Irrigating Africa: policy barriers and opportunities for enhanced productivity of smallholder farmers

Abstract

African governments have ambitious plans to expand irrigated agriculture, though existing smallholder schemes have largely failed to use land and water sustainably or become profitable. Six government-owned irrigation schemes in Mozambique, Tanzania and Zimbabwe were assessed to identify common policy barriers and opportunities for higher productivity among smallholder farmers. Issues like insecure land tenure systems, unclear institutional arrangements and poor access to markets have contributed to limited profitability. Reform of currently insecure land tenure, strengthening farmer organizations and reforming policies are recommended so that governments step back from scheme management and foster market linkages to enable more profitable irrigated agriculture.     

Understanding smallholder irrigation in Sub-Saharan Africa: results of a sample survey from nine countries

Smallholder irrigation is emerging as a development priority in Sub-Saharan Africa. Based on a survey of 1554 smallholders from nine countries, this paper compares rainfed farming with gravity-flow, manual-lift and motor-pump irrigation. Motor-pump-irrigation farmers reported the highest net value added per acre and per family worker, with gravity-flow and manual-irrigation farmers earning marginally more than rainfed-only farmers. In addition to making affordable pumps more readily available, improving the availability of working capital, enhancing security of tenure and ensuring the availability of affordable fuel are all likely to accelerate smallholder irrigation development in Sub-Saharan Africa.     

地下水灌溉服务市场对农业用水生产率的影响

基于2001年和2004年在河北省和河南省的实地调查,定量分析地下水灌溉服务市场对农业用水生产率的影响。研究结果表明,地下水灌溉服务市场有利于提高作物单位用水的生产率(产出能力和经济价值)。因而,有效地促进地下水灌溉服务市场可以在一定程度上提高水资源的管理水平,缓解水资源短缺的矛盾。     

Livelihood assets and institutions for smallholder irrigation farmer market access in Limpopo,South Africa

Despite having access to irrigation water, many smallholder irrigation farmers in rural South Africa remain subsistence-oriented, with little market participation. Their tangible and intangible assets influence production and market access. Largely qualitative data collected in rural Limpopo Province show that the farmers’ tangible assets supported production but in some instances restricted them from producing efficiently. Likewise, their intangible assets mostly limited their capacity to produce efficiently, to find markets or to organize themselves. These farmers’ tangible assets need to be upgraded and their intangible assets need strengthening to increase production capacity and marketing efficiency.     

广西节水灌溉发展的思考

广西雨量充沛 ,但是由于降雨时空分布不均匀 ,季节性、区域性缺水现象严重 ,干旱缺水是制约广西农业生产发展的主要因素之一 ,普及、发展节水灌溉是解决目前面临缺水问题的有效途径。作者对发展广西节水灌溉必要性及存在问题作了分析 ,并对今后节水灌溉工作提出了几点建议。     

现代灌溉水管理发展理念及改善策略研究综述

对现代灌溉水管理发展理念和改善策略的研究进展与趋势进行综述,探讨了有关的研究重点与内容.现有成果表明,研究探索诸如考虑农田排水或灌溉回归水再利用的灌溉效率、灌溉经济社会净收益极大化的经济效率以及灌溉用水尺度的水分生产率等灌溉水管理发展理念及其改善策略,对加强灌溉水管理、提高农业用水效率、确保食物安全、减少环境负效应、增加农业产出效益具有十分重要的意义和作用.鉴于灌溉效率、经济效率、水分生产率等指标具有明显的尺度效应,应在研究建立相应于各评价指标的尺度化特定表达式基础上,探索不同尺度特定表达式间可能存在的定量转换关系,实现相同评价指标下的尺度数量转换,为评价灌溉用水尺度效用、采用适宜于不同用水尺度的灌溉水管理策略提供科学的分析手段与定量方法.     

Theory and application of Agricultural Innovation Platforms for improved irrigation scheme management in Southern Africa

Abstract

Many small-scale irrigation systems are characterized by low yields and deteriorating infrastructure. Interventions often erroneously focus on increasing yields and rehabilitating infrastructure. Small-scale irrigation systems have many of the characteristics of complex socio-ecological systems, with many different actors and numerous interconnected subsystems. However, the limited interaction between the different subsystems and their agents prevents learning and the emergence of more beneficial outcomes. This article reports on using Agricultural Innovation Platforms to create an environment in which irrigation scheme actors can engage, experiment, learn and build adaptive capacity to increase market-related offtake and move out of poverty.     

宁夏引黄灌区井渠双灌节水效益分析

宁夏引黄灌区是重要的粮食生产基地,其农业耗水占据了绝大部分引黄耗水量。本文在以引黄水量为主要灌溉水源、适量采用开采地下水作为补充的基础上,对整个灌区采用地表水与地下水联合灌溉的节水效益进行了定量研究。结果表明,采用井渠双灌现状年引黄灌区十县市可减少渠首引水量1.53×108m3,减少损失水量将达到0.68×108m3。对2010年的预测结果表明,可减少田间引黄灌溉用水量1.95×108m3,减少渠首引黄水量为3.48×108m3,减少输水过程中的损失水量为1.54×108m3,具有显著的节水效益。     

我国农业灌溉用水定额编制和应用现状

简述了我国农业灌溉用水定额编制所经历的4个阶段及形成的定额成果分类,统计分析了各省(自治区、直辖市)农业灌溉用水定额编制、修订和应用现状,针对灌溉用水定额在应用中存在的主要问题提出了相应的对策建议,以期为各地考核水资源总量控制和定额管理,实施最严格水资源管理制度提供依据。     

农业结构调整与节水灌溉

论述农业结构调整与节水灌溉的关系 ,指出农业结构调整进行节水灌溉是发展节水高效农业及实现农业可持续发展的有效途径。     

运城市灌区农业节水途径探索

从运城市的基本情况出发,根据灌区内水资源状况,提出了引用客水置换地下水的发展战略;结合运城市灌区的实际和发展规划,认为灌区农业灌溉节水的潜力巨大,必须加大工程和管理节水力度,探索灌区农业节水新途径。     

农业高效用水研究进展与成果回顾

在系统阐述农业高效用水研究进展与发展趋势基础上,对农业高效用水研究领域取得的主要成果及创新进行回顾和综述。在应用基础与前沿技术方面,开展农田水土管理、灌区节水决策、精量灌溉预报决策、精量控制地面灌溉、喷微灌水肥高效利用、农田氮素迁移转化与控制等方法和技术研究;在关键技术与产品方面,对喷滴灌、地面灌、管道输水灌溉、灌区用水管理、农田排水与涝渍灾害防治、劣质水资源化灌溉利用、农业水资源开发利用、节水灌溉设备质量监测与评价等技术和产品进行研发;在宏观战略与发展对策方面,开展农村水利发展战略、粮食安全与灌溉发展战略、节水灌溉发展战略和农村水利科技发展战略等研究。通过国家重大科技成果推广应用项目,对取得的科技成果进行转化和推广应用,为我国农业高效用水提供了新技术、新方法和新产品。     

Irrigation and crop diversification in the 25 de Setembro irrigation scheme,Mozambique

Abstract

Crop diversification is one way of improving the profitability of small-scale irrigation schemes. The 25 de Setembro scheme is an ideal site to analyze diversification, as it is influenced by the markets in Maputo and South Africa. This study uses information gathered from observations, discussions with irrigators and an irrigator survey. Results identified seven irrigator types with different crop diversification strategies predominantly influenced by resource constraints. Most irrigators produce traditional crops, although there are opportunities for growing crops that are more profitable. Improved extension services, to identify cropping strategies that better align with market demand, would improve profitability.     

农业灌溉用水量核算方法对比研究

为了评价区域水资源承载状况,需要将区域现状年实际产生的用水量核算至评价口径。在以往工作的基础上,提出了三种较为实用的农业灌溉用水量核算方法:现状法、典型年法和长系列法。分析表明:计算分区A近几年年降雨量情况能够代表平水年或多年平均情形,可采用现状法对农业灌溉用水量进行核算,结果显示该区域应核减农业灌溉用水量0. 31亿m~3。计算分区B近几年区域降雨不能够代表丰枯变化,整体偏枯,可采用典型年法对农业灌溉用水量进行核算,结果显示该区域应核减农业灌溉用水量0. 43亿m~3。计算分区C基础资料齐全、年降雨频率偏丰及偏枯区域均适用,应采用长系列法对农业灌溉用水量进行核算,结果显示该区域应核增农业灌溉用水量1. 48亿m~3。总得来说,现状法较为简便,资料易于获取,但有一定的局限性,受近几年的降雨量影响较大;典型年法相对较为复杂,且对于评价年份降雨较丰的区域不适用。因此,在基础资料完备的情况下,长系列法适应性较强。     

Performing the success of an innovation: the case of smallholder drip irrigation in Burkina Faso

Over the last 15 years, smallholder drip irrigation has gained almost unanimous popularity as an effective tool to achieve the combined goals of sustainable water use, food security and poverty alleviation in the developing world. Based on a study in Sub-Saharan Africa, this article shows that this popularity does not stem from what the technology does in farmers’ fields, but is the result of the concerted efforts of a number of key spokespersons to align it with the projects and interests of a variety of actors, including development agents, researchers, NGO staff and pilot farmers.     

Rethinking commons management in Sub-Saharan West Africa: public authority and participation in the agricultural water sector

Promoted for over three decades, participatory irrigation management (PIM) and its organizational upshot the water user association (WUA) have been framed as a solution to the irrigation sector problems. Based on a case study of small reservoirs in two countries of West Africa, Burkina Faso and Ghana, this article shows that the PIM/WUA model is based on narrow visions of the commons and participation and does not account for the de facto pluralism and institutional bricolage that characterize natural resources management. Attempts at institutional intervention should be based on better understanding social relationships and existing processes of decision making.     

浅谈青狮潭水库灌区节水灌溉

随着社会经济的发展 ,青狮潭水库水资源利用范围不断扩大 ,青狮潭水库灌区节水问题也显得更为重要 ,主要介绍青狮潭水库灌区节水灌溉的措施和存在问题     

波涌灌溉的灌水质量评价及计算

本文通过清、浑水连续灌与波涌灌溉的大田试验，对波涌灌溉的灌水均匀度、灌水效率及储水效率进行了评价，同时在文中提出了一种无需灌后土壤水分资料即可计算灌水质量评价指标的新方法，从而为波涌灌溉技术要素优化设计的灌水质量评价，提供了数学模拟计算的可能。     

水分生产率指标随空间尺度变化规律

根据漳河灌区4年田间及中等尺度的水量平衡试验,以及同步的灌溉系统及灌区尺度的水量观测,结合利用遥感信息估算的灌溉系统及灌区尺度的腾发量获得不同年份不同尺度的水量平衡要素。根据实测或统计资料获得不同尺度的水稻产量资料。计算分析了各种水分生产率指标及水量消耗比例指标随不同空间尺度及不同水文年度的变化规律。结果表明：灌溉水分生产率及毛入流量水分生产率总体上随空间尺度的增大而增大,但于某些年份在中等尺度上有降低的现象;水稻腾发量水分生产率则随时空尺度变化不大;采用节水灌溉技术不仅可以提高田间尺度的灌溉水分生产率,也促进了灌区灌溉水分生产率的整体上升,达到了真实节水;水分生产率指标受降雨及其年内分配的影响,另外,水管理措施的好坏显著影响水分生产率指标的高低。