Root Zn Concentrations Research Articles

Interaction Effects of Zinc and Manganese on Growth, Uptake Response and Chlorophyll Content of Sweet Corn (Zea mays var. saccharata)

Manganese (Mn) and Zinc (Zn) interact with each other and this interaction can result in impacts on the yield of corn plants. This study was conducted to examine the effect of different levels of Mn and Zn on the yield, Mn and Zn concentration, root growth parameters and chlorophyll contents of corn plants. Sweet corn was grown in nutrient culture containing all combinations of Zn and Mn at levels of 0.0, 0.1, 1.0 and 10.0 mg L-1 as ZnSO4.7H2O and MnSO4.H2O, respectively and harvested at 28 days after transplanting. Mn and Zn concentrations in roots and shoots increased with increasing Mn and Zn concentration in nutrient solution. Zn concentration in both roots and shoots enhanced with increasing Mn levels. Mn concentration in shoots did not show any correlation with Zn concentration in nutrient solution, but Mn concentration in roots decreased with increasing levels of Zn. Zn0Mn1 treatment produced the highest yield. The lowest dry weight of young corn plants was recorded under Zn10Mn0 treatment due to Mn deficiency. Chlorophyll content decreased with high Zn application and this can be attributed to the interaction of Zn with iron in the growth medium. Different levels of Zn and Mn in nutrient solution did not have any significant effect on root parameters.

Feasibility of enhanced phytoextraction of Zn contaminated soil with Zn mobilizing and plant growth promoting endophytic bacteria

Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S. alfredii rhizosphere soils under Zn stress and resulted in better plant growth, as roots biomass increased from 80% to 525% and shoot biomass from 11% to 47% compared with the uninoculated ones. Strains IV8L2, II8L4 and IV8R2 significantly increased shoot and root Zn concentrations in the ZnCO3 contaminated soil. Inoculation with strain IV8L2 resulted in 44% and 39% higher shoot and root Zn concentrations, while strain IV8R2 significantly decreased shoot Zn concentration in the Zn3(PO4)2 contaminated soils. In the aged contaminated soil, isolates IV8L2, II8L4 and IV8R2 significantly increased root Zn concentration, but decreased shoot Zn concentration of Sedum alfredii. It suggested that endophytes might be used for enhancing phytoextraction efficiency.

Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31μM Cu), 5–50μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola.

Accumulation and Tolerance Characteristics of Zinc in Agropyron cristatum Plants Exposed to Zinc-Contaminated Soil

In phytoremediation, plants are used to stabilize or remove toxins from soil. In this study, a pot experiment was conducted in a greenhouse to evaluate the phytoremediation potential of Agropyron cristatum (Poaceae) grown on Zinc (Zn) contaminated soils. Results indicated that Zn accumulation in both shoots and roots increased with soil Zn concentration, and Zn concentrations in roots were greater than in shoots. A significantly negative correlation was found between translocation factor or bioconcentration factor values and Zn concentrations in soil. Overall, A. cristatum was Zn excluder with an innate capacity to tolerate Zn stress and may have potential for the phytostabilization of sites contaminated with Zn.

Zinc accumulation patterns in four Anthyllis vulneraria subspecies supplemented with mineral nitrogen or grown in the presence of their symbiotic bacteria

Aims This work examines Zn accumulation in four Anthyllis vulneraria subspecies supplemented with mineral nitrogen or grown in the presence of their symbiotic bacteria. Methods Anthyllis vulneraria subspecies were grown hydroponically in the presence of high levels of ZnSO4. The plants were either grown in symbiosis with one of two non-metallicolous or metallicolous Mesorhizobium inoculants or in the presence of KNO3. Results When exposed to 1,000 μM Zn, shoot and root biomass of three out of our four Anthyllis subspecies cultivated with NO3 dropped significantly by about 24–28 %; carpatica, the fourth subspecies, was not affected. Subspecies carpatica Zn tolerance was confirmed when in symbiosis with the metallicolous strain. In the presence of 1,000 μM Zn, the different Anthyllis subspecies concentrated more Zn in their roots than in their shoots and only subsp. carpatica accumulated a significant amount of Zn in its shoots. The most remarkable feature was the drastic decrease in Zn concentration in both roots (up to 2.5–3 fold) and shoots (2.6-fold) of subsp. carpatica exposed to 1,000 μM Zn and nodulated whatever the Mesorhizobium strain used, compared to the N-grown plants.

Effects of vegetative-periodic-induced rhizosphere variation on the uptake and translocation of metals in Phragmites australis (Cav.) Trin ex. Steudel growing in the Sun Island Wetland

To evaluate the vegetative periodic effect of rhizosphere on the patterns of metal bioaccumulation, the concentrations of Mg, K, Ca, Mn, Zn, Fe, Cu, Cr, Ni, Cd and Pb in the corresponding rhizosphere soil and tissues of Phragmites australis growing in the Sun Island wetland (Harbin, China) were compared. The concentrations of Zn, Fe, Cu, Cr, Ni, Cd and Pb in roots were higher than in shoots, suggesting that roots are the primary accumulation organs for these metals and there exists an exclusion strategy for metal tolerance. In contrast, the rest of the metals showed an opposite trend, suggesting that they were not restricted in roots. Harvesting would particularly be an effective method to remove Mn from the environment. The concentrations of metals in shoots were generally higher in autumn than in summer, suggesting that Ph. australis possesses an efficient root-to-shoot translocation system, which is activated at the end of the growing season and allows more metals into the senescent tissues. Furthermore, metal bioaccumulation of Ph. australis was affected by vegetative periodic variation through the changing of physicochemical and microbial conditions. The rhizospheric microbial characteristics were significantly related to the concentrations of Mg, K, Zn, Fe and Cu, suggesting that microbial influence on metal accumulation is specific and selective, not eurytopic.

Organic acids are not specifically involved in the nitrate-enhanced Zn hyperaccumulation mechanism in Noccaea caerulescens

Nitrogen form has been shown to affect Zn uptake, translocation and storage in the Zn-hyperaccumulating plant Noccaea caerulescens but the biochemical processes are not fully understood. Organic acids and amino acids have been implicated in Zn transport and storage. This study aimed to examine the effect of N form on concentrations of organic acids and amino acids and how these metabolites correlated with Zn hyperaccumulation. Plants were grown in nutrient solution with NO3−, NH4NO3 or NH4+, supplied with 50 or 300μM Zn, and buffered at either pH 4.5 or 6.5. The metabolomic profile was determined by gas chromatography mass spectroscopy. The concentration of Zn in shoots, xylem and roots was greatest for the NO3−, pH 6.5 and 300μM Zn treatments. For all N forms, the lower growth-medium pH raised xylem sap pH but had no influence on Zn concentration or exudation rate of the xylem sap. Nitrate enhanced organic acid production while NH4+ increased amino acid production. Organic acids in the xylem were more responsive to changes in growth-medium pH than N form, and did not correlate with Zn concentration in shoots, roots or xylem. Serine might be directly involved in Zn hyperaccumulation. Phosphoric acid was associated with reduced Zn accumulation in the shoots. Malic acid was not detected in the shoots but responded to cation uptake more than to Zn specifically in the roots. Citric acid responded to cation uptake more than to Zn specifically in the shoots but did not correlate with Zn concentration in the roots or the xylem sap, or any other cations in the roots. In conclusion, organic acids in N. caerulescens are not specifically involved in Zn hyperaccumulation but are involved in regulating pH in the xylem and cation–anion balance in plants.

Effect of compost and manure amendments on zinc soil speciation, plant content, and translocation in an artificially contaminated soil

The addition of organic matter in soil can modify the bioavailability of heavy metals. A greenhouse pot experiment was carried out using an edible plant species Eruca vesicaria L. Cavalieri grown on an artificially contaminated soil with Zn (665 mg kg(-1)). In this study, the effect of compost at 20 t ha(-1) (C20) and at 60 t ha(-1) (C60), manure at 10 t ha(-1) (M10) and at 30 t ha(-1) (M30), and chemical fertilizers (NPK) on Zn fate in a soil-plant system was evaluated. At the end of the experiment, the main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original Community Bureau of Reference sequential extraction and diethylene triamine pentaacetic acid extraction. Zinc, though an essential element for plant growth, caused toxicity effects in plants grown on control and manure treatments, while in the compost treatments, plants showed no visual toxicity symptoms. The concentrations of Zn in roots were similar for all treatments, while significant differences were observed for shoots. In fact, in the compost treatments, plants showed the lowest Zn concentration in shoots. Zinc speciation seems not to be affected by the applied treatments. Indeed, Zn plant content and translocation to shoots seems to be affected. Compost amendments significantly reduced Zn content and translocation in comparison to other treatments.

CRITICAL DEFICIENCY LEVEL OF ZINC FOR CORN ON CALCAREOUS SALT-AFFECTED SOILS IN CENTRAL IRAN

A greenhouse experiment with 11 soil series and two zinc (Zn) rates (0 and 15 mg Zn kg−1 as zinc sulfate) was performed to determine critical deficiency level of Zn for corn (Zea mays L.) on calcareous salt-affected soils in central Iran. In addition, the most important soil properties affecting Zn phytoavailability were determined. Critical Zn deficiency levels were determined using the Cate-Nelson and Mitscherlich procedures. In most soils, application of Zn increased the dry matter yield, and Zn concentration and content in the shoot and root of corn. A positive correlation was observed between the soil electrical conductivity (EC) with Zn concentration in shoots, roots and whole plant while shoot Zn content was negatively correlated with buffer capacity of Zn in soil. Critical deficiency levels of Zn in soil for corn based on the Cate-Nelson and Mitscherlich method were 1.35 and 1.23 mg kg−1 for diethylenetriaminepentaacetic acid (DTPA)-extracted soil Zn, respectively.

Micronutrients reduce root rot in red clover (Trifolium pratense)

Red clover (Trifolium pratense) is an important component of mixed grass-legume leys; however, fungal root rot decreases red clover viability over time. Application of micronutrients may be one option to reduce the severity of the pathogens causing root rot. This study investigated the relationship between micronutrient (B, Cu, Mn, Zn) concentrations in red clover roots and the development of root rot, and examined whether the addition of micronutrients reduced root rot development. A field study was performed in 2009 to determine root rot incidence in red clover plants collected from four different field leys and a pot experiment was conducted in 2010 to determine the effect of micronutrient application (B, Cu, Mn, Zn) on root rot development in red clover. Disease severity index (DSI) and nutrient concentrations were determined in the plants.

Effect of different arbuscular mycorrhizal fungal isolates on growth and arsenic accumulation in Plantago lanceolata L.

The role of indigenous and non-indigenous arbuscular mycorrhizal fungi (AMF) on As uptake by Plantago lanceolata L. growing on substrate originating from mine waste rich in As was assessed in a pot experiment. P. lanceolata inoculated with AMF had higher shoot and root biomass and lower concentrations of As in roots than the non-inoculated plants. There were significant differences in As concentration and uptake between different AMF isolates. Inoculation with the indigenous isolate resulted in increased transfer of As from roots to shoots; AMF from non-polluted area apparently restricted plants from absorbing As to the tissue; and plants inoculated with an AMF isolate from Zn–Pb waste showed strong As retainment within the roots. Staining with dithizone indicated that AMF might be actively involved in As accumulation. The mycorrhizal colonization affected also the concentration of Cd and Zn in roots and Pb concentration, both in shoots and roots.

SILICON NUTRITION AND PHYTOPHTHORA DRECHSLERI INFECTION EFFECTS ON GROWTH AND MINERAL NUTRIENTS CONCENTRATION, UPTAKE, AND RELATIVE TRANSLOCATION IN HYDROPONIC-GROWN CUCUMBER

A hydroponic experiment was performed to investigate silicon (Si) and Phytophthora drechsleri root rot effects on growth and tissue partitioning of Si, zinc (Zn), iron (Fe), and manganese (Mn) in two cucumber cultivars (Cucumis sativus L. cvs. ‘Dominus’ and ‘Super Dominus’). Root length, plant height, and root fresh weight were significantly decreased by P. drechsleri, which were all significantly alleviated by 1.0 mM Si. Increasing Si level in the nutrient solution was accompanied with its enhanced uptake by cucumbers. Plants infected with P. drechsleri transported lower Mn to shoot than non-infected plants. Influence of P. drechsleri infection on root Fe concentration was dependent on cucumber cultivar while a decrease in root Zn concentration was found in infected cucumbers. Silicon nutrition increased Zn and Fe uptake in both cucumber cultivars. It is suggested that Si nutrition improved the crop growth, particularly under biotic stress, and hereby, increased micronutrients uptake by cucumber.

Hyperaccumulation of zinc by Corydalis davidii in Zn-polluted soils

A field survey was conducted to identify potential Zn accumulators from an artisanal Zn smelting area in southwest China’s Guizhou Province. Hydroponic and soil culture experiments were performed to investigate the accumulation ability of Zn in Corydalis davidii. Zn concentrations in roots, stems and leaves of C. davidii in the smelting site were 1.1–3.5, 1.2–11.2, and 3.3–14mgg−1, respectively, whereas Zn concentrations in roots, stems and leaves of C. davidii in the contaminated site impacted by the Zn smelting were 1.0–2.4, 1.9–6.5, and 3.0–1.1mgg−1, respectively. Zn concentrations in leaves and stems of C. davidii were observed at above 10mgg−1 that refers to the threshold of Zn hyperaccumulator. The concentration distribution of Zn in C. davidii was leaf>stem>root, and the Zn bioaccumulation factors of C. davidii were above 1. It is concluded that C. davidii has high tolerance to concentrate Zn stress, and that C. davidii is a newly discovered Zn-hyperaccumulator with high biomass in the aboveground parts. Based on the cultivation experiments, C. davidii could reduce Zn concentration by 26.6, 21.2, and 10.2mgkg−1yr−1 by phytoextraction from the smelting slag, Zn-contaminated soil, and background soil, respectively.

Effects of zinc activity in nutrient solution on uptake, translocation, and root export of cadmium and zinc in three wheat genotypes with different zinc efficiencies

The interactions of zinc (Zn) and cadmium (Cd) in uptake and translocation are common but not consistent. We hypothesized that Cd2+ and Zn2+ activity in the apoplasmic solution bathing root-cells could affect Zn accumulation in plants dependent on the wheat genotype. This hypothesis was tested using seedlings of two bread wheat genotypes (Triticum aestivum L. cvs. Rushan and Cross) and one durum wheat genotype (Triticum durum L. cv. Arya) with different Zn efficiencies grown in chelate-buffered nutrient solutions with three Zn2+ (10−11.11, 10−9.11, and 10−8.81 µM) and two Cd2+ (10−11.21 and 10−10.2 µM) activity levels. Increasing Zn2+ activity in the nutrient solution significantly increased Zn concentration in root and shoots of all three wheat genotypes, although the magnitude of this increase was dependent on the genotype. Cadmium decreased Zn concentration in roots of “Cross” while it had no significant effect on root Zn concentration in “Rushan.” At Zn2+ = 10−11.11 µM, Cd decreased shoot Zn concentration in “Arya” whereas it increased shoot Zn concentration at Zn2+ = 10−8.81 µM. Cadmium increased shoot Zn concentration of “Rushan” and “Cross” at Zn2+ = 10−8.81 µM but it had no significant effect on shoot Zn concentration of these genotypes at Zn2+ = 10−11.11 µM. The zinc-inefficient genotype “Arya” accumulated significantly more Cd in its root in comparison with “Cross” and “Rushan.” Cadmium concentration in roots of “Arya” was decreased significantly with increasing Zn activity. The effect of Zn on accumulation of Cd in roots of “Cross” and “Rushan” was dependent on the dose provided, and therefore, both synergistic (at Zn2+ = 10−9.11 µM) and antagonistic (at Zn2+ = 10−8.81 µM) interactive effects were found in these genotypes. Zinc supply increased the Zn concentration of xylem sap in “Cross” and “Rushan” whereas Zn content in xylem sap of “Arya” was decreased at Zn2+ = 10−9.11 µM and thereafter increased at Zn2+ = 10−8.81 µM. Cadmium treatment reduced Zn concentration in xylem sap of “Arya,” while it tended to increase Zn content in xylem sap of “Cross.” At Zn-deficient conditions, greater retention of Zn in root cell walls of Zn-inefficient “Arya” resulted in lower root-to-shoot transport of Zn in this genotype. Results revealed that the effect of Cd on the root-to-shoot translocation of Zn via the xylem is dependent on wheat genotype and Zn activity in the nutrient solution.

Predicting Al, Cu, and Zn concentrations in the fine roots of trembling aspen (Populus tremuloides) using bulk and rhizosphere soil properties

We compared the predictions of Al, Cu, and Zn concentrations in fine roots of trees using properties of the bulk and rhizosphere soils to find the best approach to assess the ecological risks of metals to trees. Predictions were made from 18 trembling aspens ( Populus tremuloides Michx.) equally distributed on six sampling sites using multiple linear regressions with soil Al, Cu, and Zn speciation data and chemical and microbial properties as explanatory variables. Fine root Al, Cu, and Zn concentrations ranged, respectively, from 2137 to 7480, from 7.03 to 206, and from 41.2 to 360 µg·g dry root mass–1. No significant prediction was obtained for Al. The soil total water-soluble Cu and Zn concentrations better predicted the metal concentrations in fine roots than the concentration of labile metal species. The concentrations of reactive Zn, water-soluble organic C, and NH4+ together with microbial biomass of N were the other significant explanatory variables. The best regression models for Cu and Zn were obtained in the rhizosphere and explained, respectively, 79.2% and 95.7% of the variation of metal concentrations in fine roots. This work pointed out that the rhizosphere properties and processes need to be considered to correctly assess the ecological risks of metals to tree.

Zinc availability of two wheat cultivars in soil amended with organic and inorganic Zn sources

-1 ) was applied to the soil at three rates of 25 (V 1), 50 (V 2), and 100 Mg ha - 1 (V 3). To compare the effects of organic and inorganic sources, similar rates of Zn as zinc sulphate (ZnSO 4) were also applied (Zn 1, Zn 2 and Zn 3, respectively). An untreated soil sample was considered as control soil (V 0). In general, cultivation of wheat plant (cv. Backcross) resulted in a lower Zn uptake relative to the Alvand cultivar. However, the plants Zn concentration of both cultivars depended on the rate and type of the applied manure (organic or inorganic sources). Both cultivars showed that plants grown in soil treated with ZnSO 4 accumulated significantly greater Zn in their root tissue compared to those grown in soil treated with cow manure. A significant increase in the shoot, spike and root Zn concentration was observed as the loading rate of cow manure increased. The results of this experiment point to the fact that the source of fertilizer, type of the plant and the loading rate of Zn are important factors in determining Zn phytoavailability.

Physiological limits to zinc biofortification of edible crops.

It has been estimated that one-third of the world’s population lack sufficient Zn for adequate nutrition. This can be alleviated by increasing dietary Zn intakes through Zn biofortification of edible crops. Biofortification strategies include the application of Zn-fertilizers and the development of crop genotypes that acquire more Zn from the soil and accumulate it in edible portions. Zinc concentrations in roots, leaves, and stems can be increased through the application of Zn-fertilizers. Root Zn concentrations of up to 500–5000 mg kg−1 dry matter (DM), and leaf Zn concentrations of up to 100–700 mg kg−1 DM, can be achieved without loss of yield when Zn-fertilizers are applied to the soil. It is possible that greater Zn concentrations in non-woody shoot tissues can be achieved using foliar Zn-fertilizers. By contrast, Zn concentrations in fruits, seeds, and tubers are severely limited by low Zn mobility in the phloem and Zn concentrations higher than 30–100 mg kg−1 DM are rarely observed. However, genetically modified plants with improved abilities to translocate Zn in the phloem might be used to biofortify these phloem-fed tissues. In addition, genetically modified plants with increased tolerance to high tissue Zn concentrations could be used to increase Zn concentrations in all edible produce and, thereby, increase dietary Zn intakes.

Effects of elevated CO2 concentrations and fly ash amended soils on trace element accumulation and translocation among roots, stems and seeds of Glycine max (L.) Merr.

The carbon dioxide (CO2) levels of the global atmosphere and the emissions of heavy metals have risen in recent decades, and these increases are expected to produce an impact on crops and thereby affect yield and food safety. In this study, the effects of elevated CO2 and fly ash amended soils on trace element accumulation and translocation in the root, stem and seed compartments in soybean [Glycine max (L.) Merr.] were evaluated. Soybean plants grown in fly ash (FA) amended soil (0, 1, 10, 15, and 25% FA) at two CO2 regimes (400 and 600ppm) in controlled environmental chambers were analyzed at the maturity stage for their trace element contents. The concentrations of Br, Co, Cu, Fe, Mn, Ni, Pb and Zn in roots, stems and seeds in soybeans were investigated and their potential risk to the health of consumers was estimated. The results showed that high levels of CO2 and lower concentrations of FA in soils were associated with an increase in biomass. For all the elements analyzed except Pb, their accumulation in soybean plants was higher at elevated CO2 than at ambient concentrations. In most treatments, the highest concentrations of Br, Co, Cu, Fe, Mn, and Pb were found in the roots, with a strong combined effect of elevated CO2 and 1% of FA amended soils on Pb accumulation (above maximum permitted levels) and translocation to seeds being observed. In relation to non-carcinogenic risks, target hazard quotients (TQHs) were significant in a Chinese individual for Mn, Fe and Pb. Also, the increased health risk due to the added effects of the trace elements studied was significant for Chinese consumers. According to these results, soybean plants grown for human consumption under future conditions of elevated CO2 and FA amended soils may represent a toxicological hazard. Therefore, more research should be carried out with respect to food consumption (plants and animals) under these conditions and their consequences for human health.

Economic Incentive for Applying Vetiver Grass to Remediate Lead, Copper and Zinc Contaminated Soils

The application of vetiver grass (Chrysopogon zizaniodes) for phytoremediation of heavy metal contaminated soils can be promoted by economic return through essential oil production. Four levels of lead (0, 500, 2000, and 8000 mg kg−1 dry soil), copper (0, 100, 400, and 1600 mg kg−1 dry soil) and zinc (0, 400, 1600, and 6400 mg kg−1 dry soil) were used to study their effects on vetiver growth, essential oil composition and yield. This study also investigated the effect of nitrogen concentrations on vetiver oil yield. Vetiver accumulated high concentrations of Pb, Cu and Zn in roots (3246, 754 and 2666 mg kg−1, respectively) and small amounts of contaminants in shoots (327, 55, and 642 mg kg−1, respectively). Oil content and yield were not affected at low and moderate concentrations of Cu and Zn. Only the application of Pb had a significant detrimental effect on oil composition. Extraction of vetiver essential oils by hydrodistillation produced heavy metal free products. High level of nitrogen reduced oil yields. Results show that phytoremediation of Cu and Zn contaminated soils by vetiver can generate revenue from the commercialization of oil extracts.

Kinetics of zinc release from ground tire rubber and rubber ash in a calcareous soil as alternatives to Zn fertilizers

Ground rubber contains 15–20 g Zn kg−1 but very low levels of Cd and could serve as an inexpensive byproduct Zn fertilizer. The aim of this investigation was to test Zn release in a soil treated with ground tire rubber and rubber ash compared with commercial Zn fertilizer and a laboratory grade zinc sulfate. A Zn-deficient soil was chosen from wheat fields in Isfahan province, central Iran, and the ground rubber, rubber ash and fertilizer-Zn and laboratory ZnSO4 were added at 0.5 and 2 mg Zn kg−1; 0.5 kg ha−1 would usually correct Zn deficiency in such pot tests. The soil DTPA-extractable Zn was then measured with time and the results were described examining first order, Elovich, power function and parabolic diffusion kinetics models. In the pot experiment, corn (Zea mays L.) plants were exposed to three rates of Zn (0, 20, 40 mg Zn kg−1) from two different sources (ZnSO4 and ground rubber). Ground rubber was applied as 2–3 mm and <1 mm diameter particles. Zinc treatments were mixed with the soils before planting. At harvest, concentrations of Zn, Pb, and Cd in roots and shoots of corn were measured. Results showed that ground rubber and rubber ash significantly increased the concentration of DTPA-Zn in the soil and this increase was higher than achieved with the commercial Zn fertilizer. At the lower Zn application rate, Zn release followed parabolic diffusion, while at the higher rate the kinetics of release followed power function and Elovich models. There was an increase in Zn concentration of corn shoot and roots by adding of Zn regardless the source of applied Zn. With increase in the rate of rubber used, the shoot Zn uptake increased. The Pb concentration of shoot and Cd concentrations of shoot and roots were low (less than 0.02 mg kg−1) in all treatments. The results showed that the soil DTPA Zn decreases over time if the soil is amended with a soluble form of Zn whereas the reverse was observed if the Zn is added as ground rubber which only gradually transforms. Thus ground rubber and rubber ash offer strong value as Zn fertilizer for Zn deficient soils.