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为探讨绿洲区不同灌溉方式及灌溉量对苜蓿田土壤盐分空间分布及运移的影响,在苜蓿生长第2年设滴灌和漫灌2种灌溉方式,每种灌溉方式设3个灌溉梯度,对土壤电导率进行了测定与分析。结果表明,随生育进程的推进及灌水次数的增加,整个苜蓿生育期内土壤盐分含量呈波动式递减的变化趋势。滴灌方式下0~40cm土层、漫灌方式下0~30cm土层在灌溉后土壤处于脱盐状态;滴灌方式下在50~60cm土层、漫灌方式下在40~60cm土层土壤处于积盐状态。在水平及垂直方向上,随灌水量的增加,2种灌溉方式下土壤盐分峰值位均呈下移趋势,灌溉后土壤盐分含量随土壤深度的增加而增大,土壤盐分主要集中于土壤40~60cm土层,且滴灌方式下的“驱盐”效果要好于漫灌。在考虑成本、产出等综合经济效益时,当灌水量达到某种定额(滴灌下3000m3/hm2,苜蓿干草产量为1406kg/667m2,漫灌下5250m3/hm2,其干草产量为1504kg/667m2)后即可达到最佳的“驱盐”及高产效果,在绿洲区苜蓿田过多的灌溉量只会导致水资源的更多浪费。对绿洲区盐渍化较重的农田进行灌溉时,应尽量选取合理的灌溉制度及适宜的灌水量,以达到土壤盐分淋洗和经济效益最大化的双赢。
In order to explore the effect of different irrigation methods and irrigation amount on the spatial distribution and migration of soil salinity in alfalfa field, two kinds of irrigation methods of drip irrigation and flood irrigation were established in the second year of alfalfa growth. Three irrigation gradients were set for each irrigation. Conductivity was measured and analyzed. The results showed that with the advancement of fertility and the increase of irrigation times, the soil salinity content of the whole alfalfa showed a fluctuating decreasing trend. Under 0 ~ 40cm soil layer under drip irrigation and 0 ~ 30cm soil layer under diffuse irrigation, the soil was desalted after irrigation. Under drip irrigation, the soil in 40 ~ 60cm soil layer was in salt accumulation under the condition of 50 ~ 60cm soil layer and flood irrigation. In the horizontal and vertical directions, with the increase of irrigation amount, the peak value of soil salinity showed a downward trend under both irrigation modes. After irrigation, the soil salinity content increased with the increase of soil depth, and the soil salinity was mainly concentrated in 40 ~ 60cm soil layer, and drip irrigation mode “drive salt ” effect is better than flood irrigation. Considering the comprehensive economic benefits such as cost and output, when the irrigation volume reaches a certain quota (drip irrigation 3000m3 / hm2, alfalfa hay yield 1406kg / 667m2, flooding irrigation 5250m3 / hm2, hay yield 1504kg / 667m2) To achieve the best “drive salt ” and high-yielding effect, in the oasis area alfalfa field excessive irrigation will only lead to more waste of water resources. When irrigating farmland with heavy salinization in oasis area, reasonable irrigation system and proper irrigation amount should be selected so as to achieve a win-win situation of soil salinization and maximization of economic benefits.