典型岩溶断陷盆地农作物生态需水研究——以蒙自地区为例

从合理调控生态用水角度出发，探讨典型岩溶断陷盆地区农作物生态需水问题。根据蒙自断陷盆地的岩溶地貌特征，分别选取位于盆地、坡面和高原面的大洼子、朵古、牛耳坡3个观测点，利用Penman-Monteith公式、作物系数（FAO推荐）及同期有效降雨量，估算3个观测点2018年的参考蒸散量、生态需水量以及不同作物生长所需的人工灌溉水量。结果表明:（1）大洼子、朵古及牛耳坡的参考蒸散量分别为1 346.10 mm、1 200.00 mm、1 064.30 mm，远大于同期降水量，均呈现出蒸发旺盛的特点，加大了作物对于水分的需求；同时三者的参考蒸散量表现出较为明显的时空差异，使得3个观测点的农业种植条件存在差异；（2）大洼子种植的水稻、小麦、花生、油菜、大豆、马铃薯、葡萄等作物的生态需水定额均远大于大洼子同期的有效降水，在大洼子种植的作物均需要大量人工浇灌才能正常生长，而农作物的种植与其种植条件匹配度不高；（3）朵古及牛耳坡种植的玉米、万寿菊的生态需水定额与同期有效降水之间的差值较小甚至完全满足，表明玉米、万寿菊在高原山区的种植是与当地种植条件相匹配的；而种植在朵古及牛耳坡的苹果、烤烟的生态需水定额与同期有效降水之间的差值较大，表明在高原山区大量种植苹果及烤烟对于人工浇灌要求较高；（4）研究区大部分农作物在生长发育阶段内所需的水分主要依靠人工灌溉，与本地降水分布规律匹配度不高，区内农业结构与种植模式有待调整。在岩溶断陷盆地内要种植耗水较少，对热量要求较高的作物，山区则需要发展具有生态保护和经济效益的作物，但种植的重点区域仍是盆地区。 

Ecological water requirements of crops in typical karst fault-depression basins:A case study of the Mengzi area,Yunnan Province

The Mengzi fault-depression basin is a typical karst rocky desertification area, Yunnan Province. This area has serious soil erosion and leakage, difficult groundwater utilization, and prominent ecological water shortages, which seriously affect the integrity and health of the regional ecosystem. The purpose of this study is to help better solve the problems of severe water resources shortage and ecological environment problems, and provide reasonable suggestions for the agriculture development in this area. We estimate the reference evapotranspiration, ecological water requirements, and the artificial irrigation water requirements of different crops by using the Penman-Monteith formula, crop coefficients (FAO recommended) and the effective rainfall during the same period at three observation sites (Dawazi, Duogu and Niuerpo) of Mengzi in 2018. The results show that，(1) The reference evapotranspiration of these three places were 1，346.10 mm, 1，200.00 mm and 1，064.30 mm, respectively, much more than the effective rainfall in the same period, indicating the climatic characteristics of strong evaporation, which increased the requirements of crops for water. At the same time, the reference evapotranspiration at three observation points exhibits obvious spatial and temporal differences, which make their agricultural planting conditions different；(2) The ecological water requirements quota of rice, wheat, peanut, rapeseed, soybean, potato and grape grown are much greater than the effective rainfall during the same time in Dawazi, indicating that all the crops planted there require massive irrigation to ensure their normal growth. There is a low matching degree between the kinds of planting crops and the planting background conditions, indicating that the agricultural planting structure in the basin needs to be adjusted in the future；(3) The difference between the effective rainfall and the ecological water requirements quota for corn and marigolds planted in Duogu and Niuerpo in the same period is small or even nearly matched, indicating that the planting of corn and marigold in the mountainous areas matches the local planting conditions.While the difference between the effective rainfall and the ecological water requirement of apple, flue-cured tobacco planted in Duogu and Niuerpo in the same period is large, indicating that large amounts of apples and flue-cured tobacco planted in plateau mountainous areas require more artificial irrigation；(4) The water required by most crops in their growth and development stage in the study area mainly depends on the artificial irrigation, which does not well match with the law of effective rainfall, implying that the agricultural structure and agricultural planting patterns need to be adjusted in this region.In conclusion,this study suggests that some crops with less water consumption and higher heat requirements are suitable for planting in the basin. While some crops with better ecological protection and economic benefits are suitable for planting in the karst mountainous areas.