Innovations in irrigation management and development in Hunan province

Mass movement labor was an important contributor to irrigation system construction in China during the seventies, making up a third or more of system costs. Total per-ha system costs are roughly consistent with those in other Asian countries when contributed labor is valued at estimated farm wage rates, but less than average if zero labor opportunity cost is assumed.Innovative practices are being employed in managing and supporting irrigation system operations in Western Hunan Province. Many are ones which have been advocated repeatedly elsewhere but infrequently applied. These include the volumetric wholesaling of water to distribution organizations, farmer water charges with both fixed and volumetric components, financially autonomous irrigation management agencies, and delegation of water distribution and fee-collection responsibility to village-based organizations. Heavy emphasis currently rests on financial self-reliance of schemes as denoted by the slogan, let water support water. This has led to a proliferation of secondary income-generating enterprises associated with irrigation system management, as well as strenuous efforts to collect irrigation fees. Often the secondary enterprises generate a larger share of total income than does the irrigation service itself.Fee levels for rice generally fall into the $12 to $20 ha/yr range, intermediate to those prevailing in Pakistan at $8.50/ha for two crops of rice and the Philippines at $45/ha for double cropped rice. Collection of fees is typically handled by the village. Charges are usually levied on an area basis but one large system employed a more complicated system which had both fixed and variable components. Water allocation at lower system levels is also delegated to the village in many cases, with the state serving as a wholesale provider of water.Abbreviations and units ha-m hectare-meter - jin unit of weight equal to 0.5 kg - kw kilowatt - mu unit of land area equal to 1/15 ha - Rmb Renmimbi (Yuan) equal to US$ 0.27 officially in September 1988 and about half of that unofficially - RMD Reservoir Management Division - WCB Water Conservancy Bureau - WMD Water Management Department     

A study on construction costs per unit area of irrigation projects

The cost constructing for irrigation is often given in $/ha. In deciding whether a project is worth undertaking, it is important to weigh the anticipated benefits against the expected costs. In this study, unit area construction costs based on the way of project water supply (gravity, pump) and scheme type (classic canal, flume, pipe) were calculated for the 211 irrigation projects operated and constructed by DSI (State Hydraulic Works) in Turkey. In a case study of the 27 irrigation schemes constructed by DSI in the Büyük Menderes and West Mediterranean basins, construction costs per unit area, irrigation ratio, and amount of unproductive costs were determined. As a result, though the area of 76383 ha was constructed for irrigation schemes, this area wasn??t under irrigation services with several various reasons; therefore, 641 million $US according to water supply way, and 574 million $US to the scheme type were unproductive investment for irrigation projects researched in the basins.     

Irrigation of seed carrots on a sandy loam soil

Summary Little research has been reported which quantifies the response of a carrot (Daucus carrota L. var sativa DC.) seed crop to water management. While the area of seed production of this crop in the United States is less than 3000ha, the return ranges from US $2000 to $ 10 000 ha^–1. Because of the need to mature and dry the seed on the plant, carrot seed is generally grown in areas with negligible summer rain and thus depends on irrigation to supply the crop water requirement. A study was conducted to determine the effect of irrigation water management on seed production and crop water use of carrots grown by the root-to-seed method. Two carrot types (Nantes and Imperator) were evaluated in 9 irrigation treatments over a three year study period. Irrigation treatments which replaced a percentage of the calculated crop evapotranspiration on either a daily basis or when a soil water depletion reached 30 mm were used. A trickle irrigation system with the laterals placed on the carrot bed was used to apply a uniform and accurate amount of water. There was a marked difference in the crop response to the water management of the two carrot types used. The Nantes type exhibited a positive response to moderate water deficits in terms of improved pure live seed (PLS) yield while the Imperator achieved its maximum yield when it was not stressed. Higher irrigation applications in the Nantes type resulted in reduced yields while the Imperator was not affected after its non-stress water requirement was met. Soil water data indicated that the most active zone of extraction of water was to a depth of 1.5 m in the soil profile. As the depth of applied water approached the crop water requirement, the depth of extraction was reduced. Increasing the frequency of irrigation also tended to reduce the depth of extraction of soil water. A total crop water use of approximately 550 to 620 mm was needed to achieve the best PLS yield which is roughly equal to potential evapotranspiration in the San Joaquin Valley, during the time that the crop water use was calculated. In such a climate, the irrigation interval should not exceed 3 to 5 days depending on the time of year.     

Proceedings of the Sixth International Conference on Precision Agriculture and Other Precision Resources Managemen on CD-ROM | Robert,P.C. et al., (Ed.), American Society of Agronomy/Crop Science Society of America/Soil Science Society of America,Madison, WI, 2003, USA, 2095 pp. Price: US$14.00.CD-ROM

The objective of this paper is to examine the impacts of terminating rice [Oryza sativa] irrigation earlier than usual. One straightforward result of this would be the associated cost savings (≈$10 ha⁻¹ per irrigation or more with deep wells) without placing a value on the water itself. However, another option exists for some farms. An assumption is that the typical farm will be constrained from irrigating all of the soybean [Glycine max (L.) Merr] crop due to constraints in any or all of water supply, pumping capacity, and labor availability. In these cases, a portion of the land in soybean production would be non-irrigated for the first part of the growing season. This study explores the possibility of transferring irrigation water to the soybean crop after the needs of the rice crop are met. If rice and soybean planting dates are planned optimally, this partial irrigation can lead to substantial soybean yield improvements and therefore a more profitable rice/soybean production system. On average, across a 41 year period, net revenue gains from partially irrigating the soybean crop were consistently positive, ranging from $41 to $458 ha⁻¹. While these numbers are interesting, the reader is cautioned that the results are based on simulation models and therefore the marginal analysis results are more realistic. On clayey and silt loam soils at Keiser and Stuttgart, respectively, the change in returns for moving from the least to the most water saving rice irrigation strategy was $190 and $99 ha⁻¹, respectively. In addition, for any given year, financial losses are typically restricted to the irrigation setup costs of $17 ha⁻¹. The irrigation termination strategies therefore show high economic potential with little risk of loss.     

辽河平原水田灌区灌溉水源的优化开发与应用研究

针对水资源相当贫乏的辽河平原地区，运用系统工程理论，采用模拟技术，研究利用区内冲洪积层，建设地下水库；依循三水转化规律，人工强化回灌，加大地下含水体的反调节能力，大大提高水资源的重复利用率。在科学的水源开发规程下，找到了数十万公顷水田灌溉可不依靠上游水库调节供水的区内多种水源的优化开发与运用策略。灌溉节省的水量，转向工业及城市建设，综合效益巨大。     

Irrigation response of Pistachio (Pistacia vera L.)

Pistachio yields normally alternate between high and low values for consecutive years due to management and genetic effects. In this study, irrigated and non-irrigated treatments of old pistachio trees (Pistacia vera L.) were compared for 5 years from 1979 to 1983. Two irrigation treatments consisting of irrigation scheduling at 20- and 30-day interval were compared with the control treatment of no irrigation. Results showed that irrigation practice in pistachio orchards not only increased fruit yield, but also suppressed periodicity, the low fruit yield in alternating years. The frequent irrigation of 20-day interval nearly doubled the dry fruit yield irrespective of whether it was the off-yielding year, compared to non-irrigated control treatment. Three-years average for the irrigation at 20 days interval was 5710 kg per ha during the on-yielding years (1979,1981 and 1983); whereas, the control treatment of no irrigation yielded only 3450 kg per ha during the same period. Two-year average of the non-irrigated treatment, during the off-yielding years (1980 and 1982) was 1730 kg per ha; whereas, the irrigated treatment of 20-day interval, for the same period, showed significantly (P 0.05) higher fruit yield (4030 kg per ha). Irrigation treatments, during both on and off-yielding years, had no effect on fruit quality characteristics such as nut weight, blank and split shell percent, etc. The root activity under frequent irrigation treatment was confined to shallower soil depth than the longer interval irrigation treatment.     

Irrigation operation and maintenance in Vietnam under economic restructuring

Vietnam's policies to establish a market economy are reshaping the state organizations and agricultural cooperatives that have operated and maintained irrigation systems. The new policies emphasize financial autonomy for state enterprises, and a shift in the responsibilities of the agricultural cooperatives away from collective production activities. Specific policies and institutional arrangements vary considerably among the provinces. In Quang Nam-Da Nang province in central Vietnam, the agricultural cooperatives generally still play an important role in irrigation O&M at the tertiary and quaternary level, serving as intermediaries between individual households and the state enterprise that operates the headworks and the primary and secondary canal network of government irrigation schemes. The cooperatives also have full responsibility for many small pump irrigation schemes. The state irrigation enterprises have partial financial autonomy, financing their activities primarily from irrigation fees collected from the farmers. The power to set the fees, however, resides with the provincial government and not with the irrigation enterprises. The fee, which is an area-based fee differentiated by crop and season, is set in terms of paddy to facilitate maintaining its real value in the face of inflation. Both cost and equity factors are taken into consideration in setting the schedule of fees. The fees in government gravity irrigation schemes are fairly high by comparison with other Asian countries; however they are lower than typically paid by farmers in the small pump irrigation schemes operated by the agricultural cooperatives.     

微孔陶瓷渗灌与地下滴灌土壤水分运移特性对比

以微孔陶瓷灌水器为研究对象,在0 m工作水头下进行土壤水分运移特性试验,并以10 m额定工作水头下工作的地下滴灌灌水器作为对照。通过对比分析2种灌溉方式下累计入渗量、流量、湿润体特征和土壤含水率变化,结果表明:相同灌溉时间下微孔陶瓷渗灌的累计入渗量、湿润锋运移距离、湿润体截面面积均明显小于地下滴灌。微孔陶瓷渗灌的流量随时间逐渐减小,直至接近于零;试验后期,微孔陶瓷渗灌湿润体内整体土壤含水率变化较小;由于微孔陶瓷渗灌为无压连续灌溉,因此在其工作过程中可为作物提供一个恒定的水分环境。而地下滴灌的流量则会维持稳定,使得土壤含水率一直增大,停止灌溉后由于土壤水分再分布而减小。地下滴灌为被动恒压灌溉,因此其灌溉条件下作物生长的水分环境处于干湿交替的循环变化状态。     

Asset management modelling framework for irrigation and drainage systems: Principles and case study application

Sustainability of irrigation and drainage infrastructure poses many challenges to many irrigation authorities worldwide due to a mismatch between the actual cost incurred in the provision of irrigation and drainage service and pricing of this service. This shortfall often leads to inadequate expenditure on maintenance in the absence of adequate subsidies from government or other sources.The asset management modelling framework (AMMF) presented in this paper enables the quantification of on-going ownership costs and operation costs. A life cycle cost (LCC) model for the evaluation of alternative irrigation and drainage asset management strategies is also presented. The AMMF is applied to the evaluation of asset ownership costs and LCC for alternative maintenance and interest rate scenarios in the Cu Chi irrigation system, Vietnam. The cost of three renewal strategies was evaluated: linear depreciation, full annuity and partial annuity. The cost ranges between US$ 28.00/ha and US$ 41.00/ha when interest rate varies between 9 and 3%. The average maintenance expenditure during recent years was estimated to be only US$ 1.30/ha which translates into 0.68% of the total asset replacement cost.The application of a simplified LCC model reveals that the least LCC varies with the level of maintenance and interest rate between US$ 353.5/ha for 5% maintenance expenditure and 12% interest rate to US$ 522.3/ha for 3% maintenance expenditure and 6% interest rate. The importance of exercising value judgements in applying the LCC model is also emphasised and discussed.     

灌水模式对油葵耗水量产量及经济效益的影响

通过5种灌水处理模式和对照旱地油葵田间试验,探讨了灌水模式对油葵耗水量、产量、水分利用效率以及经济收入的影响。结果表明,油葵出盘前和灌浆后耗水量比其他时段多50％以上。在油葵不同生育阶段耗水量随着灌水量增加而增加;灌水定额120mm,灌两次水的灌水模式的产量最高,为2268kg／hm^2,而水分利用效率最大值出现在灌水定额66mm的灌水模式,灌水量增加反而使水分利用效率下降。经济分析结果表明,纯收入最高值出现在灌水模式93mm灌二水的处理,为2871元／hm^2,灌水定额增加或减少均导致经济收入下降。统计分析结果表明,干旱年份（全生育期有效降水量123mm）灌二水时,为了兼顾产量、水分利用效率以及经济收入,油葵最佳总灌水量以208-218mm为宜。全生育期有效降水量超过350mm的丰水年份不应该再灌水。     

大面积推广管道输水灌溉技术

济宁市多年平均降水量684.9mm,干旱季节农田灌溉水资源紧缺。随着工农业生产的发展,供需矛盾日益突出,节约用水,已成为当务之急。1986年济宁市水利局和水利部农田灌溉研究所、汶上县水利水产局共同承担了低压管道输水灌溉技术研究的课题。经过三年的努力,至1988年底完成了684ha的试区,取得显著效果。根据试点经验,决定在全市大面积推广管道输水灌溉技术。至1991年底,全市共完成地埋低压石屑混凝土管道输水灌溉面积74kha,占全市井灌面积的1/3,取得年节水量277百万m~3;年节电28.86百万kW·h;年增产粮食100百万kg;年总效益50780千元的经济效益。     

膜下滴灌技术在雨水集蓄利用工程中的研究

在黄土高原半干旱丘陵沟壑区,修建集雨蓄水工程并结合滴灌、覆膜坐水等措施,对作物进行补充灌溉,以期适应年内降雨时空分配极为不均,水分供需严重错位的现状。旨在改善土壤蒸发强度、土壤温度和降雨空间分配,提高灌水效率和水分利用效率,最终达到稳产高产的目的。通过2006年的田间试验研究,结果表明:集雨滴灌3次的增产量为2353.61~3845.62 kg/hm2,增产效果为44.07%~72.01%。在同样的补灌水量及灌水次数情况下,把灌浆期增加的灌水定额转移到拔节期更有利于提高玉米增产效果和集雨滴灌效率,将灌浆期多补灌7.5 mm的水量调配给拔节期,使得补灌效率增加2.05 kg/m3,将同样的水量由灌浆期转移给拔节期后,使得增产效果和补灌效率都有不同程度的提高,增产效果提高12.93%~21.89%,补灌效率提高3.41~4.21 kg/m3。     

自动转移喷灌机控制系统研制

现代农业要求农业生产实现机械化、规模化、自动化和智能化。设施农业作为现代农业中的高端农业，其技术和设备的发展应用具有引领典范作用。其中，节水灌溉是设施农业中一项关键技术，也是国家一直在倡导的重要举措。喷灌机通过定时定量对植物进行灌溉，以最小程度的用水量，获取最大的收益。传统喷灌机自动化程度不高，只能实现单跨自动运行，无法实现跨间自动转移，需要人工辅助，且无法进行区域选择性灌溉。为了提高温室内喷灌机自动化程度，降低劳动力成本，提高工作效率，通过总结归纳国外全自动喷灌机的结构和特点，研制了一种全自动转移喷灌机。该喷灌机系统引入RFID射频模块，它通过射频信号自动识别跨度标签，快速读取标签内数据，可用于识别不同的跨度和初定位。喷灌机主机依托转移装置可进行跨间自动转移，为了防止干扰摒弃接近开关和光电开关，使用霍尔开关作为信号检测和判断，使用西门子200CUP226作为主控制器。通过在上位机昆仑通泰触摸屏上输入喷灌次数、喷灌时间等参数，控制机器自动执行喷灌任务，而高速计数器的使用节省了转移过程中的时间。存储单元存储喷灌的次数和时间记录，方便后期数据查询和经验的数字量转化。      

Optimal Allocation of Short-Term Irrigation Supply

An optimization model has been developed toaid decision making in real time fordeficit irrigation when conflict betweenwater supply and demand arises in amultiple crop irrigation scheme. The resultis the optimal allocation of short-termsupply of irrigation water. Theoptimization model is based on DynamicProgramming. In the optimization model, theshort-term supply is optimized in functionof a specified strategy determined by theuser. The strategies that the user canselect from are: maximum benefit, equitablebenefit, equitable yield and maintainingequity in the system. The potential of themodel has been assessed through applicationof the model to Perkerra irrigation schemein Kenya. In the 680 ha scheme, maize,onion and chili are cultivated in theirrigation season. Analysis of the resultsfor the 1999/2000 season, where the watersupply was 35 percent smaller than thedemand, indicates that improvements in cropproduction can be achieved throughapplication of the optimization model.Sensitivity of production system to variouslevels of water restriction is demonstratedby sensitivity analysis.     

低压滴灌条件下提高系统灌水均匀度的途径探讨

低压滴灌是一种高效节能型灌水技术,采用低压滴灌不仅可以减少灌溉系统建设成本,而且可以降低系统运行成本,因此低压滴灌将是今后滴灌技术发展的一个重要方向。然而在灌水器工作压力小于5 m的低压条件下,采用现有的滴灌设备将会由于水力环境的变化引起毛管输水量和滴灌管(带)的有效铺设长度减小,降低滴灌系统的灌水均匀度和灌水质量等问题,为了不以牺牲灌水质量换取成本降低,通过分析低压滴灌的工作特点,提出了改进和提高低压滴灌灌水均匀度的方法和途径。     

注灌及其效果浅析

分析阐述了“坐水种”的灌溉原理及其效果，并根据其注水浇灌方式及形成覆埋式湿团．将这一灌溉方法命名为注灌。研究表明，注灌的灌水定额虽然只有６０ｍ３／ｈｍ２～１２０ｍ３／ｈｍ２．但却相当于５０ｍｍ以上的等效降雨量或５８０ｍ２／ｈｍ２的沟灌净灌水定额的湿润效果。而且有更明显的抗旱、耐旱、增温、保苗等效应．和投资少，设备简单．操作方便、适应性强、不板结土壤等优点。     

不同灌水水平对温室番茄地土壤CO_2排放影响

为分析不同灌水水平对温室番茄地土壤CO_2排放的影响,采用静态箱气相色谱法对2014年秋冬季和2015年春夏季番茄地土壤CO_2排放进行原位观测。试验设置2个灌水水平分别为:充分灌溉(FI)和亏缺灌溉(DI)。结果表明:番茄两个生长季中,不同灌水处理下土壤CO_2排放通量均呈波动性变化。2015年春夏季试验各处理土壤CO_2平均排放通量和排放量高于2014年秋冬季试验对应的各处理土壤CO_2平均排放通量和排放量,且两个生育期内高灌水处理的土壤CO_2排放在番茄生育期绝大多数时间内均高于低灌水处理。以2015年FI处理土壤CO_2累积排放量最大(5 641.57kg/hm~2),分别较2014年FI处理、2014年DI处理和2015年DI处理增加了3.9%、54.2%和16.7%。此外,研究还发现春夏茬试验中不同灌水处理下,土壤CO_2排放通量与土壤水分呈显著负相关关系。这为评估设施菜地温室气体减排提供一定的科学依据。     

Irrigation management in arid areas affected by surface crust

The effects of supplemental irrigation and irrigation practices on soil water storage and barley crop yield were studied for a crust-forming soil at the University of Jordan Research Station near Al-Muwaqqar village during the 1996/97 growing season. An amount of 0.0, 48.9, 73.3, 122.2 and 167 mm supplemental irrigation water were applied. The 48.9, 73.3 and 122.2 mm applications were applied through surface irrigation into furrows with blocked ends, and the 0.0 and 167 mm applications via sprinkler irrigation. The greatest water infiltration and subsequent soil storage was achieved with the 122.2 mm application followed by the 73.3 mm irrigation, both surface applied. Application efficiency (the fraction of applied water that infiltrated into the soil and stored in the 600 mm soil profile) and soil water storage associated with supplemental blocked furrow irrigation was significantly greater than with supplemental sprinkler irrigation. For arid zone soil, which has little or no structural stability, application of supplemental irrigation water via short, blocked-end furrows prevents runoff and increases the opportunity time for infiltration, thereby increasing the amount of applied water that is infiltrated into the soil and stored in the soil profile. Supplemental irrigation, applied by a low-rate sprinkler system, was not as effective because of the low infiltration rates that resulted from the development of a surface throttle due to dispersion of soil aggregates at the soil surface. The differences in stored water had a significant effect on grain and straw yields of barley. Without supplemental irrigation, barley grain and straw yields were zero in natural rainfall cultivation with a total rainfall of 136.5 mm. Barley yields in the control treatment, with a 167 mm supplemental sprinkler irrigation were low being 0.19 and 1.09 ton/ha of barley grain and straw, respectively. Supplemental irrigation through blocked-end furrows increased barley grain and straw yields significantly compared with supplemental sprinkler irrigation to a maximum of 0.59 and 1.8 ton/ha, respectively. The improvement coming from the increased water storage associated with furrows. Since irrigation water is very limited if available, farmers are encouraged to form such furrows for reducing runoff from rainfall thereby increasing the amount of water available for forage and field crop production.     

井灌区低压环状管网优化设计方法的研究

本文对低压管道输水灌溉环状管网的经济性进行了分析研究,得出对集中轮灌的井灌区,在一定条件下环状管网优于树状管网的结论,推导出单环和双环管网流量分配系数公式和经济管径的通用计算公式。     

Low Cost Satellite Data for Monthly Irrigation Performance Monitoring: Benchmarks from Nilo Coelho, Brazil

Irrigation performance indicators can helpwater managers to understand how anirrigation scheme operates under actualcircumstances. The new contribution ofremote sensing data, is the opportunity tostudy the crop growing conditions at scalesranging from individual fields to schemelevel. Public domain internet satellitedata have been used to calculate actual andpotential crop evapotranspiration, soilmoisture and biomass growth on a monthlybasis in the Nilo Coelho irrigation scheme,Pernambuco (Brazil). Satellite interpretedraster maps were merged with vector maps ofthe irrigation water delivery system.Monthly values of a minimum list ofirrigation performance indicators for thevarious service units in the pressurizedNilo Coelho scheme were determined. NiloCoelho is a good performing scheme. Theperformance can be improved further if 25%irrigation water is saved from February toJuly. The benchmark figures from thismodern irrigation system are presented forcomparitive analysis with other systems.The acceptable ranges in space and timeare presented. On average, 65% of thelateral pumping units on a monthly basisfall within the acceptable limits ofirrigation performance. Low cost irrigationperformance data based on low resolutionsatellite images (US$ 1/ha) will help themanagement team to focus on specificpumping units, and discuss alternativeirrigation and farm management strategieswith the stakeholders.