Water resources and water use efficiency in the North China Plain: Current status and agronomic management options

Serious water deficits and deteriorating environmental quality are threatening agricultural sustainability in the North China Plain (NCP). This paper addresses spatial and temporal availability of water resources in the NCP, identifies the effects of soil management, irrigation timing and amounts, and crop genetic improvement on water use efficiency (WUE), and then discusses knowledge gaps and research priorities to further improve WUE. Enhanced irrigation and soil nutrient (mainly nitrogen) management are the focal issues in the NCP for enhancing WUE, which are shown to increase WUE by 10-25% in a wheat-maize double cropping system. Crop breeding has also contributed to increased of WUE and is expected to play an important role in the future as genetic and environmental interactions are understood better. Agricultural system models and remote sensing have been used to evaluate and improve current agronomic management practices for increasing WUE at field and regional scales. The low WUE in farmer's fields compared with well-managed experimental sites indicates that more efforts are needed to transfer water-saving technologies to the farmers. We also identified several knowledge gaps for further increasing WUE in the NCP by: (1) increasing scientific understanding of the effects of agronomic management on WUE across various soil and climate conditions; (2) quantifying the interaction between soil water and nitrogen in water-limited agriculture for improving both water and nitrogen-use efficiency; (3) improving irrigation practices (timing and amounts) based on real-time monitoring of water status in soil-crop systems; and (4) maximizing regional WUE by managing water resources and allocation at regional scales.     

改进粒子群算法在农业种植结构优化中的应用

【目的】促进地区农业水资源高效利用,在保证粮食安全的基础上,降低灌溉需水量,推动农业节水、提高产量和效益。【方法】以安阳市为例,以经济、社会、生态和水资源效益最大为综合目标,引入惯性权重衰减和粒子变异策略,建立了基于改进粒子群算法的多目标农业种植结构优化模型。【结果】通过对现状水平年2018年、规划水平年2025年(近期)、2035年(远期)的种植结构调整,在结合现状缺水程度下,压减耗水量大的小麦、玉米等粮食作物种植比例,增加油料、蔬菜及食用菌等经济作物种植比例,经济、社会、生态、水资源目标的综合效益分别提升13.59%、10.90%、9.82%;同时,在满足农作物全生育期需水量的情况下,缺水率分别缩减9.02%、9.56%、9.95%,在一定程度上缓解了农业水资源供需矛盾。【结论】改进粒子群算法使种植结构得到平衡优化,在提高综合效益及产量的同时能够降低灌溉需水量。     

宁夏主要农作物生产水足迹及其变化趋势研究

【目的】探讨宁夏地区2008—2017年作物生产水足迹及其变化趋势为调整宁夏地区农业用水结构以改善水资源短缺问题提供理论依据。【方法】基于水足迹理论,本文利用气象和农业有关数据,对宁夏回族自治区2008—2017年主要农作物的生产水足迹进行了量化处理,并结合气象因素与作物产量,对其进行了时空分布及变化趋势分析。【结果】①宁夏地区10年研究期间各作物的生产水足迹总体上呈减小趋势,在5种主要农作物中,大豆的平均综合生产水足迹最大,为4.51 m^3/kg,玉米的平均综合生产水足迹最小,为0.91 m3/kg;②各作物蓝绿水足迹比例最高的是稻谷,为5∶1,最低的是大豆,为1.4∶1;③10年研究期各地区综合作物生产水足迹大小排序为:吴忠市(15.58m^3/kg)>中卫市(13.71m^3/kg)>石嘴山市(12.77m^3/kg)>银川市(9.46m^3/kg)>固原市(8.21m^3/kg);④各地区蓝绿水足迹比例从南到北依次递增,固原市最小为1.2∶1,石嘴山市最大为5∶1。【结论】在水资源十分缺乏的宁夏地区,需根据各作物耗水规律适当调整种植结构、灌溉模式等减少农业用水量以缓解水资源短缺问题。     

气候变化与农业用水安全

针对全球气候变化的事实,阐述了气候变化对农业用水安全的影响。在分析我国农业用水量与用水效率变化规律的基础上,指出农业用水比重偏高、用水效率低下是造成当前我国水资源危机的重要原因。在未来气候变化背景下,我国农业用水将面临更大挑战。最后,结合国内外水资源管理现状,提出对农业用水需求总量、用水效率进行调控的需水管理措施,从调控需求、提高效率的角度缓解供需矛盾,应对气候变化对农业用水安全的影响。     

Improving agricultural water use efficiency in arid and semiarid areas of China

Water shortage in China, particularly in the north and northwest of China, is very serious. The region accounts for half of the total area of China, but has less than 20% of total national available water resources. While the water shortage in this region is severe, irrigation water use efficiency is only about 40%, with a typical agricultural water use efficiency of about 0.46 kg m⁻³. Excessive irrigation in Ningxia and Inner Mongolia has had a significant influence on downstream water users along the Yellow River. It is widely believed that an increase in the agricultural water use efficiency is the key to mitigating water shortage and reducing environmental problems. This paper reviews water-saving agricultural systems and approaches to improve agricultural water use efficiency in the arid and semiarid areas of China. The paper will cover biological mechanisms of water-saving agriculture and water-saving irrigation technologies, including low pressure irrigation, furrow irrigation, plastic mulches, drip irrigation under plastic, rainfall harvesting and terracing. In addition, the paper addresses the compensatory effect of limited irrigation and fertilizer supplementation on water use efficiency and highlights the need to breed new varieties for high water use efficiency. Considerable potential for further improvement in agricultural water use efficiency in the region depends on effective conservation of moisture and efficient use of the limited water.     

北京市农业水资源供需状况及优化利用研究

北京市属于资源型缺水城市,农业用水量占据城市总用水量的大部分,如何提升区域农业水资源的利用效率,保证区域农业用水平衡,是实现北京建设节水型城市的研究重点。通过统计资料分析、田间作物与水关系定位试验、构建作物综合效益评定模型等方法,研究了北京市农业水资源当前供需平衡状况、主要农作物耗水与灌水指标变化,并对当前种植业结构进行了调整,实现了在节水条件下的种植业经济效益最大化,并对北京发展节水农业提出了政策建议。     

北京市农业用水问题及对策研究

北京市为资源型重度缺水地区,水资源的需求量随着经济发展和人口的增长而骤增,供需矛盾日益加剧.农业用水是用水大户,接近全市用水的40%.水资源紧缺导致北京农业水资源严重不足,而农业用水浪费现象还普遍存在,节水农业是解决北京水资源问题的重要途径之一.概述了北京地区的农业水资源的现状,阐述了北京农业用水特点,分析了农业用水中存在的主要问题,从优化种植结构、雨洪利用、农艺节水、工程节水以及管理节水等方面提出了农业节水的对策措施和建议.     

关于做好农业和农村节水工作的几点思考

农业用水占我国用水总量的 70 % ,开展和推进农业节水 ,是建立节水型社会的关键 ,也是实现我国水资源可持续利用的内在要求。要做好农业和农村节水工作 ,应当十分重视“预测预报、水资源保障、城乡供水、水污染防治、防洪减灾、计量监测、技术推广、投融资、抗旱服务、政策法规”等十大体系的建立和建设     

海河流域冬小麦水分生产率特征分析

以海河流域为研究对象,以农田总供水水分生产率(WUEa)和灌溉水分生产率(WUEi)为评价指标,运用对流域内典型灌区的调查资料,计算了海河流域主要作物冬小麦的用水效率并进行特征分析,得到了其水分生产率的分布和变化规律。结果表明,WUEa在田间尺度上均值为1.50 kg/m3、灌区尺度上均值为0.97kg/m3,WUE在...     

Evaluation of the water use efficiency of alternative farm practices at a range of spatial and temporal scales: A conceptual framework and a modelling approach

Water is the principal limiting resource in Australian broadacre farming, and the efficiency with which farmers use water to produce various products is a major determinant both of farm profit and of a range of natural resource management (NRM) outcomes. We propose a conceptual framework based on multiple water use efficiencies (WUEs) that can be used to gain insight into high-level comparisons of the productivity and sustainability of alternative farming practices across temporal and spatial scales. The framework is intended as a data aggregation and presentation device. It treats flows of water, biomass and money in a mixed farming system; economic inefficiencies in these flows are tracked as they are associated with a range of NRM indicators.We illustrate the use of the framework, and its place in a larger research programme, by employing it to synthesise the results from a set of modelling analyses of the effect of land use choices on long-term productivity and a range of NRM indicators (frequency of low ground cover, deep drainage, N leaching rates and rate of change in surface soil organic carbon). The analyses span scales from single paddocks and years to whole farms and have been carried out with the APSIM and GRAZPLAN biophysical simulation models and the MIDAS whole-farm economic model.In single wheat crops in one study, different land uses in preceding years affect grain yield primarily by affecting the harvest index. When the scale changes to cropping rotations, the critical factor affecting overall water use efficiency is found to be the proportion of stored soil water that is transpired by crops. When ordinated in terms of their water use efficiencies, a set of 45 modelled rotation sequences at another location are differentiated mainly by the proportion of pasture in the rotation; when rotations are ordinated using key NRM indicators, the proportion of lucerne pasture is the main distinguishing factor. Finally, we show that for whole crop-livestock farms at three different locations across southern Australia, the pattern of water use efficiencies in the most profitable farming systems changes in similar ways as cropping proportion is altered. At this scale, land use choices affect multiple water use efficiency indices simultaneously and commodity prices determine the balance of the resulting economic tradeoffs.Limitations to the use of the WUE framework arising from its relative simplicity are discussed, as are other areas of farming systems research and development to which it can be applied.     

东北半干旱抗旱灌溉区有限供水对大豆水分利用效率的影响研究

东北半干旱区是我国北方旱农地区的重要组成部分,多数地区没有灌溉水源。降水量少,时空分布不均,春风大,蒸发强,春旱已成为制约本区农业生产的主要因素。为了探索适合于东北半干旱区的农业抗旱节水技术集成模式,针对本区的资源环境和灾害特点等,选取了坐水播种和苗期补灌技术,结合盆栽试验,在坐水播种和苗期补水条件下研究了不同的供水处理对大豆的生长发育及其水分利用效率的影响,提出了水分利用效率的最佳供水模式。     

设施农业配套仪器试验

目前我国农业机械化水平还很低,不能满足设施农业发展的需要。设施新技术的引进将加速高端集约化设备的推广应用,提升设施农业的发展水平。以北京大兴区博瑞兴泽设施农业技术开发有限公司为试验点,通过植物声波助长仪试验、温室电除雾防病促蕾技术试验和土壤连作障碍电处理技术试验,对提升设施农业发展给出合理化建议。      

2000—2014年中国粮食主产区植被水分利用效率时空演变特征研究

【目的】实现在气候变化背景下对粮食产区农业水资源的优化配置和水分的高效利用。【方法】利用Python、ArcGIS软件和MODIS遥感估算的MOD17和MOD16数据产品,研究了中国粮食主产区(东北、内蒙古、华北、南部)2000—2014年植被生态系统水分利用效率(water use efficiency,WUE)的时空分布规律。【结果】①年WUE(以碳计,下同)整体呈上升趋势,增速为0.013 g/(mm·m2·a)(P<0.01),2个转折点分别出现在2003、2010年;②年内WUE的变化主要呈M型的双峰模式,峰值出现在4—5月、9—10月,而季节尺度上WUE的变化具有显著差异;③不同时间尺度的WUE空间分布上具有明显的异质性;④2000—2014年来全区年WUE整体呈上升趋势,其中呈上升趋势的面积占84.01%,但上升幅度以轻度、中度为主;⑤各季WUE整体呈上升趋势,但是不同季节WUE发生上升的区域位置、面积和显著性的大小都不同。【结论】在气候变化背景下,2000—2014年中国粮食主产区植被生态系统WUE呈上升趋势,且年内呈M型的双峰结构,季节和空间尺度上的分布具有显著差异。     

Investing in water for food, ecosystems, and livelihoods: An overview of the comprehensive assessment of water management in agriculture

The authors of the recently completed Comprehensive Assessment of Water Management in Agriculture (CA) concluded that there are sufficient water resources to produce food for a growing population but that trends in consumption, production and environmental patterns, if continued, will lead to water crises in many parts of the world. Only if we act to improve water use will we meet the acute fresh water challenge. Recent spikes in food prices, partially caused by the increasing demand for agricultural products in non-food uses, underline the urgent need to invest in agricultural production, of which water management is a crucial part. The world experienced similar pressure on per capita food supplies and food prices in the 1960s and 1970s, but the challenges now are different than those we experienced 50 years ago. The world's population is substantially larger, there are many more people living in poverty, and the costs of many agricultural inputs are much higher. The current situation and the long-term outlook require a fresh look at approaches that combine different elements such as the importance of access to water for the poor, providing multiple ecosystem services, rainwater management, adapting irrigation to new needs, enhancing water productivity, and promoting the use of low-quality water in agriculture. This special issue highlights the analysis behind a number of policy options identified by the CA, a five-year multi-disciplinary research program involving 700 scientists. This introductory article sets the background and context of this special issue, introduces the key recommendations from the CA and summarizes the papers in this issue.     

干旱区农业水资源供需水预测分析及对策研究

针对西北干旱区农业水资源短缺的问题,以新疆洛浦县为例,从作物种植结构调整和灌溉面积变化、灌溉水利用系数提高及灌溉方式改变等方面进行节水分析,并对预测水平年农业供需水平衡进行了预测计算,预测结果表明：现有的灌排工程不能满足农业可持续发展要求;提高灌溉水利用系数势在必行;采用滴灌技术极大地减少了农业用水量,是解决农业供需水矛盾的有效措施。最后,根据预测结果,提出了解决农业水资源短缺、可持续发展的对策,为其他区域水资源的合理开发利用提供有益的参考。     

The impact of water and agriculture policy scenarios on irrigated farming systems in Italy: An analysis based on farm level multi-attribute linear programming models

The objective of this paper is to evaluate the impacts of agriculture and water policy scenarios on the sustainability of selected irrigated farming systems in Italy, in the context of the forthcoming implementation of the directive EC 60/2000. Directive EC 60/2000 (Water Framework Directive) is intended to represent the reference norm regulating water use throughout Europe. Five main scenarios were developed reflecting aspects of agricultural policy, markets and technologies: Agenda 2000, world market, global sustainability, provincial agriculture and local community. These were combined with two water price levels, representing stylised scenarios for water policy. The effects of the scenarios on irrigated systems were simulated using multi-attribute linear programming models representing the reactions of the farms to external variables defined by each scenario. The output of the models consists of economic, social and environmental indicators aimed at quantifying the impact of the scenarios on different aspects of sustainability relevant for irrigated farming systems. Five Italian irrigated farming systems were considered: cereal, rice, fruit, vegetables and citrus. The results show the diversity of irrigated systems and the different effects that water pricing policy may produce depending on the agricultural policy, market and technological scenarios. They also highlight a clear trade-off between socio-economic sustainability and environmental (water, nitrogen, pesticide) sustainability. Water pricing will have, in most cases, less impact than agricultural markets and policy scenarios, though it appears to be an effective instrument for water regulation in the least intensive irrigated systems considered. This emphasises the need for a differentiated application of the Water Framework Directive at the local level as well as a more careful balance of water conservation, agricultural policy and rural development objectives.     

关于现代农业技术的推广与应用谈讨

中国作为一个农业大国，近几年来随着社会主义改革新农村这一伟大战略战略的深入实施，不断加强推广了现代农业技术的应用，对进一步发展现代农业有着深远的影响。文章着重分析了新时期现代农业技术需求和供给特点，就怎样才能推动农业技术成果应用和推广这一问题进行探讨，为增强农业的竞争力和可持续发展，进一步提高我国农业的科技的应用水平起到一定的促进作用。     

Application of GIS and crop growth models in estimating water productivity

Tighter competition in water use is projected in the future. As water demand increases, water related problems could happen along the way. Accordingly, issues on water availability and use could be crucial to study to search for ways and means on how to cope up with the present trend. Sound water management practices could play a key role to the solution of problems relating to water availability and use. Water use in agriculture is considered the highest among other water users because of the water intensive processes involved in it. Aside from the crop water requirements, water loss, which are not beneficial to crop processes can add a huge volume to the total water usage in agriculture. Base from this argument, there could be greater possibility to save water from agriculture, which can be used for other purposes thereafter. To explore this option, analysis at the crop level could be beneficial. However, the issue of scaling should be also considered because the knowledge on the field scale could not be generally true in the basin scale. The objective of the study was to apply crop growth simulation models coupled with geographic information system (GIS) to analyze water productivity, which is an indicator of water use efficiency, at the basin scale.The methodology was applied to Laoag River Basin in Ilocos Norte, Philippines to study water productivity in spatial and temporal dimensions. Three crops were considered in the analysis: rice, maize and peanut. Simulations were done for both existing and potential agricultural areas. The potential productions of the selected crops from October 1996–September 1997 were used as bases in determining water productivity for the three cropping seasons (CS) being considered in the study. Water-limited productions were simulated for each of the crops, for each of the CS in the basin. Moreover, a marginal productivity analysis was done to determine the potential of water for crop production in the basin. Subsequently, the significance of irrigation was emphasized in the analysis when availability of water, and the combination of water and nitrogen (N) are limiting, respectively. The results showed that the spatio-temporal analysis of water productivity could provide substantial information for water saving opportunities and, hence, strategies in irrigated agriculture.     

Traditional cropping systems in northwestern Spain (Galicia)

Traditional crops and cropping systems in small-farm agriculture are the result of many years of evolution and selection by the farmers, generally directed towards self-consumption. These systems have been normally based on multiple cropping and intercropping and have been described in areas of Africa, America and Asia, but not generally in Europe. This paper presents the case of Galicia, a region, located in the northwestern corner of Spain, where traditional family land division and other sociological factors have led to a small-farm situation. Surveys conducted in Galicia previous to a thorough investigation of cropping systems show that multiple cropping and intercropping have been the basis of agricultural systems and they are still used extensively. At present, there are three basic crop rotations which differ in the degree of cropping intensity. The three rotations are the annual sequence of corn-Italian ryegrass (intercropped), a 2-year system consisting of corn or potatoes-wheat or rye-turnips and a 2-year system of rye (fallow). A variety of intermediate forms is found that can be considered as having evolved from the three basic rotations. The study also shows how climatic conditions and other factors such as soil fertility, type of farming and labour requirements affect cropping intensity and how the level of intensification influences the total annual dry matter yield per unit of land. These yields can vary from 17–21 t ha⁻¹ in rainfed conditions in the most intensive areas to 2·4 to 3·5 t ha⁻¹ in the rye (fallow) system. At present, the cropping systems of many areas of Galicia are rapidly changing toward a more commercial type of agriculture, because of technical, economic or sociological factors.     

Intensive versus low-input cropping systems: What is the optimal partitioning of agricultural area in order to reduce pesticide use while maintaining productivity?

Pesticide use should be reduced for sustainable agriculture. Low-input cropping systems, centered on hardy varieties that maintain their yield in the presence of pests, allow pesticide use to be reduced. Since yield potential is generally lower for hardy varieties than for high-yielding varieties, a balance must be found between production and pesticide reduction. In order to compute the optimal partitioning of agricultural area between intensive and low-input cropping systems, we present a model that allows yield and gross margins to be computed at the landscape scale, as a function of the proportion of the area under intensive and low-input systems. The model shows that two cases must be distinguished, depending on inoculum production by each of the coexisting systems. If the low-input system produces less inoculum (e.g. because resistant varieties are used), coexistence can be optimal, whereas if the low-input system produces more inoculum (e.g. because tolerant varieties are used), it is best to devote the whole area to a single system. The model gives the gross margin for each cropping system as a function of the proportion of low-input systems - and so predicts the proportion to which the farmers’ choices will lead - and illustrates the use of different (simplified) policies that would ensure that the optimum proportion is reached.