河北滨海盐碱地浅层轻度咸水资源冬小麦灌溉安全利用研究

Study on shallow mild saline groundwater use safety in winter wheat irrigation based on the subsurface drainage system in the coastal area of Hebei Province in China

  • 摘要: 河北滨海盐碱耕地缺少灌溉水资源, 该区具有丰富的浅层微/轻度咸水资源, 冬小麦生长关键期适当进行微/轻度咸水灌溉能够缓解该区农田灌溉危机。本文以河北省滨海盐碱地为研究对象, 选择沧州市南大港产业园区马营村为试验基地, 开展浅层轻度咸水冬小麦农田灌溉试验, 分析咸水灌溉对冬小麦产量和土壤盐分含量变化的影响。结果表明: 1)河北滨海盐碱地浅层轻度咸水(6 g∙L−1)在冬小麦拔节—抽穗期进行一次600 m3∙hm−2的灌溉, 产量能够达到旱作冬小麦的1.5倍以上, 增产效果明显。2)基于暗管排水排盐工程、在雨季保持多年平均降雨量条件下, 2016—2018年雨季后试验地土壤平均含盐量分别为2.86 g∙kg−1、1.60 g∙kg−1和1.38 g∙kg−1, 呈现逐年降低的趋势。由此得出: 河北滨海盐碱地浅层咸水资源在冬小麦灌溉方面能够实现安全利用。在此基础上, 以河北滨海沧州市为例分析浅层咸水资源利用前景, 从水资源量上, 1~5 g∙L−1的浅层微/轻度咸水资源可以满足冬小麦农田因地下水压采限采造成的至少1.7×108 m3灌溉水量亏缺, 从耕地资源方面, 扩大一年两熟种植面积, 增加冬小麦种植面积约131 000 hm2。研究结果可为河北滨海盐碱地咸水资源安全利用、土壤健康和粮食安全提供科学依据。

     

    Abstract: There is a shortage of irrigation water resources in the coastal saline-alkali land of Hebei Province, which is rich in shallow saline water resources. Appropriate saline irrigation during the critical period of winter wheat growth could alleviate the irrigation crisis in this area. In this study, the coastal saline-alkali land of Hebei Province was selected as the research object, and the Maying Village of Nandagang Industrial Park, located in Cangzhou City, was selected as the test base. An experiment of shallow mild saline water irrigation of winter wheat was conducted to analyze the effects of saline irrigation on winter wheat yield and soil salt content. The results indicated that:1) mild saline water irrigation in the joint to heading stage of winter wheat increased the yield of winter wheat in the coastal saline-alkali land of Hebei Province, which was more than 1.5 times that of dry wheat. 2) Based on the subsurface drainage system, mild saline water irrigation did not cause salt accumulation in the soil surface layer. When the rainfall was maintained at multi-year average rainfall level in the rainy season, the average soil salt contents after the 2016−2018 rainy seasons was 2.86, 1.60, and 1.38 g∙kg1, and the degree of soil salinization was reduced year by year after two consecutive years of salt water irrigation. Shallow saline water resources in the coastal saline-alkali land of Hebei Province can be safely utilized to irrigate winter wheat. Based on this, we considered the coastal region of Cangzhou City of Hebei Province as an example. The analysis of shallow salt water resource prospects showed that: only winter wheat water demand was considered in Cangzhou City, irrigation water demand deficit was at least 1.7 × 108 m3. The shallow saline water resources of 1−5 g·L1 in Cangzhou City are abundant, meeting the deficit in terms of water resources. The feasibility of mild saline water irrigation for winter wheat makes the planting mode of one crop of spring maize a year in some cultivated land change to the planting mode of two crops of winter wheat-summer maize a year. The sown area of winter wheat can be increased by at least 131 000 hm2 in Cangzhou. The results provide a scientific basis for the safe utilization of mildly saline coastal water resources, guaranteed grain yield, and sustainable soil development in the coastal area of Hebei Province.