滴灌控制土壤基质势对土壤水分分布和苜蓿生长的影响

Effect of Drip-irrigation Control Soil Matrix Potential on Alfalfa Growth and Soil Moisture Distribution

采用在滴头正下20 cm深度处埋设负压计,分别设置-15、-25和-35 k Pa的土壤基质势控制滴灌,通过田间试验,研究了不同土壤基质势下土壤水分变化特点和紫花苜蓿的生长特性,分析了蒸发、降雨和灌水与土壤基质势之间的关系。从土壤剖面水分分布来看,整个生育期内-15 k Pa处理下的土壤剖面含水率整体集中在14%~15%,较-25和-35 k Pa处理的更为均匀,水分密集区域距离滴头最近;-15 k Pa处理下苜蓿株高达到41.7 cm,盖度为15.3%,生物量值达到了281.29 g/m^2,在所有处理中均为最高。

Field experiments are conducted to investigate the characteristics of soil moisture change and growth characteristics of Alfalfa under different soil matrix potential. In the experiments, the tensiometer is buried at the depth of 20 cm immediately under the emitter, -15, -25 and -35 kPa are set respectively to control the drip irrigation of soil matrix potential, and the relationship between evaporation, rainfall, irrigation and soil matrix potential is analyzed. In the whole growth period, from the point of soil profile water distribution, the water content of soil profile in -15 kPa treatment is concentrated in 15% ～14%, which is more uniform than that of -25 kPa and -35 kPa treatment, and the distance between water intensive area and emitter is the nearest; the height of alfalfa under -15 kPa treatment reaches 41.7 cm, the coverage is 15.3%, the biomass value is 281.29 g/m^2, and the growth performance is the best in all treatments.