咸淡混合水喷灌对土壤水盐运移及小麦、玉米产量的影响

探究不同矿化度咸淡水混合喷灌对冬小麦、夏玉米生长及产量的影响，并通过监测土壤水盐分布状况来选择适宜矿化度的咸淡水灌溉方式。在河北低平原地区开展大田灌溉试验，研究了淡水畦灌、淡水喷灌、2 g·L^-1和3 g·L^-1咸水与淡水混合喷灌对小麦、玉米生长及土壤水盐运移的影响。结果表明：与淡水喷灌相比，连续两年灌溉后，小麦收获时2 g·L^-1和3 g·L^-1矿化度咸淡混合水喷灌处理的根层（0~40 cm）土体含盐量平均分别增加了17.8%和42.7%，0~100 cm土体含盐量平均分别增加了32.9%和74.3%，玉米收获时根层土体含盐量平均分别增加了40.3%和86.9%，0~100 cm土体含盐量平均分别增加了39.0%和88.9%，且3 g·L^-1矿化度咸淡混合水喷灌处理的盐分累积已超出小麦和玉米生长的盐分阈值。2 g·L^-1矿化度处理的冬小麦产量较淡水喷灌处理降低了9.8%~11.4%（差异不显著），但3 g·L^-1矿化度处理比淡水喷灌处理的产量显著降低了25.0%~25.9%（P<0.05）；2 g·L^-1矿化度处理的夏玉米单株穗粒质量和产量较淡水喷灌处理分别降低了5.1%~10.4%和6.6%~10.5%（差异不显著），3 g·L^-1矿化度比淡水喷灌处理的百粒重、单株穗粒质量和产量分别降低了18.6%~22.4%、18.2%~25.9%和14.7%~15.3%（P<0.05），3 g·L^-1矿化度对冬小麦和夏玉米的产量构成因素影响显著。因此，咸淡混合水矿化度不大于2 g·L^-1的喷灌模式用于该地区冬小麦-夏玉米田间灌溉是可行的。

Effects of sprinkling irrigation with brackish and fresh water mixing on yield of wheat and maize and movement of soil water and salt

The purpose of this study was toexplore effects of sprinkling irrigation by brackish and fresh water mixing with different salinity on growth and yield of winter wheat and summer maize. By monitoring the distribution of soil water and salt, a suitable salinity of brackish water irrigation method was selected. A field experiment was conducted in the low plain area of Hebei Province. Four irrigation treatments (border irrigation with fresh water, sprinklers with fresh water, 2 g·L^-1 and 3 g·L^-1brackish water) were designed. Data collected were used to analyze effects of sprinkling irrigation with brackish and fresh water mixing on wheat and maize growth as well as soil water and salt movement. The results showed that, after two years of irrigation,compared with fresh water sprinkling, at the time of wheat harvest, the salt content of root layer soil (0~40 cm) treated by 2 g·L^-1and 3 g·L^-1 salinity sprinkler irrigation increased by 17.8% and 42.7%, respectively, and the salt content of 0~100 cm soil increased by 32.9% and 74.3%, respectively. After maize was harvested, the salt content of root layer soil increased by 40.3% and 86.9%, respectively, and the salt content of 0~100 cm soil increased by 39.0% and 88.9% respectively. The salt accumulation under 3 g·L^-1 salinity sprinkling treatment exceeded the salt threshold of wheat and maize growth. Compared with fresh water sprinkling,the yield of winter wheat treated with 2 g·L^-1 salinity was reduced by 9.8%~11.4% (no significant difference), but the yield of winter wheat treated with 3 g·L^-1 salinity was significantly reduced by 25.0%~25.9% (P<0.05). The ear weight per plant and yield of summer maize treated with 2 g·L^-1 salinity were reduced by 5.1%~10.4% and 6.6%~10.5% respectively (no significant difference), but the 100-grain weight, ear weight per plant and yield of summer maize treated with 3 g·L^-1 salinity were significantly decreased by 18.6%~22.4%, 18.2%~25.9% and 14.7%~15.3% (P<0.05), respectively. Sprinkling irrigation with 3 g·L^-1 salinity had a significant effect on the yield components of winter wheat and summer maize. Therefore, sprinkling irrigation with no more than 2 g·L^-1 mixing of brackish and fresh water should be used for field irrigation of winter wheat and summer maize in this region.