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Contents lists available at ScienceDirect

Agricultural Water Management

jou rn al hom ep age: www.elsev ier .com/ locate /agwat

chieving sustainable irrigation requires effective managementf salts, soil salinity, and shallow groundwater

ennis Wichelnsa,∗, Manzoor Qadirb,c

P.O. Box 2629, Bloomington, IN 47402, USAUnited Nations University—Institute for Water, Environment and Health (UNU—INWEH), 175 Longwood Road South, Hamilton, L8P 0A1, Ontario, CanadaInternational Water Management Institute, P.O. Box 2075, Colombo, Sri Lanka

r t i c l e i n f o

rticle history:eceived 26 July 2014ccepted 19 August 2014vailable online xxx

eywords:rid areasrop productioneleniumubsurface drainageaterloggingater policy

a b s t r a c t

Salinity and waterlogging have impacted agricultural production in arid areas for more than 2000 years.The causes of the problems are well known, as are the methods and investments required to managesalt-affected soils and shallow water tables. Yet the problems persist in many regions where farmersapply excessive irrigation water, and where farmers and irrigation departments fail to invest in adequatedrainage solutions. Long ago, Professor E.W. Hilgard described the inevitability of salinity problems in aridareas and the measures required to prevent or overcome those problems. Hilgard warned of impendingsalinization in California’s Central Valley, based partly on his understanding of salinity and waterloggingproblems in India. More recently, Jan van Schilfgaarde, Jim Oster, and others also have described theinevitable environmental impacts of irrigation. These authors suggest that irrigation likely can be sus-tained, but the cost of reducing the environmental impacts to an acceptable level might be substantialin some areas. We review the perspectives of these authors, and others, with an outlook toward a futurein which the goal of achieving sustainable irrigation coincides with the goal of intensifying agriculture

more generally, to provide food and fiber for an expanding global population. We propose five activitiesthat might be implemented in a comprehensive program to achieve successful management of salinityand waterlogging. We also introduce the notion of implementing a deposit or bond payment for thesalt contained in irrigation water deliveries. Farmers would be reimbursed in accordance with their saltmanagement and disposal practices.

. Motivation

The global population likely will increase to 9 or 10 billionetween 2015 and 2050. The increase in population, along withising incomes, will lead to greater demands for crop and livestockroducts. Faced with the challenge of increasing food productiony 50% or more by 2050, many analysts are promoting the notion ofustainable intensification of agriculture, which generally involvesigher rates of key inputs per hectare, in pursuit of higher yields,hile minimizing potential impacts on the environment and natu-

al resources (Tilman et al., 2011; Tscharntke et al., 2012; Garnettt al., 2013; Godfray and Garnet, 2014).

The call for sustainable intensification comes amidst the emerg-

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

ng understanding that the rates of increase in crop yields in keyroduction regions have fallen substantially from the growth ratesbserved during the 1960s through the 1990s (Ray et al., 2012;

∗ Corresponding author.E-mail address: dwichelns@csufresno.edu (D. Wichelns).

ttp://dx.doi.org/10.1016/j.agwat.2014.08.016378-3774/© 2014 Published by Elsevier B.V.

© 2014 Published by Elsevier B.V.

Iizumi et al., 2013). Current growth rates in the yields of maize,rice, wheat, and soybeans are insufficient to meet projected fooddemands in 2050 (Ray et al., 2013). The causes of declining growthrates include increasing pressure from salinity and waterlogging(Humphreys et al., 2010), depletion of soil nutrients and organicmatter (Chianu et al., 2012; Srinivasarao et al., 2013), climatechange (Chen et al., 2010; Lal, 2011; Lin and Huybers, 2012; Lobell,2012; Rao et al., 2014), and inappropriate crop management prac-tices (Fan et al., 2012).

Water scarcity and the rising cost of obtaining groundwateras water tables fall, due to excessive pumping, also have con-tributed to declining rates of growth in crop yields (Ambast et al.,2006; Humphreys et al., 2010). In rice–wheat production areas ofthe upper portion of the Indo-Gangetic Plain, groundwater levelshave declined by 5–15 m since the 1980s, while tubewell densityhas increased to 15 km−2. Wheat yields are still increasing in the

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

region, but rice yields appear to have stabilized (Ambast et al.,2006).

Much of the needed increase in crop yields between now and2050 will come from innovations in plant genetics and agricultural

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echnology. Substantial research is underway in several countriesn the fields of plant genomics, physiology, and agronomy (Sinclairt al., 2004). Successful outcomes of this research, when appliedn agriculture, will be necessary, but not sufficient, in producinghe amounts of food and fiber required in 2050 (Wollenwebert al., 2005). Needed also are notable improvements in agronomicractices on small and large farms in all producing regions. Such

mprovements are needed to offset some of the declines in cropields observed in recent years, and also to boost crop yieldseyond the average levels achieved in key production areas, such asorthern China, south and southeast Asia, and sub-Saharan AfricaGeorge, 2014).

The necessary improvements in agronomic practices must bemplemented in ways that are helpful in achieving sustainablerrigation in both humid and arid regions. The challenge likely

ill be more substantial in arid and semi-arid regions, wherearge production areas are impacted by soil salinity, inadequateubsurface drainage, and waterlogging. In many areas, saline andodic soils must be reclaimed before higher yields can be achievednd sustained. Reclamation can be achieved using chemical soilmendments or by implementing plant-based strategies, such ashytoremediation (Qadir and Oster, 2004; Qadir et al., 2007).

mproving the distribution uniformity of irrigation and providingdequate subsurface drainage also will be important componentsf successful efforts to achieve sustainable irrigation (Wichelns andster, 1990; Oster and Wichelns, 2003; Wichelns and Oster, 2006).

In this paper, we review the current state of knowledgeegarding sustainable irrigation, with particular emphasis on aridnd semi-arid areas, in the context of the global challenge ofnsuring food and nutritional security by 2050. Many scholars andractitioners, including Jim Oster and his research partners in sev-ral countries, have studied soil salinity and sodicity, irrigationniformity, subsurface drainage, and crop production practicesor many years. They have contributed a large volume of litera-ure regarding the scientific, policy, and management aspects ofhe efforts needed to achieve sustainable irrigation. We review amall portion of that literature and we describe several examplesf irrigation and drainage problems that might be solved, in part,y adopting some of the recommendations put forth by Jim Osternd his colleagues.

.1. The challenge is not a new one

Farmers in arid and semi-arid areas have faced the challengef achieving sustainable irrigation for more than 2000 years. Theemise of ancient civilizations due partly to crop failures causedy the accumulation of salts in agricultural soils is well knownJacobsen and Adams, 1958; Letey, 2000; Zhou et al., 2012; Zhaot al., 2013). So too are the long-standing problems of salinity andaterlogging in key production regions of the world (Hillel, 1991;illel and Vlek, 2005; Rengasamy, 2006; Proust, 2008; Qadir et al.,009; Singh, 2009).

In the second half of the 19th century, Professor E.W. Hilgardf California, while visiting with engineers from India, learned ofast areas of formerly productive farmland that had succumbed toaterlogging and salinity within a few years after farmers began to

rrigate. The farmers received water deliveries from large surfacerrigation schemes, built to supplement or replace groundwaterumping. Professor Hilgard understood the cause of the problemuite well. Both seepage from the elevated delivery canals andhe excessive application of irrigation water by farmers “relieved

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

rom the laborious processes of well irrigation” caused shallowroundwater to rise very near the soil surface, thus allowing saltso accumulate in the root zone (Hilgard, 1886). The remedy wastraightforward, although costly:

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1. lower the elevated canals to reduce seepage and force the farm-ers to lift water for irrigation, and;

2. construct a regional drainage system to carry the saline subsoilwater into rivers and the sea, “thus relieving the land more orless permanently of that scourge (Hilgard, 1886).”

Professor Hilgard understood the similarity between agronomicconditions in India and California’s Central Valley, where he sawgreat potential for agriculture to thrive, if it was managed appro-priately (Hilgard, 1893). Thus, he wrote passionately about thepotential threat of waterlogging and salinity in California, urg-ing farmers and public officials to build regional drainage systemsand to use irrigation water “sparingly” to prevent the otherwiseinevitable, future harm that could occur in California agriculture.In his words,

“It is hardly necessary to go further into the details [of theproblems occurring in India] to enforce the lesson and warningthey convey to our irrigating communities. The evils now beset-ting the irrigation districts of northwest India are already becomingpainfully apparent; and to expect them not to increase unless theproper remedies are applied is to hope that natural laws will bewaived in favor of California. The natural conditions under whichthe irrigation canals of India have brought about the scourge, areexactly reproduced in the great valley of California; and what hashappened in India will assuredly happen there also (Hilgard, 1886).”

Hilgard recommended a three-part strategy for achieving sus-tainable irrigation, management, published in the Bulletin of theUniversity of California College of Agriculture (Hilgard, 1886):

1. “Drainage correlative with irrigation.” Hilgard emphasized theneed to develop drainage solutions concurrent with irrigationschemes. He understood the potential harm that can arise whendrainage systems are not installed in a timely manner.

2. Region-based solutions. Hilgard wrote that “single individualshowever, can do but little in the matter; the action to be takenmust, of necessity, be that of whole communities.” Given thatexcessive irrigation causes a shallow water table to rise beyondthe borders of individual farms, a regional drainage system isrequired.

3. “Sparing use of water to restrict the rise of alkali.” Hilgard warnedthat if irrigation was expanded without management strategiesthat used water sparingly to “restrict the rise of alkali” [as usedby Hilgard, the term ‘alkali’ is synonymous with salinity], thenwaterlogging and salinity would plague California agriculture.

Hilgard’s prescription for achieving sustainable irrigation is asvalid in the 21st century as it was in the 19th. The salinity anddrainage problems in California and elsewhere arise and persistlargely for the same reasons Hilgard described in 1886: excessiveirrigation, inadequate drainage, and lack of a regional managementprogram. Most farmers everywhere lack sufficient incentives tooptimize their irrigation deliveries and manage deep percolation inways that minimize off-farm impacts. Community involvement inthe form of establishing regulations, providing incentives, and gen-erating funds for infrastructure development is essential to preventregional degradation of land and water resources.

Lacking regional, comprehensive efforts, salinity and drainageproblems persist in many key production regions, such as thesouthwestern United States, much of Australia, Iran, and large por-tions of the Indo-Gangetic Plain in India and Pakistan (Ritzemaet al., 2008; Singh, 2009; Singh et al., 2010; Emadodin et al., 2012;

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

Wichelns and Oster, 2014). To achieve sustainable irrigation inthese and other areas, farmers must implement the right mix ofagronomic practices, in conjunction with wise water use and care-ful management of shallow water tables, while working together

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n regional drainage associations (Letey, 2000; Oster and Wichelns,003; Hillel and Vlek, 2005; Ibrakhimov et al., 2011).

Efficient farm-level water management is essential to minimizehe size and cost of regional drainage efforts. As Hilgard has sug-ested, irrigation water must be used sparingly, particularly in aridnd semi-arid areas, as each unit of irrigation water adds salt thatontributes to higher salinity levels in surface streams and ground-ater. Too often, planners of irrigation schemes do not account

ufficiently for the downstream effects of excessive irrigation. Theyssume that the surface runoff or deep percolation from one farms beneficial to other farmers. Yet water quality inevitably degradeslong the sequence of subsequent water uses (Burkhalter and Gates,005; Duncan et al., 2008; Martín-Queller et al., 2010). Irrigationnd drainage schemes must account for water quality impacts, andarmers must be motivated to irrigate efficiently, with minimumeaching fractions (Ayars and Hanson, 2014).

Both surface runoff and deep percolation generally are morealine than the irrigation water applied on farm fields. Surfaceunoff gains salt from the soil surface and from cracks in soilshat exhibit substantial cracking upon wetting and drying (Rhoadest al., 1997; Shouse et al., 1997; Crescimanno and Garofalo, 2006;allender et al., 2006). The salinity of surface runoff leaving a

arm can be substantially higher than the salinity of the initialrrigation water. Deep percolation can dissolve native salts as it

oves through the soil profile, thus adding salt to groundwaterLin and Garcia, 2012). In areas where excessive irrigation rechargesquifers that discharge into rivers, the salinity of those rivers canncrease substantially downstream, along an irrigation scheme (vanchilfgaarde, 1994; Thayalakumaran et al., 2007; Price and Gates,008; Lin and Garcia, 2012).

.2. Sustainable blessing or perpetual curse?

Writing a bit more than 100 years after Hilgard, van Schilfgaarde1994) posed the question of whether irrigation is a blessing or

curse. He reminded us that irrigation in arid areas inevitablyegrades water quality in downstream reaches, as dissolved saltsnter irrigation return flows, thus increasing the salinity of waterourses from which other farmers and communities draw theirater supplies. van Schilfgaarde concluded that irrigation is per-aps a mixed blessing. Irrigation is vital, and additional irrigation

nvestments are needed to produce food and fiber for an expandinglobal population. Yet we must utilize the science and technol-gy available to irrigate with a keen sense of stewardship and toinimize third-party impacts (van Schilfgaarde, 1994).Writing in the same issue of Agricultural Water Management,

ster (1994) reviewed the state of knowledge regarding irrigationith poor quality water. Given that irrigation inevitably degradesater quality, farmers in arid regions will eventually need to

ccommodate lower quality water for use in irrigation. Osterescribed three essential changes from standard irrigation prac-ices:

. selecting appropriately salt-tolerant crops;

. improving water management, in some cases through the use ofadvanced irrigation methods, and;

. maintaining soil physical properties to assure soil tilth andadequate permeability to meet crop water and leaching require-ments.

Each of these practices can be implemented by individual farm-rs, as they pertain to farm-level soil, crop, and water management.

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

ustainability requires that farmers apply only the minimum leach-ng fraction needed to maintain soil salinity within an acceptableange. Hilgard’s notion of applying water sparingly must be widelydopted, particularly where farmers irrigate with lower quality

PRESSr Management xxx (2014) xxx–xxx 3

water. Excessive irrigation in such settings is incompatible withefforts to achieve sustainability.

Wide adoption of minimum leaching fractions will minimizethe cost of a regional drainage system for removing saline drainagewater and maintaining sufficient depth to shallow water tables. Thelower cost will increase the likelihood that farmers and landownerswill jointly finance investments in regional drainage facilities thatgenerate benefits which are both disperse and delayed. The cost ofeach farmer’s participation is clearer and easier to calculate than arethe expected benefits. Thus, many farmers are reluctant to invest inregional drainage solutions, even though the long-term net benefitsare positive.

1.3. Missing markets and institutional shortcomings

Given the very long history of salinity and drainage problems,it is reasonable to ask why the problems have not been solved ina manner that would prevent further degradation of agriculturallands, and the consequent negative impacts on productivity andlivelihoods. Missing markets and institutional shortcomings arepartly to blame, as is the inherent preference for near-term gainsin net revenue, in exchange for longer term declines in agriculturalproductivity. Many farmers and their representatives likely wouldchoose to maximize net revenue in the current year, while delayingcostly – but necessary – investments in salinity and drainage man-agement. Salinity and drainage problems become more intractable,the longer such delays in necessary investments accumulate.

Perhaps the most pertinent missing market is the inability offuture generations to express their desire for maintaining soil qual-ity and agricultural productivity. If those generations were presenttoday, they might be willing to compensate farmers for investmentsin salt management and drainage systems that would provide sub-sequent generations with a more viable and higher valued set ofagricultural lands. Lacking such an inter-generational exchange,current farmers are not able to earn a return on the needed invest-ments, and thus the investments are not made.

Institutional shortcomings are evident primarily in the con-text of public irrigation and drainage schemes. In many countries,the ministries of agriculture and irrigation have supported pub-lic investments that provide farmers in arid areas with access toirrigation water, while leaving the necessary investments in saltmanagement and drainage to another agency or to a later time.Large-scale irrigation schemes generate benefits that are easy todescribe and generally appreciated by the general public. The ben-efits are also photogenic. Many news reports and photo essays ofpublic efforts to make the desert bloom have accompanied suc-cessful efforts to extend irrigation into arid areas unable to supportcrop production on rainfall alone. The rationale for investing in asubsurface drainage system is more difficult to describe to the non-farming public, and photographs of drainage system componentsare not immediately compelling.

2. Examples from selected areas

2.1. The Nile Delta

Irrigation deliveries in the Nile Delta contain a mixture of freshwater and saline drainage water, as both the government and indi-vidual farmers use drainage water to extend the available irrigationsupply. The government has been practicing official drainage waterreuse since 1928, when it constructed the first of many pumping

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stations that lift drainage water from drains and place it into deliv-ery canals (Abdel Ghaffar and Shaban, 2014). Unofficial pumpingand use of drainage water by individual farmers is illegal in Egypt,but the ban is largely not enforced, as the government realizes

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hat many farmers depend on drainage water to irrigate theirrops (Barnes, 2012). The farmers generally are aware of the near-erm and long-term implications of sustained irrigation with salinerainage water, yet they place the near-term gains of crop incomebove the long-term losses due to salt accumulation in their soils.

The irrigation and drainage program in the Nile Delta reflectshe difficulty of maintaining salt balance in an arid, productive,rrigated region. Subsurface drains are needed in the Nile Delta to

aintain sufficient water table depth and to remove saline waterrom the root zone. Ideally, the collected drainage water would beischarged to an appropriate sink. Yet, the drainage water is viewedy the government and individual farmers as a viable source of

rrigation water in a region with increasing demands on limitedater resources. The government attempts to optimize drainageater use in the Nile Delta by managing the pumping and blend-

ng of drainage water at a series of large-scale pumping stations,n accordance with engineering and agronomic criteria (Abdel-ayem et al., 2007). However, the unofficial use of drainage watery thousands of individual farmers complicates the aggregate efforto manage salt balance in the region.

.2. Central Asia

The salinity and drainage problems that have arisen over timen Central Asia are well known and widely studied. The extensiveevelopment of irrigation in the region, based largely on waterrom the Amu Darya and Syr Darya Rivers, was enacted in a fashionhat focused on near-term gains in cotton and grain production,ith inadequate attention given to the sustainability of land andater resources. Excessive irrigation by farmers with little incen-

ive to manage water carefully, and the commingling of drainageater with fresh water in lower reaches of irrigated areas, have

esulted in extensive areas of saline and waterlogged soils (Qadirt al., 2009). For many years, the farmers irrigated largely accordingo water norms prepared by irrigation engineers in distant loca-ions, rather than attempting to match irrigations with crop waterequirements.

In addition to impairing current productivity, the extensive soilalinity and waterlogging in Central Asia might cause additionalarm in future, if climate change results in less annual rainfall andigher seasonal temperatures. In particular, reductions in annualainfall will complicate efforts to achieve sufficient leaching of salts,hile higher temperatures will place additional stress on areas

lready impacted by soil salinity (Sommer et al., 2013). Thus, iteems imperative that agronomic practices be improved very soon,ith the goal of reclaiming saline and waterlogged areas in advance

f climate change. In addition, farmers might consider mulchinglternate furrows when producing cotton in Central Asia, as itppears mulching enhances soil moisture conditions and slows theate of increase in soil salinity on irrigated fields (Bezborodov et al.,010).

.3. The Jordan Valley

The areal extent of soil salinity has increased in the Jordan Valleyn recent years, due partly to the increasing use of low-quality wateror irrigation. One source of the low-quality water is the dischargef untreated wastewater into streams that flow into the reservoirehind the King Talal Dam, which provides irrigation water in theegion (Al-Zu’bi, 2007). Ammari et al. (2013) reported that 63% ofhe soils in the Jordan Valley are saline, of which 46% are moder-tely to strongly saline. The authors suggest that in addition to the

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

ncreasing use of commingled irrigation return flows and moder-tely saline treated wastewater, many farmers have switched torip irrigation and they do not apply enough water to leach saltshrough the soil profile.

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Carr et al. (2011) report that the farm-level choice of flood ordrip irrigation in the Jordan Valley is determined in part by wateravailability, and that farm-level leaching strategies are constrainedby water scarcity. Many farmers are aware of the potential salin-ity impacts due to irrigating with reclaimed wastewater, yet thewastewater is essential, given the inadequate supply of fresh waterin the region (Carr et al., 2010). The excessive use of fertilizer alsohas contributed to the increasing soil salinity in the Jordan Valley(Ammari et al., 2013). Thus, agronomic practices are partly respon-sible for the degradation of soil quality in the region, with negativeimplications for productivity and sustainability.

2.4. San Joaquin Valley, California

Salinity and drainage problems have become quite challengingin California’s San Joaquin Valley, in part, because planners chosenot to address in a timely manner the inevitable need for a regionaldrainage system, despite Professor Hilgard’s prescient warnings inthe late 1800s. Construction of a regional drain to carry subsurfacedrainage water from farms on the west side of the Valley to the SanJoaquin River, and eventually to the ocean, was started in the early1980s. Yet, the drain was not completed in a timely manner, andthe drainage water it carried was discharged into a set of holdingponds in the Kesterson National Wildlife Refuge. It was there thathigh concentrations of selenium in the agricultural drainage watercaused harm to aquatic wildlife, resulting in permanent suspen-sion of plans to complete the regional drain (Ohlendorf et al., 1987;Letey, 2000; Letey et al., 2002; Lemly, 2004).

Selenium is found naturally in soils of the west side of the SanJoaquin Valley. It is mobilized by irrigation and enters subsurfacedrains as irrigation water percolates through the soil profile (Lemly,2004). The selenium-induced water quality issue at the KestersonNational Wildlife Refuge motivated new studies of irrigation anddrainage management (Kausch and Pallud, 2013; Chang and Silva,2014). Many farmers in the San Joaquin Valley had essentially lostthe opportunity to discharge salts from their farms. Sustainabilityof irrigated agriculture would need to be achieved while managingsalts either on individual farms or within an irrigation or drainagedistrict. Many farmers would need to begin incorporating salinedrainage water within their irrigation regimes.

Some of the early guidelines for irrigating with saline waterwere provided by Maas and Hoffman (1977) and Ayers and Westcot(1985). Extending this earlier work, Rhoades, of the U.S. SalinityLaboratory in Riverside, California, and others, conducted extensiveresearch on farm-level strategies for irrigating with saline water.They demonstrated the feasibility of using saline water sequen-tially with higher quality water, which allows farmers to utilizesome amount of saline drainage water without reducing crop yields(Rhoades, 1984, 1989; Rhoades et al., 1989, 1992; Oster and Grattan,2002). Sequential reuse also reduces the volume of drainage waterrequiring discharge to an evaporation pond, thus reducing the costand environmental risk of utilizing ponds for drainage water dis-posal (Tanji et al., 2002; Posnikoff and Knapp, 2006; Schwabe et al.,2006).

In recent years, several researchers have demonstrated theimportance of considering the dynamics of salt movement in soils,using transient-state models, rather than steady-state models ofsalinity impacts. Their work has suggested that successful crop pro-duction might be sustained in some areas with smaller leachingfractions than those recommended in earlier years (Corwin et al.,2007; Letey and Feng, 2007; Letey et al., 2011). Smaller leach-ing requirements might enable farmers to sustain crop production

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

using smaller volumes of fresh water, while also generating smallervolumes of subsurface drainage water. However, it is not yet clear ifirrigation can be sustained in all portions of the San Joaquin Valley,particularly in areas where the discharge of saline drainage water is

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estricted, to protect water quality in downstream areas (Schoupst al., 2005).

Using drainage water for irrigation is not a permanent solutiono the challenge of managing salts in agriculture (Grattan et al.,014). Without effective leaching and subsequent removal, saltsill continue to accumulate in soils. In areas where salt removal

annot be accomplished in an environmentally acceptable man-er, it might become necessary to discontinue production on somegricultural lands. More than 80,000 ha of irrigated lands have beenetired from agriculture in California’s San Joaquin Valley in recentears, partly to reduce the load of selenium reaching the San Joaquiniver and other waterways (Wallender et al., 2002; Wichelns andone, 2002), and also to offset declines in average water allocationser hectare, as surface water deliveries in the Valley have beene-allocated to competing uses.

Salinity and drainage issues in the San Joaquin Valley might haveeen easier and less costly to address if farmers had used irrigationater sparingly from the start, and if salt management had been

ncorporated in the earliest designs for irrigation development inhe region. The suggestion by Professor Hilgard that natural lawsegarding irrigation and drainage in arid areas would likely not beaived on behalf of California proved accurate (Hilgard, 1886). Salts

ventually accumulated in the soils of the San Joaquin Valley, and regional drainage solution became essential. The drainage situa-ion in California has been more challenging than in many similaregions, due to the unexpected problems caused by selenium ingricultural drainage water. Yet, the need for a regional drainageolution for collecting and removing salts was predictable from theutset.

. Taking a positive STEPP forward

The widespread and persistent occurrence of waterlogging andalinity suggests that the causes and complications associated withrrigation and drainage are fundamental, and they apply glob-lly, across a wide range of geographic and cultural conditions.n most areas, the two primary underlying causes of waterloggingnd salinity are inappropriate irrigation water management andelayed construction of an adequate drainage system. The causesnd impacts are similar throughout the world, as are the spatialnd temporal dimensions. In addition, potential solutions are con-trained by similar physical, economic, and societal factors.

The actions and investments needed to remove salinity andaterlogging as imminent threats to achieving sustainable agri-

ulture might be summarized as including five items: Supportivenstitutions, Training, Economic analysis, Policies, and Private sec-or participation (STEPP). We discuss each of these activities inurn.

. Supportive institutions and enhanced institutional collabora-tion are needed in the public arena of arid countries in whichfarmers rely on public investments in irrigation and drainage.It is essential that investments in adequate salt managementand drainage are made at the same time, and with the samedegree of commitment, as investments that extend irrigationin arid areas (Abdel-Dayem et al., 2007). The joint agencies orministries responsible for irrigation and drainage must developsubstantial capacity, over time, for understanding the genesisand management of saline shallow water tables and the nega-tive externalities that are sometimes associated with efforts toprovide adequate drainage (Ali et al., 2013; Oster and Wichelns,

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

2014). Farmers acting alone to address farm-level salinity anddrainage problems will not have sufficient incentive, capacity, orfinance to implement the necessarily regional, long-term solu-tions.

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2. Training and capacity building are essential in both the publicand private sectors. Ministry personnel need to learn about new,transient-state models that enhance understanding of salinityimpacts on crop yields and provide sharper insight regardingwise irrigation and drainage management (Oster et al., 2012;Visconti et al., 2014). Such models enable engineers to designmore effective drainage systems based on improved estimatesof salt leaching requirements. Planners would benefit also fromknowledge of plant-based methods of reclaiming saline andsodic soils, known also as phyto-remediation (Qadir and Oster,2004; Qadir et al., 2007; Panta et al., 2014). Such measuresincrease the options available for utilizing drainage waters andextending the usefulness of salt-impacted soils. Knowledge ofremote sensing, geographic information systems, and satelliteimagery also can expand institutional capacity to monitor andassess irrigated, salt-affected, and waterlogged areas (Dehni andLounis, 2012; El Bastawesy and Ali, 2013; Allbed et al., 2014;El Baroudy and Moghanm, 2014; Kaplan et al., 2014; King andThomas, 2014).

3. Many economic analyses of salinity and drainage problemsdescribe the observed or expected impacts on crop yields andcropping patterns, in either physical or monetary terms. Suchstudies are helpful in assessing the costs and benefits of farm-level investments in salinity and drainage management (Houket al., 2006). A broader perspective is needed to evaluate pub-lic investments in regional salt management and drainage reliefprograms, and to guide the design of new policies and incentivesregarding irrigation water use and drainage system installa-tion (Wichelns, 2002; Oster and Wichelns, 2003; Schwabe et al.,2006; Khan et al., 2009, 2011). It is essential also to evaluatethe near-term and long-term environmental impacts of salin-ity and drainage problems and solutions, particularly withinthe context of achieving truly sustainable irrigation (Wichelnsand Oster, 2006; Connor, 2008; Lee et al., 2012). Public offi-cials and planners need to know more about the off-farm andlong-term impacts of salinity and drainage problems and poten-tial solutions (Datta and de Jong, 2002; Bathgate et al., 2009;Roberts and Pannell, 2009). They need estimates also of likelyreductions in regional employment, the impacts of salts andshallow water tables on infrastructure, such as buildings, roads,and railways, and the potential losses in property values onfarms with degraded lands (Qadir et al., 2014). Such analysisis needed at the basin or watershed scale, and the analy-sis should include evaluation of both market and non-marketimpacts.

4. Public policies that reflect good social and physical science areneeded to establish the framework in which both the private andpublic sectors can contribute most effectively to solving salinityand drainage problems (Quinn, 2009, 2011, 2014; Lee et al., 2012;Scott et al., 2014). Public agencies must know the bounds of theirjurisdiction, and the opportunities they can present to farmersand communities working to achieve sustainable agriculture.Given the negative externalities inherent in salinity and drainageproblems, there is a legitimate rationale for implementing a mixof interventions that include public investments, regulations,and financial incentives, while considering farm-level capacityfor managing salt-affected soils and on-farm drainage systems.Policy makers will benefit from the types of economic analysesdescribed above. They will gain support also by engaging directlywith researchers, policy analysts, and stakeholders in discuss-ions of policy alternatives (Ritzema et al., 2008). The best publicpolicies and plans will reflect thoughtful input from many indi-

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

viduals and organizations with a stake in ensuring the successfulachievement of sustainable irrigation (Wallis et al., 2013; Ward,2014). Public leaders can enhance the pace of achieving sustain-able irrigation by placing key decisions regarding investments

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and interventions addressing salinity and drainage problemsquite high on the political agenda.

. The private sector also has much to offer, particularly in conduct-ing research and leading the development of new and promisingtechnologies that will someday reduce the cost of managing saltsand drainage water in irrigated agriculture. Of particular inter-est are emerging ideas in the fields of genomics, proteomics,biotechnology, and nanotechnology, such as efforts to breed salt-resistant and drought-tolerant crops (Parry and Hawkesford,2010; Chen and Yada, 2011; Tuberosa, 2012; Ngara and Ndimba,2014; Roy et al., 2014; Seabra et al., 2014; Singh Sekhon, 2014).Much of the finance and innovation likely will arise in the pri-vate sector, yet the public sector will serve important roles inprotecting human health, sustaining environmental quality, andpromoting the extension of new technologies into developingcountries (Chaudhry and Castle, 2011; Anthony and Ferroni,2012; Lidder and Sonnino, 2012; Bennett et al., 2013; Beumerand Bhattacharya, 2013; Mura et al., 2013; Barrows et al., 2014).

. Assigning responsibility for salt

In addition to implementing the measures described above,ublic agencies responsible for managing natural resources mightonsider assigning responsibility for salt to farmers and other watersers. This idea is similar to that of requiring consumers to pay

deposit when they purchase beverages in reusable containers.he deposit provides an incentive for consumers to return theontainers, rather than disposing them. The deposit program pro-ects environmental quality, while also enhancing resource usefficiency.

The salt delivered in irrigation water is not easily reusable,ut it is undesirable when released into streams or groundwater.equiring farmers to pay a deposit or post a bond pertaining to thealt in their irrigation water would motivate them to implement

farm-level salt management program. For example, suppose annvironmental agency imposes a deposit or bond of $10 per ton ofalt in irrigation water deliveries. Suppose also that in a particulareason, the average salinity of delivered water is 0.62 dS/m, suchhat each ML of water contains about 0.40 tons of salt. A farmerpplying 6 ML of water per ha of cotton would thus be required toay the equivalent of $24 per ha as a deposit or bond, pertaining tohe salt load applied on each ha of cotton.

The program might be structured in such a way that farmersre reimbursed for their deposit in accordance with their salt man-gement activities. For example, if a farmer collects and appliesaline drainage water on the farm, he or she might be reimbursedt the same rate of $10 for each ton of salt collected and applied.lternatively, if the farmer belongs to an irrigation or drainage dis-

rict operating an evaporation pond, the district might recover theeposit for each ton of salt in the drainage water it collects fromhe farmer. The district could then use those funds, and others, toay for disposing the salt in an environmentally acceptable manner.he annual cost of operating and maintaining evaporation ponds,hich includes the opportunity cost of land and the cost of com-lying with environmental regulations, can be substantial (Davist al., 2014).

In cases in which farmers do not capture and use saline drainageater and they do not participate in a district salt management pro-

ram, the environmental agency would retain the deposited fundsor use in implementing a regional salt management program. Thus,rom an economic perspective, it would be sensible to establish

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

he deposit rate at the per unit cost of operating the agency’s saltanagement and disposal program.Environmental agencies in some areas already implement per-

ormance bond programs pertaining to natural resources and the

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environment. The state of Wyoming in the United States requirescoal mine operators to provide a performance bond sufficient tocover the cost of reclaiming the mine, in accordance with the state’sSurface Mining Control and Reclamation Act of 1977 (Krzyszowska-Waitkus and Blake, 2011). Pennsylvania requires operators of shalegas wells to post a bond that ensures reclamation of abandonedwell sites (Mitchell and Casman, 2011). The United States Bureauof Land Management also has authority to require performancebonds from mining companies, as provided by the Mineral Leas-ing Act (Andersen et al., 2009). Performance bonds motivate firmsto achieve environmental compliance at minimum cost, yet theydo not fully obviate the need for liability rules in some applica-tions (Gerard, 2000; Mooney and Gerard, 2003; Gerard and Wilson,2009).

5. Summing up

Earlier writers predicted quite well the inevitability of salin-ity and drainage problems in arid and semi-arid areas. They alsodescribed with notable insight the challenges involved in pre-venting salinity problems and implementing effective regionaldrainage solutions. The problems that persist in many arid andsemi-arid areas today serve as long-standing reminders of the dif-ficulty of installing and maintaining large-scale drainage systemsthat collect and remove saline drainage water from agriculturalareas. They remind us also of the high costs of achieving sustainableirrigation, just as E.W. Hilgard had suggested long ago, and as Janvan Schilfgaarde, Jim Oster, and many others have advised in morerecent times.

Looking ahead to a future in which sustainable irrigation mustbe achieved, as part of a global effort to intensify agriculture inan environmentally acceptable fashion, we propose five activitiesthat are needed to improve the management of soil salinity andshallow water tables in arid and semi-arid areas. We character-ize these using the acronym STEPP, which represents supportinginstitutions, training and capacity building in ministries, enhancedeconomic analysis, appropriate public policies, and private sectorinvolvement. Implementing all five activities at once will be chal-lenging in many settings. Yet there are elements in each activitythat might be implemented in the near future, such as reformingsome institutions where possible, improving selected training andcapacity building programs, and providing incentives to stimulateprivate sector investments in salinity and drainage management.

Salinity and waterlogging will continue to impact agriculture inarid and semi-arid areas for the foreseeable future. Yet we can beginto reduce the degree to which salinity and waterlogging impair pro-ductivity and reduce crop yields by designing and implementingeffective regional solutions. We must also provide farmers withproper economic incentives to reduce excessive irrigation deliver-ies and to manage salts and shallow water tables in the context oftheir irrigation strategies. The technology for managing salinity andwaterlogging is readily available. Perhaps the only missing inputsat this time are the financial commitments and the political will todesign and implement effective solutions.

References

Abdel-Dayem, S., Abdel-Gawany, S., Fahmy, H., 2007. Drainage in Egypt: a story ofdetermination, continuity, and success. Irrig. Drain. 56, S101–S111.

Abdel Ghaffar, E., Shaban, M., 2014. Investigating the challenges facing drainagewater reuse strategy in Egypt using empirical modeling and sensitivity analysis.Irrig. Drain. 63, 123–131.

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

Al-Zu’bi, Y., 2007. Effect of irrigation water on agricultural soil in Jordan Valley: anexample from arid area conditions. J. Arid Environ. 70, 63–79.

Ali, R., Silberstein, R., Byrne, J., Hodgson, G., 2013. Drainage discharge impacts onhydrology and water quality of receiving streams in the wheatbelt of WesternAustralia. Environ. Monit. Assess. 185 (11), 9619–9637.

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Wate

A

A

A

A

A

A

A

B

B

B

B

B

B

B

C

C

C

C

C

C

C

C

C

C

D

D

D

D

E

E

E

ARTICLEGWAT-3982; No. of Pages 8

D. Wichelns, M. Qadir / Agricultural

llbed, A., Kumar, L., Aldakheel, Y.Y., 2014. Assessing soil salinity using soil salinityand vegetation indices derived from IKONOS high-spatial resolution imageries:applications in a date palm dominated region. Geoderma 230–231, 1–8.

mbast, S.K., Tyagi, N.K., Raul, S.K., 2006. Management of declining groundwaterin the trans indo-gangetic plain (India): some options. Agric. Water Manag. 82,279–296.

mmari, T.G., Tahhan, R., Abubaker, S., Al-Zu’bi, Y., Tahboub, A., Ta’any, R., Abu-Romman, S., Al-Manaseer, N., Stietiya, M.H., 2013. Soil salinity changes in theJordan Valley potentially threaten sustainable irrigated agriculture. Pedosphere23 (3), 376–384.

ndersen, M., Coupal, R., White, B., 2009. Reclamation costs and regulation of oiland gas development with application to Wyoming. Presented at the WesternEconomics Forum, Spring.

nthony, V.M., Ferroni, M., 2012. Agricultural biotechnology and smallholder farm-ers in developing countries. Curr. Opin. Biotechnol. 23 (2), 278–285.

yars, J.E., Hanson, B.R., 2014. Integrated irrigation and drainage water manage-ment. In: Chang, A.C., Silva, D.B. (Eds.), Salinity and Drainage in the San JoaquinValley, California: Science, Technology, and Policy. Global Issues in Water Policy5. Springer, New York.

yers, R.C., Westcot, D.W., 1985. Water quality for agriculture. FAO Irrigation andDrainage Paper 29 (Revised). Food and Agriculture Organization of the UnitedNations, Rome, Italy.

arnes, J., 2012. Mixing waters: the reuse of agricultural drainage water in Egypt.Geoforum (in press).

arrows, G., Sexton, S., Zilberman, D., 2014. Agricultural biotechnology: the promiseand prospects of genetically modified crops. J. Econ. Perspect. 28 (1), 99–120.

athgate, A., Seddon, J., Finalyson, J., Hacker, R., 2009. Managing catchments formultiple objectives: the implications of land use change for salinity, biodiversityand economics. Anim. Prod. Sci. 49 (10), 852–859.

ennett, A.B., Chi-Ham, C., Barrows, G., Sexton, S., Zilberman, D., 2013. Agricul-tural biotechnology: economics, environment, ethics, and the future. Annu. Rev.Environ. Resour. 38, 249–279.

eumer, K., Bhattacharya, S., 2013. Emerging technologies in India: developments,debates and silences about nanotechnology. Sci. Public Policy 40 (5), 628–643.

ezborodov, G.A., Shadmanov, D.K., Mirhashimov, R.T., Yuldashev, T., Qureshi, A.S.,Noble, A.D., Qadir, M., 2010. Mulching and water quality effects on soil salinityand sodicity dynamics and cotton productivity in Central Asia. Agric. Ecosyst.Environ. 138, 95–102.

urkhalter, J.P., Gates, T.K., 2005. Agroecological impacts from salinization andwaterlogging in an irrigated river valley. J. Irrig. Drain. Eng. 131 (2),197–209.

arr, G., Nortcliff, S., Potter, R.B., 2010. Water reuse for irrigated agriculture in Jordan:challenges of soil sustainability and the role of management strategies. Philos.Trans. R. Soc. A 368, 5315–5321.

arr, G., Potter, R.B., Nortcliff, S., 2011. Water reuse for irrigation in Jordan: percep-tions of water quality among farmers. Agric. Water Manag. 98, 847–854.

hang, A.C., Silva, D.B., 2014. Salinity and drainage in San Joaquin Valley, California:science, technology, and policy, Global Issues in Water Policy 5. Springer, Dor-drecht.

haudhry, Q., Castle, L., 2011. Document food applications of nanotechnologies: anoverview of opportunities and challenges for developing countries. Trends FoodSci. Technol. 22 (11), 595–603.

hen, C., Wang, E., Yu, Q., Zhang, Y., 2010. Quantifying the effects of climate trends inthe past 43 years (1961–2003) on crop growth and water demand in the NorthChina Plain. Clim. Change 100 (3–4), 559–578.

hen, H., Yada, R., 2011. Nanotechnologies in agriculture: new tools for sustainabledevelopment. Trends Food Sci. Technol. 22 (11), 585–594.

hianu, J.N., Chianu, J.N., Mairura, F., 2012. Mineral fertilizers in the farming systemsof sub-Saharan Africa. A review. Agron. Sustain. Dev. 32 (2), 545–566.

onnor, J., 2008. The economics of time delayed salinity impact management in theRiver Murray. Water Resour. Res. 44 (3), W03401.

orwin, D.L., Rhoades, J.D., Simunek, J., 2007. Leaching requirement for soil salin-ity control: steady-state versus transient models. Agric. Water Manag. 65,165–180.

rescimanno, G., Garofalo, P., 2006. Management of irrigation with saline water incracking clay soils. Soil Sci. Soc. Am. J. 70, 1774–1787.

atta, K.K., de Jong, C., 2002. Adverse effect of waterlogging and soil salinity oncrop and land productivity in northwest region of Haryana, India. Agric. WaterManag. 57 (3), 223–238.

avis, D.E., Charles, H., Hanson, C.H., 2014. Management of evaporation basins toreduce and avoid adverse impacts to waterbirds. In: Chang, A.C., Silva, D.B. (Eds.),Salinity and Drainage in the San Joaquin Valley, California: Science, Technology,and Policy. Global Issues in Water Policy 5. Springer, New York.

uncan, R.A., Bethune, M.G., Thayalakumaran, T., Christen, E.W., McMahno, T.A.,2008. Management of salt mobilisation in the irrigated landscape: a review ofselected irrigation regions. J. Hydrol. 351, 238–252.

ehni, A., Lounis, M., 2012. Remote sensing techniques for salt affected soil mapping:application to the Oran Region of Algeria. Proc. Eng. 33, 188–198.

l Bastawesy, M., Ali, R.R., 2013. The use of GIS and remote sensing for the assess-ment of waterlogging in the dryland irrigated catchments of Farafra Oasis, Egypt.Hydrol. Process. 27 (2), 206–216.

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

l Baroudy, A.A., Moghanm, F.S., 2014. Combined use of remote sensing and GISfor degradation risk assessment in some soils of the Northern Nile Delta, Egypt.Egypt. J. Remote Sens. Space Sci. (in press).

madodin, I., Narita, D., Bork, H.R., 2012. Soil degradation and agricultural sustaina-bility: an overview from Iran. Environ. Dev. Sustain. 14 (5), 611–625.

PRESSr Management xxx (2014) xxx–xxx 7

Fan, M., Shen, J., Yuan, L., Jiang, R., Chen, X., Davies, W.J., Zhang, F., 2012. Improv-ing crop productivity and resource use efficiency to ensure food security andenvironmental quality in China. J. Exp. Bot. 63 (1), 13–24.

Garnett, T., Appleby, M.C., Balmford, A., Bateman, I.J., Benton, T.G., Bloomer, P.,Burlingame, B., Dawkins, M., Dolan, L., Fraser, D., Herrero, M., Hoffmann, I., Smith,P., Thornton, P.K., Toulmin, C., Vermeulen, S.J., Godfray, H.C.J., 2013. Sustainableintensification in agriculture: premises and policies. Science 341, 33–34.

George, T., 2014. Why crop yields in developing countries have not kept pace withadvances in agronomy. Glob. Food Secur. 3, 49–58.

Gerard, D., 2000. The law and economics of reclamation bonds. Resour. Policy 26,189–197.

Gerard, D., Wilson, E.J., 2009. Environmental bonds and the challenge of long-termcarbon sequestration. J. Environ. Manag. 90 (2), 1097–1105.

Godfray, H.C.J., Garnet, T., 2014. Food security and sustainable intensification. Philos.Trans. R. Soc. B 369, 20120273.

Grattan, S.R., Oster, J.D., Letey, J., Kaffka, S.R., 2014. Drainage water reuse: con-cepts practices and potential crops. In: Chang, A.C., Silva, D.B. (Eds.), Salinity andDrainage in the San Joaquin Valley, California: Science, Technology, and Policy.Global Issues in Water Policy 5. Springer, New York.

Hilgard, E.W., 1893. The physical and industrial geography of California. Geogr. J. 1,536–539.

Hilgard, E.W., 1886. Irrigation and Alkali in India. College of Agriculture Bulletin 86.University of California, Berkeley, CA, pp. 35.

Hillel, D., 1991. Out of the Earth. Free Press, New York.Hillel, D., Vlek, P., 2005. The sustainability of irrigation. Adv. Agron. 87, 55–84.Houk, E., Frasier, M., Schuck, E., 2006. The agricultural impacts of irrigation induced

waterlogging and soil salinity in the Arkansas Basin. Agric. Water Manag. 85,175–183.

Humphreys, E., Kukal, S.S., Christen, E.W., Hira, G.S., Balwinder-Singh, Sudhir-Yadav,R.K., Sharma, R.K., 2010. Halting the groundwater decline in north-west India:which crop technologies will be winners? Adv. Agron. 109, 155–217.

Ibrakhimov, M., Martius, C., Lamers, J.P.A., Tischbein, B., 2011. The dynamics ofgroundwater table and salinity over 17 years in Khorezm. Agric. Water Manag.101 (1), 52–61.

Iizumi, T., Yokozawa, M., Sakurai, G., Travasso, M.I., Romanenkov, V., Oettli, P., TerryNewby, T., Ishigooka, Y., Furuya, J., 2013. Historical changes in global yields:major cereal and legume crops from 1982 to 2006. Glob. Ecol. Biogeogr. 23,346–357.

Jacobsen, T., Adams, R.M., 1958. Salt and silt in ancient Mesopotamian agriculture.Science 128, 1251–1258.

Kaplan, S., Blumberg, D.G., Mamedov, E., Orlovsky, L., 2014. Land-use change andland degradation in Turkmenistan in the post-Soviet era. J. Arid Environ. 103,96–106.

Kausch, M.F., Pallud, C.E., 2013. Science, policy, and management of irrigation-induced selenium contamination in California. J. Environ. Qual. 42 (6),1605–1614.

Khan, S., Rana, T., Hanjra, M.A., Zirilli, J., 2009. Water markets and soil salinity nexus:can minimum irrigation intensities address the issue? Agric. Water Manag. 96(3), 493–503.

Khan, S., Rana, T., Hanjra, M.A., Robinson, D., 2011. Decision support model for waterpolicy in the presence of waterlogging and salinity. Water Policy 13 (2), 187–207.

King, C., Thomas, D.S.G., 2014. Monitoring environmental change and degradationin the irrigated oases of the Northern Sahara. J. Arid Environ. 103, 36–45.

Krzyszowska-Waitkus, A., Blake, C., 2011. Tracking bond release at a large Wyomingcoal mining operation. Presented at the 2011 National Meeting of the Amer-ican Society of Mining and Reclamation. In: Barnhisel, R.I. (Ed.), Reclamation:Sciences Leading to Success. Published by the American Society of Mining andReclamation. Kentucky, Lexington.

Lal, M., 2011. Implications of climate change in sustained agricultural productivityin South Asia. Reg. Environ. Change 11 (Suppl. 1), S79–S94.

Lee, L.Y., Ancev, T., Vervoort, W., 2012. Evaluation of environmental policies targetingirrigated agriculture: the case of the Mooki catchment. Aust. Agric. Water Manag.109, 107–116.

Lemly, A.D., 2004. Aquatic selenium pollution is a global environmental safety issue.Ecotoxicol. Environ. Saf. 59 (1), 44–56.

Letey, J., 2000. Soil salinity poses challenges for sustainable agriculture and wildlife.Calif. Agric. 54 (2), 43–48.

Letey, J., Feng, G.L., 2007. Dynamic versus steady-state approaches to evaluateirrigation management of saline waters. Agric. Water Manag. 92, 1–10.

Letey, J., Hoffman, G.J., Hopmans, J.W., Grattan, S.R., Suarez, D., Corwin, D.L., Oster,J.D., Wua, L., Amrhein, C., 2011. Evaluation of soil salinity leaching requirementguidelines. Agric. Water Manag. 98, 502–506.

Letey, J., Williams, C.F., Alemi, M., 2002. Salinity, drainage and selenium problems inthe Western San Joaquin Valley of California. Irrig. Drain. Syst. 16 (4), 253–259.

Lidder, P., Sonnino, A., 2012. Biotechnologies for the management of geneticresources for food and agriculture. Adv. Genet. 78, 1–167.

Lin, Y., Garcia, L.A., 2012. Assessing the impact of irrigation return flow on riversalinity for Colorado’s Arkansas River Valley. J. Irrig. Drain. Eng. 138 (5), 406–415.

Lin, M., Huybers, P., 2012. Reckoning wheat yield trends. Environ. Res. Lett. 7, 024016.Lobell, D.B., 2012. The case of the missing wheat. Environ. Res. Lett. 7, 021002.Maas, E.V., Hoffman, G.J., 1977. Crop salt tolerance: current assessment. Am. Soc.

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

Civil Eng. J. Irrig. Drain. Div. 103 (2), 115–134.Martín-Queller, E., Moreno-Mateos, D., Pedrocchi, C., Cervantes, J., Martínez, G.,

2010. Impacts of intensive agricultural irrigation and livestock farming ona semi-arid mediterranean catchment. Environ. Monit. Assess. 167 (1-4),423–435.

ING ModelA

8 l Wate

M

M

M

N

O

O

O

O

O

O

P

P

P

P

P

Q

Q

Q

Q

Q

Q

Q

R

R

R

R

RR

R

R

R

Rlandscape during the late Holocene: palynological evidence from the Xintalasite in Xinjiang. NW Chin. Quat. Int. 311, 81–86.

ARTICLEGWAT-3982; No. of Pages 8

D. Wichelns, M. Qadir / Agricultura

itchell, A.L., Casman, E.A., 2011. Economic incentives and regulatory frameworkfor shale gas well site reclamation in Pennsylvania. Environ. Sci. Technol. 45 (22),9506–9514.

ooney, S., Gerard, D., 2003. Using environmental bonds to regulate the risks of GMcrops: problems and prospects. Environ. Biosaf. Res. 2 (1), 25–32.

ura, S., Seddaiu, G., Bacchini, F., Roggero, P.P., Greppi, G.F., 2013. Advances ofnanotechnology in agro-environmental studies. Ital. J. Agron. 8 (3), 127–140.

gara, R., Ndimba, B.K., 2014. Understanding the complex nature of salinity anddrought-stress response in cereals using proteomics technologies. Proteomics14 (4-5), 611–621.

hlendorf, H.M., Hothem, R.L., Aldrich, T.W., Krynitsky, A.J., 1987. Selenium contam-ination of the grasslands, a major California waterfowl area. Sci. Total Environ.66, 169–183.

ster, J.D., 1994. Irrigation with poor quality water. Agric. Water Manag. 25 (3),271–297.

ster, J.D., Letey, J., Vaughan, P., Wua, L., Qadir, M., 2012. Comparison of transientstate models that include salinity and matric stress effects on plant yield. Agric.Water Manag. 103, 167–175.

ster, J.D., Grattan, S.R., 2002. Drainage water reuse. Irrig. Drain. Syst. 16 (4),297–310.

ster, J.D., Wichelns, D., 2003. Economic and agronomic strategies to achieve sus-tainable irrigation. Irrig. Sci. 22 (3-4), 107–120.

ster, J.D., Wichelns, D., 2014. E.W. Hilgard and the history of irrigation in the SanJoaquin Valley: stunning productivity slowly undone by inadequate drainage.In: Chang, A.C., Silva, D.B. (Eds.), Salinity and Drainage in the San Joaquin Val-ley, California: Science, Technology, and Policy. Global Issues in Water Policy 5.Springer, New York.

anta, S., Flowers, T., Lane, P., Doyle, R., Haros, G., Shabala, S., 2014. Halophyte agri-culture: success stories. Environ. Exp. Bot. 107, 71–83.

arry, M.A.J., Hawkesford, M.J., 2010. Food security: increasing yield and improvingresource use efficiency. Proc. Nutr. Soc. 69 (4), 592–600.

osnikoff, J.F., Knapp, K.C., 2006. Regional drainwater management: source control,agroforestry, and evaporation ponds. J. Agric. Resour. Econ. 21 (2), 277–293.

rice, J.M., Gates, T.K., 2008. Assessing uncertainty in mass balance calculation ofriver nonpoint source loads. J. Environ. Eng. 134 (4), 247–258.

roust, K., 2008. Salinity in colonial irrigation: British India and southeasternAustralia. Aust. Geogr. 39 (2), 131–147.

adir, M., Noble, A.D., Qureshi, A.S., Gupta, R.K., Yuldashev, T., Karimov, A., 2009.Salt-induced land and water degradation in the Aral Sea basin: a challenge tosustainable agriculture in Central Asia. Nat. Resour. Forum 33 (2), 134–149.

adir, M., Oster, J.D., 2004. Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture. Sci.Total Environ. 325, 1–19.

adir, M., Oster, J.D., Schubert, S., Noble, A.D., Sahrawat, K.L., 2007. Phytoremediationof sodic and saline-sodic soils. Adv. Agron. 96, 197–247.

adir, M., Quillérou, E., Nangia, V., Murtaza, G., Singh, M., Thomas, R.J., Drechsel, P.,Noble, A.D., 2014. Economics of salt-induced land degradation and restoration.Nat. Resour. Forum (in press).

uinn, N.W.T., 2009. Environmental decision support system development for sea-sonal wetland salt management in a river basin subjected to water qualityregulation. Agric. Water Manag. 96 (2), 247–254.

uinn, N.W.T., 2011. Adaptive implementation of information technology for real-time, basin-scale salinity management in the San Joaquin Basin, USA and HunterRiver Basin, Australia. Agric. Water Manag. 98 (6), 930–940.

uinn, N.W.T., 2014. The San Joaquin Valley: salinity and drainage problems andthe framework for a response. In: Chang, A.C., Silva, D.B. (Eds.), Salinity andDrainage in the San Joaquin Valley, California: Science, Technology, and Policy.Global Issues in Water Policy 5. Springer, New York.

ao, B.B., Chowdary, P.S., Sandeep, V.M., Rao, V.U.M., Venkateswarlu, B., 2014. Risingminimum temperature trends over India in recent decades: implications foragricultural production. Glob. Planet. Change 117, 1–8.

ay, D.K., Mueller, N.D., West, P.C., Foley, J.A., 2013. Yield trends are insufficient todouble global crop production by 2050. Plos One 8 (6), 1–8.

ay, D.K., Ramankutty, N., Mueller, N.D., West, P.C., Foley, J.A., 2012. Recent patternsof crop yield growth and stagnation. Nat. Commun. 3 (1293), 1–7.

engasamy, P., 2006. World salinization with emphasis on Australia. J. Exp. Bot. 57(5), 1017–1023.

hoades, J.D., 1984. Use of saline water for irrigation. Calif. Agric. 38 (10), 42–43.hoades, J.D., 1989. Intercepting, isolating and reusing drainage waters for irrigation

to conserve water and protect water quality. Agric. Water Manag. 16 (1–2),37–52.

hoades, J.D., Bingham, F.T., Letey, J., Hoffman, G.J., Dedrick, A.R., Pinter, P.J., Replogle,J.A., 1989. Use of saline drainage water for irrigation: imperial valley study. Agric.Water Manag. 16 (1-2), 25–36.

hoades, J.D., Lesch, S.M., Burch, S.L., Letey, J., LeMert, R.D., Shouse, P.J., Oster, J.D.,O’Halloran, T., 1997. Salt distributions in cracking soils and salt pickup by runoffwaters. J. Irrig. Drain. Eng. 123 (5), 323–328.

hoades, J.S., Kandiah, A., Mashali, A.M., 1992. The use of saline waters for cropproduction. FAO Irrigation and Drainage Paper 48. Food and Agriculture Orga-nization of the United Nations, Rome, Italy.

itzema, H.P., Satyanarayana, T.V., Raman, S., Boonstra, J., 2008. Subsur-

Please cite this article in press as: Wichelns, D., Qadir, M., Achieving ssalinity, and shallow groundwater. Agric. Water Manage. (2014), http

face drainage to combat waterlogging and salinity in irrigated lands inIndia: lessons learned in farmers’ fields. Agric. Water Manag. 95 (3),179–189.

PRESSr Management xxx (2014) xxx–xxx

Roberts, A.M., Pannell, D.J., 2009. Piloting a systematic framework for public invest-ment in regional natural resource management: dryland salinity in Australia.Land Use Policy 26 (4), 1001–1010.

Roy, S.J., Negrão, S., Tester, M., 2014. Salt resistant crop plants. Curr. Opin. Biotechnol.26, 115–124.

Schoups, G., Hopmans, J.W., Young, C.A., Vrugt, J.A., Wallender, W.W., Tanji, K.K.,Panday, S., 2005. Sustainability of irrigated agriculture in the San Joaquin Valley,California. Proc. Natl. Acad. Sci. 102 (43), 15352–15356.

Schwabe, K.A., Kan, I., Knapp, K.C., 2006. Drainwater management for salinity miti-gation in irrigated agriculture. Am. J. Agric. Econ. 88 (1), 133–149.

Scott, C.A., Vicuna, S., Blanco-Gutiérrez, I., Meza, F., Varela-Ortega, C., 2014. Irrigationefficiency and water-policy implications for river basin resilience. Hydrol. EarthSyst. Sci. 18 (4), 1339–1348.

Seabra, A.B., Rai, M., Durán, N., 2014. Document Nano carriers for nitric oxide deliveryand its potential applications in plant physiological process: a mini review. J.Plant Biochem. Biotechnol. 23 (1), 1–10.

Shouse, P.J., Letey, J., Jobes, J., Fargerlund, J., Burch, S.L., Oster, J.D., Rhoades, J.D.,O’Halloran, T., 1997. Salt transport in cracking soils: bromide tracer study. J.Irrig. Drain. Eng. 123 (5), 329–335.

Sinclair, T.R., Purcell, L.C., Sneller, C.H., 2004. Crop transformation and the challengeto increase yield potential. Trends Plant Sci.V 9 (2), 70–75.

Singh, A., Krause, P., Panda, S.N., Flugel, W.-A., 2010. Rising water table: a threat tosustainable agriculture in an irrigated semi-arid region of Haryana, India. Agric.Water Manag. 97 (10), 1443–1451.

Singh, G., 2009. Salinity-related desertification and management strategies: Indianexperience. Land Degrad. Dev. 20 (4), 367–385.

Singh Sekhon, B., 2014. Nanotechnology in agri-food production: an overview. Nan-otechnol. Sci. Appl. 7 (2), 31–53.

Sommer, R., Glazirina, M., Yuldashev, T., Otarov, A., Ibraeva, M., Martynova, L.,Bekenov, M., Kholov, B., Ibragimov, N., Kobilov, R., Karaev, S., Sultonov, M.,Khasanova, F., Esanbekov, M., Mavlyanov, D., Isaev, S., Abdurahimov, S., Ikramov,R., Shezdyukova, L., de Pauw, E., 2013. Impact of climate change on wheat pro-ductivity in Central Asia. Agric. Ecosyst. Environ. 178, 78–99.

Srinivasarao, C., Venkateswarlu, B., Lal, R., Singh, A.K., Kundu, S., 2013. Sustainablemanagement of soils of dryland ecosystems of India for enhancing agronomicproductivity and sequestering carbon. Adv. Agron. 121, 253–329.

Tanji, K., Davis, D., Hanson, C., Toto, A., Higashi, R., Amrhein, C., 2002. Evaporationponds as a drainwater disposal management option. Irrig. Drain. Syst. 16 (4),279–295.

Thayalakumaran, T., Bethune, M.G., McMahon, T.A., 2007. Achieving a salt balance:should it be a management objective? Agric. Water Manag. 92, 1–12.

Tilman, D., Balzer, C., Hill, J., Befort, B.L., 2011. Global food demand and the sustain-able intensification of agriculture. Proc. Natl. Acad. Sci. 108 (50), 20260–20264.

Tscharntke, T., Clough, Y., Wanger, T.C., Jackson, L., Motzke, I., Perfecto, I., Vander-meer, J., Whitbread, A., 2012. Global food security, biodiversity conservation andthe future of agricultural intensification. Biol. Conserv. 151, 53–59.

Tuberosa, R., 2012. Phenotyping for drought tolerance of crops in the genomics era.Front. Physiol. 3 (SEP) (Article 347).

van Schilfgaarde, J., 1994. Irrigation—a blessing or a curse? Agric. Water Manag. 25(3), 203–219.

Visconti, F., de Paz, J.M., Martínez, D., Molina, M.J., 2014. Irrigation recommendationin a semi-arid drip-irrigated artichoke orchard using a one-dimensional monthlytransient-state model. Agric. Water Manag. 138, 26–36.

Wallender, W., Rhoades, J., Weinberg, M., Lee, S., Uptain, C., Purkey, D., 2002. Irrigatedland retirement. Irrig. Drain. Syst. 16 (4), 311–326.

Wallender, W.W., Tanji, K.K., Gilley, J.R., Hill, R.W., Lord, J.M., Moore, C.V., Robinson,R.R., Stegman, E.C., 2006. Water flow and salt transport in cracking clay soils ofthe Imperial Valley, California. Irrig. Drain. Syst. 20 (4), 361–387.

Wallis, P.J., Ison, R.L., Samson, K., 2013. Identifying the conditions for social learningin water governance in regional Australia. Land Use Policy 31, 412–421.

Ward, F.A., 2014. Economic impacts on irrigated agriculture of water conservationprograms in drought. J. Hydrol. 508, 114–127.

Wichelns, D., 2002. An economic perspective on subsurface drainage programmesin developing countries, with an example from Egypt. Int. J. Water Resour. Dev.18 (3), 473–485.

Wichelns, D., Cone, D., 2002. A water transfer and agricultural land retirement in adrainage problem area. Irrig. Drain. Syst. 20 (2-3), 225–245.

Wichelns, D., Oster, J.D., 1990. Potential economic returns to improved irrigationinfiltration uniformity. Agric. Water Manag. 18 (3), 253–266.

Wichelns, D., Oster, J.D., 2006. Sustainable irrigation is necessary and achievable, butdirect costs and environmental impacts can be substantial. Agric. Water Manag.86, 114–127.

Wichelns, D., Oster, J.D., 2014. Beyond California: an international perspective on thesustainability of irrigated agriculture. In: Chang, A.C., Silva, D.B. (Eds.), Salinityand Drainage in the San Joaquin Valley, California: Science, Technology, andPolicy. Global Issues in Water Policy 5. Springer, New York.

Wollenweber, B., Porter, J.R., Lübberstedt, T., 2005. Need for multidisciplinaryresearch towards a second green revolution. Curr. Opin. Plant Biol. 8, 337–341.

Zhao, K., Li, X., Zhou, X., Dodson, J., Ji, M., 2013. Impact of agriculture on an oasis

ustainable irrigation requires effective management of salts, soil://dx.doi.org/10.1016/j.agwat.2014.08.016

Zhou, X., Li, X., Dodson, J., Zhao, K., Atahan, P., Nan, S., Yang, Q., 2012. Land degra-dation during the bronze age in Hexi Corridor (Gansu China). Quat. Int. 254,42–48.