沟灌条件下不同灌溉水质对玉米产量和土壤盐分的影响

通过田间试验，研究在灌水定额相同的情况下，沟灌灌水方式（波涌灌，连续灌）、PAM（0、10和20ppm）处理、灌溉水质(对照即完全用黄河水灌溉，黄河水中加入10%和20%的地下咸水)及入沟流量(3、5L/s)对灌水沟中土壤剖面盐分累积和玉米产量的影响。地下咸水的矿化度从玉米生育初期的3.3dS/m到收获期的4.8dS/m，其钠吸附比SAR为8。方差分析结果表明，4种因素中，只有灌溉水质是影响产量的显著性因素。不考虑其他因素，只考虑灌溉水质的影响，生育期不同的灌溉水质都引起土壤剖面盐分的累积。随着灌溉水中地下咸水含量的增加，盐分累积也在增加，3种灌溉水质灌溉条件下玉米收获期1m土层平均盐渍度分别为：0.41、1.17和2.01dS/m。与对照（黄河水）相比，沟灌灌溉水中加入10%的地下咸水，作物减产9.2%，加入20%的地下咸水，则减产达到13.2%。与传统的地面漫灌方式相比，不同水质沟灌的玉米平均产量提高15.1%，用黄河水沟灌的玉米则较同水质地面漫灌的玉米增产24%。尝试建立了沟灌灌水沟中土壤盐渍度和玉米产量之间的相关关系，并据此确定了当地玉米的零产量极限盐渍度。

Effect of water quality in furrow irrigation on corn yield and soil salinity

Field experiment was conducted to investigate the effects of irrigation method, PAM treatment, water quality and flow rate on salinity in soil profile and corn yield. The result shows that only water quality has significant influences on corn yield and soil salinity. Salt was accumulated in soil profile under different water quality levels and salt accumulation increases with the increase of saline in groundwater. The corn yield under the conditions of 10% and 20% salinity of groundwater reduces by 9.2% and 13.2% respectively. The average corn yield under furrow irrigation is 15.1% higher than that under conventional irrigation. The corn yield under furrow irrigation is 24% higher than that under conventional flood irrigation with water from Yellow River. An attempt was made to relate the corn yield with soil salinity under furrow irrigation condition. Further more, the salinity limit for zero corn yield under furrow irrigation was estimated.