论文部分内容阅读
通过野外定位观测,对塔里木河下游典型绿洲防护林地灌溉周期内、不同滴灌年限以及不同质地类型土壤水盐动态进行监测分析。研究结果表明:①绿洲幼龄防护林地土壤水盐变化属于灌溉周期型;灌后土壤湿润体呈“半椭球型”分布,积盐区位于湿润峰附近;当前防护林(沙壤土)滴灌周期为10d较为合适。②实施滴灌1a、2a和5a林地(沙壤土)土壤水分亏缺量逐年增大;0～20cm土层随滴灌年限的增大先脱盐后积盐,20～120cm土层均表现为脱盐。③滴灌5a后,粉黏土林地表层板结层的形成显著抑制40～60cm土壤水分蒸发,盐分呈“表聚型”分布;细沙土林地土壤持水性差,各土层盐分呈“均匀型”分布;沙壤土林地持水性较细沙土林地略高,盐分呈“波动型”分布。
Through the field observation and observation, the monitoring and analysis of the soil moisture and salt dynamics of typical oasis shelterbelts in the lower reaches of the Tarim River during the irrigation cycle, different drip irrigation years and different types of soil texture were conducted. The results showed as follows: ①The changes of soil water and salt in the young shelterbelts of oasis belonged to the irrigation cycle type; the distribution of soil wetting body was “semi-ellipsoid” after irrigation, the salt accumulation area was near the wetting peak; the current shelterbelt For 10d more appropriate. (2) The amount of soil water deficit in larvae 1a, 2a and 5a forest land (sandy loam soil) increased year by year. Soil desalting increased after drip irrigation in 0-20 cm soil layer, and desalted in 20-120 cm soil layer. (3) After drip irrigation for 5 years, the formation of the surface layer nodules in silty clay soil significantly inhibited the evaporation of soil moisture at 40 ~ 60cm and the salinity showed “polygamy” distribution; the soil moisture of fine sandy soil was poor, Sandy soil of sandy loam soil has a slightly higher water holding capacity than that of fine sandy soil, and salt content is in a “fluctuating” distribution.