干热河谷不同水分处理石榴的水量平衡研究

对元谋干热河谷微区域集水造林试验区不同水分处理下石榴的水量平衡研究结果表明:(1)降雨和坡面汇集径流是集水系统植树带的水分输入,其中降雨占输入的90.2%;坡面汇集径流量占水分输入量的9.8%。蒸散是水分输出项,整个生长季内,不同水分处理的土壤水分均有盈余,但不同水分处理间的蒸散量和土壤水分盈余量存在差异,土壤含水率为10.08%,11.63%,13.23%,14.79%,16.85%和19.14%的总蒸散量分别占系统水分输入的44.5%,60.8%,67.0%,82.0%,85.4%和87.0%;土壤水分盈余量分别占系统水分输入的55.5%,39.2%,33.0%,18.0%,14.6%和13.0%,表现出蒸散量随土壤含水率的增大而增大,土壤水分盈余量随土壤含水率的增大而减小。(2)石榴的生长状况与土壤水分状况相关。土壤含水率的增加有利于石榴的生长发育。对于元谋干热河谷而言,土壤含水率控制在14%~15%的供水较好,这时,在节水的同时又对石榴的生长未造成严重影响。

Study on Water Balance of Punica Granatum Under Different Soil Moisture Conditions in Dry-hot River Valley

We studied the water balance of Punica granatum under different conditions of soil moisture management in the micro-catchment afforestation experimental site in the Yuanmou dry-hot river valley. The result shows that the water input of the tree strips of catchment system depends on rainfall and slope runoff, which contribute 90.2 % and 9.8 % respectively, and the water output relies on evapotranspiration. The soil water storage under all the conditions has surplus from May to November. Both the evapotranspiration amount and the water surplus amount under different soil moisture conditions are different. When soil water contents are controlled at 10.08 %, 11.63%, 13.23%, 14.79%, 16.85% and 19.14% levels, the total evapotranspiration amounts are 44.5%, 60.8 %, 67.0%, 82.0 %, 85.4 % and 87.0 % of the water input, and the water surplus amounts are 55.5 %, 39.2 %, 33.0 %, 18.0 %, 14.6 % and 13.0 %, respectively. It shows that the evapotransiration amouat increases with the increase in soil water content, however, the water surplus amount decreases with the increase in soil water content. The correlation between Punica granatum growing state and soil moisture state is significant. soil water condition is beneficial to the growth of Punica granatum and the best soil water content range for it is 14% -15 % in terms of water-saving in dry-hot river valley.