New Salt Tolerant Crops for the Sonoran Desert

Item Type Article

Authors Yensen, Nicholas P.; Fontes, Migues R.; Glenn, Edward P.; Felger,Richard S.

Publisher University of Arizona (Tucson, AZ)

Journal Desert Plants

Rights Copyright © Arizona Board of Regents. The University of Arizona.

Download date 20/06/2018 00:37:47

Link to Item http://hdl.handle.net/10150/550916

Yensen et al.

New Salt TolerantCrops For the SonoranDesert1

Nicholas P. Yensen,Miguel R. Fontes,Edward P. Glenn andRichard S. FelgerEnvironmental Research Laboratory,University of Arizona

1A project of the Desert Development Foundation, ERL,Tucson International Airport, Tucson, Arizona 85706 (A.Blake Brophy, Director). An earlier draft of this paper waspresented at the VI Simposio Sobre el Medio Ambiente delGolfo de California in Hermosillo, Sonora, 8 -12 April,1981, and is due to be published in the Memorial of theSymposium.

Salt Tolerant Crops 111

The United States loses 200,000 to 300,000 acresof cropland to salt build -up each year. Thisphenomenon is not unique to the United States. Theworld's first agricultural region, the Tigris -

Euphrates, is a classic example of how salt build -upcan contribute to the fall of a civilization. In Perúthe original Inca civilization survived by retreatinginto the Andes as the salt in their fields exceeded thetolerance limits of their crops. Today's conventionalcrops cannot survive more than 5 parts per thousand(ppt) or 5,000 parts per million (ppm) of salt.

Because only about one percent of the land onearth [according to Espenshade (1960) this is equalto 14.6 x 109 hectares or 57.467 x 106 square miles]can be irrigated with fresh water (Israelsen and Han-sen, 1962:9) and since our population needs are ex-ceeding our food supply, the ancient dream of grow-ing food with salt water may become a necessity.-This type of agriculture, however, is extremely dif-ficult since conventional crops are 1)derived primar-ily from plants without salt tolerance (Somers, 1979)and 2) highly inbred with little variability for salttolerance. Yet, Dr. Emanuel Epstein and associates(1979) at the University of California at Davis haveproduced highly salt tolerant tomatoes and barley;albeit productivity was lower.

Another idea is to find salt tolerant plants(halophytes) in nature and see if they are edible, asDr. Fred Somers of the University of Delaware hasdone. Boyko and Boyko (1966) and Somers (1979)have conducted pioneering work in finding naturaledible halophytes. This concept capitalizes on thefact that halophytes grow well in seawater and mayeven have high productivity rates. The object, then,is "to find halophytes that can be eaten."

We began our search for edible halophytes in theSonoran Desert with the participation of Dr. FredSomers of the University of Delaware, Juan Reprietoand Alejandro Castellanos of CICTUS (Centro de In-vestigaciones Científicas y Tecnológicas), RaulAguilar of Ciencias Marinas in Ensenada, and even-tually with Ing. Carlos Mota of INIF. The searchused 4 -wheel drive vehicles and satellite photo-graphs to determine the collection localities.

One of the first edible halophytes collected, Dis-tichlis palmeri (Fig. 1), has a seed similar to that ofwheat (Felger, 1978:143). The plant grows in densestands in the esteros of the northern Gulf of Califor-nia where Cocopa Indians once gathered the grainfrom the beach (Fig. 2) and made bread (Vasey, 1889;Castetter and Bell, 1951).

In the Sonoran Desert we found 24 species ofhalophytes that can grow in seawater. We germi-nated their seeds on fresh water in greenhouses at

Figure A. Vertical columns of matted salt grass (Distichlissp.) in northern Chile growing through rock salt over ameter deep.

Dr. Ricardo Luti examines Cereus validus, a cactus grow-ing in highly saline soil at Salinas Grandes in Argentina.

One aisle of the living portion of the world halophytegermplasm bank in Tucson, Arizona.

Figure 1. Distichlis palmeri, a halophyte endemic tothe northern Gulf of California, has wheat -like seedswhich were harvested by the Cocopa Indians to makeinto bread.

Figure 3. Greenhouses in Puerto Peñasco, Sonora, Mexicoused to germinate halophyte seeds. Dr. Ed. Glenn inbackground.

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Figure 2. Beach drift of Distichlis palmeri seed.

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Figure 4. Halophyte fields in Puerto Peñasco, Sonora,Mexico. Blake Brophy examines the seed head of Atriplexlentiformis which was grown on full strength sea water.

Figure 5. Seawater drip- irrigated Batis maritima beingused as a ground cover in Puerto Penasco, Sonora, Mexico.The Seri Indians are reported to have used the starchyroots to sweeten their teas.

Puerto Peñasco, Sonora (Fig. 3). As the seedlingsgrew they were switched to seawater and planted insand plots where their productivity was measured.Productivity rates of some species were greater thanthe United States average for alfalfa. With these en-couraging results we planted larger fields.

Irrigated with waste seawater from a shrimpaquaculture facility, the plants showed rapid growthand in nine months some were over a meter high(Fig. 4). Over two acres of irrigated Sonoran Desertwere used to grow new potential foods such as Dis-tichlis palmeri and Batis maritima (Fig. 5). The lat-ter species has an edible root. Salicornia europaeaproduced 22.7 metric tons per hectare, dry weight, ormore than the average tonnage produced by wheat,corn or barley.

The Rockefeller Foundation was impressed withthese results and supported a world search for morespecies. In 1980 we visited South Africa, Chile, Perú,Brazil, Argentina, New Zealand and Australia. Wefound species in the high Andes where burros andllamas grazed on plants in water saltier than the

ocean and growing under ice (Fig. 6). We also col-lected obscure tropical halophytes such as thosefrom Brazil's arid region. Everywhere we met withenthusiasm.

In Perú Dr. Pedro Aguilar learned the collectingtechniques and has started a halophyte agricultureprogram. In Argentina Dr. Ricardo Luti showed usSalinas Grandes where halophytes grow in watertwice as salty as the ocean. Ing. Rolando Braun, Di-rector of IADIZA (Instituto Argentino de Inves-tigaciones de las Zonas Anidas), showed us speciesof Atriplex (among the fastest growing plants) thatare being used as forage.

In Australia Dr. Clyde Malcom gave Dr. MiguelFontes seeds from his world collection of Atriplexspecies. In Chile scientists from CORFO (Corpora -ción Fomento de la Producción) guided us to salineareas where the ground was covered with rocksalt ... except for some amazing halophytes thatformed vertical columns over a meter high (Fig. A). InArgentina with the aid of Ing. Jaime Serrra we foundhalophytes growing in a mixture of oil and seawater

Figure 6. Halophytes in the high Andes Mountains beinggrazed by burros. Some of the halophytes are under iceand in salty water (10 ppt).

Figure 8. Halophytes growing in a mixture of oil and sea-water may be seen around Ing. Jaime Serra of I.N.T.A.where a natural river of oil flows into an estuary alongthe coast ofPatagonia, Argentina.

Figure 9. In Argentina Spartina longispica grows in tidalflats where it is grazed by cattle. The plant also producesa grain.

Autumn 1981 117

(Fig. 8) near Tierra del Fuego.But, what good are halophytes? Some are obvi-

ously ornamentals. Others have grain or berries.Goats and cattle readily forage on halophytes, suchas Maireana brevifolia which is well liked by Cattlein Australia. Spartina longispica of Argentina is alsograzed by cattle (Fig.9), has a wheat -like seed andgrows in seawater. Prosopis algarobo, which cangrow through salt, feeds goats, cattle and sheep on20,000 hectares in Chile (Fig. 10).

Some halophytes have potato -like tubers withleaves and flowers that may be eaten. Even mush-rooms were found at Salinas Grandes growing inwater twice as salty as the ocean. In Argentina at-tempts were being made to drip -irrigate plants withhighly saline water half the salinity of the ocean. InPuerto Peñasco we use full- strength seawater fromwells such that the water can recycle back (Fig. 11) tothe sea. With this system the soil salinity and perco-lation rate has not changed in two Years.

The use of halophytes, however, could make animpact on today's food production. Using salt -affected lands we might grow animal feeds such asCressa truxillensis. Our preliminary studies indicatethat food conversion ratios are not significantly af-

Figure 10. The legume bearing trees Prosopis algarobaand P. tamarugo feed hundreds of sheep, cattle and goatsin CORP() maintained forests in northern Chile.

Seawater Well FieldSand Dune

Halophyte Field

Gulf

Caliche

Fine E th Caliche lenses

Coquinoid Beachrockorte..t

- -Granitic Bedrock

Fie( IL FI, drologv of a seawater halophyte field atPeiiasco, Sonora, Mexico, Not to scale, Arrows

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feeted when halophytes 1:1 fiftem percent ofthe total diet. Although we are Just beginning toevaluate the world material in our halophyte germplasm hank tapproximately 1,000 collections), theresults suggest that much can be done to feed our

A.ckliowledgementsThis work was sponsored by the Rockefeller Foundation

and made possible through the initiative and foresight ofMr. fohn R. Carpenter, ot the Coca-Cola Corporation. Ad .chtional logistic support from Coca -Cola was graciousb,given by Mr. R Blase, F. Fogarty, S. Clark, G. Barna, T.Ornstein, R. Massiff, R. Safrana, A. Pastor, A. Van DenBrock, M Thomas M Adams and R. DeLaGrave.

The following scientists assisted in many ways! [ng. A.Villa Salas, Ing. M. Ennquez, Ing. C. Mora Mrs L. Bond deSilva, 1)r. P Elpida, Dt J Prisco. Dr L. Gonzaga, Di, A.Franio, Dr G. foamier, Dr F. Alba.ni. Di. A. Ragonese, IngC Petetin, Dr L. Mendoza, Eng. 1 Serra, Ing E. Griffin, Ingf. Escobar, Dr. R. I wt. Ing. R. Braun, [ng. B Caraguare, Ing.R. Candia, Ing. C. Passera, lug E Azpillaga, S. Godoy, Du.T, Darrigrandi, Ing. L Zelada, Ing, G. Bravo, Dr S.Lailhaear, Dt. Gasto, Ing. D. Contreras, Dr. E. Fuentes,Sra. M. Menoz, Ing R. Meneses, Ing R. Osorro, Dr, A Gea,Ing T. Campbell, lug. P. oear, Ing A. Aguilera, Du, J.Paez Dir. G Navarro, Sr. M Figaroa, Sr. T. Paredes, Du.V. Ahumada, Lic. J Infante. [ng N. Gallardo, Ing. P Baez,Sr. C. Fuchs, Dr C Lopez, Dr, P Aguilar, Dr. R. Ferreyra,Sr G, Ing. C. Morales, Ï. Infante, R. and M. Agui-lar A. Castellanos, and I. Reprieto

Special thanks are due for the constant encour eementand moral suppo: . p, .BrophyandCar1Nwhose dream :4 ,

1ettr11-ces

Boyko, H and E. Boyko. 1966 Experiments on plantsgrowing under irrigation with saline waters from 20(10mgliter T.D.S. ¡total diluted solids) up to sea-water ofoceanic concentration without desalination. In. Salin-ity and Aridity-New Approaches to Old Problems. H.Boyko, ed.! Junk. The Hague. pp 214-282.

Castettet, Edward F. and Willis H Bell, 1951. Yuman In-dian Agriculture. Primitive SubsistencE on the LowerColorado and Gila Rivers Univ New Mexico Press.Albuquerque.

Epstein. Emanuel, R W Kingsbury, T. D. Norlyn and D W.Rush. 1979. Production of food crops and other bio-mass by seawater culture, In: The thosaline Concept

Approach to the Utilization of Under-cYploited Resources (A. Hollaenderd, ed 1 PlenumPress. pp 77-99.

Espenshade, E B ¡ed ) 1960. Goode's World Atlas. 11th ed.Rand McNally 285 pp.

Feiger, Richard S and Gary P. Nabhan, 19'8. Agroccosys-tem diversity: A model from the Sonoran Desert. In-Technological Management in Dty Land. Past andPresent, Indigenous and Imposed Narciel L Gonzales(ed ) Social and AAAS Selected Symposium #10 pp.129-149.

Israelsen, O. W. and V. E. Hansen. 1962, Irrigation Princi-ples and Plact ices. Wiley.

Somers, G. Fred 1979 Natural halophytes as a potentialresource for new salt-tolerant crops. Sonic progress andprospects. In 7 he B:osahne Concept -An Ipprua,hto the Utilization of Uncierexploited Resourcc.s. (A.Hollaenderd, ed.1Plenum Press pp 101-115.

Vascy, Georg, 1889. New or little known plants Cardenand Forest 2. 401402.