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1.
The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers’ fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to help develop some guidelines to the farming community. Water management alternatives at the field level were suggested to increase the yield and to maintain soil salinity below threshold level. The application of frequent irrigation in precisely leveled field would help in achieving 10% higher yield even when saline groundwater of 11 dS/m is used for irrigation. 相似文献
2.
Waterlogging and salinization are major impediment to the sustainability of irrigated lands and livelihoods of the farmers, especially the smallholders, in the affected areas of the Indus Basin. These problems are the result of a multitude of factors, including seepage from unlined earthen canals system, inadequate provision of surface and subsurface drainage, poor water management practices, insufficient water supplies and use of poor quality groundwater for irrigation. About 6.3 million ha are affected by different levels and types of salinity, out of which nearly half are under irrigated agriculture. Since the early 1960s, several efforts have been made to improve the management of salt-affected and waterlogged soils. These include lowering groundwater levels through deep tubewells, leaching of salts by excess irrigation, application of chemical amendments (e.g. gypsum, acids, organic matter), and the use of biological and physical methods. However, in spite of huge investments, the results have in general been disappointing and the problems of waterlogging and salinity persist.This paper reviews sources, causes and extent of salinity and waterlogging problems in the Indus Basin. Measures taken to overcome these problems over the last four decades are also discussed. The results reveal that the installed drainage systems were initially successful in lowering groundwater table and reducing salinity in affected areas. However, poor operation and maintenance of these systems and provision of inadequate facilities for the disposal of saline drainage effluent resulted in limited overall success. The paper suggests that to ensure the sustainability of irrigated agriculture in the Indus Basin, technical and financial support is needed and enhanced institutional arrangements including coordination among different federal and provincial government agencies to resolve inter-provincial water allocation and water related issues is required. 相似文献
3.
BP网络在焉耆盆地土壤积盐影响因素分析中的应用 总被引：5，自引：2，他引：5
以焉耆盆地为例，采用BP网络技术，对土壤舍盐量与各种影响因素的关系作了初步定量评价，发现潜水矿化度和潜水位埋深是土壤舍盐量的最敏感因素，其次是灌区引水量、引盐量和地下水蒸发量，其中灌区引水量大是焉耆盆地土壤次生盐渍化加剧的最主要因素；而潜水位埋深是土壤脱盐最敏感的因素。焉耆盆地土壤次生盐渍化防治应从减少灌溉引水量和降低地下水位入手。 相似文献
4.
土壤盐渍化是制约干旱区农业发展的主要障碍,而浅埋地下水区域的地下水环境是影响土壤盐渍化的直接因素。为调控合理的地下水埋深和矿化度,以防控区域盐渍化,以河套灌区永济灌域为研究区,运用指示Kriging法比较了春灌前和生育期不同阈值条件下土壤表层含盐量、地下水埋深和矿化度的概率分布,从概率空间分布的角度研究了不同时期防治土壤盐渍化的地下水临界埋深和矿化度。结果表明：地下水埋深属于中等变异性,土壤表层含盐量和地下水矿化度属于强变异性。春灌前较生育期土壤表层盐渍化高风险区扩大、浅埋地下水高概率区缩小、地下水矿化高风险区缩小。春灌前永济灌域土壤表层发生轻度、中度盐渍化时的地下水埋深临界值分别为2.6、2.2 m,地下水矿化度临界值分别为2.0、2.5 g/L;生育期土壤表层发生轻度、中度盐渍化时的地下水埋深临界值分别为2.2、1.8 m,地下水矿化度临界值分别为2.5、3.0 g/L,春灌前更易发生土壤盐渍化。春灌前较生育期土壤盐分受外界因素（气象因素和人为因素）影响小,且土壤表层含盐量、地下水埋深和矿化度变异性也相对较小,地下水环境对土壤盐渍化的影响更强烈。研究区北部、东南部和中部小部分区域为地下水埋深小于临界值且大于矿化度临界值的高概率区,是土壤返盐的高风险区,建议进一步完善该地区的排水系统。 相似文献
5.
Assessing basin irrigation and scheduling strategies for saving irrigation water and controlling salinity in the upper Yellow River Basin, China 总被引：5，自引：0，他引：5
Water saving in irrigation is a key concern in the Yellow River basin. Excessive water diversions for irrigation waste water and produce waterlogging problems during the crop season and soil salinization in low lands. Supply control and inadequate functionality of the drainage system were identified as main factors for poor water management at farm level. Their improvement condition the adoption of water saving and salinity control practices. Focusing on the farm scale, studies to assess the potential for water savings included: (a) field evaluation of current basin irrigation practices and further use of the simulation models SRFR and SIRMOD to generate alternative improvements for the surface irrigation systems and (b) the use of the ISAREG model to simulate the present and improved irrigation scheduling alternatives taking into consideration salinity control. Models were used interactively to define alternatives for the irrigation systems and scheduling that would minimize percolation and produce water savings. Foreseen improvements refer to basin inflow discharges, land leveling and irrigation scheduling that could result in water savings of 33% relative to actual demand. These improvements would also reduce percolation and maintain water table depths below 1 m thereby reducing soil salinization. 相似文献
6.
内陆河流域绿洲灌区盐碱地改良分区及治理模式探究——以新疆焉耆县平原灌区为例 总被引：2，自引：0，他引：2
干旱区土壤盐碱化是土地退化的主要问题,并威胁着绿洲农业的可持续发展,而盐碱地改良分区是因地制宜、综合治理盐碱地的前提。通过综合运用地理信息系统的各种空间数据分析功能,以焉耆平原灌区为典型区域,将土地盐碱化现状分为:非盐碱地、轻度盐碱地、中度盐碱地、重度盐碱地、盐土等5个区,并结合地下水、土壤、植被、岩性等调查资料,进行成因分析,建立了内陆河流域绿洲灌区盐碱地改良分区模型。立足土地盐碱化的现状,充分考虑地下水埋深和矿化度,把焉耆平原灌区按改良难易程度分为:易改良区、较难改良区、难改良区、不宜改良区,并针对不同的盐碱地改良分区特征、水盐平衡模型和现状灌排模式,提出了相应的综合治理对策。 相似文献
7.
基于SALTMOD模型的灌溉水矿化度对土壤盐分的影响 总被引：4，自引：0，他引：4
以河套灌区沙壕渠灌域为例,运用SALTMOD模型探讨了区域尺度灌溉水矿化度对根层土壤盐分的影响。结果表明,根层土壤盐分随灌溉水矿化度的增大而增加,加大排水沟深度和提高渠道衬砌水平可缓解高矿化度灌溉水对土壤积盐的影响;采用地下微咸水和黄河水混合灌溉可有效控制盐渍化的发展,混合比在1∶1范围内时,根层土壤处于脱盐状态,最高脱盐率为23%,脱盐率高于引用黄河水灌溉的脱盐率(4%)。因此,适度利用地下微咸水灌溉,可有效的控制地下水位,节约淡水资源。 相似文献
8.
A simulation study on alternative water management strategies was carried out for Sirsa Irrigation Circle in Haryana, covering an area of about 4800 km2. Results showed that crop evapotranspiration and soil salinity development under reduction in canal water supply and increase in groundwater use, are largely influenced by the amount and distribution of rainfall. Reduction in canal water supply by 25% during the rainy season is unlikely to have any adverse effect on the salinity development in the study area. Reduction in crop evapotranspiration due to decreased canal water supply can partly be compensated by the increase in groundwater use. Leaching of salts due to monsoon rains in the study area shows that groundwater of even relatively poor quality can be used for irrigation without excessive long-term build up of soil salinity under deep groundwater depth conditions. However, increased groundwater extraction without associated actions will not be very effective to solve the problem of rising groundwater levels. 相似文献
9.
Subsurface drainage to combat waterlogging and salinity in irrigated lands in India: Lessons learned in farmers’ fields 总被引：1，自引：0，他引：1
The introduction of irrigated agriculture in the arid and semi-arid regions of India has resulted in the development of the twin problem of waterlogging and soil salinization. It is estimated that nearly 8.4 million ha is affected by soil salinity and alkalinity, of which about 5.5 million ha is also waterlogged. Subsurface drainage is an effective tool to combat this twin problem of waterlogging and salinity and thus to protect capital investment in irrigated agriculture and increase its sustainability. In India, however, subsurface drainage has not been implemented on a large scale, in spite of numerous research activities that proved its potential. To develop strategies to implement subsurface drainage, applied research studies were set-up in five different agro-climatic sub-regions of India. Subsurface drainage systems, consisting of open and pipe drains with drain spacing varying between 45 and 150 m and drain depth between 0.90 and 1.20 m, were installed in farmers’ fields. The agro-climatic and soil conditions determine the most appropriate combination of drain depth and spacing, but the drain depths are considerably shallower than the 1.75 m traditionally recommended for the prevailing conditions in India. Crop yields in the drained fields increased significantly, e.g. rice with 69%, cotton with 64%, sugarcane with 54% and wheat with 136%. These increases were obtained because water table and soil salinity levels were, respectively, 25% and 50% lower than in the non-drained fields. An economic analysis shows that the subsurface drainage systems are highly cost-effective: cost-benefit ratios range from 1.2 to 3.2, internal rates of return from 20 to 58%, and the pay-back periods from 3 to 9 years. Despite these positive results, major challenges remain to introduce subsurface drainage at a larger scale. First of all, farmers, although they clearly see the benefits of drainage, are too poor to pay the full cost of drainage. Next, water users’ organisations, not only for drainage but also for irrigation, are not well established. Subsurface drainage in irrigated areas is a collective activity, thus appropriate institutional arrangements for farmers’ participation and organisation are needed. Thus, to assure that drainage gets the attention it deserves, policies have to be reformulated. 相似文献
10.
The study describes the capacity of trees to control the rise in water table and thus prevent the formation of waterlogged soils and development of secondary salinization in canal irrigated areas. It was conducted in RCC lysimeters of 1.2 m dia. and 2.5 m depth filled with sandy loam alluvial soil (Typic Ustochrept), with provisions to maintain water table depth at 1, 1.5 and 2 m from the surface and groundwater salinity at 0.4, 3, 6, 9 and 12 dS m-1. The amount of water biodrained by eucalyptus (Eucalyptus tereticornis) and bamboo (Bambusa arundinacea) at the given water table depths and groundwater salinity levels was monitored over four years by daily measuring the water needed for maintaining the water table. The trees continued to absorb and transpire water throughout the year, the capacity being more in summer and rainy than that was in the winter season. The eucalyptus plant could biodrain 2880, 5499, 5518 and 5148 mm of water in the first, second, third and fourth year of study period, from non-saline groundwater and a water table depth of 1.5 m. The amount of water biodrained was more at 1.5 m as compared to 1 and 2 m water table depths. The biodrainage capacity of trees was significantly affected by the salinity of the groundwater. However, even at salinity of 12 dS m-1, the eucalyptus plant biodrained 53% of that under non-saline conditions. It was calculated that biodrainage could control water table rises upto 1.95, 3.48, 3.76 and 3.64 m in first, second, third and fourth year, respectively. The secondary salinity developed in the root zone, upto 45 cm depth, did not exceed 4 dS m-1 even at water table depth of 1 m with salinity of 12 dS m-1. The volume of water biodrained by bamboo increased with time and could control water table rises upto 1.09, 1.86, 2.46 and 2.96 m in first, second, third and fourth year of growth, respectively.This study indicates that due to high transpiration capacity and an ability to extract water from deeper layers containing saline groundwater, the trees can control the rise in water table in irrigation command areas and prevent the formation of waterlogged and eventually the saline wastelands. 相似文献
11.
The sustainability of the rice-wheat cropping system in an irrigated semi-arid area of Haryana State (India) is under threat due to the continuous rise in the poor quality groundwater table, which is caused by the geo-hydrological condition and poor irrigation water management. About 500,000 ha in the State are waterlogged and unproductive and the size of the waterlogged area is increasing. We analyse the hydrology and estimate seasonal net groundwater recharge in the study area. Rainfall is quite variable, particularly in the monsoon season, and the mean monthly reference evapotranspiration shows a high inter-annual variation, with values between 2.45 and 8.47 mm/day in December and May. Groundwater recharge analysis during the study period (1989-2008) reveals that percolation from irrigated fields is the main recharge component with 57% contribution to the total recharge. An annual groundwater table rise of 0.137 m has been estimated for the study area. As the water table has been rising continuously, suitable water management strategies such as increasing groundwater abstraction by installing more tubewells, using the groundwater conjunctively with good quality canal water, changes in cropping patterns, adoption of salt tolerant crops, changes in water-pricing policy, and matching water supply more closely with demand, are suggested to bring the water table down to a safe limit and to prevent further rising of the water table. 相似文献
12.
[目的]监测渭-库绿洲土壤盐渍化的空间分布特征,探究驱动因子作用机理,对当地因地制宜进行土壤盐渍化调控。[方法]采用决策树、克里金插值和灰色关联度分析研究了渭-库绿洲土壤盐渍化的剖面分布特征,着重分析了样本点海拔、植被覆盖度、地下水位、TW( I 地形湿度指数)、地下水矿化度5个驱动因子对土壤盐渍化的影响。[结果]①研究区表层土壤(0~10 cm)属于重度盐渍化土壤,10~20、20~40、40~60 cm各深度剖面土壤属于中度盐渍化土壤。土壤EC1:5有强的空间变异性,其分布格局受灌溉等人为驱动因素的影响较大。②绿洲内部(即耕作区)表层土壤属于非盐渍化区域,绿洲东部10~20、20~40、40~60cm土层有轻、中度的盐渍化现象。绿洲内部表层以下土壤盐分高于表层,绿洲存在潜在的盐渍化风险。耕作区外围绿洲-荒漠交错带区域各剖面层均属于盐渍化区域,随着剖面深度的增加,盐渍化程度在不断减弱。③样本点海拔、植被覆盖度、地下水位、TWI、地下水矿化度与土壤EC1:5的灰色关联度大小次序为:0~10 cm土层:地下水矿化度>TWI>样本点的海拔>植被覆盖度>地下水位;10~20、20~40 cm土层:地下水矿化度>样本点的海拔>TWI>植被覆盖度>地下水位。[结论]渭-库绿洲土壤盐渍化主要分布在绿洲-荒漠交错带区域,土壤盐分表聚强烈,地下水矿化度是造成该研究区土壤盐渍化问题的首要原因。 相似文献
13.
滴灌年限对土壤盐分分布及棉花的影响 总被引：2，自引：0，他引：2
针对新疆盐碱地的改良及土壤次生盐渍化的问题,定点监测了121团开荒应用膜下滴灌技术种植棉花从第2年到第4年连续3年的盐分变化,并与荒地盐分对比。结果表明:滴灌2年,各个土层土壤含盐量在生育期初与生育期末变化较小,积盐现象与荒地相比有所减轻;随着滴灌年限的增加,各个土层土壤含盐量均呈减少趋势;滴灌4年后各个土层土壤含盐量再分布比较明显,0～20cm土层及120～140cm土层含盐量最大,40～60cm与80～100cm土层土壤含盐量较小,棉花根系主要分布的40～60cm土层土壤含盐量最小;滴灌4年土壤含盐量基本满足种子出苗,平均成活率从6.9%,增加到94.5%,但是棉花平均株高、平均单株铃数及产量仅为正常棉花的66%、53%和57%,相对较低。对于滴灌4年后的盐碱地应继续加大水盐调控的力度。 相似文献
14.
不同滴灌年限土壤盐分分布及对棉花的影响初步研究 总被引：4，自引：0，他引：4
随着膜下滴灌应用年限增加,农田土壤盐碱变化及对作物影响引起关注.通过在新疆石河子121团,选择地块相近连续应用膜下滴灌2～14 a棉田8块进行盐分变化监测.结果初步表明,膜内0～20 cm土壤脱盐;40～80 cm积盐;膜间裸地盐分表聚,60 cm以上积盐,100 cm以下与膜内土壤盐分接近.滴灌4 a以内盐分含量较高,滴灌6 a以上较低.生育期末0～40 cm土壤盐分随滴灌年限增加而降低;60～100 cm以滴灌4 a积盐最高.滴灌8 a以上棉花成活率较高、株高和单株铃数相差不大.棉花产量以滴灌8 a地块最高,滴灌8 a以内随滴灌年限增加产量增加,滴灌8 a以上随滴灌年限增加产量降低.建议滴灌6 a以内农田加大盐分调控力度,滴灌8 a以上要对土壤盐分进行综合调控. 相似文献
15.
Using shallow saline groundwater for irrigation and regulating for soil salt-water regime 总被引：7，自引：0，他引：7
Drought and fresh water shortage are the main limiting factorsfor sustainable development of agriculture in North China Plain.Using saline water for irrigation plays important role forovercoming the constraints and increasing crops yields. Theexploitation and utilization of shallow saline groundwaterenables to regulate the groundwater depth and to promote thetransform of precipitation into available water resources.Thispaper reviews the research and practice on the utilization ofshallow saline groundwater in the part east of South GreatCanal in Haihe River Plain. Findings are presented on the useof saline water, cycling and blending of saline and fresh waterfor irrigation, indexing of crops salt tolerances, regulating forsoil salt-water regime, saline-alkali land reclamation andgroundwater quality freshening. These approaches help therational regulation and utilization of the local water resourcesfor comprehensive control of drought, waterlogging and salinity. 相似文献
16.
17.
Modeling irrigated cotton with shallow groundwater in the Aral Sea Basin of Uzbekistan: I. Water dynamics 总被引：4，自引：3，他引：1
I. Forkutsa Rolf Sommer Y. I. Shirokova J. P. A. Lamers K. Kienzler B. Tischbein C. Martius P. L. G. Vlek 《Irrigation Science》2009,27(4):331-346
In Khorezm, a region located in the Aral Sea basin of Uzbekistan, water use for irrigation of predominantly cotton is high
whereas water use efficiency is low. To quantify the seasonal water and salt balance, water application, crop growth, soil
water, and groundwater dynamics were studied on a sandy, sandy loam and loamy cotton field in the years 2003 and 2005. To
simulate and quantify improved management strategies and update irrigation standards, the soil water model Hydrus-1D was applied.
Results showed that shallow groundwater contributed a substantial share (up to 399 mm) to actual evapotranspiration of cotton
(estimated at 488–727 mm), which alleviated water stress in response to suboptimal quantities of water applied for irrigation,
but enhanced concurrently secondary soil salinization. Thus, pre-season salt leaching becomes a necessity. Nevertheless, as
long as farmers face high uncertainty in irrigation water supply, maintaining shallow groundwater tables can be considered
as a safety-net against unreliable water delivery. Simulations showed that in 2003 around 200 mm would have been sufficient
during pre-season leaching, whereas up to 300 mm of water was applied in reality amounting to an overuse of almost 33%. Using
some of this water during the irrigation season would have alleviated season crop-water stress such as in June 2003. Management
strategy analyses revealed that crop water uptake would only marginally benefit from a permanent crop residue layer, often
recommended as part of conservation agriculture. Such a mulch layer, however, would substantially reduce soil evaporation,
capillary rise of groundwater, and consequently secondary soil salinization. The simulations furthermore demonstrated that
not relying on the contribution of shallow groundwater to satisfy crop water demand is possible by implementing timely and
soil-specific irrigation scheduling. Water use would then not be higher than the current Uzbek irrigation standards. It is
argued that if furrow irrigation is to be continued, pure sandy soils, which constitute <5% of the agricultural soils in Khorezm,
are best to be taken out of annual cotton production. 相似文献
18.
The effect of replacing furrow irrigation with subsurface trickle irrigation on some soil physical and chemical properties of hardsetting red Alfisols when sown to cotton were evaluated on two farms (Bellevue and Brae Park) in the Macquarie valley of New South Wales, Australia, during 1998 and 1999. The soil at Bellevue had a heavier soil texture than that at Brae Park. Soil was sampled from depths of 0-0.15 m, 0.15-0.30 m, 0.30-0.45 m and 0.45-0.60 m in "paired" fields sown to either trickle- or furrow-irrigated cotton. The soil properties evaluated were soil structural stability as dispersion index, hardsetting characteristics, salinity as electrical conductivity (EC) of a 1:5 soil:water suspension, and sodicity as EC/exchangeable Na ratio. Compared with furrow irrigation, salinization, soil structural stabilization, hardsetting behaviour reduction and EC/exchangeable Na ratio increase were faster with trickle irrigation in the surface (0-0.15 m) of the heavier-textured soil at Bellevue. Changes at other soil depths were negligible. In contrast, in the lighter-textured soil at Brae Park, furrow irrigation increased the rates of salinization, structural stabilization, and hardsetting behaviour reduction in the subsoil more than trickle irrigation. Dispersion decreased rapidly at all depths and with both irrigation systems at both locations. The reduction in hardsetting was correlated to the reduction in dispersion in the 0-0.3 m depth at Bellevue and at the 0-0.6 m depth at Brae Park. The fall in dispersion in the 0.3-0.6 m depth at Bellevue was not accompanied by a corresponding reduction in hardsetting. Replacement of furrow irrigation with subsurface trickle irrigation in heavier-textured loamy soils can, therefore, result in short-term improvements in some soil properties, whereas in lighter-textured soils similar changes do not occur. 相似文献
19.
新疆气候干旱与土壤盐碱化并存,是制约新疆农业发展的主要因素,开沟覆膜滴灌技术综合了膜下滴灌技术与开沟技术的优点,理论上可有效治理盐碱地。在开沟覆膜滴灌技术下,设置不同灌水定额与灌水次数,利用试验土槽模拟盐分调控规律,结果表明:1第1次合适灌水定额对盐分的淋洗起主要作用,可使土体盐分达到较稳定的状态,盐分也随水分侧向运移,并在土埂表层聚集;2灌水定额的增加促进盐分随水分向远离滴头和向深层方向运移,使得覆膜间、覆膜边盐分淋洗的深度增加,脱盐区增加;3在灌水定额为300m3/hm2时,可以在滴灌带横向0~23cm,下部58cm处迅速形成一个含盐量小于1.5%的达标脱盐区,满足当地作物正常出苗,故建议当地可选择300m3/hm2作为第1次灌水洗盐定额。 相似文献
20.
Comparing water management in rice-wheat production systems in Haryana, India and Punjab, Pakistan 总被引：1，自引：0，他引：1
Olaf Erenstein 《Agricultural Water Management》2009,96(12):1799-1806
The intensive irrigated rice-wheat systems in the northwest Indo-Gangetic Plains of South Asia are built on a long tradition of canal irrigation and the more recent advent of tubewells. Findings from farm surveys are used to examine water management and water productivity in the rice-wheat belt of India's Haryana State and Pakistan's Punjab province. Attributes of the irrigation sources help explain the widespread interest in groundwater use and the relative demise of canal water use. In each area groundwater now is the main irrigation source, used either solely or in conjunction with surface water. The ownership of tubewells is near universal among the surveyed farms, whereas conjunctive water use is more widespread during the monsoon season, among better endowed farmers and in the Pakistan Punjab. In Pakistan Punjab farmers primarily rely on diesel powered tubewells whereas Haryana farmers mainly use relatively cheaper electric power. Water productivity indicators for rice are markedly lower than those for wheat—largely reflecting significantly higher water inputs in paddy cultivation—but also vary between the study areas and by the prevailing water use, reflecting the limited incentives for farmers to use water wisely. A combination of technological, land use and market based approaches is likely to be most effective in achieving sustainable water management in these intensive cereal systems. 相似文献