河套灌区盐渍化土壤下玉米多水源灌溉模式研究

为合理有效利用河套灌区水资源,本研究采用井水(地下水)、渠水(地表水)2种水源联合灌溉,研究较适宜的多水源灌溉模式对玉米生长特性及土壤水盐动态的响应机制。试验设置8个多水源灌溉模式:井井井(JJJ)、井井渠(JJQ)、井渠井(JQJ)、渠井井(QJJ)、井渠渠(JQQ)、渠渠井(QQJ)、渠井渠(QJQ)、渠渠渠(QQQ)及空白对照处理。结果表明:随着灌溉井水次数的增加,对玉米株高和茎粗抑制作用明显,抑制程度依次为拔节期灌浆期抽雄期;生育期内各处理均呈现出不同程度的积盐现象,耕层积盐程度大于深层;井水灌溉次数增加,土壤积盐程度明显,QJQ处理的土壤盐分变化量在玉米耕层均低于其他井灌参与的处理,且与QQQ处理差异较小;拔节期灌溉渠水能有效淋洗土壤盐分;灌溉两次及以上井水比灌溉一次及不灌井水的水分利用效率减少25.77%～31.61%;QJQ处理水分利用效率高于井灌参与的其他处理;收获指数和氮肥偏生产力均呈现出QQQ处理最高,其次为QJQ处理,JJJ处理最低的现象,且QQQ与QJQ处理无显著差异。综合土壤水盐动态和作物指标等因素的分析,QJQ处理为适合当地玉米的较优多水源联合灌溉方案。

Effects of Irrigation Patterns of Multi Water Sources on Maize Growth and Water and Salt Accumulation in Saline Soil in Hetao Irrigation Area

In order to find the optimal irrigation pattern and reasonably and effectively utilize the water resources of Hetao Irrigation Area, joint irrigation patterns with two kinds of water sources, well water (groun dwater) and canal water (surface water) was adopted to study their effects and mechanism on the growth of corn and water and salt accumulation in soil. Nine different irrigation patterns were designed, which included: well-well-well(JJJ), well-well-canal(JJQ), well-canal-well(JQJ), canal-well- well(QJJ), well-canal-canal(JQQ), canal-canal-well(QQJ), canal-well-canal(QJQ), canal-canal-canal(QQQ), and CK (no irrigation and fertilization). The results showed that with increase of well irrigation time, the inhibition became more obvious to the plant height and stem diameter of corn, and the inhibition degree was in an order of the jointing stage > filling stage > heading stage. Salt accumulation happened under all treatments but with different degrees during the growth period of corn. Salt was accumulated more in the tilling layer than in the deep layer. Soil salt accumulation became more evident with the increase of well irrigation times. The change of soil salt content in the tillage layer was lower under QJQ treatment than under other well irrigation treatments, and was near to QQQ treatment. Canal irrigation at the jointing stage could effectively wash soil salt. Well irrigated twice or more decreased water use efficiency by 25.77%-31.61% than those of well irrigated one time and irrigation without well water. Water use efficiency of QJQ treatment was higher than those of other treatments with well irrigation. QQQ treatment had the highest harvest index and nitrogen fertilizer partial productivity, followed by QJQ treatment, while JJJ treatment was the lowest, and no significant difference was found in harvest index and nitrogen fertilizer partial productivity between QQQ and QJQ treatments. Comprehensive analysis the dynamics of water and salt in soil and crop index and so on, QJQ treatment is recommended as the optimal multi-water irrigation scheme for local maize in the study area.