\r\ tri l(J t T I ., i 'l 1 'J 1 D EVE t-O PIJ E NT OF A PPRO PR IATE CR OP T [C}j I.,.IC) LOGYFOR IRITIGATED AGRICUI.TURE iN SEI4'.ARID RHG|ONS by pefer Oram. Deputy Director International Foocl irolicy ltcjsg2lsll Instituie . Waslrington, l).C., USiA t l I I L + c I Pa;rcrr presentecl at tlrc lntcrnational fxllcrt consultation on lrrigalion anir A6riculrurc Dcvclop'rcnt organizcd by rhcyil';iril#;:ff]il'c conrnission for lvcsrcrn Asi;r (rcw^), loinr l:iurnlrlno nr,,irrtrurc t)ivisio tt,24 28 tofA riate icul1"urc in Semi--Aricl for Trri dTed ons Contents Digest 1. The need. for technological improvemen'b in irri-gated agriculture 2. Conceptual probleros in d'efining t'approprier'te" technology 3. Opportuni'biesr and constraints to developing itnproved technology for irrigated" agriculture i)Developingthepoterrtialforshiftsincropping Patterns: a) Ameliorating physical constraints b)interactionsbetween'narketsandtechnology ii) Raising cropping intensities a) OPPortunities b) Problenis related to intensification iii) A strategy for increasing crop yields a) Extending genetic improvement to a vider range of croPs l+ b) Developing a better understand'ing of crop-soil- vat'er relationshiPs c) lmproving design of irrigation and drainage syster''s d) Increasing the efficiency of input use e) Conserving energy The influence of policy on choice of technology List of References Li.st of Tables ].:GrowthTrendsirrMaJorCrops,lvled.iterraneanCountri.es' t96L_75. Fgu (r) - (iv) 7 L2 l-6 l-6 2L 23 23 27 32 36 3B Jo 39 Irr ltz hB Pagc 2 Llst of Tabl-es Grovth Rates of Agri.cultural, Food and Cereal Imports 1953-T\, Near' Ilast and North African Countries trend.s in Prod.uction and. Consumptlon of MaJor Staples, I975-I99O and ProJected Net Deficits 1990 Eleven Geoclimatic Regions !: Growbh of lruigated. Area in Selected. Med"iterranean and West Asian Countries 5: Population and GNP Characteristics - Med.iterranean and 't/est Asia 11 6: Application of Descriptors to Components of P::oduction Systems 1l+ fhe Extent to Which Various Constraints Apply to fntensification of lrrigated Land - Use in the Region Effect of Water Management Practices on the Grain Yiel-d. and Effective Water Use for Rice Comparative Yields and. Energy Usage for Greenhouse and Field.-Grorvn Vegetables fhe Effect of Duration of Waterl-ogging on the Percent Gern- ination of Six Major Upland Crops Population Density and. Ind.lcators of Agricultural Prod.uctivity Selected. Asian, Afriean, and. Latin Ameriean Countries l2z Estinates of fncreases in Val-ue Ad.d.ed. to Rice Production due to lrrigation Construction Figure 1: Raising Livestock Output Through Crop-Livestock Integration Within a Stratified l4arketing System 28 ?geq 3 5 l+ 2 3 t5 20 2l+ 30 3)+ 35 Tz B: o. l-0 11 \4, Dig-est Ttre paper draws attention to the increasing difficulties of meeting demand for- food and. agricultural products in the scmi-arid winter rainfall cLirnatic zone of the Mediterranean and Near East beeause of the limited potential for expand.ing the rainfed. cultivateti area, ancl the low productivity and d.eclining rate of expansion of irrigated land. This is leading to rapidly rising food. imports Conceptqal problems in defini.ng appropriate technology are discussed in the light of the variable constraints imposed by the physical environment in the static sense, and the dynamics of eeonomic and social change,income growbh and. d.istribution, demand for agricultural products, and labou:: availabjlity eLnd- cost. ft is suggested. that historically, economic growbh, population pressure, and mi.gration fiorn the 1and, have led in many countries to an increasingiy energy and. capi.tal- intensive agriculture vith shifts of. cropping patterns to higher-value crops in lrrigated land, and that reeent trend.s in the Merliterranean and Near East point to the d"evelopment of this type of farrning pattern there also. Tn view of the trend.s apparent from Tab1e 5 a hypothesis could be advanced for the countries of the Mediter'ranean and West Asia that l.and and. vater lri1l remain scarce ' that agricultural labour may become scarce as a resul.t of ind.ustrialization and migration within and between countries and that capital and teehnical and managerial skills will become more abundant. ff so, agriculture should become increasingly intensive, with higher yields and. croppj-ng intensities' more enerry inputs, and greater emphasis on irrigation efficiency, ancl the use of capital and. skills to substitute for labour bnd Iand. The rapid expansion of urbanization and incomes implied. by this hypothesis woul-d accelerate the demand for higher-value agricttltural products already generated by the pulI of inereasing afflucnce in Europe ahd vithin the region itsel-f, and would" also al1ov prices for food staples to tre increased. This coull lerr,tl to furtlrer expansfon of lrrigated area by Justi{Ving the clevelopment IJ.I' of more costly sites and./or .lorver quality witer ancL soils Guiclel-lnes &re suggested for dleveloping a conbeptual framework vithiu vhich to took at the potential for in'bi'oducing technologicaf c::tange,by the use of physical and socio-economic variables to describe the system accordi.ng to the degree.to vhich these variables can be nod.ified, at what point in the system, and. by vhom. fhe need. for governments to atternpt to remove constraints beyond- the reach of the farmer or the local communit,y, and to a'void imposing further rigid.ities either deliberately ttrrough policy, or through error and onission is stressed. The opportunities for improving the efficietrcy or productivity of irrigated- agriculture are discussed. in terms of (i) shifts to higher vafue or':therwise more beneficial cropping patterns; (ii) raising cropping intensitiesl and (iil) increas j.ng yie1d.s. In 1ooking at the possibilit,ies of moving tor+arcls bigher value or nore efficient (water conserving, etc. ) cfopping patterns.. the constraj.nts i.mposed by low ternperature, day-lengtho soil factors (especialfy salinity and impedecl clrainage) an6 seasonalit,y of trater supply are examirred. A cautionary note is soundeC concerning locating new irrigation proJectsrin pursuit of socj'a1 or other obJectives, in areas where such constraints limit flexibility. Comparisorrs are d.rawn between the respective influences of narket factors nnd technology in determining and shifting the cropping pattern in ttre Medite::ranean/Near llast region and" the warni temperate regions of Tndia and Pakistan; and it is eoncluclecl that in recent years mqrket influences have tend.ed. to be dominant in the' former and techuologl; in the latter Based on the expected continuation of a t,rend tovards more exoti-c and diversil'ied eonsumption patterns in temperate Errope, as well as ri-sing incomes bogr d"ue to oil, and to industrial development in countries vith large dcmestic narkets, such as ligypt, fndia, Iran and Pakis'ban' a scentlr:i'o is d'evetoped of a teclurology for ir::iggted agriculture vhich will recluire increasing use of plastics to grov off-season prod.uce, to eonserve moisture, ancl control veeqls; se1-ective (rri ) urechanization'to red,uce labour bott-lenecks so as to permit more crops to be grovn in a year and to release human a.n ,\.2 ,6.1+ aAE 83.2 -O ^- 50.2 - 21.8 - 39.0 - 2I+., - 5.8 - )_2.2 ztt.6 - '7.9 - 1\.5 8I ,zjo 27 ,82o 116,570 1\,650 10 ,210 12,000 8,76o 850 l+t ,l+Lo 3,290 22,67O r,880 11,100 !rLZ|J ro,\30 T,o7o 3 rggo 3,>60 29 '1450 1,15c - 2.26 : 5r.8 - 22.8 l-8,830 z6.o l+9.8 18.8 2? 2 5l+.1+ \6.5 2,\90 1 ,310 2,82O -1 ,530 2E0 1,110 130 ou. I \g.g 67.7 79.2 2.5 u !'8 \.6 1\.8 l+.2 5.8 ll 6.3 ]-r25O 1,070 2,830 1t-0 730 l+so li,}+)+o L30 560 5ro 750 r8o o. I 3.1 8.1+ 0.5 1,3 0.9 12.5 1.8 l+.0 2!.' rr.7 10 .7 fi. L LO.y 29.4 18.5 38.5 _LO. b L9.7 10. \ 5.' trl 5\,.2 // 13.1 ro.o ' 3.2 18.2 2\. 8 20.3 3L.7 - 39.7 - 9.1 - 11.5 - j5.o - \.8 7.9 5.8 6.2 2 ro9o 6.8 Greece Spain Yugoslavia ft,aiy Portugal Egrpt Iraq ?altible to acti'on by groups or society), and managerial (within the contrcl of an indivj.clua.l farmer. Regression moclel-s shov that a poor envirorunent can also substantially reduce yield.s but that rnost of 'bhe factors determining yielcl verrierbil ity within comparable environments (even when they &re comparcd j.n diflierent se&sons), can be accountecl for by managerial I'actors theoreti.ca.Lly corrtrqll.able by the farnre:r:, Table 7. The Exbent to Which Various Constraints Apply to Intensification of lrrigated Lancl-Use in the Region Constrsints Sucla.n U.A.R" Fertile Crescent Central Euphrates in Syria Lower Iraq Khuzistan Peninsul-a lran and Afehanistan Traditiona]- Modern Approxinate Per- centage of Total Area in Region Affeoted J Skil-ls anal knovledge VSU VS vsv vs vs vs VD VS VS VS vs Incl-" UAR !xcl. Ul'R Seasonality of flov Dralnage and sallnity Clinate ifrost) Capaci'"y of ce.:ral-s . PLart nutrients Labour Draft power @erating capital oo far"ns Key to the letters used in the table: G = great constraint M = noderate cons',:'aint S = slight constraint ' vS = verxr sJ-i"ght or no constraint :' Inprovenents in drainage in the U.A,R. contribute significantly to yield increases, but are Judged as not being lirniting to intensifieation. tl:' In the Sud.an the centrally managed Gezira and Menagil schenes represent a very large percentage of total irrlgated area. 2l fce figrres in this coLunri are veighted averages for the region, vhere, for each cor:ntry, the area u:rCer imigation is used as weight" Source: FAO Indicative World Pl-an ]965 M c vs s M s e G M M vs M e tt G c D M M M 22 Ll0 29 5L 5' 2rl 55 6t l+? I F\,l I 26 l+8 35 69 66 29 65 73 57 e c VS M VS VS S G VS VS (r VS VS 5 vs s(syria) s(syria) MM G M M G G G M G tt (\ G s M -1T- vhich is feasible in a proJect as wcll as reducing yields. fn most countries of the semi-arid sub-tropj.cs salinity and alkalinity are more serious than acid soil conditions and where they appear in existing irrigation areas, particularly with old irrigation systems vhich lack drainage, drastic rerneclial action m.y b" the only alternative to the 1and. going out of produetion. This rnay requi.re soil amendmen'bs, leaching of salts vith heavy appli-cations of canal- water, canal lining to red.uce vaterlogging, pumping to lower the vater tabfe, and measures to reduce evaporation and capillary ri-se of salts such as changing to a d-ifferent system of irrigation. However both the costs of transporting the large quantities of l-ime or' gypsun required to alleviate severe acidity or alkalinity and. the provision of d.rainage or other vorks to remove the root cause of these conclitions may be high.' Rather than trying to ameliorate such problens, therefore, technology might try and live with the condition by growing crops re-latively tolerant of salinity (bar1.ey, rice, sugar beet and spinach, berseern, atriplex, e'bc. ) o" aciclity ("y.0 oats, potatoes, cassa\ra, eerl;ain brassicae, lupinsr.vetches, and sone gresses). Yet most of these crops are of relatively low value, and at the l-evel-s of yield" imposed. by soils with adverse physical and. nutrient properties it is unlikely that they would repay investment in irrigation systems. Moreover the unrlerlying cause of the problem in the case of salini.ty and al-kalinity would remain. Any decision to site a new project in areas where such cond,itions exist or may be a hazard must, therefore, be r.reighed very earefully against alternati.ves. Soil- texture and" depth can also have an important j.nflueuce on the optimum range of crops whicir ean be grolm, as well .as on their managenlent under irrigation and the costs of proCuction. While many crops can yield well in heavy soi1s, inelud.ing wheat, rice, sorghum, sugar cane, beet, cotton aud many vege'bables; poor drainage and unstable textural characteristics (swelling vhen r+et) can l-ead to imped.ed root*zone penetration or anaerobic cond.itions vhich reduce yields of crops other than rj.ce as vell as mahing tillage difficult. Ilarvesting of root crops and groundnuts nray also be more costly in soils with a hi.gh clay content or vhere structural problerns are caused by alkalinity. Some practices such a.s lirning ancl the addj-tion of dung can improvc the physical. properties of clay soils; and vertical nul.ching hers. been founcl betteficial r1-g- crops suctr as rice or sugar cane with a high water demand. may have to be exeluderl. It may, nevertheless, be possible to achieve gains in prod.uctivity through substitution of a less.demanding erop where irrigation water is limited; the replacement of rice by high-yietding wheat as a d.ry-season crop irrigatcd by low lift pumping in Bangladesh is one example. An alternative approa.ch may be to conserve and increase the efficicncy of vater use by changing to a different method of water scheduling designed. to deliver water at critical periods in crop growth, as shor,m for rice in Table B' or to move from basin or furrow to sprinkler or drip-fed irrigation. Hillel (lgtt ) algues that raising crops by the period.ic saturation and dcssication characteristic of fixed-schedule d.elivery systems with infrequent heavf irrigations is anal.ogous to raising babies by occasional force-feeding, then vaiti.ng until they are nearly famished before stuffing them again! IIe claims that modern high frequency irrigation is like spoon-feeding a baby with frequent smal-l- portions so that he is neither over nor underfecl. Hillel defines irrigation efficiency a,s the amount of vater added to the root zone divid.ed. by the amount supplied. from the source. The difference, represerrting losses in conveyance and d.istribution, varies enormonsly accord-ing to the method and frecluency of water distribution and" the porosity of the soil. Accord.ing to Cheorrg (tgff), surveys show that in many projects only LO percent. of water d.elivered at the source finally reaches the fiel-cl, and tha,t tlistributi"on losses often reduce this to 20-30 pereent. Shoji (L977) states tjrat while the efficiency of traditional- furrow irrigation systems in Hawaii is no more than 50 percent; sprinkler systems can raise this to 70-80 percent (although operating and. equipment costs are high); while with drip irrigation efficiency rises to BO-95 percent because it depends very little on the soil-s ability to store vater. llowever, the flexibility of clrip-fed. installations is rather less than sp::inirlers, as the system becomes too costly with crops sor,rn at close spacings such as most cereals, grain legumes, pastures and annual oilseecls; ancl it al-so requires fairly sophisticatecl controls and monitoring devices. It has been most widcly used on fruit trees, vi.nes, bananas, vegctables, sugar canc arrcl ornamentals and, although the total estimated area vas only 1O0,O0O ha in -f977 (90 perccnt of whi.ch was in clcvelope ) and other authors he"ve d.ram attention to the fact that crop and particularly animal production in d"eveloping countries is more energy efficient than commercial agriculture in most developed. countries ' and Pimentel et. al (l-glS) have suggested that energy inputs in corn production could be reduced. by about a half without sacr:ificing yields. This would be achieved through some substitution of hand labour for mechanized operatlons sueir as herbicid.e applieation, greater use of biological nitrogen to replace fertilizer, rninimun tiIIage, breeding shorter-maturing disease resistant, high pro'bein varieties and growing less corn under irrigation. Although there are a.1.reu.ciy a rrurrrber of r;rrr:h options open to farmers to minimiz,e energy inputs in the short run, governmertts -b3- instruments vhich infl-uence rainfed farming such as prices, subsidies, credit anrl extension, irrigation introduces a new set of pol.icy variabl.es. Thus tire focation of projects, the nature of the irrigation and drainage systems, infrastructure farm size, management, the enterprise-mix, and the technological options are al--l- strongly inffuenced. and. in many cases virtually pre-determined. by the governmenl;. A number of examples can be ci.ted from the Mediterranean ancl llest and South As j-a where decisions with respect to the locertion, otrjectives, ancl structurc of new irrigation projects have placed farmers in a straitjacket as far as their ability to innovate is concerned.. This has often been the result of using irrigation to al-leviate poverty and ereate employment in d.isad.vantaged areas, vhich ha.s led to projects being located in unfavourable ecological regions whose comparative ad.vantage for the products they can grow is lor"er than for those same products in more favourable regions of the sa.rne or competing countries. Sometimes water' has been spreacl too thin in an atteinpt tottbenefj.t'r as many people as possibleo or farm sizes have been established. which are smaller than optinrr-rm for reasona.bfe living standard.s Other consequences have been heavy subsidies on vater (resultjng in its wasteful use), the establ-ishment of inefficient high-cost processing industries linked to the projects, and. distortions of prices or subsj.dj"es which have affected the whole econor(y of a country in an attempt to make marginal producers viable in a maJor irrigation project. This is not to say that irrigation cannot or should not serve social- objectives, as well as being a vehicle for increasing individual incomes or attaining national procluction or export targets, but there are pitfalls in atternpting to achieve rnultip1e objectives which governments have often failed to avoid, and vhich have made both the choice and effecti.ve a,pplication of approprieLte technology extremel.y difficult. An important reason for this has been the l.ack of a holistic €rpproa.ch to irrigation planning at the national level1 several countr:ies still ltave sepat'ate rnirristries of imigation and agriculture, and cven within rninistrjes thele is often insufficient interaction betwccn engineers, a{lronolnists, ahd economir;ts. This has resul.tecl in a piecemeal irrigation policy ancl somc-tirncs in unrcrlistic -t+j, stantial- evasion of the system by farmers, both in terrns of their land use and. how they nrarket their Procluce. Yet even though farmers attempt to obtain greater freedom from controls and more equitable prices try poiitical pressure, or to evade taxes and quotas and grow what is more profitabJ-e to tltem, most of them still retain a rninimum base of staple food and traditj.onal cash crops, wh.ich are to some extent protected by governlnent controls and. price guarantees, and which are fess vulnerable to market fl-uctuations or less perishable than fruit, vegetabJ-es, and aninal products. This is an irnportant reason why the share of those commoditj-es, whose contribution to value of ou'Lput is often out of al-l proportion to the area they oceupy, is 1/ not higher in irrigated 1and.=' Conflicts be'r,rseen national. objectives and. ind.ividua.I pr"ofit maximisation are always present to sorne degree i-n any system, but they can be minitnized or exacerbated by govetinment policies, particula::ly in respect of input-output relationships. Where governments atiempt to fl-out market forces 'boo obviously it is not sur.prising 1,ha'1, procluc'bion targets are rarely ar.chievecl and yieids of the targetetl crops are low. l'he real- yi.elcls may be understated. to al1ow black rnarket tracling, inputs use 6n other crops and" so on. Controversial issues also arise in trying to eval-uate the influence of price and subsidy policiesl for example, it is concluded by llayarni, Barker or ancl Bennagen (tgtl ) and by IFDC (I9TT ) tnat the benefits of price.support ancl fertilizer-subsidy progrannnes are captured prirnarily by the larger producers in favourable environmental conditions such as irrigation creates, thns tending to viden inter-regional- income disparities. It shoul.d be added that altnough the high rice prices and favourable fcrbilizer-rice price ratios in East Asian countries have often been advanced as the main reasons for tire high rice yields and cropping intensities in those countries, it can also be sholrn that whe:re the Thus in Spain, olives, forage, winter cereals, maize and vines occupied l0 percent of total irriga'bed area in f.950, but contrj.bu'Led only 2l percent of gross valuc. Potatocs, sugar beet, cotton, tobacco and rice contributed 33 percen'b of va1.ue frorn 33 percent of areal and vcgetables, citruso tomrr,t:ocs and bananas as much as )t2 percent of value fr:orn only IJ perccnt of area. In Parl) has estitnated that public financj.ng of agrir:ulture j.1 llgypt t.rerttrc pcriod 1960-71 tota.Llecl LiJ B93,nitl.ion, in"irrui,,t,"i""i"rr,Jra" i' the w*tersto::age eonlponcr tj rizcr. ,;,rr,i;i