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0～40 cm 土层、漫灌方式下0～30 cm 土层在灌溉后土壤处于脱盐状态；滴灌方式下在50～60 cm 土层、漫灌方式下在40～60 cm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40～60 cm 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3000 m3／hm2，苜蓿干草产量为1406 kg／667 m2，漫灌下5250 m3／hm2，其干草产量为1504 kg／667 m2）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。%Salination is a major problem in oasis agricultural systems.This study explored the effects of differ-ent irrigation methods and quantities on soil salt spatial distribution and transfer in oasis alfalfa crops.A two-factor experiment including two irrigation methods and three irrigation gradients was conducted.Soil electrical conductivity was measured and analyzed during alfalfa growth in the second year of the experiment.With the advancement of crop growth and an increase in irrigation frequency,soil salt content fluctuated significantly but tended to decrease as the growing season progressed.Reduced soil salt levels occurred at 0-40 cm depth under drip irrigation and at 0-30 cm depth under flood irrigation;salt was deposited at 50-60 cm depth under drip irrigation and at 40-60 cm depth under flood irrigation.Increased irrigation resulted in peak soil salinity tren-ding downwards under both irrigation methods.Soil salt content increased with increasing soil depth after irri-gation with most salt concentrated at 40-60 cm depth,but the “salt drive”effect was greater under drip irriga-tion than flood irrigation.The benefits of “salt drive”for crop yield were maximized at irrigation rates of 3000 m3/ha and 5250 m3/ha under drip and flood irrigation,respectively.
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