Influence of mulching and irrigation scheduling on productivity and water use of turmeric (<Emphasis Type="Italic">Curcuma longa</Emphasis> L.) in north-western India

A field experiment was conducted to compute the water use and productivity of turmeric as a function of straw mulching and irrigation scheduling at Punjab Agricultural University, Ludhiana, during 2013 and 2014. The experiment was laid out in split plot design, keeping mulch levels (no mulch and straw mulch 6 t/ha) and irrigation methods (drip and check basin) in main plots and irrigation schedules at 0.6, 0.8, 1.0 and 1.2 irrigation water/cumulative pan evaporation (IW/CPE) in subplots. Turmeric yield was 125.2 % higher with mulching than no mulch with 50 % saving in irrigation water. Drip irrigation resulted in significantly higher turmeric yield and benefit/cost (B/C) than check basin. Irrigation scheduling at 1.2 IW/CPE recorded significantly higher turmeric yield than other schedules. Drip irrigation at 0.8 IW/CPE resulted in statistically at par yield with check basin irrigation at 1.2 IW/CPE, thus saving 40 % irrigation water with significantly higher B/C. However, turmeric yield was at par between drip irrigation at 1.2 and 1.0 IW/CPE schedule, while a significant reduction in yield was recorded in check basin at 1.0 IW/CPE compared to 1.2 IW/CPE. Turmeric should be irrigated with drip at 1.0 and with check basin at 1.2 IW/CPE to realize potential yield.     

Farmers’ incentives to save water with new irrigation systems and water taxation—A case study of Serbian potato production

Drip irrigation systems and irrigation strategies like deficit irrigation (DI) and partial root drying (PRD) are potential water saving irrigation systems and strategies. This paper analyses the Serbian farmer's economic incentive to use these water saving systems and strategies instead of the present sprinkler irrigation. The analysis is a partial budgeting analysis, based on irrigation application efficiency from the literature, standard figures for power requirements, pumping efficiency and friction losses for various sources of water and pressure requirements, yields and water use from recent Serbian field experiments, as well as prices and cost structures for potatoes collected in the Belgrade region. The analysis shows that changing the present system and strategy can save a significant amount of water (almost 50%). At the same time, however, irrigation costs are also significantly increased (more than doubled), and the total production costs are increased by 10% (deficit drip irrigation) and 23% (PRD). Increased taxes on water, investment subsidies, increased energy prices, and an increased yield or yield quality may provide incentives for farmers to change to new systems and strategies. The analysis indicates that a 0.80 to 1.97 € m⁻³ water tax is needed to make deficit drip irrigation and PRD profitable. The socioeconomic cost of providing water for irrigation and the alternative value of saved water are probably not that high. Thus, water taxation may not be a socioeconomic efficient means to improve the irrigation water productivity of Serbian potato production. Drip irrigation and PRD may, however, also increase the yield quality, and a 10-23% quality premium (price increase) is needed to make deficit drip irrigation and PRD profitable.     

Economic feasibility of growing capsicum crop under drip irrigation in West Bengal, India

Drip irrigation system has been one of the technical means to improve water use efficiency. In India, this system is gaining popularity among fruit growers and in water scarced area but a substantial area is being covered annually under vegetables crops. One of the major concerns raised by farmers about this system is its economic viability. In present study, the economic viability of drip irrigation system for growing capsicum crop based on discounted cash flow technique (Net present worth and Benefit cost ratio) was explored. Eight irrigation treatments were laid under drip with and without plastic mulch. The irrigation levels were taken as 1, 0.8 and 0.6 of the crop evapotranspiration. The pan evaporation method was used for estimation of reference evapotranspiration and Water Balance Approach was used for irrigation scheduling. The average amount of water supplied under treatment VD (100% irrigation requirement supplied with drip) was found to be 415 mm for whole growing season of the crop. Similarly the amount of water was found to be 332 mm and 249 mm for the treatment 0.8VD (80% irrigation requirement supplied with drip) and 0.6VD (60% irrigation requirement supplied with drip) respectively. Highest yield was recorded in case of treatment VD + PM (100% irrigation requirement supplied with drip plus plastic mulch) followed by VD. Yield under treatments 0.8VD, 0.6VD, 0.8VD + PM and 0.6VD + PM were significant while treatments VD, VF and VF + PM were at par with the treatment VD + PM. Net Present Worth (NPW) was found to be positive for all the treatments. The highest NPW was obtained under treatment VD as Rs. 309,734.90 and lowest was in case of 0.6VD + PM as Rs. 144,172.24. The yield per mm of water used was reported to be at higher side as 35 in both the treatments VD and VD + PM. But the yield per mm of water used was found to be lowest as 18.07 and 19 in case of VF and VF + PM respectively.     

塔里木灌区棉花滴灌发展与效益分析

棉花是塔里木灌区主要种植作物.通过对该灌区历年滴灌面积、常规灌溉与滴灌棉花灌溉定额、单产及单方水效益等具体数据进行分析表明,棉花实施滴灌后每公顷可节水1 200 m3,计144元;到"十一五"末,滴灌比常规灌溉可节水约1亿m3;每公顷可使籽棉增产215 kg,计1 182.5元.     

I Ssues of Irrigation of Horticultural Crops by Smallholder Farmers in Kenya

Although smallholder farmers have practised irrigation in Kenya, the introduction small-scale irrigation for horticultural production is relatively a recent development. The increase in irrigation practice has been promoted by the rapid increase in the growth of the horticultural industry. This research examined factors influencing irrigation of horticultural crops on smallholdings in Kenya. The key informants were smallholder irrigation farmers (including low-cost drip), representatives of the irrigation industry, Non Governmental Organisations and the government. The informants were interviewed in a survey of semi-structured open-ended questionnaires.The main problems reported were inadequate technical support service, unreliable water supply, and poor marketing of produce. The government policy on promotion of low cost technology was apparently not clear to the extension staff. Manufactures considered the sector especially the low-cost drip irrigation too small to promote actively. Some of these factors are likely to present a major challenge to developers in the promotion of smallholder irrigation technology in parts of the country.     

Reliability of drip irrigation systems under different operation conditions in Poland

Present crop production in Poland depends on climatic, hydrologic, pedologic, social and economic conditions. Drip irrigation systems will play a significant role in the future by fulfilling the requirements of intensive, energy-saving agricultural production. The total area under micro-irrigation in Poland is estimated to be approximately 3000 ha. Drip irrigation is currently applied mainly in orchards, vegetable farms and greenhouses. The investigations of drip irrigation have shown a high influence of the operating conditions on the reliability and productivity effects of the irrigation system. This paper contains the results of the investigations on the reliability of drip irrigation systems under different operation conditions such as system components, crops, water quality, fertigation and irrigation technology.     

Investment decision model for drip irrigation system

Drip irrigation is becoming popular in India although the decision to shift to drip irrigation from surface irrigation is not backed up by solid economic factors. It is not that the factors do not justify the shift, but that insufficient study has been done to document the conditions under which a change is justified. The investment decision for shifting to drip irrigation will depend upon many factors; including cost of cultivation, productivity, yield gain factor, cost of produce, electricity charges, depth of groundwater and irrigation requirement. These parameters vary from crop to crop, place to place, size of plot, and farmer to farmer. Therefore a sweeping recommendation suitable for all conditions cannot be made. In view of this, a software program has been developed for estimating the threshold economic value of the investment cost of drip irrigation. In addition to the threshold value of investment cost, the software provides information on energy consumption and net return. The software can be used both for annual crops such as sugarcane or seasonal crops such as vegetable rotations (winter–summer). To demonstrate the interdependence of various input parameters, an analysis has been made using local data in this software. The analysis has provided the relationship between the investment cost and the yield gain factor, the returns from the crop, as well as the savings in energy and the size of the prime mover with regard to the size of the farm.     

滴灌技术在农业节水灌溉中的应用探讨

滴灌是农业灌溉技术的一项革命性变革。这种灌溉方式,对节省灌溉用水、实现高产、控制杂草等有它独到之处。本文对滴灌进行了简述并分析了滴灌技术在我国节水灌溉中的应用,对其优势、节水效果等方面的进行了分析探讨,为我国节水灌溉的发展提供借鉴。     

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.     

The effect of an intelligent surface drip irrigation method on sorghum biomass, energy and water savings

Over the last few decades, precipitation has decreased as a result of climate change. This change increases crop water requirements, while irrigation water is wasted because of improper irrigation scheduling. Soil moisture sensors could be used to improve irrigation scheduling and save both water and energy. The objective was to study the energy and water savings, and the gross margin achieved, when using an intelligent surface drip irrigation method on sorghum bicolor (L.) Moench. In the years 2008 and 2009, a study was conducted at the farm of the University of Thessaly, Central Greece. A Class A evaporation pan and an automated frequency domain reflectometry soil moisture sensor were used for irrigation scheduling. Two treatments in four replications were organized in a randomized complete block design: (1) pan surface drip irrigation (PSDI100) and amount of water equal to 100 % of the daily evapotranspiration (ETd), as determined by a Class A evaporation pan, and (2) automated surface drip irrigation (ASDI100) and amount of water equal to 100 % of the ETd, as determined by an automated soil moisture sensor. The mean dry biomass production and the gross margin were greater in the PSDI100 treatment. The fully automated treatment remained profitable despite the high first costs. The mean water saving was 12.5 %, while the mean energy saving was 12.4 %, and the irrigation water-use efficiency was higher in the ASDI100 treatment.     

塑料大棚蔬菜膜下滴灌技术试验研究

塑料大棚蔬菜膜下滴灌技术是一种节水高产的先进灌水技术。它集水利、农业、生物、物理、化学等多学科于一体,实现塑料大棚蔬菜生产优质高产高效。本文论述了膜下滴灌的灌水量、湿度、地温、气温及抗病虫害等技术要素,并相应地与沟畦灌、无膜滴灌作了对比试验。膜下滴灌较传统沟畦灌、无膜滴灌,节水３０．５％、１０．９％,增产３０．１％、５．９３％。     

滴灌对农田N2O排放影响的研究进展

灌溉作为调控土壤水分状况的重要措施,直接影响农田温室气体的排放过程。滴灌是一种高效节水灌溉技术,其对温室气体排放的影响受到广泛关注。通过查阅大量文献,综合分析了滴灌对农田土壤N2O排放影响的研究进展与发展趋势。文献资料显示,滴灌通过调控土壤湿度和温度环境,改变土壤微生物菌群和土壤中气体传输速度,进而影响土壤N2O的产生以及排放速率;与其他灌溉方式相比,滴灌不破坏土壤结构,土壤内部水、肥、气、热条件稳定,适宜于作物生长,有利于土壤有机氮的矿化。但目前滴灌条件下温室气体排放的空间异质性和多种温室气体的同步定量研究等方面仍存在一些不足(例如:滴灌条件下土壤干燥区和湿润区N2O排放通量间差异研究和不同种类温室气体的同期影响研究)。今后,要加强监测滴灌下多种温室气体同期排放和不同土壤区域N2O排放差异,加强从分子水平探究滴灌模式下土壤微生物对N2O气体产生过程的作用机理等方面的研究,为构建环境友好型农业模式提供科学依据。     

新疆干旱区膜下滴灌土壤水平衡模拟

膜下滴灌技术是干旱农业区高效节水灌溉的重要手段,以玛纳斯河流域石河子试验站实测数据为基础,运用HYDRUS-2D模型对1膜4行方式下新疆棉田的土壤水运动进行了二维模拟,探讨膜下滴灌在1膜4行覆膜方式下土壤水平衡状况。结果表明,1膜4行覆膜方式下的膜下滴灌技术使新疆棉田无效水分蒸发量以及深层渗漏量大大减少,数值模拟方法可较好地模拟新疆棉田的土壤水平衡状态。上述研究可为宏观尺度上的膜下滴灌模拟与研究提供借鉴,同时对保障干旱区农业生产也有积极作用。     

痕量灌溉对温室种植球茎茴香产量、干物质分配和水分利用率的影响(英文)

痕量灌溉是基于土壤毛细管力原理和膜过滤技术而发明的一种新的灌溉技术.以滴灌为对照处理,研究了温室条件下,痕量灌溉对球茎茴香（Foeniculum vulgare Mill. subsp. vulgare var. dulce (Mill.) Batt.）产量、干物质分配和水分利用率的影响.结果表明,痕量灌溉条件下球茎茴香球茎和地上部分（茎和叶）的鲜重和干物质重量显著高于滴灌条件下栽培的球茎茴香,且痕量灌溉的总耗水量显著低于滴灌.试验条件下采用痕量灌溉的水分利用率是滴灌的2.3倍.     

滴灌技术的特点及应用

滴灌技术具有节水节肥、控制温度和湿度、保持土壤结构、增产增效的优点,是目前干旱缺水地区最有效的节水灌溉方式。介绍滴灌技术在我国的发展应用现状及其广阔的发展前景,以期为此项技术的推广应用提供有益参考。     

滴灌水肥耦合技术在西北干旱区作物栽培中的应用

水分和养分是影响作物生长发育的关键因素,明确作物需水需肥规律及其交互作用有助于农作物优质高产栽培。我国西北干旱区水资源极端匮乏,滴灌水肥耦合技术可以准确而均匀地将水肥施用于作物根部。对滴灌水肥耦合技术的优点及其对西北干旱区作物的影响研究进行了综述。滴灌水肥耦合技术通过扩大水分和养分在作物根区的运移范围,有利于作物对水分和养分的汲取和利用,实现节水省肥增产调质的目标。滴灌水肥耦合技术的优点为提高农作物水肥利用效率、促进农作物优质高产栽培、减少田间劳动力和有利于健康绿色可持续农业的发展。      

‘More crop per drop’: how to make it acceptable for farmers?

In countries facing water scarcity, governmental water agencies try to transfer this constraint to farmers, e.g. by encouraging them to shift from traditional to localized irrigation methods to save water. However, water shortage is often much less a problem for farmers than soil limitations, their objective being mostly to maximize their income per cultivated area (US$ per hectare rather than per cubic meter of water). This discrepancy can only be solved if governments find ways to ‘transfer’ water scarcity, e.g. through economic incentives such as water pricing and/or subsidies. The aim of this study was to address the question of how to match the interest of both water managers and farmers. We aimed particularly at evaluating whether shifting to drip irrigation is a relevant way to save water and increase farmer's income.Our analysis was based on the interactive impacts among economic, environmental, technical and methodological parameters on the net productivity of two crops. We focused on the case study of Turkey considering two crops with contrasted gross productivity, tomato and cotton, characterized by partial vegetation cover during a large part of crop cycle. A 3D crop energy balance model was applied showing that crop transpiration is increased by up to 10% when shifting from furrow to drip irrigation. These results were used to correct the maximal evapotranspiration (ET_m), estimated with the simple “crop coefficient” (K_c) method, and then used to enhance net productivity estimation both for furrow and drip irrigation.The results suggest that water managers and farmers share a common interest in adopting drip irrigation of tomato. Inversely, interests divergence may increase with low/medium value crops as cotton; the combination between water pricing and subsidies could be a way of agreement, but it would require subsidies for irrigation equipment of at least 40%, for low water tariffs, to 60%, for high water tariffs, to make the transfer from furrow to drip irrigation acceptable. This approach appeared generic enough to be applied for other economic, technical or environmental conditions, to modernize irrigation by harmonizing constraints faced by water managers and farmers.     

Prospects of micro-irrigation in India

The demand for land and water in India is continuously escalating due to increased population. The land can be used intensively on even up to 3 crops in a year for which water is needed. Therefore water management and increased production are very essential and crucial for the development.Research studies conducted in India by various institutions have indicated that water saving is about 40–80% and the yield increase is up to 100% for different crops by using micro-irrigation. The incremental benefit-drip cost ratio (B_I/C_D) worked out for various crops ranges from 1.35 to 13.35 excluding water saving and 2.78 to 32.32 including water saving. It has also been proved that drip irrigation, which is a type of micro-irrigation, is technically feasible and socially acceptable not only for large farms but also in small and marginal farms.Drip irrigation can be adopted to large areas irrigated from wells especially for wide spaced high value crops. This method is also suitable for hilly and undulated tracts, coastal sand terrains, and to a great extent in the water scarce areas of South and Western India. About 18 million ha are under fruit, vegetables and plantation crops and the present area under drip is only about 55,000 ha. Therefore the potential and prospects of drip irrigation is very high in the coming years.     

Managing subsurface drip irrigation in the presence of shallow ground water

A 3-year project compared the operation of a subsurface drip irrigation (SDI) and a furrow irrigation system in the presence of shallow saline ground water. We evaluated five types of drip irrigation tubing installed at a depth of 0.4 m with lateral spacings of 1.6 and 2 m on 2.4 ha plots of both cotton and tomato. Approximately 40% of the cotton water requirement and 10% of the tomato water requirement were obtained from shallow (<2 m) saline (5 dS/m) ground water. Yields of the drip-irrigated cotton improved during the 3-year study, while that of the furrow-irrigated cotton remained constant. Tomato yields were greater under drip than under furrow in both the years in which tomatoes were grown. Salt accumulation in the soil profile was managed through rainfall and pre-plant irrigation. Both drip tape and hard hose drip tubing are suitable for use in our subsurface drip system. Maximum shallow ground water use for cotton was obtained when the crop was irrigated only after a leaf water potential (LWP) of −1.4 MPa was reached. Drip irrigation was controlled automatically with a maximum application frequency of twice daily. Furrow irrigation was controlled by the calendar.     

日光温室油桃节水灌溉试验研究

临夏州降水量稀少,水资源匮乏,为了提高水资源利用率,实行节水灌溉,在该地区进行了日光温室油桃节水灌溉试验研究,研究了滴灌与沟灌技术在生育期内对土壤含水率、作物的生育动态以及产量的影响。结果表明,滴灌比沟灌平均节水1251 m3/hm2,"92-1"品种在滴灌条件下比沟灌每株增产5.9 kg,每公顷增产29475 kg,日光温室反季节油桃栽培应选择滴灌节水技术。为了取得较好的经济效益,应采用滴灌最优灌溉制度。