Automation of border irrigation in South-East Australia: an overview

There exists a growing interest in automating border irrigation after a large number of irrigated farms in South East Australia have upgraded their layout design. Several manufacturing companies are producing automated equipment which rely on controllers fitted with timers or field water sensors to monitor the advance of the water front down the border (bay). Labor saving together with potential for increase in pasture yield and additional flexibility to perform other farming tasks are the main benefits considered by farmers who decide to adopt automation. Environmental benefits can also be realized provided that the system is properly managed. Correct sensor placement and timer setting are critical factors to achieve high hydraulic performance as they can influence the application efficiency of a typical border irrigation event by as much as 40%. Further efforts will be required in future to incorporate feedback control, improve operational reliability and adapt existing systems or develop new ones to meet the requirements of new irrigation techniques such as surge flow.     

Modeling farm-level adoption of deficit irrigation using Positive Mathematical Programming

Irrigated agriculture in the European Union (EU) is currently adapting to new conditions including the principle of the full recovery of water service costs, the reduction of water availability and the increasing variability in the prices of agricultural products. This has fostered an increasing number of economic analyses to investigate farmers’ behaviour by means of mathematical programming techniques including Positive Mathematical Programming (PMP) models.However PMP models generally consider only activities observed in the reference period even if, under new policies and market conditions, farmers can adopt irrigation techniques they have not used previously. In particular, under increasing water costs or decreasing water availability, farmers can introduce Deficit Irrigation (DI) techniques that might not have been profitable earlier.We propose an extension of the PMP approach to include DI techniques not observed in the reference period. These alternative techniques are identified by means of a crop growth model developed by the FAO. We apply our methodology to a Mediterranean area using three sets of simulations involving: increases in water costs, reductions in water availability, and changes in the prices of the products obtained from irrigated crops.Lacking observations of alternative irrigation techniques, our approach captures potential technology adjustments and assesses the impact of changes in water policy and market conditions in a better way.Simulation results show that increasing water costs do not motivate adoption of DI techniques. Rather, farmers are induced to save water by switching from full irrigation to deficit irrigation when water availability is reduced or the prices of irrigated crops are increased.     

Examining traditional irrigation methods,irrigation scheduling and alternate furrows irrigation on vertisols in northern Ethiopia

In northern Ethiopia, where traditional (farmers) irrigation management on Vertisols is widely practiced, sustainable food security has always been a challenge. The reasons for this are multi-dimensional, but of utmost importance is, low-tech irrigation water management. The main objective of the present study is, therefore, to examine technologies of irrigation water management that might enable farmers to increase water productivity (WP) on vertisols.A comparative study has been undertaken between the traditional irrigation management (every furrow-traditional scheduling) and alternative water management options on maize plots in northern Ethiopia. The options include alternate furrows-scientific scheduling and every furrow-scientific scheduling. A field experiment was undertaken over two irrigation seasons (1998/1999 and 1999/2000). Results were compared on the basis of yield, WP and economic productivity concepts.Yield-based comparison has shown that every furrow-scientific scheduling generates the highest yield levels followed by alternate furrows-scientific scheduling. The yield increase (by every furrow-scientific scheduling) over the traditional management was found to be 54%.WP-based comparison has shown that alternate furrows-scientific scheduling generates the highest WP values followed by every furrow-scientific scheduling. The increase (by alternate furrow irrigation, scientific scheduling) over the traditional irrigation management was 58%.Economic productivity-based comparison has shown that the highest economic return was obtained from every furrow-scientific scheduling followed by alternate furrows-scientific scheduling. The increase in income (by every furrow-scientific scheduling) over the traditional irrigation management was 54%.The overall observation is that depending on the availability of water and labour resources, one can decide to use either of the alternate management options to obtain economically reasonable yield. In northern Ethiopia, where water is limiting (and not labour), every furrow-scientific scheduling can be an option.     

基层农民节水意识与节水技术采用取向探讨

通过问卷调查与实地调研,对河南省封丘县102个基层农户进行了节水意识与节水技术采用取向研究。结果表明,受访农户中仅有极少数具有较强节水意识,农户节水意识主要取决于其文化素质、种植作物种类、灌溉费用等。调查区内基层农户采用的节水技术中应用最普遍、效果最好的是管道输水。超过半数的受访农户表示如果节水技术合意则乐于采用,而对节水技术的要求最普遍是经济性和实用性。     

Irrigation management from space: Towards user-friendly products

Irrigation Advisory Services (IAS) are the natural management instruments to achieve a better efficiency in the use of water for irrigation. IAS provide the farmers with irrigation scheduling information, based on crop water requirements for different crops, and thus, help farmers to optimise production and cost-effectiveness. Current IAS rely on labour- and cost-intensive field work, yet are unable to cover each plot in large areas at regular short time intervals. Earth observation (EO) is naturally destined to fill this gap. It allows for efficiently monitoring crop water requirements and related parameters within each field in extended areas. The incorporation of IT in the generation and distribution of information makes that information easily available to IAS and to its associated farmers in a personalised way. Farmers can opt to receive a wide variety of products, tailored to their needs and infrastructure, ranging from simple irrigation scheduling recommendation (irrigation volume, time) to colour-coded images (providing quick intuitive information on the crop vigour within their plots), both on PC and/or mobile phones. This work is based on the project DEMETER (DEMonstration of Earth observation TEchnologies in Routine irrigation advisory services), which assesses and demonstrates the EO- and IT-induced improvements in IAS day-to-day operations. This paper describes the methodology and discusses examples of products.     

On-farm labour allocation and irrigation water use: case studies among smallholder systems in arid regions

On-farm measurements and observations of water flow, water costs and irrigation labour inputs at the individual parcel level were made in case studies of smallholder irrigation systems in sub-Saharan Africa and south-eastern Arabia. The systems, in which the water source supplied either single or multiple users, were analysed to address the fundamental issues of labour allocation for on-farm water management as this has important consequences for the success of such systems. Results show that the costs associated with accessing water influenced labour input, because when they were low the farmers tended to increase the irrigation rate and reduce the amount of time they spent distributing the water within their parcels. Conversely when water costs were high, lower flow rates and more time spent in water distribution were observed, and this resulted in more uniform irrigation and higher irrigation efficiency. Also, opportunities and demands for farmers to use their labour for activities other than irrigation can lead them to modify operational or physical aspects of the system so that they can reduce the time they spend distributing water within the parcels, particularly when the water is relatively cheap. Awareness and better understanding of how farmers may allocate their labour for water management will lead to more effective planning, design and management of smallholder irrigation systems.     

A measure for the efficiency of water use and its determinants,a case study of small-scale irrigation schemes in North-West Province,South Africa

This paper analyses the efficiency with which water is used in small-scale irrigation schemes in North-West Province in South Africa and studies its determinants. In the study area, small-scale irrigation schemes play an important role in rural development, but the increasing pressure on water resources and the approaching introduction of water charges raise the concern for more efficient water use. With the data envelopment analysis (DEA) techniques used to compute farm-level technical efficiency measures and sub-vector efficiencies for water use, it was shown that under constant returns to scale (CRS) and variable returns to scale (VRS) specification, substantial technical inefficiencies, of 49% and 16%, respectively, exist among farmers. The sub-vector efficiencies for water proved to be even lower, indicating that if farmers became more efficient using the technology currently available, it would be possible to reallocate a fraction of the irrigation water to other water demands without threatening the role of small-scale irrigation. In a second step, Tobit regression techniques were used to examine the relationship between sub-vector efficiency for water and various farm or farmer characteristics. Farm size, landownership, fragmentation, the type of irrigation scheme, crop choice and the irrigation methods applied showed a significant impact on the sub-vector efficiency for water. Such information is valuable for extension services and policy makers since it can help to guide policies towards increased efficiency.     

关于我国节水农业技术研究的探讨

总结了我国近期节水农业技术研究在农用水资源的合理开发技术、输配水节水工程技术、田间节水灌溉工程技术、提高作物从农田土壤中获取水分形成产量的技术等方面的最新进展。指出了我国节水农业技术研究中存在的主要问题。提出了我国节水农业技术应研究的重点为 :适合我国国情的节水灌溉工程技术 ,研究新工艺、新配方加速节水农业新设备及新材料的产业化 ,节水高效灌溉制度与控制灌溉技术 ,研究开发多种可用于灌溉的水资源 ,研究提高灌溉用水管理水平。     

河北平原井灌区农户灌溉用水量差异的分析

由于各种客观因素的限制,一直以来人们往往习惯于讨论和研究不同节水灌溉工程技术形式间的灌溉节水量的差异,而对同一种灌溉技术在不同农户之间差异几乎没有涉及.利用在河北平原井灌区三河市大曹庄村安装的农用机井IC卡智能灌溉控制计量系统,对全村20余眼机井320户农户冬小麦春灌用水量的记录数据进行整理统计,发现农户之间灌水定额差异非常大,但是这种用水量的差异符合随机变量正态分布规律.根据这些数据,给出了相应的数学模型的表达形式.     

农业水价改革情景中农户的节水意愿——基于河北省地下水超采区的实地调研

农业水价改革是黄淮海平原地下水压采的重要措施之一。基于河北省地下水超采综合治理区的实地调研,运用交叉分析法和二元Logistic模型分析了农业水价改革情景中农户节水意愿的影响因素。调查结果显示75.32%的农户在农业水价改革情景中没有节水意愿。研究结果表明年龄越大、家中有耕地参加休养生息政策的农户,在农业水价改革情景中的节水意愿越强;农户认为冬小麦春灌节水会导致小麦减产的程度越高,节水意愿越弱。因此得出推广农作物抗旱育种技术以及促进田间灌溉技术升级、加强农业节水宣传和培训、设计并实施系统和综合的农业水价改革三点政策含义。     

Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured performances to farmers’ irrigation practices, and these practices to the underlying logic of farmers who operate these systems. This approach was applied to 22 farms in Morocco. Four sets of variables helped explain the gap between the actual irrigation performance and the performance obtained in experimental conditions: (1) farmers have agro-economic motivations or want to improve their social status, and for them, irrigation performance is at best an intermediate objective. (2) Irrigation performance is not a static value, but a rapidly evolving process, related to the (perceived) ability of farmers to change irrigation practices and renew irrigation equipment, but also to farmers’ aspirations. (3) The social network of farmers, supporting the introduction and use of drip irrigation, determines how farmers may share experience, information and know-how related to drip irrigation. (4) Today, there is no social pressure to irrigate carefully to save water; only the state explicitly links the use of drip irrigation to saving water. Making the drip user visible in research and policy studies would lead to more realistic assessments of irrigation performance and draw the attention of policy makers to the actual conditions in which drip irrigation is used, and as a consequence help incorporate ‘saving water’ as an objective for drip irrigation users.     

On-farm performance evaluation of improved traditional small-scale irrigation practices: A case study from Dire Dawa area, Ethiopia

Field evaluation of surface irrigation systems play a fundamental role to determine the efficiency of the system as it is being used and to identify management practices and system configurations that can be implemented to improve the irrigation efficiency. This study evaluated the performance of an ‘improved’ traditional small-scale irrigation practice at Adada, a representative small-scale irrigation practice in Dire Dawa Administrative Council, Eastern Ethiopia. In order to determine numerical values of performance measures, certain parameters were measured/observed before, during and after an irrigation event while farmers are performing their normal irrigation practice. These parameters include: irrigated crop, irrigation method, stream size, cutoff time, soil moisture deficiency, and field size, shape and spacing. The results showed that the irrigation water applied to a farmer's plot during an irrigation event/turn was generally higher than the required depth to be applied per event. Since the irrigation method used was end-dyked, the major cause of water loss was due to deep percolation. The deep percolation loss was 32% in sorghum, 57% in maize, and 70% in tomato and potato fields. The type of irrigation system used, the ridged irrigation practice and the poor irrigation scheduling in the study sites were the main problems identified in the management and operations of the schemes. The following corrective measures are recommended to improve the system: (1) farmers should regulate the depth of irrigation water they apply according to the type of crop and its growth stage, change the field irrigation system and/or configuration especially for shallow rooted row crops, to furrow system, (2) guidance and support to farmers in developing and introduction of appropriate irrigation scheduling, and (3) future development interventions towards improvement of traditional irrigation practices should also focus in improving the on farm irrigation systems in addition to improving physical infrastructure of the scheme.     

调亏灌溉在农业中的应用

该文系统地阐述了调亏灌溉理论的发展及在农业生产中的应用,并提出来调亏灌溉技术运用过程中需要注意的问题,以期为调亏灌溉技术更好地服务于我国农业发展提供参考。      

A methodology for up-scaling irrigation losses

This paper presents a methodology for up-scaling field irrigation losses and quantifying relative losses at the irrigation area level for potential water savings. Two levels of analysis were considered: First, the field level where irrigation is applied. Second, the irrigation area level, where the field level losses are aggregated, or up-scaled, using average loss functions. In this up-scaling approach, detailed crop-soil-water modelling can capture the variability of physical parameters (such as soils, crops, water table depth, and management practices) at the field level which are then used to derive loss functions for aggregating losses at higher scales (irrigation area level). This allows potential field-level adaptations and water management changes made by individual farmers to be assessed for impact at the larger irrigation area level. The APSIM farming systems model was used for simulation of crops (wheat, rice, and soybean) and their interaction with the wider system processes at the field level. Given the climate, soil, and management information (sowing, fertilisation, irrigation, and residue management), the model simulates infiltration, the soil moisture profile, plant water uptake, soil evaporation, and deep drainage on a daily basis. Then, by placing the field level analysis in the context of the wider irrigation system or catchment, it is possible to correlate field level interventions (e.g. water savings measures) with water requirements at these higher levels. Application of this method in the Coleambally Irrigation Area in NSW, Australia, demonstrated that an exponential function can describe the relationship between deep drainage losses and the water table depth for different soil, crop, and water table depth combinations. The rate of loss increase (slope of the curve) with the water table depth is higher on lighter (higher intake rates) soils than on heavy soils and is more pronounced in areas under rice cultivation. We also demonstrate that this analysis technique can assist in identifying spatial distribution of losses in irrigation areas, considering water table depth as an additional factor, leading to targeted areas for water-saving measures.     

Water charges and irrigation efficiencies

Charging farmers for irrigation water is generally believed to lead to a more efficient water use. This paper contrasts measured irrigation efficiencies with characteristics of charges and irrigation systems. It discusses, for instance, the relation of field data with the generally endorsed presumption that water charges only influence irrigation efficiency if they are levied by volume.     

我国节水灌溉技术体系概述

近年来我国节水灌溉领域出现了许多新技术、新标准、新材料和新设备,我国节水灌溉领域进入了新的发展时期。节水灌溉技术体系主要包括工程技术和农艺技术,对我国节水灌溉技术体系现状进行了总结,为工程应用提供参考。在具体应用过程中,要根据各地水土资源条件、农业生产布局等实际情况,因地制宜地实施节水灌溉工程。      

Guilan,a successful irrigation project in Iran

This rapid appraisal study compares the actual and projected performance of a large, rice monoculture irrigation project in the humid climate of the Caspian Sea in Iran. The uniqueness of this project is the co-existence of East-Asia rice farming techniques with advanced technologies of automatic water control found generally in the Mediterranean countries. The paper emphasizes the need to do field tests at the design stage in order to make realistic assumptions on water efficiency and deep percolation. The study confirms that the advanced water control technologies are appropriate for small farm irrigation projects in the humid tropics, a conclusion often debated among experts. The Guilan project now provides some evidence to support that conclusion.     

Canal irrigation at night

Most canal irrigation water in South and Southeast Asia and elsewhere continues to flow at night and much is badly used or wasted. Yet what happens to water at night is a neglected subject, a matter for anecdotes more than analysis. Darkness, cold, fear, normal working hours, and desire for sleep deter irrigation staff, farmers and labourers from activities at night. At the farm level, irrigation at night entails extra labour and costs. It requires smaller streamflows and well shaped fields. Paddy and trees are the easiest crops to irrigate, and younger, lower and more thinly spread crops are usually easier than those which are older, taller and denser. On the lower parts of main systems, control at night often passes informally from irrigation staff to irrigators. Potential productivity of water at night is slightly raised by lower evaporation losses, but this gain is negligible compared with losses from breaks in channels, inefficient water application, and wasted water flowing into drains. Reuse of night drainage water lower down sometimes makes waste less wasteful than it appears. Equity effects at night are mixed: some farmers poach at the expense of others, but some get water at night who are denied it during the day. Night irrigation increases costs and inconvenience to small farmers, but raises labourers' incomes. Flooding and waterlogging can result from uncontrolled water flows at night.Practical implications are of two types: a)reducing irrigation at night, especially where water can be saved and stored by regulating releases from main reservoirs; in storage or by travelling in canals; by use of intermediate reservoirs; by pondage on-farm; or as groundwater. Care is needed in analysing what is waste and what is water saved. b)improving irrigation at night — by making flows predictable and manageable; by improving convenience and efficiency including lighting, ease of movement and field shaping; by choosing easy crops; by zoning for night flows; and by phasing for short nights, warmth and visibility. The potential for better performance on canal irrigation systems is probably large. It is hoped that this paper will encourage and provoke system managers, designers and researchers to explore the practical potential of this neglected subject about which much more needs to be known. Canal irrigation at night is too important to remain a blind spot any longer.B.C. Punmia & Pande Brij Basi Lal,Irrigation and Water Power Engineering, 7th ed., 1983, p. 48The magnitude of waste involved in not irrigating at night is so huge that savings from other sophistications in the field of water management like the lining of watercourses etc. pale into insignificance.S.P. Malhotra, 1983.Night irrigation and what we know about it is truly a blank page in our books.Gabriel J. Tibor, 1985.     

Decentralised water and wastewater treatment technologies to produce functional water for irrigation

The EU project SAFIR aimed to help farmers solve problems related to the use of low quality water for irrigation in a context of increasing scarcity of conventional freshwater resources. New decentralised water treatment devices (prototypes) were developed to allow a safe direct or indirect reuse of wastewater produced by small communities/industries or the use of polluted surface water. Water treatment technologies were coupled with irrigation strategies and technologies to obtain a flexible, easy to use, integrated management of the system. The challenge is to apply new strategies and technologies which allow using the lowest irrigation water quality without harming food safety or yield and fruit or derivatives quality. This study presents the results of prototype testing of a small-scale compact pressurized membrane bioreactor and of a modular field treatment system including commercial gravel filters and heavy-metal specific adsorption materials. Decentralised compact pressurised membrane biobooster (MBR), was able to remove up to 99.99% of the inlet Escherichia coli and 98.52% of total coliforms. E. coli was completely removed from irrigation water in 53% of the samples by the last MBR prototype version. In 2008, 100% of samples fulfilled WHO standards (1989) and Global Gap requirement for faecal contamination. MBR removed from inlet flow in the average 82% of arsenic, 82% of cadmium, 97% of chromium, 93% of copper and 99% of lead. Boron and manganese were not removed from permeate. The field treatment system (FTS) proved to be effective against faecal contamination when applied with its complete set up including UV treatment. The sole gravel filter and heavy metal removal device (HMR) cannot provide sufficient and steadily treatment for microbial contamination. Nevertheless, gravel filter can remove up to 60% of E. coli but the removal process was not stable nor predictable. FTS removed 76% of arsenic, 80% of cadmium and copper, 88% of chromium and lead, and up to 97% of zinc. Like the MBR, boron and manganese were not removed from the irrigation water. Gravel filter directly fed with secondary treated wastewater was found able to remove 41% of arsenic, 36% of cadmium and lead, 48% of chromium and 46% of copper. The residual heavy metals concentration after the gravel filter was further reduced by the HMR: 35% for arsenic, 22% for cadmium, 25% for chromium, 33% for copper and 53% for lead.     

Irrigation water prices for farmer-managed irrigation systems in Tanzania: a case study of Lower Moshi irrigation scheme

A computer program model for pricing irrigation water among beneficiaries was developed and tested. The data used for the purpose was collected from Lower Moshi farmer-managed irrigation scheme (FMIS) in northern part of Tanzania as a case study. The scheme has two intakes; namely Rau and Mabogini irrigation systems. Allam's mathematical model for allocating irrigation water price which was developed in Egypt (Allam, 1987) was adopted and adapted for the purpose. The results indicate that the irrigation water price depends on a number of structures serving the area, their installation costs, amount of water received by each tertiary block and water rights. The prices differ between different tertiary blocks within the same system and also between two systems that exist in Lower Moshi Irrigation Scheme (LMIS). This indicates that the model can be used as a tool by designers and planners for selecting the best designed irrigation system that farmers can afford to pay for its operation, maintenance and management. The mean irrigation water price value for Mabogini is Tshs. 12 151/-¹ while that of the Rau system is 10 414/-. To maintain uniformity of irrigation water price in the scheme, it is recommended that a mean value of Tshs. 11 283/- is used. Generally, farmers in Tanzania are used to contribute one bag of paddy which costs about Tshs. 10 000/- for maintenance works. Therefore, the irrigation water price derived from the model is reasonable and one the farmers can afford.