WHEAT GROWTH AND PHYTOAVAILABILITY OF COPPER AND ZINC AS AFFECTED BY SOIL TEXTURE IN SALINE-SODIC CONDITIONS

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1 Pk. J. Bot., 43(5): , WHEAT GROWTH AND PHYTOAVAILABILITY OF COPPER AND ZINC AS AFFECTED BY SOIL TEXTURE IN SALINE-SODIC CONDITIONS MUHAMMAD ARSHAD 1,2,*, GHULAM MURTAZA 1, MUHAMMAD ARIF ALI 1,3, MUHAMMAD SHAFIQ 1, CAMILLE DUMAT 4 AND NIAZ AHMED 3 1 Institute of Soil & Environmentl Sciences, University of Agriculture, Fisld, 38000, Pkistn 2 Institute of Environmentl Sciences & Engineering (IESE-SCEE) - Ntionl University of Sciences & Technology, H-12, Islmd, 44000, Pkistn 3 Deprtment of Soil Science, University College of Agriculture Bhuddin Zkriy University, Multn Pkistn 4 ECOLAB, UMR5245 CNRS-UPS-INPT, Avenue de l Agroiopole, 31326, Cstnet-Tolosn, Frnce. Astrct Nutrient disorders in sline-sodic soils cn dversely ffect crop growth. In order to evlute the growth response of whet (Triticum estivum L.) to Cu nd Zn nd the phytovilility of these essentil elements, pot experiment ws conducted in three different textured sline-sodic soils [sndy lom (SL), sndy cly lom (SCL) nd cly (C)] hving n EC e 8.63, 8.80, 8.98 ds m 1 nd SAR 21.66, 23.48, (mmol L 1 ) 1/2 respectively. Seven tretments including levels of Cu (4, 6 nd 8 mg kg 1 ) nd levels of Zn (4, 6 nd 8 mg kg 1 ) were seprtely pplied together with single control tretment. Dry mtter yield (strw + grin) of whet incresed up to 35.2% with Cu nd up to 31.2 % with Zn ppliction reltive to the control. As soil cly content incresed, dry mtter yield decresed up to 39.2% in SCL nd up to 62.7% in C soil when compred to SL soil. Appliction of Cu incresed the concentrtion in oth whet strw nd grins up to 2.46 nd 2.20 mg kg 1 DW respectively reltive to the control. Zinc concentrtion in whet strw nd grins ws lso incresed up to nd mg kg 1 DW respectively reltive to the controls. Copper ppliction significntly incresed Zn concentrtions in whet plnts. Introduction Micronutrient deficiencies re ecoming serious prolem s result of enhnced nutrient demnd from highly intensive nd exploittive griculture, coupled with the use of single-nutrient fertilizers nd low mounts of orgnic mnures. Phenotypic plsticity nd physiologicl verstility of plnts cn uffer nutrient deficiency nd toxicity to some extent, therey moderting the effect on crop yields (Svithri et l., 1999). While drought nd slinity oth threten crop productivity worldwide (Hu & Schmidhlter, 2005), slinity stress remins one of the world's oldest nd the most serious environmentl prolems, nd continues to sustntilly hmper crop productivity in mny rid nd semi rid regions (Ali et l., 2007). Currently, worldwide out 50% of irrigted lnd, which hs t lest twice the productivity of rin-fed lnd nd produces s much s one-third of the world s food, is ffected y sliniztion (Hillel, 2000). Crop yields decline drmticlly when ph of the soil solution exceeds 8.5 or the EC e exceeds 4 ds m 1 nd when EC e vlues re very high, crop yields would e seriously ffected (Zheng et l., 2008). Phytovilility of essentil nutrients in sline-sodic nd sodic soils my vry from deficiency of severl nutrients to high levels of N + nd Cl - (Curtin & Nidu, 1998; Qdir & Schuert, 2002). Sodic soils usully hve poor vilility of most micronutrients, which is generlly ttriuted to high soil ph (Pge et l., 1990; Nidu & Rengsmy, 1993). In generl, the soluility of ctionic trce elements decreses with incresing ph, while the soluility of the nionic trce elements increses with incresing ph (Pge et l., 1990). Therefore, in sodic soils, the soluility of micronutrients such s copper (Cu), iron (Fe), mngnese (Mn), nd zinc (Zn) is prticulrly low (Curtin & Nidu, 1998), nd plnts grown on these soils often experience deficiency of these elements (Pge et l., 1990). However, elementl deficiency is not lwys experienced (Qdir & Schuert, 2002) ecuse the soilinding gents, especilly soil orgnic mtter nd hydrous ferric nd mngnese oxides s well s cronte cn ll *Corresponding uthor: rshd_m@live.com influence the phytovilility of metls (Suvé et l., 2000; Dumt et l., 2006). In ddition to these fctors, the presence of multiple elements cn give rise to complex interctions ffecting not only plnt uptke ut lso trnsloction within the plnt (Luo & Rimmer, 1995). Diverse results y different uthors hve een reported regrding Cu-Zn interctions. Beckett & Dvis (1978) oserved slight ntgonistic effect etween Zn nd Cu for rley. Brley growth ws regulted y phytoville Zn nd Cu where, Cu incresed the toxic effect of Zn (Luo & Rimmer, 1995). Tni & Brrington (2005) reported n ntgonistic effect of Cu on Zn uptke in Buckwhet for ll prts of the plnt exmined, except for the roots where the reverse ws true, while Snders et l., (1987) reported tht Cu hd no significnt effect on Zn uptke y red eets. Whet (Triticum estivum L.) is the most widely grown cerel grin in the world nd s stple food it is second only to rice in consumption. Around one third of whet in the developing world is produced in environments which re considered to e mrginl for whet production, prticulrly due to high soil slinity nd sodicity. However, the need to improve the productivity of these mrginl res is ecoming incresingly importnt with regrd to world food pressure. Whet is reltively sensitive crop to copper (Brown & Clrk, 1977) nd zinc (Hmid & Ahmd, 2001) deficiencies. At present, phytovilility studies regrding essentil nutrients im to lnce the quntities of nutrients dded to the soils in order to fvour plnt growth without inducing risk of toxicity. Understnding of the mechnisms nd soil properties influencing nutrient vilility cn help to increse crop productivity. Prticulrly, coupling of slinity prolems with nutrient constrints cn improve crop production nd mngement of mrginl soils. The ojective of the present study is to determine the response of whet to Cu nd Zn ppliction nd to ssess plnt vilility of these two essentil micronutrients in three different textured sline-sodic soils.

2 2434 M. ARSHAD ET AL., Mterils nd Methods Smpling nd chrcteriztion of soils: Three different soils for the present study were collected from the region of Fisld (Pkistn) with men nnul precipittion of 370 mm. The cropping pttern is dominted y whet, mize nd sorghum t Fisld (Muhmmd et l., 2008). Physicl nd chemicl properties of the smples hving different textures [Sndy lom (SL), sndy cly lom (SCL) nd cly (C)] re presented in Tle 1. The soils were ir-dried, ground nd pssed through 2 mm sieve. Soil chrcteristic determined included the frction of snd, silt nd cly y Hydrometer method (Bouyoucos, 1962), sturtion percentge, ph of sturted soil pste (ph s ), electricl conductivity of sturtion extrct (EC e ), ctions (C+Mg, N, K), nions (crontes, icrontes, chlorides, sulphtes) nd Sodium Adsorption Rtio-SAR (US Slinity L. Stff, 1954), ville phosphorus, totl nitrogen, orgnic mtter (Jckson, 1962), Cu nd Zn (AB DTPA method; Soltnpour, 1985). The AB-DTPA method of extrction is prticulrly used for determintion of micronutrients in lkline soils. AB-DTPA solution ws prepred y dissolving g NH 4 HCO 3 nd 1.97 g of DTPA in one liter of distilled wter. Soil (10 g) ws susequently extrcted with freshly prepred extrcting solution (20 ml) in 250 ml Erlenmeyer flsk. The mixture ws shken on reciprocting shker t 180 cycles per minute for 15 minutes in n unstoppered flsk. The extrct ws filtered nd nlyzed for Cu nd Zn using n tomic sorption spectrophotometer (Perkin Elmer Anlyst 100). These properties of soil minly indicte tht ll the three soils were sline-sodic in nture nd were copper ([Cu] Soil <0.5 mg kg 1 ) nd zinc ([Zn] Soil <0.9 mg kg 1 ) deficient (Soltnpour, 1985). Tle 1. Some physicl nd chemicl properties of soils used for the experiment. Chrcteristic Unit SL SCL C Snd g kg Silt g kg Cly g kg Sturtion % ph s EC e ds m CO 3 mmol c L HCO 3 mmol c L 1 ` Cl mmol c L *SO 4 mmol c L C 2+ + Mg 2+ mmol c L N + mmol c L K + mmol c L SAR (mmol L 1 ) 1/ Phosphorus mg kg Nitrogen % OM % **Cu 2+ mg kg **Zn 2+ mg kg Slinity clss - Sline sodic Sline sodic Sline sodic * = y difference, ** = AB DTPA extrctle, SL = Sndy Lom, SCL= Sndy Cly Lom, C = Cly. Tretments nd culture experiments: Whet culture experiments were conducted in the wirehouse, Institute of Soil nd Environmentl Sciences, University of Agriculture, Fisld, Pkistn. The pots were filled with 12 kg of soil. There were seven tretments, replicted thrice in completely rndomized design. The tretments were: control (0), 4 mg Cu kg 1 soil (Cu4), 6 mg Cu kg 1 soil (Cu6), 8 mg Cu kg 1 soil (Cu8), 4 mg Zn kg 1 soil (Zn4), 6 mg Zn kg 1 soil (Zn6) nd 8 mg Zn kg 1 soil (Zn8). Clculted mounts of Cu nd Zn were mixed directly in to the soil efore sowing whet. Whet vriety Inql 91 ws plnted y the field cpcity sowing method. Whet seedlings were thinned to five per pot 25 dys fter the sowing dte; uprooted plnts were cut into pieces nd mixed into the sme pot y hoeing. The whet crop ws fertilized with NPK; g per 12 kg soil respectively s sl dose. Sources of NPK were ure, dimmonium phosphte nd potssium sulphte. The whole mount of P nd K, nd hlf the mount of N were pplied t the time of sowing. While remining nitrogen ws pplied in two equl splits 45 nd 75 dys fter sowing. The crop ws irrigted with fresh wter ccording to the crops wter requirements. Mesure of whet growth prmeters: At hrvest, plnt height ws mesured mnully using meter-rod. Numers of tillers per plnt were lso counted. Plnts were hrvested from the se, put into pper gs nd oven-dried t 65 C over 72 h. The dried plnt mteril ws susequently weighed nd fter drying, strw nd grins were seprted for nlysis of Cu nd Zn concentrtions. Determintion of Cu nd Zn sorption: Oven-dried strw nd grin smples were ground using steel Wiley Mill to otin fine powder (<1 mm size). Dried nd ground plnt mteril (1 g) ws digested in dicid mixture consisting of concentrted HNO 3 (20 ml) nd 10 ml 70% HClO 4 (10 ml) in conicl flsk through hot plte. After digestion, smples were cooled to room temperture nd diluted to 50 ml with deionized wter nd stored in clen, irtight ottles prior to the determintion of Cu nd Zn y tomic sorption using Perkin Elmer Anlyst 100 spectrophotometer. Sttisticl nlysis: The dt otined ws sujected to Anlysis of Vrince (ANOVA) nd DMR (Duncn s Multiple Rnge) test to differentite ny tretment effects (Steel & Torrie, 1980).

3 WHEAT GROWTH AND PHYTOAVAILABILITY OF COPPER AND ZINC 2435 Results Morphologicl plnt chrcteristics: Blnced plnt nutrition ensures good plnt growth. The results regrding plnt height re shown in Fig. 1. The effect of soil texture, tretments nd their interctions were significnt (p<0.01). The mximum plnt height (79.3 cm) ws oserved with Cu8 in SL soil while minimum plnt height (50.3 cm) ws oserved for control in C textured soil. In generl, more tillers ensures etter crop yield. Results regrding numer of tillers per plnt re given in Fig. 1. The effect of texture nd tretments ws significnt (p<0.01) while the interction etween soil texture nd tretments were sttisticlly non significnt. The mximum men vlue for tillers per plnt ws 5.67 with Zn6 in SCL nd ws the minimum in the control for the sme soil. Tretment Zn4 ws non significnt reltive to control while ll the other tretments were significntly etter over these two. Tretments Cu4 nd Zn6 were mutully significnt ut non-significnt with respect to Cu6, Cu8 nd Zn8. Totl iomss (strw + grins) per pot for whet crop vried considerly with different tretments (Fig. 1c). The tretments differed significntly (p<0.05) while interction of soil texture nd pplied tretments ws non-significnt. Mximum iomss ws found in Zn6, i.e., g/pot in SL soil while minimum iomss (11.85 g/pot) ws otined in C soil with the control. Men vlues for totl iomss were significnt (p<0.01) with respect to texture of soil. Overll mens for tretments showed tht there ws grdul increse in totl iomss with incresing levels of Cu nd Zn pplied. Plnt height (cm) Tiller per plnt (g) Biomss per pot (g) c 0 Cu 4 Cu 6 Cu 8 Zn 4 Zn 6 Zn 8 Cu/Zn pplied (mg kg -1 ) Fig. 1. Effect of soil texture, Cu nd Zn ppliction on growth prmeters: ) plnt height, ) numer of tillers per plnt nd c) iomss per pot. Brs with different letters indicte tht texture x tretment interction is significnt. [Sndy Lom ( ): Sndy cly lom ( ): Cly ( )]. Concentrtion of Cu in whet strw nd grins (mg kg 1 ): Copper concentrtions in whet strw s influenced y the soil texture nd ppliction of tretments re given in Fig. 2. The effect of vrious tretments on Cu concentrtion in strw ws sttisticlly significnt. The verge copper concentrtion rnged from 4.43 to 7.54 mg Cu kg 1. The mximum concentrtion of Cu ws found for Cu6 in SCL soil while the lowest vlues were oserved for the control in SCL nd C soil. There ws no pronounced effect of soil texture on copper concentrtion in whet strw. Sttisticl nlysis showed tht there ws not significnt effect of soil texture on Cu concentrtions in whet strw. The interction etween soil texture nd tretments ws lso not significnt. However, Cu nd Zn tretments showed significnt (p<0.01) differences over controls. There ws grdul increse in Cu concentrtion with incresing levels of Cu pplied. With ppliction of Zn lone, concentrtion of Cu incresed when compred to the control, ut vlues for Cu concentrtion in whet strw were low when compred to Cu tretments. Copper concentrtion in whet grins s ffected y vrious soil textures nd tretments is given in Fig. 2. Sttisticl nlysis of the dt indicted tht soil texture nd tretments hd significnt effects on Cu concentrtions in whet grins (p<0.01), ut the interction etween texture nd tretments ws not significnt. Overll mens showed tht the concentrtion of Cu in whet grins ws the highest for the SL soil nd ws sttisticlly different to Cu concentrtions in whet grins for the SCL nd C textured soil. However, Copper concentrtion in whet grins in SCL nd C soil were not significntly different from ech other. All the tretments hd significnt effect (p<0.01) when compred to the control. The mximum concentrtion ws oserved in whet grins grown with Cu8.

4 2436 M. ARSHAD ET AL., Cu conc. in whet strw (mg kg -1 ) Cu conc. in whet grins (mg kg -1 ) 0 Cu 4 Cu 6 Cu 8 Zn 4 Zn 6 Zn 8 Cu/Zn pplied Fig. 2. Effect of texture, Cu nd Zn ppliction on Cu concentrtion in whet: ) Strw nd ) Grins. [Sndy lom ( ): Sndy Cly Lom ( ): Cly ( )]. Concentrtion of Zn in whet strw nd grins (mg kg 1 ): Concentrtion of zinc in whet strw depicting the influence of vrious textures nd different levels of Cu nd Zn re presented in Figs. 3 & 3. The effects of texture on Zn concentrtion of whet strw were significnt (p<0.01). Overll mens showed tht there ws grdul decrese in Zn concentrtion with incresing percentge of cly in the soil. Mximum men vlue for Zn concentrtion ws recorded for SL nd the minimum Zn concentrtion for C soil. Tretment effects were significnt (p<0.01). Zinc concentrtion rnged from 8.45 to mg kg 1 DW. The mximum vlue of Zn ws oserved for Zn8 in SL soil nd the minimum concentrtion ws recorded for the control in C soil. Overll mens for tretments showed tht ll the tretments were significntly (p<0.01) different from the control. There ws grdul increse in the concentrtion of zinc in whet strw with incresing levels of Cu nd Zn pplied over control. Soil texture nd tretments lso intercted significntly (p<0.01). However, the effect of texture for SL nd SCL ws not significnt. In generl, Zn concentrtion in whet grins ws lower in the SCL soil. The effect of soil texture nd tretments on Zn concentrtion in whet grins were oth sttisticlly significnt (Figs. 4 & 4). The interction etween texture nd tretments ws lso significnt (p<0.01). The mximum Zn concentrtion (54.42 mg kg 1 DW) ws oserved for Zn8 in SCL nd the minimum (58.23 mg kg 1 DW) ws oserved for the control in SCL soil. Zinc concentrtion in whet grins incresed grdully with Cu nd Zn pplied. With increses in Cu pplied, Zn concentrtion of grins ws enhnced significntly over the control, ut ws consistently lower thn tht t the lowest level of Zn pplied. Discussion Growth response of whet to Cu nd Zn ppliction in terms of plnt height, tillering nd iomss: Plnt height incresed y 10.3 cm with Cu nd 8.0 cm with Zn ppliction in the SL soil. In the SCL soil, the increse ws up to 9.6 nd 9.3 cm with Cu nd Zn ppliction respectively. Copper nd Zn tretments lso enhnced plnt height up to 10.0 nd 8.7 cm respectively in C soil. A decrese in plnt height of 8.1 cm ws oserved in SCL nd 18.1 cm in C soil when compred to the SL soil. High cly content in soil negtively ffected the numer of tillers. Compred to the control, dry mtter whet yield incresed up to 35.2% with Cu nd 31.2% with Zn ppliction. With incresing mounts of cly in the soil, the dry mtter yield decresed to 39.2% in SCL nd to 62.7% in C soil. Decrese in growth ws ttriuted to incresed Cu nd Zn inding t exchnge sites of the clys which ultimtely suppressed plnt vilility. Different fctors control whet growth in sline-sodic soils. Field studies hve shown significnt increses in crop yields with the ppliction of Zn fertilizer to sodic soils (Gupt & Arol, 1990). Copper nd Zn pplictions ensure etter plnt growth (Chudhry & Lonergn, 1970). Dry mtter yield of whet incresed y incresing the rtes of pplied Cu nd Zn (Imtiz et l., 2003). High cly content nd SAR resulted in high moisture content which ultimtely reduced whet growth due to reduced soil ertion. Soil cly content is importnt in influencing oth the stility of the soil structure nd hydrulic properties ecuse of the lrge surfce re of cly prticles, their thin plty shpe, nd their negtive lttice chrge, which is lnced y exchngele ctions (Qdir et l., 2002).

5 WHEAT GROWTH AND PHYTOAVAILABILITY OF COPPER AND ZINC R 2 (SCL) = 0.97 Zn conc. in whet strw (mg kg -1 ) R 2 (SL) = 0.96 R 2 (SCL) = 0.99 R 2 (C) = 0.94 Zn conc. in whet grins (mg kg -1 ) R 2 (SL) = 0.86 R 2 (C) = Cu pplied (mg kg -1 ) 20 Zn pplied (mg kg -1 ) Zn conc. in whet strw (mg kg -1 ) R 2 (SL) = 0.98 R 2 (SCL) = 0.97 R 2 (C) = 0.96 Zn conc. in whet grins (mg kg -1 ) R 2 (C) = 0.97 R 2 (SL) = 0.93 R 2 (SCL) = Zn pplied (mg kg -1 ) Fig. 3. Zn concentrtion in whet strw influenced y soil texture nd Cu/Zn ppliction: ) effect of Cu pplied, ) effect of Zn pplied. [SL ( )-Sndy lom: SCL ( )-Sndy cly lom: C ( )-Cly]. Concentrtion of Cu nd Zn in whet influenced y Cu nd Zn pplictions nd soil texture: Copper concentrtion in plnts generlly vries from 5 to 20 mg kg 1 (Ktyl & Rndhw, 1983). The threshold vlue elow which plnts exhiit deficiency symptoms nd respond to Cu fertiliztion vries mong plnt species. In generl, less thn 5 mg Cu kg 1 dry plnt mtter is considered deficient (Ktyl & Rndhw, 1983). Copper concentrtion in whet strw nd grins from the controls were in the mrginl rnge. With ppliction of Cu, concentrtion in whet strw ws incresed up to 2.46 mg kg 1 when compred to the control. In whet grins, Cu concentrtion ws incresed up to 2.20 mg kg 1 for Cu8 when compred to the control. High cly concentrtions in soils reduced Cu concentrtion to 1.00 mg kg 1 in SCL nd C when compred to SL soil. Zinc concentrtion in helthy plnt rnges from mg kg 1 dry mtter (Ktyl & Rndhw, 1983). Zinc concentrtion < 20 mg kg 1 suggests Zn deficiency (Ktyl & Rndhw, 1983; Mrschner, 1995). Zinc concentrtion in whet strw ws incresed up to mg kg 1 DW t the highest level pplied when compred to the control. Zinc concentrtion decresed to 2.69 mg kg 1 nd 8.73 mg kg 1 DW in SCL nd C respectively 20 Cu pplied (mg kg -1 ) Fig. 4. Zn concentrtion in whet grins influenced y soil texture nd Cu/Zn ppliction: ) effect of Cu pplied, ) effect of Zn pplied. [SL ( )-Sndy lom: SCL ( )-Sndy cly lom: C ( )-Cly]. when compred to the SL soil. A strong reltionship ws oserved etween Cu nd Zn pplied to resulting Zn concentrtions in strw in ll three soils. There ws liner increse in Zn concentrtion with incresing levels of Cu pplied nd high vlues of R 2 (Fig. 3) were recorded irrespective of the soil texture. Similr trends were oserved for Zn concentrtions (Fig. 3) showing strong dependency (R ) on Zn pplied. Zinc concentrtion in grins incresed up to mg kg 1 for Zn8 when compred to the control. While with incresing quntity of cly in soil, uptke decresed y 1.08 mg kg 1 nd 3.88 mg kg 1 in SCL nd C respectively when compred to the SL soil. There ws liner reltionship etween Cu pplied nd the Zn concentrtion in whet grins with R 2 vlue 0.93 (Fig. 4) in ll the three soils. The correltion etween Zn pplied nd resulting concentrtions of Zn in whet grins ws liner for SCL (R 2 = 0.97) wheres R 2 vlues dropped to 0.86 nd 0.78 for SL nd C soils respectively. The reltionship etween slinity/sodicity nd micronutrient nutrition is complex nd these stresses cn increse, decrese, or hve no effect on the micronutrient concentrtion in plnt shoots (Grttn & Grieve, 1999). Copper (CuSO 4 ) ppliction incresed Cu concentrtion

6 2438 M. ARSHAD ET AL., in plnt roots nd tops in whet crop (Chudhry & Lonergn, 1970). Mlhi et l., (2005) nd Brennn & Bollnd (2003) reported tht copper concentrtion in dried shoots of whet incresed with incresing Cu pplied to the whet crop. A liner increse in Zn concentrtion in plnt prts with incresing supplies of Zn fertilizer ws lso reported y Imtiz et l., (2003). Retention of Cu y the solid phse of the soil nd in consequence its iovilility depends on prticle-size distriution: metl enrichment in the cly frction is generlly oserved (Besnrd et l., 2001; Dumt et l., 2006). In high cly content nd dispersed structure due to high N + in soil, Zn 2+ ions might well e fixed tightly nd unville for plnts (Pendis & Pendis, 1992). Copper nd zinc reltionship: A reciprocl effect for oth Cu nd Zn ws oserved with single ppliction of either Cu or Zn. Both metls incresed the vilility of ech other resulting in enhnced concentrtions compred to when the individul element ws pplied. The uptke of Cu ws incresed to 2.33 nd 2.20 mg kg 1 in strw nd grins respectively. Zinc concentrtion incresed with incresing levels of Cu up to 6.35 nd 7.08 mg kg 1 DW in strw nd grins respectively. Comprtively, Cu is more electropositive nd therefore more strongly ound t exchnge sites thn Zn. Copper lso hs the ility to replce Zn on exchnge site resulting in incresed concentrtions of Zn in soil solution since Cu nd Zn compete for the sme exchnge sites in soil (Pendis & Pendis, 1992). Kusr & Hmid, (1998) reported tht oth Cu nd Zn increse soluility of ech other in soil solution y depressing their fixtion on soil components. According to Tni & Brrington (2005), incresing levels of Cu significntly incresed Zn uptke y the plnt shoots, grins nd roots, while the higher level of Zn only slightly decresed Cu uptke, except in the root where Zn significntly incresed Cu uptke. However, using young rley plnts, Beckett & Dvis (1978) oserved tht Cu slightly reduced Zn uptke, wheres with whet, Zn ws found to reduce Cu uptke. Luo & Rimmer (1995) lso found similr effects with plnts grown in soils irrigted with wter ering, singly or in comintion, Zn t 0, 10, nd 100 mg L -1 nd Cu t 0 nd 50 mg L -1. Criticl exmintion of pst reserch revels tht Cu-Zn interction remins inconclusive ecuse pst reserch hs een conducted using rnge of different experimentl conditions including the type of soil, field or pot studies, hydroponics nd presence of multiple elements. Creful mngement of these two essentil nutrients cn ensure sustinle production without cusing ny dmge to the environment y leching t toxic levels, prticulrly in sline soils where the plnts re lredy under stress conditions. Conclusion Soil texture ppered to e n importnt prmeter ffecting growth of whet nd vilility of Cu nd Zn in sline-sodic soils to whet plnts. Appliction of Cu nd Zn to whet in different textured sline-sodic soils significntly incresed crop growth nd whet nutrient qulity. Copper ppliction incresed Zn concentrtions in whet suggesting its higher tendency towrds inding sites, susequently mking Zn more ville to plnts. Our results indicte tht creful considertion of soil texture is needed while plnning for fertilizer requirements in sline-sodic soils. Acknowledgments The uthors re thnkful to Directorte of Reserch, University of Agriculture, Fisld, Pkistn for the finncil support to conduct this reserch. We especilly thnk to Dr. Att Muhmmd Rnjh, Professor, Institute of Soil nd Environmentl Sciences, University of Agriculture, Fisld, Pkistn for his expert opinion nd guidnce throughout the study. We lso thnk Dr. Gry Owens, Centre for Environmentl Risk Assessment nd Remedition, for reding this mnuscript prior to sumission nd for mking mny helpful suggestions nd corrections. References Ali, Z., A. Slm, F.M. Azhr nd I.A. 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