2015 Second Quarter 2015 Second Quarter THE PRESIDENT Dr. Saeed Nairizi 2-3 Inside

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1 2015 Second Quarter ICID NEWS 2015 Second Quarter ICID NEWS MANAGING WATER FOR SUSTAINABLE AGRICULTURE Message from THE PRESIDENT Dear Coeagues, The United Nation is panning to submit a resoution to the Genera Assemby in September this year, to adopt Sustainabe Deveopment Goas (SDGs), by a member countries for impementation of a sustainabe deveopment regime from 2015 beyond. Goba food security and poverty eradication are at the top of the SDGs ist; wherein water for drinking and sanitation use is ined up next. To fufi these two and support a number of other SDGs there is a need to increase goba food production by 60% by the year The key eements of augmentation in food production stem from productivity enhancement of both irrigated and rainfed farming. Considering that the future expansion of cropped and may not be promising, the soution ies in expoiting the considerabe potentia that exist by increasing food production in rainfed agricuture as we as within the existing irrigated area. Using esser water and thereby increasing the irrigated crop and has the potentia to ensure both water and food security at a eves around the word. ICID, through its technica Working Groups and Nationa Committees, is aiming to contribute effectivey to this goba endeavor with prospective of reaching to the state of The Word with Secured Food Suppy and no Hunger. In this process, individua centered irrigation practices, particuary in deveoping and emerging countries, cas for more attention. At the same time modernization of the existing arge and medium irrigation schemes, capacity deveopment, institutiona improvement, supporting farmers initiatives and rura transformation focusing on irrigation deveopment are the means of materiaizing action in this direction. The newy introduced ICID working groups, Modernization and Revitaization of Irrigation Schemes (WG-M&R) and Institutiona Aspects of Irrigation / Drainage System Management (WG-IOA) woud provide patforms for the experts from NCs and internationa organizations to embark on extensive studies and deiberations to find and recommend methods and best practices to revitaize the irrigation schemes negected up unti now. ICID invites NCs, particuary the member countries with vast experience in the operation of arge and sma irrigation schemes, as we as pubic and private schemes to join these WGs and share their experiences with the goba community. ICID and its Nationa Committees have demonstrated their commitment to modernization process by organizing sessions and discussions on the roe of modernization of irrigation schemes at the recenty concuded 7th Word Water Forum in South Korea, Apri The deiberations during the Forum, particuary on the roe payed by storages in mitigating the risk of uncertainty of rains, given the widespread drought conditions prevaiing in many parts of the word, requires ICID to reconsider its poicy towards means of water storages of a kinds for use in agricuture. Profitabiity and ong-term sustainabiity of agricuture sector aso depend on its use of energy and how it can make itsef green by managing its energy requirements efficienty and by harnessing the renewabe sources of energy. A number of poicy and fied eve innovations are being used around the word to harness soar power in conjunction with agricutura practices. A coupe of such innovations are presented in this issue of ICID News to initiate the process. I am sure that this issue of ICID News wi provide the readers some of the cues to work towards sustainabe agricuture water management. I am hopefu that the readers must be benefitting from our efforts to present the compex scientific issues in simpe anguage in this quartery ICID News. Best regards Dr. Saeed Nairizi President, ICID Use of Renewabe Energy for Irrigation Soar Energy for the Irrigation Water Suppy in Spain, and Soar Pants atop Canas to Save on Land and Water in India 5-6 New Approach of Farm Management under Surface Irrigation to Improve Water Saving and Productivity 6-7 Improved Irrigation Technoogies in Paddy Cutivation 8 Non-Point Sources Poution and Best Management Practices Inside 1

2 ICID NEWS 2015 Second Quarter Use of Renewabe Energy for Irrigation The chaenge of scarcity of resources: Water-food-energy is highy interinked. Poicy and other interventions must take this into account. Whie, taking an integrated view of these issues is essentia but highy compex, individua soutions can pave the way for meeting diverse and opposing objectives. This artice brings forth a coupe of exampes from Spain and India where soar power is heping irrigation and vice-aversa to meet this chaenge. In recent years, due to the modernization of irrigation schemes, where od open channe distribution networks have been repaced by new pressurized networks, the overa amount of energy required for the irrigation suppy has drasticay grown in many countries. The energy and power requirements are around kwh/ha when water is diverted from rivers or dams, and these vaues can be much higher where water comes from deep aquifers or it is suppied to steep areas with arge differences in eevation from the water source to the suppy point. Due to the increased energy dependence and higher energy costs, since energy prices have foowed a growing trend, energy represents an important percentage of the tota water costs (around 40%) which has an important impact on farmers returns. Thus, water and energy use in pressurized irrigation systems cannot be considered independenty as energy is becoming a major factor as important as water avaiabiity, rainfa or evapotranspiration. Efficient water and energy use take on greater importance in agricuture due to the widespread tendency of reduced water avaiabiity and increasing energy costs, which determine the viabiity of irrigated agricuture in many areas of the word. Moreover, the energy used in the pumping stations impies higher GHG (greenhouse gasses) emissions, which increases the carbon footprint of the agricutura sector and invoves a significant environmenta impact which is particuary important in the current cimate change context. This fact highights the need to improve the efficiency in the water-energy nexus, essentia for the economic, socia and environmenta deveopment of the sector. In the interest of sustainabe deveopment and the minimization of cimate change impacts, nationa and internationa poicies are prioritizing the improvement in the use of the natura resources. Soar Energy for the Irrigation Water Suppy in Spain J.A. Rodríguez-Díaz 1 In Spain, eectricity is produced mainy from fossi and mineras fues, which are nonrenewabe resources and causes significant environmenta impacts. By contrast, renewabe energy resources reduce the negative effects on the environment and contribute to the sustainabe deveopment of the agricutura sectors. In Southern Spain, the irrigation season is mainy concentrated between March to October. Simutaneousy, the PV (Photovotaic) systems have their peak energy production in these months. Then, soar radiation and evapotranspiration have parae time distribution curves (monthy and daiy), so the peak soar power generated coincide in time with the maximum irrigation water requirements. Consequenty, PV systems have potentia to be the most suitabe renewabe source for irrigation, even more when considering that the price of soar panes has dropped dramaticay in recent years. One good exampe of soar irrigation is the Sun Water Project system deveoped by IWES ( a spin-off of the University of Córdoba. The major innovation of this system ies in its capacity to suppy energy from soar panes to conventiona AC pumps, so there is no need to repace the current pumping system by soar pumps, which usuay cost up to four times higher than conventiona pumps. The Sun Water Project system reduces the instaation costs significanty and the payback period is between 3 to 6 years depending on the farm size. The system is instaed in a variabe speed drive, which connects the pumping system and the soar panes to operate the water suppy. It can be configured off-grid, independent of the conventiona energy suppier grid, or as a grid-tie PV system, connected to the suppier grid so when the eectricity generation is not enough, overnight or ower radiation days, and the energy from the main grid can make up the shortfa. In the 2014 irrigation season, a prototype of the Sun Water Project system was instaed in the Viaseca farm (Córdoba, Andaucia) to suppy water to a 14 ha citrus fied with drip irrigation. The instaed power was kw with an estimated annua energy production of kwh. After the first year of operation, the economic savings in energy were 100% since soar panes produced a the energy requirements and no additiona energy was purchased from the main grid. The environmenta benefits were estimated in 1688 kg CO 2 /year by avoiding the use of fossi fues. 1 Department of Agronomy, University of Córdoba, Campus Rabanaes, Edif, da Vinci, 14071, Córdoba, Spain. E-mai: jarodriguez@uco.es 2

3 2015 Second Quarter ICID NEWS T h i s e x p e r i e n c e demonstrates that soar energy is a technicay and economicay viabe aternative, which offers great advantages such as the reduction of energy costs, farmers profit is decouped from fuctuations in conventiona energy prices and it represents a cean and environmentay friendy energy source with practicay zero CO 2 emissions to the atmosphere. To achieve optimum efficiency, the instaation of PV systems must be accompanied by measures aimed at reducing the energy requirements of irrigation systems such as the organization of farmers in irrigation turns (sectoring), detection of critica points, and optimum operation of pumping stations, ow energy emitters and better irrigation scheduing. Soar Pants atop Canas to Save on Land and Water in India In deveoping countries with fast popuation growth, in addition to water, and resources are becoming scarcer. The arge surface area required for the instaation of soar panes poses a chaenge, athough the cost of photovotaic ces is coming down making soar power more economicay viabe. Dr. Mukesh Joshi 2 As India, a densey popuated country moves to ramp up investment in soar power, it is exporing innovative paces to insta soar pants, incuding across the top of canas. The 10 MW pant on the outskirts of Vadodara city in India s western state of Gujarat, which began generating power in November, is buit across 3.6 km ong irrigation cana, and has 33,800 soar panes mounted on stee scaffoding. Connected to the state grid, its output is intended mainy to meet demand from irrigation pumping stations. On a sunny day, the pant generates 50,000 units of eectricity (1 unit equas 1 hour of 1,000-watt usage), and is schedued to produce 16.2 miion units in its first year, decining 1 percent annuay as the panes degrade. During the inauguration of the new canatop soar energy pant in January 2015, U.N. Secretary Genera Ban Ki-moon said that he sees more gittering panes and the future of India and the future of the word. He aso said that he sees India s bright creativity, ingenuity and cutting-edge technoogy. Experts identify two major advantages in buiding soar pants atop canas viz. efficient and cheap and use, and reduced water evaporation from the channes underneath. Competed in six months, the pant s $18.3 miion cost - incuding 25 years of operation and maintenance - is recoverabe in 13 years, according to Sardar Sarovar Narmada Nigam Ltd (SSNNL), the Gujarat government agency that administers this faciity and another smaer one. The cost of producing 1 unit of eectricity at the pant is 6.5 rupees ($0.105) and SSNNL is entited to use the same amount of power it feeds into the grid without paying the standard price of Rs.7.5 to Rs.8 per unit. According to Eng. Navin Reddy, Megha Engineering & Infrastructures Limited (MEIL), Hyderabad, which constructed the pant, Cana-top pants are more expensive to maintain. But the company incorporated side bars on the scaffoding and wakways between the panes so they can be reached easiy for maintenance. The 10 MW pant foows another smaer pant in Gujarat, commissioned in Apri Set up aong a 750-metre stretch of cana, the 1 MW pant has so far generated Soar Park, Gujarat, India 4.35 miion units of eectricity. The pants are part of the Sardar Sarovar Project, a hydropower and irrigation scheme that aims to water 1.8 miion hectares (4.45 miion acres) of and in Gujarat and Rajasthan through 75,000 km of cana, which is yet to be competed. Both the soar power pants are buit on branches of the main cana, though which irrigation water runs from a dam on the Narmada River. According to SSNNL, the 10 MW pant has saved on 16 hectares of and, and wi potentiay prevent 90 miion itres of water from evaporating each year. The 1 MW cana-top pant cost $2.8 miion, according to SSNNL, whereas a 1 MW and-based soar pant costs $2.3 miion. Another probem is that PV panes are usuay mounted facing southwards for optima performance, but a cana might curve and change direction. Using ony north-south stretches of water coud imit the scae of cana-top pants. Long-term exposure to environmenta stresses and ingress of water into the panes coud aso reduce their performance. 2 Sarovar Narmada Nigam Ltd (SSNNL), Gandhinagar, Gujarat, India E-mai: dr.mbjoshi@gmai.com> 3

4 ICID NEWS 2015 Second Quarter Drainage for Sustainabiity Maintaining Sub-surface Drainage Systems Increased competition in food producing countries demands maximum effort to achieve high yied against ow costs. One of the pre-requisites to achieve this is by we-maintained irrigation and subsurface drainage methods: on the and or in the greenhouse. Reiabe water eves in the fied can hep pants grow even under difficut circumstances. Drainage probems are serious on about miion hectares of irrigated and ocated in the word's semi-arid and arid zones. At present, about miion hectares of irrigated and are seriousy damaged by the buid-up of sats and miion hectares are estimated to be ost from production every year as a resut of sat buid-up. Drainage, by virtue of man-made surface or sub-surface conduits, attempts to create we drained arabe ands, preventing sainization of the sois, owering of groundwater tabe and remova of accumuated sats or toxic eements. Reguar maintenance keeps your soi heathy Product Lineup The high investments in equipment demands provision for adequate maintenance. The sub-surface conduits have a tendency to cog for a variety of reasons such as design of the system, materias used for construction, and instaation procedures. A predominant phenomenon in cogging of agricutura drainage systems is formation of iron deposits. For the past 35 years HOMBURG in Hoand is the word eading manufacturer for the maintenance of sub-surface drainage systems. The extremey rigid HPE hose is pushed into the drain (up to 500 metres), in combination with the unique ow-pressure system (ony 10 to 12 bar) making it possibe for the speciay deveoped nozze to cean the drain and remove the dirt. HOMBURG drain ceaners are economica to use, reiabe and extremey robust. Their simpe operation guarantees a safe and efficient working environment. The patented system ceans without affecting the structure of the soi or the drain. For more information or free CD-ROM? Check or send an emai to info@homburghoand.com 4

5 2015 Second Quarter ICID NEWS New approach of farm management under surface irrigation to improve water saving and productivity Prof. Dr. Yousri Ibrahim Atta 1 The WatSave Innovative Water Management Award 2014 was awarded to Dr. Yosri Ibrahim Mohamed Atta (Egypt) for his research work on Improving growth, yied and water productivity of some maize cutivars by new panting method. Dr. Atta was engaged in a project for investigating the efficiency of an improved technique of panting crops in furrows and ensuring that water appication was just sufficient to reach saturation eve at top of furrows. This innovative irrigation management method resuted in considerabe water saving due to increased irrigation appication efficiency, decreased percoation and evaporation osses, and increase in yied at ess abour cost. Introduction Maize is one of the most important cerea crops in Egypt. The oca production of maize does not cover the oca consumption. Therefore, great efforts are directed to increase the productivity of the cutivated area by using high yieding cutivars. Irrigation of maize during growing season using optimum amount of water is important for increasing productivity. Therefore, it is necessary to find out a new panting method and improved irrigation technique to increase the irrigation appication efficiency, water saving, fied water use efficiency as we as yied and quaity. Description of the Innovation Method This method depends on reducing irrigated area of furrows by adapting different spacing (80 or 160 cm) apart as shown in Figure 1. Top and bottom of the furrow are named as border and tape respectivey. A borders and tapes are named (Strip of furrow). Grains were panted in tapes as per the pant density recommended in one or two rows of pants according to strip width. In first stage irrigation was given enough amounts for saturation effect at borders to fix the dimension of strip. Next irrigations were given for tapes ony in addition to a sma part on both sides of the furrows as a resut of water fow in these tapes. Accordingy, wetted area of the strip is decreased by about 30 to 50 per cent and consequenty water saving by Figure 1. Cross section indicating traditiona panting method (Furrow 80 cm width) with one row of pants on top of furrow 22 cm in between to gave give pant/ha. about the same ratio without decreasing the yied. By using this new method, there is an increase in irrigation appication efficiency, fertiizers use efficiency, water productivity, and decrease in percoation osses and evaporation. This innovative method was first impemented in the year 2005 on a sma piot project. It was ater introduced in 2007 and being practiced in the oca authority of "Governorate of Sharkia" in cooperation with Water Management Research Institute (WMRI). The tota cutivated areas using this method is around 50 hectares distributed in different sites. Farm Management Methods In treatment A, the traditiona method, rows were panted 0.80 m apart with one row of pants on each ridge between furrows with one pant/hi and 0.22 m between pants within the rows to attain recommended pant density, pants per hectare, (Figure 1). The pots were approximatey 20 m ong and the furrows were about 0.20 m deep, with cosed ends to prevent runoff from the fied. When water was appied to treatment A, the appication was stopped when the water eve in the furrows approached the top of the furrow ridge, which is simiar to the typica farmer practice in the region. To overcome this new farm management treatments were panned to decrease the wetted area and reduce the need for ong irrigation time to set-up water from the furrows to the ridges of the borders. In treatment B, the same pant with distance (0.80 m 0.22 m) was used to maintain the pant density as in the traditiona method except that rows of maize were panted in the bottom of each furrow (Figure 2). The irrigation frequency was simiar to the oca farming practices, as furrows with 80 cm, with one row of pant, 22 cm Figure 2. Cross section indicating strips of furrows 80 cm width with one row of pants in bottom of furrow (Tapetape) 22 cm in between to gave give pant/ha. between each pant. Grains were panted in (tapes) using the same pant density of the traditiona method. 1 Prof. and Deputy-Director, Water Management Research Institute, Nationa Water Research Center, Egypt. E-mai: prof.yosri2008@yahoo.com 5

6 ICID NEWS 2015 Second Quarter Treatment C had a furrow spacing of 1.60m, which is doube that of treatments Figure 1 and Figure 2, but there were two rows of maize panted in the bottom of each furrow (Figure 3) with 0.22 m between pants, so that pant density is same in a three treatments. Because the furrow wetted area in treatment C was haf of that in treatment B, consideraby ess water was appied to the same pant density. Figure 3. Cross section indicating strips of furrows 160 cm width with two rows of pants in bottom of furrow (Tapetape) 22 cm in between to gave give pant/ha. Water reations Irrigation water appied (IWA) In tota maize pant received 7 irrigations during growing seasons. First irrigation started after 21 days from panting then irrigation interva was every 14 days. After 90 and 95 days from panting in both seasons, the irrigation was stopped. Water productivity (WP) Costs were cacuated for different panting methods of maize crop. The net return from the new method is higher than the traditiona method. Contribution of the Innovative Method in Water Saving The panting methods had a significant effect on grain yied/ha. The highest grain yied/ha (6.786 t/ha.) was obtained from C-treatment, whie the owest was recorded from A-treatment (6.256 t/ha). Thus, panting maize on strips add new advantages such as: Good distribution of pant density; Less fooded area; Water saving about 30-50%; Raising water productivity; and Increasing fertiizers use efficiency. Impact Expansion of the Innovative Method As a nationa goa, by appying this innovative method a over Egypt for the maize cropped area can save about 4.0 Miiard Cubic Meter of irrigation water from cutivating miion hectare of maize, this amount of water can aso serve for horizonta expansion of new ands. Improved Irrigation Technoogies in Paddy Cutivation Avinash C. Tyagi * and M.L. Baweja ** In the traditiona 'shaow fooding' irrigation method for rice production, water is ost to deep percoation, surface runoff and evaporation. Athough some of this water can be used downstream, the irrigation infrastructure estabished to make water avaiabe, and the financia resources used therein are put to inefficient use. A number of techniques have been deveoped to achieve economy in water use in recent years which are briefy introduced in this artice. Irrigated agricuture is the main engine of growth in most deveoping economies and is ikey to pay a greater roe in stabiization of agricutura production under increasing cimate variabiity and change. However, as the per capita avaiabiity of fresh water shrinks the irrigated agricuture has to compete with other water use sectors. The major chaenge facing irrigated agricuture today is to produce more food using ess water per unit of output i.e. increasing water productivity in irrigated agricuture. Rice crop is grown on about 150 miion ha wordwide and is the most important crop for the countries in the Asian monsoon region. Rice is stape food in a most a countries of Asia and its consumption is substantia in other regions of the word. Asia which produce three-quarters of a rice harvested accounts for about 90% of the word s rice area. Rice accounts for over 39% of the tota food grain production in China where out of 113 miion ha sown under food crops, 28% are covered by rice. Asia s food security depends argey on irrigated rice production. More than 30% of Asia s irrigated and accounts for 50% of the tota irrigation water withdrawas. Some studies indicate that in Asia, 17 miion ha of irrigated rice areas may experience physica water scarcity and 22 miion ha may have economic water scarcity by In order to meet the chaenges of growing shortage of avaiabiity of water for irrigation many countries have intensified efforts for water saving in rice production. Based on the resuts of experiments and the experience in adoption the foowing three main types of water efficient irrigation regimes were found to be contributing to the sustainabe increased water productivity: System of Rice Intensification (SRI), Combining shaow water ayer with wetting and drying (SWD), Aternate wetting and drying (AWD), and Semi-dry cutivation (SDC). China has been a pioneer in these efforts. Various water efficient regimes for rice irrigation were tested, appied and extended * Secretary Genera, ICID, E-mai: avinash.c.tyagi@gmai.com, icid@icid.org, ** Consutant, ICID, E-mai: mbaweja@gmai.com 6

7 2015 Second Quarter ICID NEWS in different regions of the country. More than 10 Water Efficient Irrigation regimes (WEI) for rice have been adopted in China for different conditions of weather, soi topography, rice varieties, and water resources and irrigation projects. Some of these are briefy presented beow. 1. System of Rice Intensification (SRI) Dubbed as a civi-society innovation, the main feature of SRI regarding to water treatment is keeping the soi both moist and aerated so that roots have access to both water and oxygen. SRI method does not require continuous fooding. Irrigation is given to maintain soi moisture near saturation initiay and water is et in when surface soi deveops hairine cracks. The irrigation intervas, however, vary with soi texture. Sois having ow water hoding capacity require frequent irrigation. As the soi is not fooded, the roots of the paddy pants grow heathy, deepy in a directions. The root growth is extensive aso due to the wide spacing. As the fied is intermittenty irrigated and dried, the microorganisms grow we which make nutrients avaiabe to the pants. This method aso heps in better growth and spread of roots. The fied shoud be irrigated again when the soi deveops hair ine cracks. Depending upon the soi and the environment conditions, the frequency of irrigation shoud be decided. At the time of weeding operation to avoid shouder pain, the fied shoud be irrigated to have 2-3 cm of water. After competion of weeding the water shoud not be et out of the fied. After the panice initiation stage unti maturity, one inch of water shoud be maintained in the fied unti maturity. The water can be drained after 70 per cent of the grains in the panice get hardened. 2. Aternate wetting and drying (AWD) Aternate Wetting and Drying (AWD) is a water-saving technoogy that farmers can appy to reduce their irrigation water use in rice fieds without any decrease in yied. In AWD, irrigation water is appied a few days after the disappearance of the ponded water. Hence, the fied is aternatey fooded and non-fooded. The number of days of non-fooded soi between irrigations can vary from 1 day to more than 10 days depending on a number of factors such as soi type, weather and crop growth stage. AWD irrigation technoogy can improve crop water use efficiency without significant yied reduction. AWD has now spread in many rice producing countries and is haied as a method which aims at improving crop water use efficiency by expoiting the pant physioogica responses to partia soi drying at the root zone. It invoves part of the root system being exposed to drying soi whie the remaining part is irrigated normay. The wetted and dried sides of the root system are aternated with a frequency according to soi drying rate and crop water requirement. A practica way to impement AWD without oss of yied is to monitor the depth of ponded water on the fied using a fied water tube. After irrigation, the water depth wi graduay decrease. When the water eve has dropped to about 15 cm beow the surface of the soi, irrigation is appied to re-food the fied to a ponded water depth of about 5 cm. From one week before to one week after fowering, the fied is kept fooded, topping up to a depth of 5 cm as needed. After fowering, during grain fiing and ripening, the water eve can be aowed to drop again to 15 cm beow the soi surface before re-irrigation. AWD can be started a few weeks (1-2) after transpanting. When many weeds are present, AWD shoud be postponed for 2-3 weeks to assist suppression of the weeds by the ponded water and improve the efficacy of herbicide. 3. Combining shaow water ayer with wetting and drying (SWD) The basic feature of this new method is that the soi surface is not submerged after the stage of recovering. This technique known as Shaowness Wetness Drying (SWD) technique consists of determining the optima water demand for various growth stages of paddy with respect to different areas, sois and cimate conditions. This invoves maintaining shaow water ayer at transpanting/ recovery stage, just sufficient to keep wet at pre-tiering phase, fied drying at post-tiering stage, and again keeping shaow water ayer at fowering/ emusifying stages, and finay keeping wet during yeow maturity stage. The research showed that by keeping a shaow water depth of about mm for transpant recovery phase, wet or irrigating every 3-5 days during pre-tier phase, fied drying and irrigating every 5-10 days for post tier phase, again shaow water depth for jointing/fowering/emusifying phase, and finay keeping wet for yeow maturity phase resuted into 21.1% of water saving and 11.4% of yied increase. This technique improves the water, fertiity, aeration, and therma conditions of the soi, and brings tier into fu pay eading to higher yieds. It is earnt that this technique was appied at first to an area of 16,000 ha. Which has now expanded to more than 950,000 ha, which is neary 40% of the tota paddy rice area of the province where this system was adopted. The technique renders tremendous economic, socia and environmenta benefits. 4. Semi-dry cutivation (SDC) Semi-dry cutivation or Direct Seeded Rice is the technoogy which avoids pudding and transpanting processes very simiar to wheat and corn cutivation (2) There can be situations when water scarcity may compe the farmers to sow rice in dry soi which is subsequenty brought under submerged condition on receipt of rain or cana water. In this method there is a great difference of fied water contro between SDC and the above mentioned regimes (SWD and AWD). For SDC, the water depth is maintained ony in the reviva of green or reviva of green to the midde stage of tiering. There is no water depth on paddy fied in the other stages in entire growing season. SDC have been adopted in some irrigation districts in the East and South China. 5. Sprinker Irrigation An innovation was pioneered in Brazi where Center Pivot Sprinker System was used for rice cutivation aso. Initiating experiments with a 3 ha farm these were further extended to the commercia production in 85 ha. The initia experience with irrigating rice by center pivots has proved that it was possibe to produce 1 kg of rice with 683 iters of water a reduction of 31.7% over that achieved by surface methods. Simiar efforts have been made in other South American countries of Argentina and Uruguay. There has been an increase in the area under center pivots but the increase is sti ower than expected considering the great potentia offered. The possibe reasons coud be: (i) resistance of some farmers who insist on raising rice according to the traditiona method, (ii) ack of commitment of research and deveopment institutes, (iii) unfavorabe rice market during the past few years. Generay, the farmers are resistant to change. The approximate ranges of water savings were as under: percoation and seepage osses were decreased by 30-65% in case of SDC, and 20-35% when using SWD and AWD, whie the SRI and center pivot system achieve a water saving of up to 50%. evapotranspiration was decreased by 3-10% in case of SWD, and by 5-15% in case of AWD and SDC. as the rice under SRI, SDC and sprinker pivots does not have saturated soi conditions, there us reduction of methane (CH 4 ) emissions. 7

8 ICID ICID NEWS Second Second Quarter Quarter Non-Point Sources Poution and Best Management Practices Anna Tedeschi 1 and Ezee G.C. 2 Environmenta issues such as cimate change, ozone depetion, biodiversity, erosion, deforestation, desertification, and NPS poution are goba concerns. These chaenges are exacerbated by the rising trend of the word popuation and consumption. The most important goba issue is satisfying the ever-growing need for natura resources to meet food and iving-standard demands, whie minimizing adverse impacts on an environment that aready show signa of degradation. Acknowedging that agricuture is currenty the singe greatest contributor of NPS poutants to soi and subsurface water resources, ICID organized a workshop on Sustainabe Management of Tida Area in the Era of Cimatic Change during the 22nd ICID Congress to review the issues. Point source and non-point source poution (NPS) differ in the scae of the area extent of their source. NPS is a terrestria system refers to those contaminants in surface and subsurface soi and water resources that are diffused, or rather, are spread over arge area (Corwin, 1996). NPS cannot be traced to a point ocation or source. In contrast, point source poutants are connected with a point ocation and are generay highy toxic resuting in acute toxicity. On the other hand the point source poutants are identifiabe and more easiy controed than NPS. Non-point sources poutants are a consequence of agricutura activities, industria and urban runoff, mining and forest harvesting activities, path sat runoff, atmospheric deposition, and hydroogica modification i.e., diversion, dam, over pumping of groundwater etc. The NPS poution is of greater environmenta concern than point source poutants because they are ubiquitous and the task of ceanup is costy and neary impossibe to accompish. The evauation of the effect of agricutura management practices on NPS poution on oca, regiona, and goba scae has become a key component of strategies for achieving sustainabe agricuture and mitigating harmfu environmenta impacts. Decision makers want and need to know in advance the fate and behavior of agrochemicas appied to the soi surface and whether 1 Institute for Agricuura and Forestry System, Itay, E-mai: anna.tedeschi@cnr.it 2 Minbhawan, Kathmandu, GPO Box 21360, E-mai: gcezee@yahoo.com they pose a threat to soi and groundwater resources in order to deveop poicies that ead to sustainabe agricuture. This is a chaenging requirement as the assessment of NPS poutants is a compex, mutidiscipinary environmenta probem that encompasses couped physica and chemica processes that occur across disparate spatia and tempora scaes. The detrimenta environmenta heath effects of NPS poutants, even at ow concentrations, are chronic rather than acute. Less expensive poution prevention strategies are preferred that advantageousy anticipate and prevent NPS poution before it occurs and avoid the future need for costy remediation efforts. Therefore, Best Management Practices (BMP) poicies and strategies, are needed to hep reducing NPS poution and thereby ensuring sustainabiity in food production. Unexpected technoogica breakthroughs towards sustainabe agricuture are viewed as the most viabe means of meeting the food demands of the projected word s popuation. The target of sustainabe agricuture is predicted on a deicate baance of maximizing crop productivity and maintaining economic stabiity whie minimizing the utiization of finite natura resources and detrimenta environmenta impacts associated with NPS poutants. This is a diemma because on one hand there is the growing pressure of meeting the food demands of a constanty growing popuation, but in doing so the ikeihood of detrimentay impacting the environment with NPS poutants seems inevitabe. Concusion The reated assessment studies are often undertaken on sites of imited extension (from a few hundred square meters to few thousands of square meters) and in the aboratory. It is, therefore, uncear whether these studies do reay represent the behaviour of NPS, rather than point source poution. A particuary reevant issue is whether these studies address the spatia and tempora variabiity of the sites. In this scenario, a true assessment of the proposed Best Management Practise (BMP), or rather the indirect deduction of a BMP that can be inferred, is not yet possibe to draw because it shoud be confirmed in the ong-term evauation. Further, it is observed that NPS poution oad is sensitive to cimate change parameters thus there is need to deveop adaptation measures for reducing the impacts of cimate change on NPS poution based on various cimate change scenarios presented by downscaed GCM modes. As a genera concusion, there are a number of potentia areas of interest that coud be put on tabe for discussion and to eaborate recommendations for future work necessary to cope with the topics. 8 Internationa Commission on Irrigation and Drainage (ICID) was estabished in 1950 as a scientific, technica and vountary not-for-profit non--governmenta internationa organization. The ICID News is pubished quartery by ICID Centra Office, New Dehi, India Madhu Mohanan Communication Officer ICID, 48 Nyaya Marg Chanakyapuri, New Dehi, India Te: / 5679 E-mai: icid@icid.org Editor