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1.
Recent droughts in the humid southeastern United States have focused attention on the need for and use of supplemental irrigation. Total annual rainfall amounts are sufficient for most crops in the region. However, erratic distribution of rainfall and the low water-holding capacities of most soils in the region cause frequent drought stresses in many crops. An on-farm study was conducted in southeastern Alabama to evaluate the effects of farmers' irrigation scheduling decisions on soil moisture variations in peanut fields irrigated with center-pivot irrigation systems. The study showed that the way irrigation was practiced in this high rainfall area often caused soil moisture deficit (SMD) level higher than the desired SMD limit during over 20% of the 140-day growing season. This is partially due to farmers' tendency to delay irrigation in anticipation of rainfall which may or may not occur, as rainfall during the growing season is often erratic and local. In contrast SMD in non-irrigated fields was higher than the SMD limit for half of the growing season.Abbreviations SMD
soil moisture deficit
- ET
evapotranspiration
- Reff
effective rainfall
- WHC
water holding capacity 相似文献
2.
The sustainability of self-governingirrigation schemes is currently underpressure in many countries as publicfinancial support is decreasing.Furthermore, growing global concernregarding water scarcity means thatefficient water use is essential.Theoretically the choice and implementationof a water-pricing system should play acentral role in achieving this objective,both by recovering water costs and byencouraging farmers to adopt more efficientbehaviour. In the Senegal River Delta newlyestablished water users associations (WUAs)have chosen low water charges, which areaffordable for the majority of farmers butwhich underestimate long-term maintenancecosts. Combined with the difficulty ofcollecting and managing farmers' fees, thischoice has drawn them into a vicious circleleading to scheme deterioration and poorwater service. New alternatives have beendiscussed with them using a simulation toolthat takes into account both the watercosts and the farmers' incomes. Comparedwith the present fixed water charge basedonly on cultivated land, a two-part optionbased both on equipped and irrigated areasensures the recovery of fixed expenses suchas maintenance, while encouraging farmersto intensify their farming systems byadopting double cropping. Neverthelesschoosing a relevant water charge does notensure by itself the sustainability of anirrigation scheme. Combined supportproviding WUAS and farmers with efficientadvice regarding management andorganisational skills should alsocontribute significantly to achieve thisprime objective. 相似文献
3.
农民对农业水价承受能力研究 总被引：9，自引：1，他引：9
农民是农业水价承受的主体，其承受能力的大小决定着农业水价改革的力度和进程，通过对人民胜利渠道灌区农民对农业水价承受能力的调查:揭示了灌区的运行能力是随着农业水价的上调逐步增加的，而用水是逐步减少的;农民对农业水价改革的承受能力是非常有限的;当农业水费占到农民年收入的4%一6%(支出的6%一8%)、农业投入的10%-12%和产出的8%-10%时，农民普遍认为水价合理或者基本合理，表示可以接受、愿意缴纳，说明水费没有超出农民的经济和心理承受能力;提出了促进农业水价改革的综合对策。 相似文献
4.
Mahmoud M. Moustafa 《Irrigation and Drainage Systems》2004,18(2):109-125
The Government of Egypt is mandated toplan, construct, operate, manage, andmaintain the water system. However, withthe growing water demands over supplies inthe country, water management became a verydifficult task. This has led Egypt toreform policies, technologies,institutions, and development strategies tomanage water more effectively. One of thesestrategies is the irrigation managementtransfer (IMT) that has been a majorstrategy adopted to encourage farmers toplay a more important role in irrigationmanagement and related water services andalso share the cost of O&M of irrigationand drainage systems. IMT policy islaunched in Egypt as a pilot phase toexpand water users' participation atsecondary levels of the irrigation anddrainage systems. Four pilot areas (5,000–8,000 acre) representing all categories andgeographical locations of agriculturallands of Egypt were selected to implementthis policy.This study was conducted in these pilotareas prior to the start of any IMTactivities to describe, analyze, andexplain farmers' attitudes towardirrigation maintenance and implementationof IMT process. Socio-economicquestionnaires were designed and used asthe main tool for data collection. Afterthe field pre-test of the surveyinstrument, a sample of 240 farmers, 60from each pilot area, was selected usingthe sampling frame of multi-tiered process,and the statistical data analysis was doneusing SpssWin software.The major result of this study is that,without proper education and interface withfarmers, there is widespread resistance tothe idea farmers assuming management andmaintenance responsibilities beyond theon-farm level. It would have to proceedvery cautiously, and yield responsiveresults if it were to survive in the faceof the attitudes the farmers have shown,with their strong belief in the necessityof the role of the government. Meanwhile,farmers expressed great confidence in theIMT process and its objectives. 相似文献
5.
Luis Santos Pereira 《Irrigation and Drainage Systems》1988,2(1):63-77
In recent years, the traditional concept of an irrigation project has been changing. From just a physical structure for the storage, conveyance and distribution of water, it is now being regarded as a more complex system, including farmers' participation. This implies an improved management in all phases, from reservoir operation to farm management, and therefore the change from simple operation and maintenance to operation, maintenance and management.To face this new challenge, existing projects must be modernized. The Sorraia Irrigation Project is one of those projects. In this paper major problems are identified and it is showed how research (namely through modelling) can be oriented towards an improved management, regarding the conveyance and distribution systems as well as the on-farm systems.Finally it becomes evident that beyond the technical problems to be solved, the involvement and participation of farmers must be improved at all levels of management. Hence, there is also a need for implementing programs on education, training and extension. 相似文献
6.
虚拟仪器技术及其在农业自动化中的应用 总被引：32，自引：0，他引：32
随着计算机技术的发展,基于标准个人计算机平台－－ＰＣ（包括ＰＣ／ＩＰＣ、Ｍａｃｉｎ－ｔｏｓｈ、工作站等）的虚拟仪器技术正成为测试测量与控制领域的重要应用工具。本文概括了虚拟仪器的系统构成及软件结构,简述了虚拟仪器在农业自动化领域的应用实例,介绍了用于精播机性能检测及苹果等级分选的虚拟仪器系统。 相似文献
7.
灌溉水价与灌区灌溉用水量关系研究 总被引：2，自引：0，他引：2
运用经济学理论分析了灌溉水价与灌区灌溉用水量的关系,根据2000—2009年对关中地区冯家山、羊毛湾、石堡川3个灌区的实际调查资料,对不同灌区建立农业灌溉用水需求函数,计算灌溉用水需求价格弹性。研究表明,关中地区3个灌区中,石堡川灌区弹性最高,为-1.11;冯家山灌区和羊毛湾灌区弹性分别为-0.47和-0.69,即灌溉水价提高1%,灌溉用水量将下降0.47%～1.11%。对于现行水价较低的灌区,水价调高对该灌区将产生明显的节水效应;对现行水价较高的灌区,水价继续调高。 相似文献
8.
W. Ray Norman 《Irrigation and Drainage Systems》1998,12(2):161-184
This article provides a detailed case study of land tenure and use during 30 years of small irrigation system operation in Niger Republic. In contrast to larger systems in the region, the state-sponsored system that was studied has developed certain management polices which accommodate farmer preferences and increase farmers' sense of control over the lands they cultivate. The initial process of land expropriation and redistribution, subsequent changes in parcel tenure and land use practices, and concessionary changes in system management by state authorities are reviewed in detail. A long-term policy of parcel inheritance and subdivision within households has resulted in a 37% reduction in mean holding size, a 54% increase in parcel holder population, and greater equity of parcel distribution among beneficiaries. Most parcels have remained within the extended families of the original parcel recipients during the life of the system. Characteristics of land tenure and use policy that have enhanced beneficiary incentives and project sustainability are summarized and a closer examination of the applicability of similar policies and practices among other systems in the region is suggested. Specific areas for future, related research are also proposed. 相似文献
9.
The benefits of improved irrigation efficiency on production and income in rice-based irrigation systems is analyzed using a combination of simulation and structural model estimation techniques for five diversion irrigation systems in the Philippines. The results show that increased efficiencies generate substantial production and income benefits. With the limitations on new system development, designing and enforcing appropriate real-time water resource management policies to capture high potential benefits of improved irrigation efficiency should be an increasingly high priority for policy-makers. 相似文献
10.
灌溉农业在我国有着悠久的历史，我国农业的可持续发展很大程度上依赖于水资源的利用状况。阐述了灌区农户节水行为的影响因素，根据对农户节水行为、农户收支状况等实地调查资料，通过构建农户节水行为决策模型,对农业节水决策等相关方面的问题进行了定量的分析与讨论。研究表明：在农户节水决策过程中，农户受到灌区改革、国家农业政策和自身条件等各种因素的影响，其行为会反映到水资源利用、土地利用变化上，完全可以通过有关数量模型对农户的农业节水行为进行预测。最后，提出了有关政策建议。 相似文献
11.
James J. Layton Frank A. Santopolo Mohamed Naguib 《Irrigation and Drainage Systems》1993,7(4):291-304
The principal finding of the study is that social power positions held by Egyptian farmers sharings a common watercourse do not have significant influence in the farmer's ability to control irrigation water distribution. Other variables used to describe irrigation management; location on the water course and farmers' use of more than one source of water to irrigate; also do not yield any explanations as to why particular farmers have more control over their irrigation than others. Farmers who have more control are less likely to be affected by other farmers' actions, physical problems on delivery canals, breakdown in pumps, and government officials actions. While differences in irrigation control among farmers exist, no single cause is identified. Two explanations for the findings are (1) water control is sufficient for a large percentage of Egyptian farmers, and (2) adequately explaining irrigation behavior cannot be done with separate variables.Deceased 相似文献
12.
新时期农田水利基本建设的战略思考 总被引：7，自引：4，他引：7
分析了我国实施第三步发展战略、全面建设小康社会中所面临的突出问题 ,讨论了农田水利基本建设与农民增收、农业增效、农村发展的关系 ,从不同的角度论证了农田水利基本建设的战略地位 ,并提出了新时期加强农田水利基本建设的建议 相似文献
13.
针对沟（畦）灌技术要素实际存在的模糊性，本文采用模糊规划理论，建立了沟（畦）灌技术要素的模糊优化模型。该模型能广泛吸取专家经验，考虑对灌水的具体要求，又能充分体现科学的计算，对地面灌溉田间用水管理具有一定的指导意义。 相似文献
14.
The logit technique is used to analyze the relationship between dichotomous reactions of satisfaction (satisfied/dissatisfied) with the irrigation system and certain independent variables. The result shows that five important variables — water availability on time, fertilizer availability, landholding size, farmers' participation in irrigation activities and location of farmland along the canal — significantly determine satisfaction. 相似文献
15.
陈晓杰 《农业机械化与电气化》2011,(4):102-103,105
简要介绍我国防渗渠道、喷灌、滴灌、渗灌等节水灌溉技术的发展现状及应用区域,分析我国节水灌溉在应用和技术上存在的问题,提出大力推进节水灌溉的措施,包括：必须综合运用法律、技术、经济和管理等各种手段,建设有中国特色农业的节水技术体系,调动广大农民节水的积极性。 相似文献
16.
王学渊 《中国农村水利水电》2010,(1):8-13
根据2007年西北地区432个农户的实地调查数据,采用随机前沿分析(SFA)和数据包络分析(DEA)方法对微观层面的农户灌溉用水效率进行测度,在此基础上利用配对样本t检验和Spearman相关检验比较分析两类方法的效率估计得分,结果表明虽然规模收益不变假设下的DEA效率值显著小于SFA效率估计值,但两种方法所测算的农户灌溉用水效率排名具有显著一致性。可为深入开展运用不同方法考察农户灌溉用水效率问题提供有益的参考。 相似文献
17.
U Win 《Irrigation and Drainage Systems》1989,3(1):47-61
Irrigation projects are usually planned and designed at national levels. Farmers are considered as one of the inputs for irrigation development. Governmental authorities generally assume that the goal of increasing agricultural production will be achieved when the problem of inadequate water during the cultivation season can be solved by providing irrigation water to the farmers. But it is not uncommon to learn of low production rates and various indicators which exhibit below success rates after the irrigation water is provided to the farmers.This paper addresses a first-time experience with irrigation in a village-tract that lies at the tail of a sublateral of an irrigation project in Burma. It shows that the potential of an agricultural economic boon can easily be frustrated due to a single factor: lack of irrigation know-how at the farmers' level. A discussion of agricultural problems under a military socialistic political economic setting follows. 相似文献
18.
Government disengagement from day-to-daymanagement of irrigation infrastructure hasbecome a widespread strategy in Asia,Africa and Latin America. This paperexamines a case study of managementtransfer of a rice irrigation scheme inGhana. The criteria used relate toagricultural, financial and economicperformance and environmental sustainability.The study showed that whilstboth cropping intensity and cultivated areadecreased after transfer, the relativelyhigh yields were sustained. The averageproduction cost before transfer decreasedby about 7% from $827/ha to $774/haafter transfer. Most importantly, averagenet income increased by more than 100%from $260/ha to $549/ha after transfer.Very high financial self-sufficiency ratioscoupled with low running cost achieved bythe farmers' co-operative led to theconclusion that transfer has resulted inbetter performance so far. 相似文献
19.
Soil salinity has often become a long-term problem associated with irrigated agriculture in the arid and semi-arid regions. But the problem can be controlled by good management of surface and groundwater resources. Management of groundwater is achieved through drainage, although drainage may not be necessary for some time after the initial construction of a scheme. This paper introduces a regional model for predicting expected soil salinity conditions and groundwater depths over an irrigation scheme. The model considers all the main hydrological systems which influence soil salinity and makes optimal use of sparse point field data from grid surveys. The model can be used to identify priority areas for reclamation measures, ie areas where conditions combine to produce high salinity levels. Thus drainage development can be phased over a period of time and targeted where it will be most effective. 相似文献
20.
A methodology for ranking and classifying performance of irrigation systems through multidimensional performance indicators is developed using fuzzy set theory. The procedure uses the concepts of fuzzy resemblance and fuzzy dominance. Preference levels reflecting management priorities are incorporated into the analysis using appropriate weighting factors. The application of the procedure is demonstrated through two case studies: the Shi-Jin irrigation district in Hebei Province, China and the Goulburn irrigation region in Victoria, Australia. The classification of performance periods for the Australian system shows three clusters indicating the predominant effect of the increase in waterlogged area when higher priority is given to this indicator. No clear trend appeared when equal weight was assigned to all indicators. The effect of economic reforms implemented in 1977–78 in China is clearly reflected in the resulting ranking and clustering of the performance periods in the Shi-Jin irrigation district. Performance levels following reforms are shown to be consistently higher.Units mu
unit of area equal to 1/15 ha (666 m2)
- jin
unit of weight equal to 0.5 kg. 相似文献