华北半干旱地区农田微型蒸渗仪关键参数优化及精度提升研究OA

Soil evaporation is an important part of the water cycle in farmland.Accurately measuring inter-plant soil evaporation is particularly important for precise farmland water management.To explore effective measures to improve the accuracy of soil evaporation measurement,this study took loam soil in the North China Plain as the research object.The effects of different specifications of micro-lysimeters such as material,height,inner diameter,and bottom sealing materials on soil evaporation were compared,and the observation accuracy of different burial positions and soil replacement cycles was analyzed.The results showed that the evaporation amount of PVC material was lower than that of galvanized iron sheet,and the difference in evaporation amount between the two materials was not significant;the measured evaporation of the micro-lysimeter decreased with the increase of the diameter,and the highest accuracy was achieved when the diameter was 10 cm;the measured evaporation of the micro-lysimeter increased with the height of the micro-lysimeter,and the accuracy was highest at a height of 20 cm;the relative error of observation results for gauze sealing was generally lower than that for plastic cloth sealing;when the soil replacement cycle was 1～2 d,the observation accuracy was the highest;and inter-row evaporation was greater than that between plants and near plants.Therefore,in the North China Plain,in order to ensure the stability and operability of sampling,it is recommended that the micro-lysimeter should be made of galvanized iron sheet,the bottom sealing material should be gauze,with a diameter of 10 cm and a height of 10 cm respectively.The suitable burial location of the micro-lysimeter is inter-row,and the suitable soil replacement cycle is 1～2 d.