地理学报 ›› 2023, Vol. 78 ›› Issue (7): 1718-1730.doi: 10.11821/dlxb202307012

• 水文地理 • 上一篇    下一篇

地理学视角的农业节水理论框架与水资源可持续利用

沈彦俊1(), 齐永青1, 罗建美2, 张玉翠1, 刘昌明1   

  1. 1.中国科学院遗传与发育生物学研究所农业资源研究中心 中国科学院农业水资源重点实验室 河北省节水农业重点实验室, 石家庄 050022
    2.河北地质大学土地科学与空间规划学院, 石家庄 050031
  • 收稿日期:2023-03-15 修回日期:2023-06-20 出版日期:2023-07-25 发布日期:2023-08-01
  • 作者简介:沈彦俊(1971-), 男, 河北康保人, 研究员, 博士生导师, 主要从事农业水文学与水资源研究。E-mail: yjshen@sjziam.ac.cn
  • 基金资助:
    河北省自然科学基金创新群体项目(D2021503001);国家自然科学基金重点项目(41930865)

The combined pathway to sustainable agricultural water saving and water resources management: An integrated geographical perspective

SHEN Yanjun1(), QI Yongqing1, LUO Jianmei2, ZHANG Yucui1, LIU Changming1   

  1. 1. Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, CAS/Key Laboratory of Agricultural Water Resources, CAS/Hebei Laboratory of Water-Saving Agriculture, Shijiazhuang 050022, China
    2. School of Land Science and Space Planning, Hebei GEO University, Shijiazhuang 050031, China
  • Received:2023-03-15 Revised:2023-06-20 Published:2023-07-25 Online:2023-08-01
  • Supported by:
    The Innovation Group Project of Agricultural Hydrology and Groundwater Sustainability by Hebei Natural Science Foundation(D2021503001);The Key Program of National Natural Science Foundation of China(41930865)

摘要:

水资源亏缺是中国农业可持续发展面临的主要挑战。本文从地理学的综合性视角出发,提出区域农业耗水与生产、生态效益关系的概念模型,拓展了“土壤—作物—大气系统界面节水调控理论”,构建了节水与适水并重的农业综合节水研究体系及其理论框架。并以华北平原为例,探究了中国缺水区农业水资源可持续利用途径。基于田间水循环及节水潜力的研究表明,华北平原小麦—玉米一年两熟农田年水分净亏缺220 mm,要实现农田尺度水平衡,需改为二年三熟,甚至一年一熟;京津冀区域尺度模型模拟表明,若通过调整农业种植规模和结构来平衡区域地下水超采,则小麦产量只能满足75%的口粮需求,要实现地下水采补平衡下的粮食自给,需要外部调水来补足水资源亏缺;基于农田耗水结构的节水试验表明,与地面灌相比,地下滴灌的小麦季、玉米季蒸散分别减少88 mm、60 mm,年均可节约耗水1480 m3/hm2。因此,深度田间节水技术会对种植结构和种植制度调整的节水效应产生显著支撑,从而实现稳定农业产能和水资源可持续利用的双重目标。从地理学综合视角出发,未来应更多关注变化环境下水资源的形成、转化和利用,从水量和水质两方面开展农业节水和水资源可持续利用研究,为平衡区域农业发展和健康水循环提供科学依据。

关键词: 农业节水, 农业水资源, 适水农业, 种植结构, 节水潜力

Abstract:

Water shortage is becoming a key factor of agricultural sustainable development in China, and threatening food security. It is an urgent need to establish an integrated water saving framework, including theory and related countermeasures, to support society for seeking a better and sustainable solution. In the this paper, we proposed an integrated agricultural water saving study framework from the perspective of geographical science, and introduced how it was applied to pursue the pathways to sustainable agricultural water utilization and solve the groundwater depletion issue in the North China Plain (NCP), where groundwater is suffering most severe depletion due to irrigation. We proposed a conceptual model of regional agricultural water consumption and its productive and ecologic effects, enlarged the scope of "SPAC interface regulatory theory for agricultural water saving", and established a combined "water saving" and "water adaptive" agriculture research framework, namely, the integrated water saving agricultural study. We applied this integrated water saving study in the NCP as a typical case. Firstly, the evapotranspiration (ET) from a wheat-maize double cropping field was quantified as 710 mm/a, the net water deficit is 220 mm/a, based on a 13-year field measurement of water fluxes and budget. It is necessary to achieve water balance at a farmland scale so as to change the current double cropping system to the alternatives, such as three harvests in two years or even monoculture system. At regional scale, under the precondition or scenario of groundwater zero depletion, which could be achieved through reducing planting area and optimizing planting structure, the production of wheat can only meet 75% of the demand for grain self-sufficiency in the Beijing-Tianjin-Hebei region, based on the model simulation. With the current agricultural technology, we have to rely on import of water or food from external basins to bridge the deficit if we want to pursue high agricultural productivity without groundwater depletion. We quantified the apparent water-saving potential by analyzing ET partitioning structure, i.e. E and T, through combining observation and modeling, and further interpreted the major soil depths for evaporation loss (top 0-20 cm layer) and crop root uptake (top 0-40 cm layer). Then, we developed the sub-surface drip irrigation technology, which set up the drip line at 20-40 cm depth below the ground surface with intervals of 80-100 cm according to the soil texture. Compared with the surface irrigation, the sub-surface drip irrigation could reduce ET of wheat and maize season as 88 mm and 60 mm, respectively, without reduction in yield. The water saving effect is equivalent to 1480 m3/hm2. We believe that this advanced water-saving technology will have a significant positive effect on water budgets of optimizing the planting structure and cropping system, so as to achieve the sustainable goals for both the agricultural production and groundwater conservation. In this study, we also appeal that we should make more efforts on studying water resource yield, transformation, and utilization in dimension of both quantity and quality under a changing environment in future.

Key words: agricultural water saving theory, agricultural water resources, water adaptive agriculture, advanced water saving technology