Zinc and Boron Fertilization on Concentration and Uptake of Iron and Manganese in the Corn Grain

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1 Journl of Americn Science 2010;6(8) Zinc nd oron Fertiliztion on Concentrtion nd Uptke of Iron nd Mngnese in the Corn Grin Frshid Aref 1 1 Deprtment of Soil Science, Fculty of Agriculture, Islmic Azd University of Firouzd, Irn Tel: frshidred@yhoo.com Astrct: A frm experiment with mize plnt grown on Zn nd deficient soil ws conducted to study the effect of Zn nd interction on the concentrtion nd totl uptke of Fe nd Mn in corn grin during 2009 t Frs Province, Irn. Tretments including five levels of Zn (0, 8, 16 nd 24 kg h -1 nd Zn folir spry) nd four levels of (0, 3, nd 6 kg h -1 nd folir spry) in completely rndomized lock design were set up. The findings showed tht the effects of Zn nd nd the interction of Zn nd on the Fe concentrtion in the grin were insignificnt. The effect of Zn on Fe uptke in the grin ws insignificnt nd mong different levels of, only ppliction of 3 kg/h incresed Fe uptke in the grin. oron use hd no effect on Fe uptke in the grin in ny level. Only t high level of (6 kg/h ), ppliction of 16 kg/h Zn incresed Fe uptke in the grin. oron use nd Zn nd interction ws not significnt on Mn concentrtion in the grin. Appliction of 24 kg/h Zn incresed Mn concentrtion in the grin from 3.67 to 4.75 mg/kg ut other levels of Zn hd no effect. Appliction of Zn to the soil nd sprying it incresed Mn uptke in the grin. Appliction of to the soil incresed Mn uptke in the grin ut sprying hd no effect on it. Appliction of t low levels nd Zn sprying hd no effect on Mn uptke in the grin ut t higher Zn levels (16 nd 24 kg/h Zn) incresed Mn uptke in the grin. Appliction of Zn t zero nd 6 kg/h levels incresed Mn uptke in the grin ut t other levels, it hd no significnt effect on Mn uptke. [Journl of Americn Science 2010;6(8): ]. (ISSN: ). Keywords: Interction, zinc, oron, iron, mngnese, concentrtion, corn grin 1. Introduction Zinc (Zn) deficiency is very importnt nutrient prolem in the world s soils. Totl Zn concentrtion is in sufficient level in mny griculturl res, ut ville Zn concentrtion is in deficient level ecuse of different soil nd climtic conditions. Soil ph, lime content, orgnic mtter mount, cly type nd mount nd the mount of pplied phosphorus fertilizer ffect the ville Zn concentrtion in soil (Adiloglu et l., 2006). Zinc deficiency rte ws determined s 30 % in the world (Sillnp, 1982). The interction mong nutrient elements is very importnt for plnt nutrition. oron x Zn interction mong these interctions hs een curicil in the Zn deficient soils, in recent yers (Alkn et l., 1998). Plnt root cell memrne permeility increses in Zn deficient soils[5], which my led to ccumulte nd other nutrient elements in plnt roots. Therefore, excess uptkes y plnts my cuse toxicity for the plnts in this soil conditions (Singh et l., 1990). Zinc nd Fe re ntgonistic; of course this is not lwys the cse nd even in some cses they re comined nd used, they cn ply useful nd effective role on plnt growth nd increse in the hrvest (yordi et l., 2000; Hghni et l., 1989). when the corn plnt is under Zn stress, it sors lrge mount of Fe nd Mn, worsening the dverse effects of Zn deficiency (Tisdle et l., 1993; Wrnocke et l., 1973). Moreover, n interction exists etween nd Mn; high content leds into ppernce of signs of Mn deficiency in the plnt. For uptke, N nd K must e present in desired mounts. An Fe- ntgonism s well hs een reported. Of course, in deficiency conditions, uptke incresed y dding Fe. Also, n ntgonism etween nd Fe in the plnt hs een oserved (Slrdini, 1994). Kumr et l. (1981) reported tht dding Zn to the soil reduced the plnt Fe, Mn nd Cu nd incresed plnt Zn content. Concurrent Zn nd Fe ppliction delyed plnt ging nd incresed the grin crohydrte content (Hemntrnjn nd Gry, 1988). Zinc use, y incresing hrvest, reduces the concentrtion of other elements, including Fe nd Mn, due to the dilution effect (Rengel nd Grhm, 1995). Ming nd Yin (1992) reported tht the use of ech of fertilizers contining Zn nd Mn, reduced the concentrtions of other elements. Grhm et l. (1987) reported tht whenever the soil Zn content reduced, the rley plnt P, K nd Cu content incresed while its Fe content ws not ffected. Prker et l. (1992) showed tht Zn ppliction incresed plnt Mn content ut hd no effect on its Fe nd Cu contents. Mozfr (1987), y studying the effects of 12 nutrients on corn grining, oserved tht the corn er Zn,, Cu, Mn, c, Mg, N, P, K nd sodium contents nd unripe er stem Zn,, Fe, Cu, Mn, molydenum, c nd P contents hd the sme sttus nd showed no significnt difference. Studies mde on whet showed tht y increse in whet grin Zn content, the grin K, c, Mn nd Fe decresed, significntly editor@mericnscience.org

2 Journl of Americn Science 2010;6(8) while the grin N, P, Cu, nd Zn content incresed nd Mg content did not chnge (Ming nd Yin, 1992). According to Rengel nd Grhm (1995) report, y increse in whet grin Zn content, Fe, Mn, Cu,, c, Mg, sodium, K nd P contents decresed. Touchton nd oswell (1975), in study on the effect of on the corn oserved tht y ppliction, the plnt content incresed ut the Fe, Zn, Mn, Cu, P nd K contents did not chnge. Considering the numerous pplictions of corn in humn, niml nd poultry nutrition nd extrction of out 500 different products from it, richness of its grin in Fe nd Mn elements plys n effective role in the humn helth. Also, the grin's eing rich in these elements reflects n increse in the grin hrvest, qulittively nd quntittively. Therefore, y studying the effect of Zn- interction on the grin, while enriching the grin, we cn use its indirect effects to know out its indirect effects, which re the increse in grin hrvest, qulittively nd quntittively. Moreover, it hs een estlished tht if grins rich in these elements re used d seeds, the hrvest will increse, qulittively nd quntittively. 2. Mterils nd Methods This reserch ws conducted in the field experiment of Firouz Ad University, Frs province of Irn, during April efore implementing the project smpling from the soil (0-30 cm depths) ws mde in order to select zone in which the ville mount of Zn nd ws low (less thn 1mg/kg extrcted y methods DTPA nd hot wter, respectively). This soil hd lom texture, ph of 8.4, 0.78 % orgnic mtter, 210 mg kg -1 exchngele potssium (K), 9.9 mg kg -1 ville phosphorus, DTPA extrctle Fe, Mn, Zn nd Cu concentrtion were 1.4, 6, 0.38 nd 1 mg kg -1 nd ville with hot wter extrctle ws 0.9 mg kg -1. For performing the experiment, 20 tretments in 3 replictions in the form of rndomized complete lock design nd fctoril were considered. The tretments used consisted of 5 levels Zn (0, 8, 16 nd 24 kg/h Zn nd Zn spry with 0.5 percent concentrtion) nd 4 levels (0, 3 nd 6 kg/h nd spry with 0.5 percent concentrtion). Nitrogen, P nd K, from sources of ure, triple super phosphte nd potssium sulfte t 350, 200 nd 200 kg/h, respectively, were dded to ll tretments (plots). Moreover, 50% of the ure ws used when plnting nd the reminder two times: At vegettive growth nd when the corn ers were formed. Zinc nd, from Zinc sulfte nd oric cid sources, respectively, were used y two methods, dding to the soil nd sprying. Addition to the soil ws mde t the time of plnttion nd the spryings were mde t 5 per thousnd (0.5%) Zinc sulfte nd 3 per thousnd (0.3%) oric cid two times: one t vegettive growth stge nd the other fter corn ers formtion. Ech experimentl plot ws 8m length nd 3m width, hd 5 eds nd 4 rows, eqully spced, nd seeds 20cm prt on the rows. Anlysis of the grin ws crried out using common l procedures. Phosphorous ws mesured y Olsen method, ville K y cette mmonium extrction method nd K ssessment in the extrct y flme photometer, orgnic cron y the Wlkley nd lck method. Aville Fe, Zn, Mn nd Cu in the soil were first extrcted y DTPA nd then were red y tomic sorption setup. The soil's ville ws extrcted y hot wter nd then ws mesured y spectrophotometer y Curcmin method, considering the intensity of the color produced. Digestion method y dry urning ws used to mesure Fe nd Mn, nd then they were mesured y tomic sorption setup. Sttisticl nlysis of dt ws mde using MSTATC nd SAS softwre with Duncn test nd regression equtions vi the SPSS progrm. 3. Result nd Discussion Soil test results from soil smples tken in the spring of 2008 re presented in Tle 1. Depth of soil (cm) Soil texture ph EC (ds m -1 ) Tle 1.The result of soil nlysis Orgnic mtter P K Fe Mn Zn Cu (%) mg kg Lom The grin Fe content Different Zn levels showed no significnt on the grin Fe content (mg/kg) (tle 2). Appliction of to the soil nd its sprying hd no effect on the grin Fe content reltive to no level ut sprying significntly decresed the grin Fe content reltive to ppliction to the soil (3 nd 6 kg/h ). The minimum nd the mximum grin Fe content, nd mg/kg, were oserved t sprying nd 3 kg/h levels, respectively, ut showed no significnt difference s compred with the no level. The Zn- interction effect on the grin Fe content ws insignificnt t 5% level editor@mericnscience.org

3 Journl of Americn Science 2010;6(8) Tle 2. The effect of Zn nd on Fe concentrtion in the grin (mg kg -1 ) Zn (kg h -1 ) (kg h -1 ) Folir Spry Men Folir Spry c Men *Mens with sme letters lck significnt difference t 5% level y Duncn's test 3.2. Iron uptke y the grin Different Zn levels showed no significnt on the Fe uptke y the grin (g/h) ut the min effect on Fe uptke ws significnt t 5% level (tle 3). The minimum men Fe uptke y the grin, g/h, ws t the sprying level ut showed no significnt difference reltive to the no level. Appliction of 3 kg/h significntly incresed Fe uptke y the grin, from to g/h (36.74 % increse reltive to no use); ut more use (6 kg/h ), showed no significnt difference from no nd 3 kg/h levels. oron sprying significntly reduced Fe uptke y the grin reltive to 3 kg/h ; ut showed no significnt difference from the no level. The mximum Fe uptke y the grin, g/h, ws seen t 3 kg/h level. The Zn- interction effect on Fe uptke y the grin showed tht ppliction left no significnt difference from the no use in ny of Zn levels. At high levels (6 kg/h ), only the use of 16 kg/h Zn incresed Fe uptke y the grin from to g/h (84.15 percent increse reltive to no Zn use t tht level). ut t other levels, Zn ppliction hd no significnt effect on Fe uptke y the grin. The mximum nd the minimum Fe uptke y the grin, nd g/h, were seen y ppliction of 24 kg/h Zn + 3 kg/h nd 6 kg/h, respectively; showing % increse nd % decrese reltive to the control, with n uptke of g/h, respectively. No tretment, including those with the mximum nd the minimum Fe uptke y the grin, showed significnt difference from the control. Tle 3. The effect of Zn nd on Fe uptke y the grin (gr h -1 ) Zn (kg h -1 ) (kg h -1 ) Folir Spry Men A c Folir Spry Men *Mens with sme letters lck significnt difference t 5% level y Duncn's test 3.3. The grin Mn content Appliction of Zn t high level (24 kg/h Zn), incresed grin Mn content from 3.67 to 4.75 mg/kg (29.42% increse reltive to no level), ut the use of other Zn levels showed no significnt effect on the grin Mn content reltive to no Zn level (tle 4). The mximum nd the minimum men grin Mn content, 3.67 nd 4.75 mg/kg, were seen t no Zn nd 24 kg/h Zn levels, respectively. The use of different levels hd no significnt effect on the grin Mn content reltive to no level ut there ws significnt difference etween ppliction to the soil nd sprying; sprying significntly decresed grin Mn content reltive to 3 nd 6 kg/h levels. The minimum men grin Mn content, 3.73 mg/kg, ws seen t editor@mericnscience.org

4 Journl of Americn Science 2010;6(8) sprying level ut showed no significnt difference reltive to no level. The effect of Zn- interction on grin Mn content ws not significnt t 5% level. Joint use of 6 kg/h nd 16 kg/h Zn mde the mximum increse in grin Mn content (6mg/kg) showing 100% increse reltive to the control (3 mg/kg). The minimum grin Mn content, 3 mg/kg, ws seen t no Zn nd use (control). Except for the tretment with the highest grin Mn content, other tretments showed no significnt difference from the control. Tle 4. The effect of Zn nd on Mn concentrtion in the grin (mg kg -1 ) Zn (kg h -1 ) (kg h -1 ) Folir Spry Men 0 3 c Folir Spry Men *Mens with sme letters lck significnt difference t 5% level y Duncn's test 3.4. Mngnese uptke y the grin Zinc ppliction t ll levels significntly incresed Mn uptke y the grin (g/h) reltive to the no Zn level (tle 5). The minimum nd the mximum Mn uptke y grin, nd g/h, were seen t no Zn nd 24 kg/h Zn levels, respectively. The use of 8, 16, nd 24 kg/h Zn, significntly incresed Mn uptke y the grin from t no Zn level to 39.53, nd g/h, respectively (43.53, nd % increse in tht order); ut there ws no significnt difference t ppliction to the soil levels. Zinc sprying incresed Mn uptke y the grin from to g/h, % increse reltive to no Zn level, ut showed no significnt difference from the Zn pplied to the soil level. Thus synergism ws seen etween Zn ppliction nd Mn uptke y the grin. The min effect of on Mn uptke y the grin ws significnt t 5% level. oron ppliction to the soil incresed Mn uptke y the grin reltive to no level ut sprying hd no significnt effect on Mn uptke. The minimum men Mn uptke y the grin, g/h, ws seen t no level. The use of 3 nd 6 kg/h, significntly incresed Mn uptke y the grin from to nd g/h, respectively (26.76 nd % increse reltive to no use, in tht order), ut there ws no significnt difference etween the two. oron sprying showed significnt reduction reltive to ppliction of to the soil. The Zn- interction effect on Mn uptke y the grin showed tht ppliction of Zn t low levels (0 nd 8 kg/h Zn) nd Zn sprying hd no effect on the Mn uptke y the grin ut t higher Zn levels (16 nd 24 kg/h Zn), it incresed Mn uptke y the grin. At 16 kg/h Zn, only the use of 6 kg/h incresed Mn uptke y the grin from 35.1 to 57.8 g/h (6% increse reltive to no use). The use of 3 kg/h t 24 kg/h Zn level, incresed Mn uptke y the grin from to g /h (75.7 % increse); ut other levels of hd no significnt effect. Zinc ppliction t zero nd 6 kg/h levels incresed Mn uptke y the grin ut t other levels (3 kg/h nd sprying) it hd no significnt effect on Mn uptke. At no level, only the use of 8 kg/h Zn incresed Mn uptke y the grin from 20.2 to g/h (118 % increse). At 6 kg/h s well, only ppliction of 16 kg/h Zn incresed Mn uptke y the grin from to 57.8 g/h (97 % increse). The lest Mn uptke y the grin, 20.2 g/h, ws y no Zn nd use (the control). The highest Mn uptke y the grin, 57.8 g/h, ws y joint use of 6 kg/h nd 16 kg/h Zn, 186 % increse reltive to the control editor@mericnscience.org

5 Journl of Americn Science 2010;6(8) Tle 5. The effect of Zn nd on Mn uptke y the grin (gr h -1 ) Zn (kg h -1 ) (kg h -1 ) Folir Spry Men d d d d d d d Folir Spry d Men *Mens with sme letters lck significnt difference t 5% level y Duncn's test 3.5. Correltion etween the concentrtion nd totl uptke of Fe nd Mn in grin with other vriles The correltion coefficients (R) etween different vriles y the Person method nd the relevnt equtions were otined y the step y step method using the SPSS softwre. One cn use ech of the following equtions depending on wht re the vriles mesured nd R nd R 2, ut the lst eqution derived, is the most complete eqution contining dependent nd independent vriles nd we must mesure more vriles to derive tht eqution. The symols * nd ** in equtions nd correltion coefficients (R or R 2 ), re significnce t 5% ( α = 0.05) nd 1% ( α = 0.01) levels The grin Fe content The grin Fe content showed positive correltion with the grin P content (R=0.35), nd the Fe uptke y the grin (R=0.89 ** ) nd negtive correltion with the lef K content (R= * ). The equtions of which were: 1) FeG = FeUG R = ** 2) FeG = FeUG TGY R 2 = ** 3) FeG = FeUG TGY FeL R 2 = ** 4) FeG = FeUG TGY FeL ZnG R 2 = ** 5) FeG = FeUG TGY FeL ZnG GTW R 2 = ** 6) FeG = FeUG TGY FeL ZnG GTW P R 2 = ** FeG, FeUG, TGY, FeL, ZnG, GTW nd P denote grin Fe content (mg/kg), Fe uptke y the grin (g/h), totl grin yield (kg/h), lef Fe content (mg/kg), grin Zn content (mg/kg), grin weight (g) nd grin protein content (%), respectively The grin Mn content There ws positive correltion etween grin Mn content nd the grin P content (R=0.35), Zn content (R=0.49 * ) nd content (R=0.61 ** ); the uptke of N (R=0.38), P (R=0.52 * ), K (R= 0.41), Fe (R= 0.47 * ), Mn (R= 0.94 ** ), Zn (R= 0.71 ** ) nd (R= 0.66 ** ) y the grin; totl grin yield (R= 0.46 * ), the numer of grins in the er length (R= 0.4) nd the numer of grins cross the er dimeter (R=0.45 * ), nd negtive correltion with lef content (R= -0.3) nd the percentge of grin in the er (R= -0.37). The relevnt equtions were: 1) MnG = MnUG R = ** 2) MnG = MnUG TGY R 2 = ** MnG, MnUG nd TGY re grin Mn content (mg/kg), Mn uptke y the grin (g/h) nd totl grin yield (kg/h), respectively The Fe uptke y the grin The Fe uptke y the grin showed positive correltion with the grin P content (R= 0.48 * ), Fe content (R= 0.89 ** ), Mn content (R= 0.47 * ) nd content (R= 0.45 * ); the uptke of N (R=0.31), P (R=0.49 * ), Mn (R=0.52 * ), Zn (R=0.35) nd (R=0.49 * ) y the grin; nd totl grin yield (R= 0.33) nd negtive correltion with lef K content (R=-0.43). The equtions were: 1) FeUG = FeG R = ** 2) FeUG = FeG TGY R 2 = ** 3) FeUG = FeG TGY FeL R 2 = 0.99 ** 4) FeUG = FeG TGY FeL ZnG R 2 = ** 5) FeUG = FeG TGY FeL ZnG GTW R 2 =0.996 ** 6) FeUG = FeG TGY FeL ZnG GTW P R 2 = ** FeUG, FeG, TGY, FeL, ZnG, GTW nd P re Fe uptke y the grin (g/h), grin Fe content (mg/kg), totl grin yield (kg/h), lef Fe content (mg/kg), grin Zn content (mg/kg), 1000-grin weight nd grin protein content (%), respectively The Mn uptke y the grin editor@mericnscience.org

6 Journl of Americn Science 2010;6(8) There ws positive correltion etween Mn uptke y the grin nd the lef Zn content (R= 0.31); grin P content (R= 0.43), Mn content (R= 0.94 ** ), Zn content (R= 0.35) nd content (R= 0.66 ** ); the uptke of N (R= 0.63 ** ), P (R= 0.73 ** ), K (R= 0.61 ** ), Fe (R= 0.52 * ), Zn (R= 0.76 ** ), Cu (R= 0.41) nd (R= 0.8**) y the grin; er weight (R= 0.48), grin weigh in the er (R= 0.42), totl grin yield (R= 0.71 ** ), the numer of grins in the er length (R=0.57 ** ), the numer of grins cross the er dimeter (R= 0.51 * ). The relevnt equtions were: 1) MnUG = MnG R = ** 2) MnUG = MnG TGY R 2 = ** 3) MnUG = MnG TGY UG R 2 = ** MnUG, MnG, TGY nd UG re Mn uptke y the grin (g/h), grin Mn content (mg/kg), totl grin yield (kg/h) nd uptke y the grin (g/h) 4. Conclusion The effects of Zn, (reltive to no level) nd the effect of Zn- interction on the grin Fe content were insignificnt. Zinc ppliction hd no effect on Fe uptke y the grin nd mong different levels, only ppliction of 3 kg/h significntly incresed Fe uptke y the grin. The effect on Fe uptke y the grin did not depend on the soil Zn content. Also, Zn ppliction only t high levels (6 kg/h ) incresed Fe uptke y the grin ut hd no effect t other levels. The effect (reltive to no level) nd the effect of Zn- interction on grin Mn content ws not significnt nd mong different Zn levels, only ppliction of 24 kg /h Zn incresed grin Mn content. The min Zn, nd Zn- interction effects on Mn uptke y the grin, ws significnt. Zinc ppliction t ll levels incresed Mn uptke y the grin. The minimum nd the mximum Mn uptke y the grin were seen t no Zn nd 24 kg/h Zn levels, respectively. oron ppliction to the soil incresed Mn uptke y the grin ut sprying hd no effect on it. The minimum men Mn uptke y the grin, g/h, ws seen t no level. Therefore, there ws synergism etween Zn nd Mn s well s nd Mn. oron use t high Zn levels (16 nd 20 kg/h Zn) incresed Mn uptke y the grin, ut t other Zn levels, no effect ws seen. Therefore, high Zn level helped with ffecting the increse in Mn uptke y the grin. Appliction of Zn t 0 nd 6 kg/h levels incresed Mn uptke y the grin ut hd no effect t other levels. References 1. Adiloglu A, Adiloglu S. The Effect of oron () Appliction on the Growth nd Nutrient Contents of Mize in Zinc (Zn) Deficient Soils. Reserch Journl of Agriculture nd iologicl Sciences 2006: 2(1): Alkn A, Torun, Özdemir A, ozy G, Çkmk I. Effect of zinc on oron toxicity different whet nd rley cultivrs. Ntionl Zinc Congress, My, EskiÕehir, Turkey, 1998: yordi M, Mlkouti MJ. Amirmokri H, Nfisi M. Optiml chemicl fertilizer production nd use towrds the ojectives of sustined griculture. First edition, griculturl eduction pulishing, Irn Grhm RD, Welch RM, Grunes DL, Cry EE, Norvell WA. Effect of zinc deficiency on the ccumultion of oron nd other minerl nutrients in rley. Soil Sci. Soc. Am. J. 1987: 51: Hghni G, Rizi Hmedni SA. Principles nd views on plnt minerl nutrition. first edition, Tehrn University Press Center, Irn, Hemntrnjn A, Gry OK. Iron nd zinc fertiliztion with reference to the grin qulity of Triticum estivum L. J. Plnt Nutr. 1988: 11: Krimin N. Effect of N nd phosphorus on zinc nutrition of corn in clcreous soil. J. Plnt Nutr. 1995: 18: Kumr V, hti K, Shukl UC. Mgnesium nd zinc reltionship nd uptke of nutrients in whet. Soil Sci. 1981: 131: Meht VS, Singh V, Singh R. Evlution of some soil test methods for ville sulfur in some lluvil soils. J. Indin Soc. Soil Sci. 1988: 39: Ming C, Yin CR. Effects of Mn nd Zn - fertilizers on nutrient lnce nd deficiency dignosis of winter whet crop in pot experiment. In: Portch S, ed. Interntionl Symposium on the Role of Sulphur, Mgnesium, nd Micronutrients in lnce Plnt Nutrition. Sulphur Institute, Wshington, USA. 1992: Mozfr A. Review of mjor cuses including minerl nutrient deficiency. J. Plnt Nutr. 1987: 10: Pls I, enton JJ. The hnd ook of trce elements. Stloeie Pu. Co. Florid, USA Prker R, Agniler JJ, Thmson DN. Zinc phosphorus interctions in two cultivrs of tomto (Lycopersicon eseulentum L.) grown in cheltor uffered nutrient solutions. Plnt Soil, 1992: 143: Rengel Z, Grhm RD. Importnce of seed Zn - content for whet growth on editor@mericnscience.org

7 Journl of Americn Science 2010;6(8) zinc deficient soil. II. Grin yield. Plnt Soil, 1995: 173: Slrdini AA, Mojthedi M. Principles of plnt nutrition, volume one, fundmentl spects, Tehrn University Press, Irn, Sillnp M. Micro nutrients nd the nutrient sttus of soils. A glol study. FAO Soils ulletin, No: 48, FAO, Rome, Itly, Singh JP, Dhiy DJ, Nrwl RP. oron uptke nd toxicity in whet in reltion to zinc supply. Fertilizer Reserch, 1990:24: Tisdle SL, Nelson WL, eton J. Soil Fertility nd Fertilizers. 5th ed. Mcmilln Pu. Co, New York, Touchton JT, oswell FC. oron ppliction for corn growth on selected Southestern soils. Agron. J. Res. 1975: 32(4): Wrnocke DD, rer SA. Diffusion of zinc in soils. III. Reltion of zinc dsorption isotherm. Soil Sci. Soc. Am. Proc. 1973: 37: /5/ editor@mericnscience.org