concentrations for H. ammodendron and C. karshiskii respectively were 381 and 295mm, 290 and 248mm, 213 and 188mm,
dclenche pour une humidit du sol atteignant une valeur critique donne. Sur la base des rgressions quadratiques ajustes
IRRIGATION AND DRAINAGE
Irrig. and Drain. 61: 107115 (2012)
Published online 16 March 2011 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ird.619aux donnes exprimentales, lirrigation ajuste aux besoins avec les trois concentrations de sel pour ammodendron H. et C.karshiskii taient respectivement 381 et 295mm, 290 et 248mm, 213 et 188mm, en moyenne pendant deux ans. Deux typesde fonctions de production vgtale ont t employs pour dcrire la relation entre laccroissement de la biomasse vgtale, ladose deau sale et sa qualit. Ces fonctions ont donn un bon ajustement aux donnes exprimentales et lucid les valeurstrouves pour la zone frontale (I.E. les zones directement exposes aux vents dominants). Cela pourrait tre utile lexploitation des eaux de qualit mdiocre et lestimation de la croissance et du rendement des plantes brisevent dans lecadre de la planification forestire. Copyright 2011 John Wiley & Sons, Ltd.
mots cls: irrigation saline; plantes brisevent; production de biomasse; ammodendron Haloxylon Bunge; Caragana karshiskii Komaveraged for two years. Two kinds of plantwatersalinity production functions, quadratic and square root functions wereemployed to describe the relationship between plant biomass increment and quality and quantity of applied saline water. Thefunctions performed well with experimental data and showed a positive marginal productivity with water and a negativemarginal productivity with salt for the frontal area. That could be useful for evaluating lowquality water exploitation andestimating the growth and yield of shelterbelt plants in connection with forest planning. Copyright 2011 John Wiley &Sons, Ltd.
key words: saline irrigation; shelterbelt plants; biomass production; Haloxylon ammodendron Bunge; Caragana karshiskii Kom
Received 17 January 2010; Revised 9 November 2010; Accepted 10 November 2010
Dans les zones o leau est rare, leau douce est alloue en priorit aux villes et lagriculture pendant que les bnfices issusdes cosystmes sont obtenus avec de leau de qualit mdiocre. Alors que lutilisation de leau sale des fins agricolesrequiert encore dun point de vue scientifique des besoins de quantifier leffet de la qualit et la quantit deau sur la croissancedes plantes, une exprience dirrigation avec des eaux saumtres a t ralise pour deux plantes utilises pour faire des brisevent, respectivement ammodendron Haloxylon Bunge et Caragana karshiskii Kom. Ce travail a t conduit en 200708 dans largion aride du nordouest de la Chine. Trois concentrations en sels (3, 7 et 12 g l1) ont t examines et lirrigation a tPOTENTIAL USE OF SALINE WATER FOR IRRIGATING SHELTERBELT PLANTS INTHE ARID REGION
MENG HU1, SHAOZHONG KANG1*, JIANHUA ZHANG2, FUSHENG LI3, TAISHENG DU1 AND LING TONG1
1Centre for Agricultural Water Research in China, China Agricultural University, Beijing, China2Department of Biology, Hong Kong Baptist University, Hong Kong, China
3Agricultural College, Guangxi University, Nanning, Guangxi, China
In waterscarcity areas fresh water is allocated with priority to urban areas and agriculture, and ecosystem function benefits areobtained from marginal quality water. Meanwhile the scientific use of saline water needs to quantify the effect of quality andquantity of water on plant growth. A saline irrigation experiment was carried out for two shelterbelt plants, Haloxylonammodendron Bunge and Caragana karshiskii Kom, during 200708 in the arid region of northwest China. Three saltconcentrations (3, 7 and 12 g l1) were considered and irrigation was controlled when soil moisture reached an enacted criticalvalue. Based on the quadratic regressions fitted to the experimental data, the befitting irrigation with the three salt* Correspondence to: Dr. Shaozhong Kang, Centre for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China,Tel: +861062737611; Fax: +861062737611. Email: email@example.comLutilisation de leau saumtre pour irriguer les plantes brisevent dans les rgions arides.
Copyright 2011 John Wiley & Sons, Ltd.
and burial of farmland (Bielders et al., 2000; Kang et al.,2004). Haloxylon ammodendron Bunge (H. ammodendron)
108 M. HU ET AL.mental Station for WaterSaving in Agriculture and Ecology height and canopy diameter (Wolfe and Nickling, 1993):and Caragana karshiskii Kom (C. karshiskii) are nativedominant shrubs in northwest China and have beencommonly used for controlling desertification. In manyareas there, rainfall is so limited that the newly plantedshelterbelts cannot work effectively unless supplied withsome saline groundwater. However, indiscriminate exploi-tation of marginal quality water for irrigation in the absenceof proper saltwatervegetation management practices posesgrave risks to soil health. Because of the scarce precipitationand considerable evapotranspiration, a moderate accumula-tion of salt in shallow soil is unavoidable when saline wateris used for irrigation (Kang et al., 2004; Singh et al., 2009).To tackle the salt accumulation problem, we should
estimate the plant yield in response to salinity and waterstress at the same time and find an appropriate irrigationstrategy. There are many studies that have attempted toestimate the separate or combined effect of water andsalinity on plant production functions. Some agriculturalpractices showed that the salinity and amount of salinewater used for irrigation generally exceeded experimentallevels but could result in good agricultural income (Knappand Sadorsky, 2000; Wang et al., 2007). Nevertheless, untilrecently there was little information available in theliterature about the quantitative relationship between annualbiomass increment of shelterbelt plants and the quantity andsalinity of applied water.The objective of the study was to quantify the effects of salt
concentration and amount of irrigation water on the annualbiomass increment and to develop a plantwatersalinityproduction model that could be used for supplementaryirrigation with poor quality water. And we focused on theplantwatersalinity production functions of plant height,branch length, canopy diameter and frontal area in response tosaline water irrigation for H. ammodendron and C. karshiskiion the basis of experimental data. With the establishment ofsome quantitative relationships, it was possible to determinethe separate and interactive effects of the quantity and salinityof applied water on particular items of growth of the plants.
MATERIALS AND METHODS
Experimental site and design
The experiment was conducted at the Shiyanghe Experi-INTRODUCTION
In arid regions, wind erosion and dust storms do lots of harmto agricultural production and human health. Some winderosion control methods, such as mulching and shelterbelts,have been tested to prevent soil loss, sand dune movementCopyright 2011 John Wiley & Sons, Ltd.ature is 8 C and annual accumulated temperature (>0 C) is3550 C. Duration of average annual sunshine is over3000 h with 150 frostfree days.The experiment started on 1 May 2007 and ended on 21
October 2008.Haloxylon ammodendronBungeandCaraganakarshiskiiKomplants that were 23 years oldwere used for theexperiment; the oneyearold saplings were cultivated in theusual manner, with sufficient soil water and no salt stress. Theexperimental soil was irrigated desert soil (siltigicorthicanthrosols), soil texture was loamy sand (sand (2 ~ 0.05mm) 90.1%, silt (0.05 ~ 0.002mm) 9.1% and clay (0.002mm) 0.8%). Soil electrical conductivity was 0.113 dS m1, organicmatter content 2.1 g kg1 and pH 7.8. Mean bulk density was1.41 g cm3, the field capacity (f) 0.20 cm
3 cm3 and theinitial salt content 2.3 g kg1. The concentrations of K+, Na+,Ca2+, Mg2+, Cl, CO3
2 and SO42 were 12, 290, 254, 80, 180,
97 and 1201mg kg1, respectively.Three salt concentrations were considered, i.e. 3 , 7, 12 g
l1 or electrical conductivity (ECw) of 3.2, 7.1 and 11.2 dSm1, respectively. Irrigation was based on soil water deficit,and two kinds of critical soil moisture were considered,0.10 cm3 cm3 (50%f) and 0.05 cm
3 cm3 (25%f). Foreach salt treatment, irrigation started when soil watercontent reached the critical soil moisture, which is shownin Table I for different growing stages, and four replicateswere taken. Soil water content was determined using aportable soil moisture monitoring system (Diviner 2000,Sentek Pty Ltd, Australia), emendated by a gravimetricmethod. The saline water was obtained from a 2 : 2 : 1weight mixture of NaCl, MgSO4 and CaSO4, to representlocal groundwater chemical composition; the main concen-trations of ions in groundwater were Na+ + K+ 129.76mgl1, Mg2+ 45.71mg l1, Ca2+ 31.92mg l1, SO4
2 296.22mgl1, Cl 150.19mg l1, HCO3
Measurements and methods
Growth parameters were measured every two weeks. Plantheight (H), from ground surface to tip, and annual branchlength (B) were measured using a tape with the accuracy of1mm. Canopy area (Ca) was calculated from digital photos(GuevaraEscobar et al., 2005; Boese et al., 2008). Thencanopy diameter (Cd) was calculated as follows:
The frontal area (Fa) was calculated as a product of planta. The area is characterized by a continental temperateate with mean annual precipitation of 160mm and openr evaporation of 2000mm. The mean annual temper-(37 5049 N, 102 5101 E) of China AgricultureUniversity, located in the Shiyang River Basin, northwestIrrig. and Drain. 61: 107115 (2012)
Fa =H Cd (2)
The annual increment was calculated as the differencebetween the beginning and the end of the growing period in
factors that may affect biomass increment were consideredconstant.Based on previous studies (Dinar et al., 1991; Kaushal
et al., 1985; Singh et al., 2009) on the development of saltwater production functions, the analysis here was undertakenusing quadratic and square root functional forms. Thequadratic forms imply that (while holding all other variablesconstant) an increase in the level of one of the humancontrolled variables results in a change (increase or decrease depending on the relationship) in the level of the dependentvariable up to a certain point. Any further increase in its levelresults in an opposite response (decrease or increase,respectively) in the dependent variable level. The square rootfunction is similar to the quadratic. It imposes nonzeroelasticity of substitution among factors with no growth plateauand diminishing marginal productivity, but allows for sharpercurvature near the maximum and a less rapid decrease in totalproduct than the quadratic (Llewelyn and Featherstone, 1997).The implicit relationships to be estimated were:
Table I. The minimum critical soil moistures (cm3 cm3) atdifferent growing stages of H. ammodendron and C. karshiskii in2007 and 2008. Irrigation started when soil moisture reached thesecritical values
Period 22/4 ~ 20/5 21/5 ~ 19/6 20/6 ~ 10/9 11/9 ~ 20/10
Tr0 0.10 0.10 0.10 0.10Tr1 0.05 0.10 0.10 0.10Tr2 0.10 0.05 0.10 0.10Tr3 0.10 0.10 0.05 0.10Tr4 0.10 0.10 0.10 0.05
Each treatment contained three saline concentrations: 3, 7 and 12 g l1.
109USE OF SALINE WATER FOR IRRIGATING SHELTERBELT PLANTS
CopyII. The salinity and amount of irrigation water (Ir), and thea year. Table II shows the quality and quantity of appliedwater, annual increment of plant height, branch length,canopy diameter and frontal area for the Tr0 soil moisturetreatment in the two years.
Plantwatersalinity production functions
In this study, the annual increment of plant height, branchlength, canopy diameter and frontal area forH. ammodendronand C. karshiskii were related to two humancontrolledvariables quantity and quality of the irrigation water (hereonly the salinity component of quality is considered). Otherh length (B), canopy diameter (Cd) and frontal area (Fa) for Tr0 i
Salinity (g l1) Ir (mm)
modendron3 337 a7 305 a12 250 b3 389 a7 295 b12 190 c
rshiskii3 280 a7 216 b12 195 b3 293 a7 284 a12 187 b
h year, treatments with the same letter were not significantly different at P
right 2011 John Wiley & Sons, Ltd.al increment of H. ammodendron and C. karshiskii in height (H),n 2007 and 2008
H (cm) B (cm) Cd (cm) Fa (cm2)
57.75 a 49.48 a 61.42 a 6 890 a50.17 b 44.60 ab 55.09 ab 5 587 b45.49 b 41.60 b 47.38 b 6 317 a68.05 a 68.10 a 97.78 a 13 944 a58.66 b 57.30 b 94.57 a 12 456 ab61.86 b 50.65 b 85.20 b 11 632 b
62.65 a 39.10 a 36.86 a 2 167 a34.33 b 26.00 b 24.44 b 1 619 ab28.50 b 24.70 b 22.95 b 1 368 b79.39 a 65.45 a 73.99 a 9 674 a53.75 b 35.65 b 45.28 b 5 016 b31.52 c 22.20 c 44.10 b 3 000 c
< 0.05.(SAS Institute Inc., USA).ll data were statistically analyzed and ANOVA analysesperformed using the SAS System for Windows V8Bio= a0 + a1Ir + a2Ir + a3C+ a4C + a5IrC (3)
Bio= b0 + b1Ir + b2Ir0.5 + b3C+ b4C
0.5 + b5Ir0.5C0.5 (4)
where the annual biomass increment (Bio) was detailed byplant height (H), branch length (B), canopy diameter (Cd)and frontal area (Fa). The amount of irrigation water (Ir)and its salt concentration (C) were indicated in millimeters(mm) and grams per liter (g l1).AIrrig. and Drain. 61: 107115 (2012)
with saline concentration of 3, 7 and 12 g l1, the befitting
110 M. HU ET AL.RESULTS AND DISCUSSION
Annual biomass under different saline irrigation
The annual growth of H. ammodendron and C. karshiskiiin plant height, branch length, canopy diameter and frontalarea during the two years (Table II, Tr0 presented) reflectedthe effects of various amounts of irrigation water and theirsalt concentration. Response of their annual growth wassimilar for various qualities and quantities of irrigationwater. Compared to the plants irrigated with salt concen-tration of 3 g l1, the amount of irrigation water with saltconcentration of 12 g l1 applied to H. ammodendron and C.karshiskii reduced the annual growth by 26 and 30%(2007), 51 and 36% (2008), respectively. Meanwhile thereductions for the annual growth of H. ammodendron andC. karshiskii irrigated with salt concentration of 12 g l1inplant height, branch length, canopy diameter and frontalarea were 21 and 55, 16 and 37, 23 and 38, 8 and 37% in2007, 9 and 60, 26 and 66, 13 and 40, 17 and 69% in 2008,respectively. From the aforementioned statistical data, thegrowth reduction of C. karshiskii was significantly greaterthan that of H. ammodendron when the salinity of irrigationwater increased from 3 to 12 g l1, and it could be concludedthat the annual growth of C. karshiskii was more sensitive tosalt stress than H. ammodendron. And moreover, thepercentages of reduction for both H. ammodendron andC. karshiskii were greater in 2008 than in 2007, with theimpact of quite different precipitation in the growing seaso...