Valuing groundwater recharge through agricultural production in the Hadejia-Nguru wetlands in northern Nigeria

This study applies a production function approach to value the groundwater recharge function of the Hadejia‐Nguru wetlands in northern Nigeria. The groundwater recharge function supports dry season agricultural production which is dependent on groundwater abstraction for irrigation. Using survey data this paper first carries out an economic valuation of agricultural production, per hectare of irrigated land. We then value the recharge function as an environmental input into the dry season agricultural production and derive appropriate welfare change measures. Welfare change is calculated using the estimated production functions and hypothetical changes in groundwater recharge and hence, groundwater levels. By focusing on agricultural production dependent solely on groundwater resources from the shallow aquifer, this study establishes that the groundwater recharge function of the wetlands is of significant importance for the floodplain.     

Rice productivity in Bangladesh: What are the benefits of irrigation?

Green Revolution technologies transformed Bangladesh’s agricultural system through the introduction of high-yielding rice and wheat varieties, chemical fertilizers and pesticides, and the expansion of tubewell-irrigated area, enabling crop production during the dry season. However, serious challenges continue to plague the agriculture sector, including scarcity of land due to high population density, unbalanced use of fertilizers and pesticides, and great variation in water supply across seasons – from drought to stagnant flood conditions. Further expansion of irrigated area – including through the continued development and improvement of surface water systems – is being eyed by Bangladesh’s Ministry of Agriculture to address many of the remaining challenges facing the country. However, such expansion is not without risks or consequences, and a careful analysis of who benefits from irrigation, and how, must guide development priorities.We examine plot-level data for rice production during Bangladesh’s three rice seasons – aus, boro, and aman – across a nationally-representative household survey in Bangladesh. While rainfall is the most important determinant of rice yield during aus and chemical inputs are most important during aman, access to irrigation has the greatest influence on boro rice yield during the dry season, particularly for the coastal south. The government of Bangladesh is planning massive investments in the southern region for the improved provision of surface water irrigation. The expected decline in groundwater, coupled with our econometric findings, suggests that expanding boro production in the south may not be a good strategy to promote, for the region. Whether brackish shrimp aquaculture can provide an equitable and sustainable livelihood alternative should continue to be a focus of research.     

Delayed monsoon,irrigation and crop yields

Most of the empirical literature assessing the impacts of climate change on agriculture has modeled crop yields as a function of the levels or deviations in the growing-period rainfall. However, an aspect that has received little attention in the empirical literature relates to the relationship between the timing of monsoon rains and crop yields. Using a pan-India district-level panel dataset for 50 years, this article investigates two interrelated issues critical to understanding the impacts of weather-induced agricultural risks and their management. It first examines the impact of the timing of monsoon onset on crop yields and then assesses the role of irrigation in mitigating its effects. The article finds that the delayed onset of monsoon is detrimental to crops, and its effects are realized beyond the rainy season. The findings also demonstrate that irrigation helps mitigate the harmful effects of delayed monsoon. Finally, to link these findings to farm-level adjustments, the article shows that farmers explicitly adjust the timing of irrigation in response to delays in monsoon rains.     

湄公河流域水资源开发利用现状

根据湄公河流域自然特征、水资源现状、水利工程现状及规划资料,分析湄公河各流域国水资源开发利用特点及未来趋势,为湄公河水资源可持续开发利用及我国同湄公河各流域国开展相关合作提供最基本的依据。研究结果表明,湄公河水资源开发利用率呈上升趋势;老挝未来将加快水电开发节奏,其规划水电总装机容量占湄公河总装机容量的70.0%;泰国对湄公河水资源的开发利用主要体现在农业灌溉方面,未来泰国灌溉引水有增加的趋势;柬埔寨和越南分别在湄公河干支流上有水电工程规划,但柬埔寨的用水需求主要体现在为保证其洪泛区土壤肥力,对湄公河上游雨季充足的洪峰流量的需求,越南是湄公河流域灌溉面积最大的国家,其主要的用水需求是旱季湄公河三角洲灌溉需水。     

Smallholder dairy cattle feeding technologies and practices in Tanzania: failures,successes, challenges and prospects for sustainability

In Tanzania, milk production under smallholder farming systems is season sensitive, fluctuations of feeds in both quantity and quality being the major driver. A dry season decline in milk production of over 40% due to feed scarcity is a common phenomenon. Adoption of improved feed production, conservation and utilization technologies and practices in dairy farming communities is poor. This review work was based on a key question which states “Why is adoption of improved dairy nutrition technologies and practices in Tanzania still poor despite being promoted for decades?”. We have shown that major opportunities for curbing dry season animal feed shortage include on-farm optimization of production and use of high yielding pasture varieties including napier grass (Pennisetum purperium Schumach.) and leguminous fodder species. Crop residues in particular maize stover needs to be optimized for effective dry season feeding. The major reasons for low adoption of proven technologies include limited technical knowhow among smallholder dairy farmers augmented by limited extension services and technological costs. For enhancing sustainable uptake; we suggest promotion of on-farm research, public-private partnerships and dairy farmers’ cooperative associations. These are vital for facilitating smooth access to information, investment capital, reliable inputs and markets among the smallholder dairy farmers.     

山东省雪野水库灌区管理体制与运行机制改革浅析

介绍了雪野水库灌区管理体制与运行机制改革情况，在分析借鉴其经验的基础上，对我国水库灌区管理体制与运行机制改革提出了对灌区产权制度、人事劳动分配制度、农业用水水价制度、水费征收制度进行改革，建立以农户参与灌溉管理为主的灌区基层管理体制的建议。     

Growing struggle over rising demand: How land use change and complex farmer-grazier conflicts impact grazing management in the Western Highlands of Cameroon

Continuous population growth and rapid urbanization rates in West and Central Africa are associated with rising demand for fresh vegetables and animal-based products, providing market opportunities for local producers from the surrounding areas. However, in regions such as northwestern Cameroon where pastoral cattle breeding remains an important part of the local livestock sector, competition over dwindling resources with local crop farmers are increasing due to progressive land-use change from natural and traditional grazing areas into agricultural land.In order to determine the main areas of conflict and their interdependencies, we used a multi-temporal land-use classification and a multi-dimensional participatory approach of collecting spatial data from six representative Mbororo cattle herds, equipped with GPS collars. We combined this with 162 map-based interviews with randomly sampled pastoralists on seasonal grazing areas, grazing management, land ownership, and major constraints to herding. This data set was complemented by the perspectives of 40 randomly sampled crop farmers from four major transhumance zones.Both parties identified farmer-grazier conflicts as a serious constraint for their activities in the rainy season (graziers: 23.9 %; farmers: 22.5 %) and particularly in the dry season (36.3 %; 47.2 %). Land tenure issues will be of critical importance in the future as only very few respondents held an official land title, and pastoralists appeared less prepared for land disputes than crop farmers, who more often claimed land ownership through fencing. Therefore, there is an urgent need for developing and implementing alliance farming strategies that are based on dialogue between both interest groups to avoid further escalation within a region already in a conflict-ridden political environment.     

河道生态基流价值研究进展

分别从水资源价值、水生态环境价值与生态基流价值以及保障补偿等方面,评述了国内外河道生态基流的研究进展与存在问题。认为应将河道生态基流价值的定量计算和保障补偿作为后续研究的重点,以便为缺水地区生态基流长效保障机制的建立与枯水期有限水资源的科学管理等提供理论支撑与科学依据。     

中国传统灌溉工程及技术的传承和发展

中国兴修灌溉工程的历史悠久，积累了丰富的工程技术经验。文章认为我国人民因地制宜创造的传统灌溉工程类型，如引水渠道、陂塘堰坝、陂渠串联、圩垸、井灌、御成蓄淡等在现今皆得到了继承。传统的灌渠工程技术、塘堰和开发地下水工程技术、圩田和海塘工程等许多卓越技术在现今也得到传承和发扬。在阐述以上事实的基础上进一步分析总结了传统工程及技术继承的特征、要点，及改造利用的途径与意义。     

Private irrigation investment in Colombia: effects of violence,macroeconomic policy,and environmental conditions

This paper identifies and estimates the effects of several determinant, on private investment in irrigation in Colombia. It attempts to quantify macroeconomic policy, environment, and violence variables that have been identified in previous studies as significantly affecting investment, in agriculture in genera., and in irrigation in particular. Variables such as violence, climate, and governmental price credit policies are used to explain changes in private investment in irrigation across regions and over time. Violence negatively affects private investment. Climate affects the investment such that in regions with favorable climate condition, investment in irrigation is less attractive, and appropriate government crop-price and credit policies promote investment in irrigation.     

DEVELOPMENT AND ANALYSIS OF INPUT-OUTPUT RELATIONS FOR IRRIGATION WATER

Recent developments in climatology mean that economists now have a highly acceptable physical theory which can underlie their analysis of the economic aspects of water as an input to the production process, as a source of production instability, and as a major component of error in their estimated crop production functions. This paper presents a model and a procedure for synthesising and analysing irrigation water crop input output relations based on this theory. The importance of time of application of water as well as quantity is shown. Different frequencies of irrigation are optimal at different times of the growing season.     

Adoption of Drought Tolerant Maize Varieties under Rainfall Stress in Malawi

We examine adoption of drought tolerant (DT) maize varieties using a four‐round panel dataset from six districts in Malawi. There is an increase in adoption of DT maize from 3% in 2006 to 43% in 2015 in our data. We focus on the effect of past drought exposure on adoption and the likelihood of DT maize being distributed under the Farm Input Subsidy Programme (FISP). Results show that past exposure to drought increases the probability of DT maize seed being distributed through FISP. Farmers who accessed maize seed subsidy coupons and were previously exposed to late season dry spells are more likely to use the seed subsidy coupon to redeem DT maize seed. The likelihood of adoption and adoption intensity (area under DT maize) are positively influenced by previous early season dry spells and access to seed subsidy. Previous late season droughts also positively affect adoption intensity. On the other hand, area share under DT maize is positively correlated with early season dry spells and past exposure to late season dry spells but negatively related to seed subsidy. FISP in Malawi appears to have stimulated adoption of DT maize directly through subsidy and indirectly through generating farmers’ experiences of the performance of DT varieties under drought conditions.     

中国的灌溉发展及其作用

分析中国发展灌溉的必要性,回顾农业灌溉的发展状况,从提高作物产量、保障供水安全、粮食安全、增加农民收入、创造就业机会和改善生态环境等6个方面论述了中国灌溉及农村水利事业的巨大成就,并提出提高灌溉用水利用率和效益、改善农业生产条件、解放农村劳动力、促进农业结构调整以及增加生态系统用水、改善农村地区生态环境等建议。     

Economic assessment of acquiring water for environmental flows in the Murray Basin*

This article is an economic analysis of reallocating River Murray Basin water from agriculture to the environment with and without the possibility of interregional water trade. Acquiring environmental flows as an equal percentage of water allocations from all irrigation regions in the Basin is estimated to reduce returns to irrigation. When the same volume of water is taken from selected low-value regions only, the net revenue reduction is less. In all scenarios considered, net revenue gains from freeing trade are estimated to outweigh the negative revenue effects of reallocating water for environmental flows. The model accounts for how stochastic weather affects market water demand, supply and requirements for environmental flows. Net irrigation revenue is estimated to be 75 million less than the baseline level for a scenario involving reallocating a constant volume of water for the environment in both wet and dry years. For a more realistic scenario involving more water for the environment in wet and less in dry years, estimated net revenue loss is reduced by 48 per cent to 39 million. Finally, the external salinity-related costs of water trading are estimated at around 1 million per annum, a quite modest amount compared to the direct irrigation benefits of trade.     

粮食主产区妇女的农田水利管理模式偏好及参与灌溉管理意愿研究

粮食主产区担负着保障国家粮食安全的重任,农田水利是农业生产的基础。在新型城镇化背景下,妇女是农业生产的主要劳动力。粮食主产区妇女的农田水利管理模式偏好及参与灌溉管理意愿对确保粮食安全至关重要。结果表明,集体化、家庭化解决了分散、细碎农地的灌溉问题,乡村精英能降低农田水利市场化程度,男性青壮年劳动力可缓解农田水利的灌溉压力。"单打独斗"的灌溉管理模式不足以保障水田作物的季节性需求。农村教育、耕地面积、乡村精英管理有助于增进妇女参与农田灌溉管理的意愿。     

Water access,farm productivity,and farm household income: Sri Lanka's Kirindi Oya irrigation system

Income differences attributed to differential access to water in irrigation systems are common. Prior studies of farm‐level water use in developing areas have typically been limited to using number of irrigations as a proxy for water use. We develop a volumetric measure in Sri Lanka's Kirindi Oya Irrigation System through recent farmer recall and use it in production function estimation and welfare analysis. Findings indicate substantial differences in water use by farms across seasons and across subareas of the irrigation district. Alternative plans for allocating additional water among seasons and subareas to elevate net rice revenues are examined. The recommended plan predicts higher net returns from rice and greater equality in the distribution of household income than would be generated if the additional water were allocated based on the current allocation criteria. Concurrent application of fertilizer at recommended levels would further increase net revenues and reduce income inequality.     

Technical,Allocative, Cost and Scale Efficiencies in Bangladesh Rice Cultivation: A Non‐parametric Approach

Applying programming techniques to detailed data for 406 rice farms in 21 villages, for 1997, produces inefficiency measures, which differ substantially from the results of simple yield and unit cost measures. For the Boro (dry) season, mean technical efficiency was 69.4 per cent, allocative efficiency was 81.3 per cent, cost efficiency was 56.2 per cent and scale efficiency 94.9 per cent. The Aman (wet) season results are similar, but a few points lower. Allocative inefficiency is due to overuse of labour, suggesting population pressure, and of fertiliser, where recommended rates may warrant revision. Second‐stage regressions show that large families are more inefficient, whereas farmers with better access to input markets, and those who do less off‐farm work, tend to be more efficient. The information on the sources of inter‐farm performance differentials could be used by the extension agents to help inefficient farmers. There is little excuse for such sub‐optimal use of survey data, which are often collected at substantial costs.     

Pastoralism within land administration in Kenya—The missing link

In land administration (LA), the right to exercising property/ownership rights on land is based on cadastral processes of adjudication, survey and rights registration. Private ownership rights are now being taken up in pastoral areas, where they must contend with pastoralists’ land rights. Pastoral land use requires seasonal migrations determined by climatic conditions. This study aimed to find out how well the existing land laws and property rights in LA are able to serve the requirements of pastoralists land use, identify mismatches and put forward possible solutions. A case study was carried out in the Samburu–Laikipia–Isiolo–Meru landscape in Kenya. Data on the degree of livestock dependency among pastoralist communities, the spatial extent and patterns of dry season migrations, the resulting encounters between herders’ and non-pastoralist land use actors, and the perceptions of land rights held by actors were collected through a variety of methods and analysed. The results show that pastoralism is still active. The migration corridors reveal that herders maintain extensive dry season mobility, even though some of the corridors currently overlap with areas where land is privately owned by non-pastoralist land use actors. Moreover, the results show that most non-pastoralist land use actors have their land rights registered, but seasonal encounters with migrating pastoralists persist as pastoralists continue to exercise customary rights of communal use. We conclude that existing land laws and property rights in LA are suitable for sedentary land use, but do not address how to serve pastoralists land rights in time and space. The pastoralist's migration routes and patterns obtained indicated that it is possible to predict where pastoralists will be at a given time/drought period. This information could be used by decision makers and land administrators to identify where and when pastoralists’ land rights apply. This could provide the foundation for including pastoralists’ spatiotemporal land rights in LA. Arguments emphasize that adjudication, surveys and registration of rights should focus not only on ownership and full control of land, but also on defined periods when spatiotemporal mobility and access rights could be granted to pastoralists.     

‘Second-generation’ MVs and the evolution of the Green Revolution: the case of Central Luzon, 1966–90

By now new modern rice varieties (MVs) with multiple pest and disease resistance have completely replaced early MVs, such as IR5 and IR8, except in a few areas of Asia. This study attempts to identify the changing impacts of ‘first-generation’ and ‘second-generation’ MVs on productivity in rice farming by estimating the yield function, while correcting selectivity bias arising from the choice of varieties. For this purpose, we used farm-level survey data collected for eleven cropping seasons in Central Luzon in the Philippines from 1966 to 1990. We found that while the yield advantage of first-generation MVs over traditional varieties was limited, the yield-increasing effect of second-generation MVs over first-generation MVs was highly significant. In particular, the adoption of improved MVs significantly contributed to yield growth under the irrigated condition and during the dry season. Thus, we conclude that the Green Revolution would not have been revolutionary without the development and the diffusion of second-generation MVs with multiple pest and disease resistance.