APPLICATION OF INCREASING LEVELS OF ZINC TO SOIL REDUCED ACCUMULATION OF CADMIUM IN LUPIN GRAIN

Yellow lupin (Lupinus luteus L.) and narrow-leafed lupin (L. angustifolius L.) are grown as grain legumes in rotation with spring wheat (Triticum aestivum L.) on acidic sandy soils of south-western Australia. Yellow lupin can accumulate significantly larger cadmium (Cd) concentrations in grain than narrow-leafed lupin. A glasshouse experiment was undertaken to test whether adding increasing zinc (Zn) levels to soil increased Zn uptake by yellow lupin reducing accumulation of Cd in yellow lupin grain. Two cultivars of yellow lupin (cv. ‘Motiv’ and ‘Teo’) and 1 cultivar of narrow-leafed lupin (cv. ‘Gungurru’) were used. The soil was Zn deficient for grain production of both yellow and narrow-leafed lupin, but had low levels of native soil Cd (total Cd <0.05 mg kg^?1) so 1.6 mg Cd pot^?1, as a solution of cadmium chloride (CdCl₂·H₂O), was added and mixed through the soil. Eight Zn levels (0–3.2 mg Zn pot^?1), as solutions of zinc sulfate (ZnSO₄·7H₂O), were added and evenly mixed through the soil. Yellow lupin accumulated 0.16 mg Cd kg^?1 in grain when no Zn was applied, which decreased as increasing Zn levels were applied to soil, with ～0.06 mg Cd kg^?1 in grain when the largest level of Zn (3.2 mg Zn pot^?1) was applied. Low Cd concentrations (<0.016 mg Cd kg^?1) were measured in narrow-leafed lupin grain regardless of the Zn treatment. When no Zn was applied, yellow lupin produced ～2.3 times more grain than narrow-leafed lupin, indicating yellow lupin was better at acquiring and using indigenous Zn from soil for grain production. Yellow lupin required about half as much applied Zn as narrow-leafed lupin to produce 90% of the maximum grain yield, ～0.8 mg pot^?1 Zn compared with ～1.5 mg Zn pot^?1. Zn concentration in whole shoots of young plants (eight leaf growth stage) related to 90% of the maximum grain yield (critical prognostic concentration) was (mg Zn kg^?1) 25 for both yellow lupin cultivars and 19 for the narrow-leafed lupin cultivar. Critical Zn concentration in grain related to 90% of maximum grain yield was (mg Zn kg^?1) 24 for both yellow lupin cultivars compared with 20 for the narrow-leafed lupin cultivar.     

Agronomic biofortification of chickpea with zinc and iron through application of zinc and urea

ABSTRACT

Zinc (Zn) and iron (Fe) deficiency-related health problems in humans may be solved by improving their concentration in edible grains. The study, conducted in 2015–16 and 2016–17, investigated the effects of soil and foliar application of Zn and foliar application of urea on grain Zn and Fe accumulation of chickpea grains. Soil application of ZnSO₄ @ 25 kg ha^?1 + foliar spray of ZnSO₄ @ 0.5% at flowering and pod formation stages resulted in the highest Zn (45.06 & 44.69 mg Zn kg^?1 grain in the first and second year of study) and Fe (59.74 & 62.88 mg Fe kg^?1 grain) content. Urea application @ 2% at flowering and pod formation stages also resulted in the highest grain Zn (41.12 & 40.26 mg Zn kg^?1 grain) and Fe (58.95 & 61.95 mg Fe kg^?1 grain) content. Grain yield and protein content were significantly increased over control with these treatments. As compared to the sole application of Zn, the combined use of Zn and urea improved the grain Zn and Fe contents. Zinc and urea can be applied to improve Zn and Fe content in chickpea grains and, therefore, can help in ameliorating malnutrition in burgeoning human population.     

Zinc fertilization approaches for agronomic biofortification and estimated human bioavailability of zinc in maize grain

Maize (Zea mays L.) is generally low in bioavailable zinc (Zn); however, agronomic biofortification can cure human Zn deficiency. In the present experiment, Zn was applied in pots as ZnSO₄ · 7H₂O to maize cultivar DK-6142 as foliar spray (0.5% w/v Zn sprayed 25 days after sowing and 0.25% w/v at tasseling), surface broadcasting (16 kg Zn ha^?1), subsurface banding (16 kg Zn ha^?1 at the depth of 15 cm), surface broadcasting + foliar and subsurface banding + foliar in comparison to an unfertilized control. As compared to control, all treatments significantly (P ≤ 0.05) increased growth, yield and nutritional attributes in maize. Grain Zn and protein concentrations were correlated and ranged from 22.3 to 41.9 mg kg^?1 and 9 to 12 %, respectively. Zinc fertilization also significantly reduced grain phytate and increased grain Zn concentration. Zinc fertilization, especially broadcasting and subsurface banding combined with foliar spray decreased grain [phytate]:[Zn] ratio to 28 and 21 and increased Zn bioavailability by trivariate model of Zn absorption to 2.04 to 2.40, respectively. Conclusively, broadcasting and subsurface banding combined with foliar spray is suitable for optimal maize yield and agronomic Zn biofortification of maize grain. This would also be helpful to optimize Zn and protein concentration in maize grain.     

The effectiveness of seed priming and foliar application of zinc- amino acid chelates in comparison with zinc sulfate on yield and grain nutritional quality of common bean

Abstract

The efficacy of seed priming and foliar application of zinc-amino acid chelates including zinc-histidine [Zn(His)₂] and zinc-methionine [Zn(Met)₂] in comparison with zinc sulfate (ZnSO₄) on yield and grain nutritional quality of two common bean cultivars (Phaseolus vulgaris L., cvs Talash and Sadri) was investigated in a severely Zn-deficient calcareous soil (DTPA-Zn: 0.38?mg kg^?1 soil) in a pot experiment. Bean response to Zn application varied depending on the Zn fertilizer, application method and cultivar. In ‘Talash’, seed priming with [Zn(His)₂] and [Zn(Met)₂] led to 24.1 and 11.6% increase in the grain yield of bean in comparison with ZnSO₄ treatment, respectively. In both cultivars, foliar application of [Zn(His)₂] led to significant increase in the grain yield in comparison with ZnSO₄. The highest grain Zn concentration was obtained by seed priming with [Zn(Met)₂] in ‘Sadri’ and [Zn(His)₂] in ‘Talash’, respectively. For Zn-amino acid chelates, seed priming was more effective than foliar application in increasing grain yield and Zn concentration. Foliar application of [Zn(His)₂] and [Zn(Met)₂] in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ resulted in higher protein content in bean grain as compared with ZnSO₄. In both cultivars, foliar application of [Zn(Met)₂] was the more effective than seed priming to increase grain protein content. The highest water-soluble carbohydrates concentration of grain was obtained by seed priming with [Zn(Met)₂] and [Zn(His)₂] in ‘Sadri’ and ‘Talash’ cultivars, respectively. Therefore, seed priming with [Zn(His)₂] and ZnSO₄ in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ can effectively be used for improving yield of common bean in Zn-deficient calcareous soils.     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

Zinc accumulation in lettuce cultivars grown with organic or chemical based nutritional regimes

This study determined the potential to increase Zn density of lettuce (Lactuca sativa L.) through cultivar selection and nutrient management. Organic fertilizer and Hoagland and Arnon no.1 solution factored with three zinc (Zn) levels provided as zinc sulfate (ZnSO₄) were the fertilizer regimes in a greenhouse experiment. Modern cultivars had a 32% higher fresh head weight than heritage cultivars, but each accumulated the same Zn concentration (65 mg kg^?1 dry wt). Butterhead phenotypes had a 38% lower yield than loose-leaf and had the highest Zn concentration (78 mg kg^?1 dry wt) followed by romaine (66 mg kg^?1 dry wt) and loose-leaf (53 mg kg^?1 dry wt). Concentration of Zn did not differ between fertility regimes, being about 66 mg kg^?1 dry wt with each regime. Differences in Zn concentrations were significant among individual cultivars with ranges from 42 mg g^?1 dry wt to 91 mg kg^?1 dry wt. ‘Tom Thumb’, ‘Adriana’, ‘Claremont’, and ‘Focea’ were the top in cultivar ranking, with mean Zn concentration of 63 mg kg^?1 dry wt. The results signify that selection of cultivars may be utilized to increase Zn accumulation in lettuce but that nutritional regimes had little effect on accumulation.     

Type and placement of zinc fertilizer impacts cadmium content of harvested durum wheat grain

Due to potential international marketing concerns, North Dakota durum wheat (Triticum turgidum L. Desf.) producers require strategies that limit cadmium (Cd) in harvested grain. These trials were conducted in order to determine the impact of type and placement of zinc (Zn) fertilizer on harvested grain seed Cd levels and to determine the best timing of foliar Zn-ethylenediaminetetraacetic acid (EDTA). Foliar Zn-EDTA applied at Feekes 10 growth stage had the lowest grain Cd of 0.97 mg kg^?1 when evaluating different fertilizer sources and application timings. Application of 22.4 kg ha^?1 potassium chloride with the seed at planting resulted in the highest grain Cd of 0.151 mg kg^?1 and might be a concern when environmental conditions are conducive for Cd uptake from soil. Stepwise linear regression determined that soil pH and chloride explained 96% of the variability of grain Cd. Applying 1.1 kg Zn ha^?1 as foliar Zn-EDTA in combination with 33 kg nitrogen ha^?1 at Feekes 10.54 growth stage resulted in significantly lower grain Cd, and significantly higher grain Zn, iron, and protein content. Treatments that significantly lowered grain Cd did not decrease grain yield, test weight, or protein content. The treatments that most reduced grain Cd resulted in the most benefits from a production, marketing, and nutritional standpoint and represents an agronomic approach to biofortification of durum wheat.     

Influence of Foliar and Ground Fertilization on Yield,Fruit Quality,and Soil,Leaf, and Fruit Mineral Nutrients in Apple

ABSTRACT

The effectiveness of nitrogen (N)+ zinc (Zn) soil and foliar fertilizer applications on growth, yield, and quality of apple (Malus domestic Borkh ‘Golden Delicious’) fruit was studied in the Zanjan province, Iran. There were eight treatments 1) control (no fertilizer), 2) soil applied N, 3) soil applied Zn, 4) soil applied N+Zn, 5) foliar applied N, 6) foliar applied Zn, 7) foliar applied N+Zn and 8) combined soil and foliar applied N+Zn. The N source was urea [CO(NH₂)₂, 46% N] applied at 276 N tree^{? 1} yr^?1 and the Zn source was zinc sulfate (ZnSO₄,7H₂0, 23% Zn) applied at 110 g Zn tree^{? 1} yr^{? 1}. The soil treatments of N and Zn, were applied every two weeks during June through August (total of 6 times/year) in a 1 m radius around the tree trunk (drip line of trees). The foliar solutions of N (10 g l^{? 1} urea) and Zn [8 g l^{? 1} zinc sulfate (ZnSO₄)] were sprayed at the rate of 10 L tree^{? 1} every two weeks at the same times as described for soil applications. The highest yield (49 kg tree^{? 1}), and the heaviest fruits (202 g) were obtained in the soil and foliar combination of N+Zn treatment. The lowest yield (35 kg tree^{? 1}), and the smallest fruits (175 g) were recorded in the control. Nitrogen, and to a lesser extent Zn, foliar application resulted in decreasing fruit quality (caused russeting, and lower soluble solid), but increasing N leaf and fruit concentrations (2.4% DW and 563 mg kg^{? 1}, respectively). There were significant differences among yield and leaf mineral nutrient concentration in different treatments. But there was no significant difference between fruit mineral nutrient concentration (except N). Ratio of N/calcium (Ca), potassium (K)/Ca, and [magnesium (Mg)+K]/Ca in fruits were found suitable for fruit quality prediction. Combining the zinc sulfate with urea in the foliar applications increased the concentration of Zn from 0.7 to 1.5 mg per kg of apple tissue. Leaf N concentration varied during growth season. Foliar applied nutrient can be more efficient than soil applied, but a combination of soil and foliar applications is recommended for apple tree nutrient management.     

Zinc in wheat grain as affected by nitrogen fertilization and available soil zinc

Greenhouse and field experiments were conducted to determine the influence of nitrogen (N) fertilization and DTPA‐extractable soil zinc (Zn) on Zn concentration in wheat (Triticum aestivum L., cv. Pioneer 2375) grain. Application of zinc sulfate (ZnSO₄) in the range of 0 to 8 mg Zn kg^‐1 increased linearly DTPA‐extractable Zn in an incubated calcareous soil from 0.3 to 5.0 mg kg^‐1. Application of these rates of ZnSO₄ to the same soil under greenhouse conditions increased Zn concentration of wheat grain from 26 to 101 mg kg^‐1. The influence of 134 kg urea‐N ha^‐1 on Zn concentration in wheat grain at eight field sites, with DTPA‐extractable soil Zn levels ranging from 0.3 to 4.9 mg kg^‐1, was studied. Nitrogen fertilizer increased wheat‐grain yields in four of the eight experiments but had little effect on grain‐Zn concentration. Grain‐Zn concentration ranged from 31 to 45 mg kg^‐1 in N‐fertilized plots at the various sites and was related (r=0.74*) to DTPA‐extractable soil Zn.     

Response of wheat genotypes to zinc fertilization for improving productivity and quality

Field experiments were conducted to evaluate the effects of zinc (Zn) fertilization on yield potentiality and quality of promising wheat varieties during winter seasons of 2013–14 and 2014–15 at the research farm of the Indian Agricultural Research Institute, New Delhi. Among genotypes, HD 2967 genotype proved as best in realizing the highest grain yield (4.89 Mg ha^?1), net returns and benefit–cost ratio besides increased protein (13.4%) and wet gluten (29.4%) content in grain. Highest grain Zn concentration and recovery efficiency (RE) recorded in HD 2851 and HD 2687, respectively. HD 2932 registered lowest grain hardiness index (GHI) followed by PBW 343, indicating their better bread-making quality. With respect to Zn fertilization, application of 1.25 kg Zn Zn–ethylene diamine tetra acetic acid (Zn–EDTA) + 0.5% foliar spray at maximum tillering and booting stages resulted in the highest yields, grain Zn concentration and RE followed by 2.5 kg Zn (ZnSO₄·7H₂O) + 0.5% foliar spray at both stages. These treatments are also superior most with respect to grain quality parameters such as protein, wet gluten and starch content. From profitability viewpoint, 2.5 kg Zn (ZnSO₄·7H₂O) + 0.5% two foliar sprays were most remunerative with maximum net returns and benefit–cost ratio.     

Zinc biofortification of bread wheat,triticale, and durum wheat cultivars by foliar zinc fertilization

Poor zinc (Zn) nutrition of wheat is one of the main causes of poor human health in developing countries. A field experiment with no zinc and foliar zinc application (0.5% ZnSO₄.7H₂O) on bread wheat (8), durum wheat (3), and triticale (4) cultivars was conducted in a randomized block design with three replications in 2 years. The experimental soil texture was loamy sand with slightly alkalinity. The grain yields of bread wheat, triticale, and durum wheat cultivars increased from 43.6 to 56.4, 46.5 to 51.6, and 49.4 to 53.5 t ha^?1, respectively, with foliar application of 0.5% ZnSO₄.7H₂O. The highest grain yield was recorded by PBW 550 (wheat), TL 2942 (triticale), and PDW 291 (durum), which was 5.22, 4.24, and 4.56% and significantly higher over no zinc. Foliar zinc application increased zinc in bread wheat, triticale, and durum wheat cultivars grains varying from 31.0 to 63.0, 29.3 to 61.8, and 30.2 to 62.4?mg kg^?1, respectively. So, agronomic biofortification is the best way which enriching the wheat grains with zinc for human consumption.     

Effect of split application of zinc on yield of rice (Oryza sativa L.) in an inceptisol

Abstract

Rice is mostly transplanted under puddled low land soil conditions in India, where Zinc (Zn) deficiency is a common problem. The objective of this study was to find out the efficacy of split application of Zn on growth and yield of rice in an inceptisol. The split application of Zn as ZnSO₄ · 7H₂O performed better than its single basal application, while the split application of Zn-EDTA did not show any significant difference on yield and yield components of rice over its single basal application. Zn-EDTA was found to be better for growth and yield of rice among the two sources of Zn. The soil application of Zn at 1.0 kg ha^?1 as Zn-EDTA (T₇) recorded highest grain yield of 5.42 t ha^?1, filled grain percentage of 90.2%, 1000-grain weight of 25.41 g and number of panicles m^?2 of 452. The Zn content of grain and straw were found to be maximum in the treatment T₇ i.e. 38.19 and 18.27 mg kg^?1, respectively. Linear regression studies indicated that grain yield of rice is significantly influenced by Zn content of grain, Zn content of straw and DTPA extractable Zn content of soil at the level of 95.96, 96.74 and 95.57%, respectively.     

Effect of Sources,Methods and Time of Application of Zinc on Productivity,Zinc Uptake and Use Efficiency of Oats (Avena Sativa L.) Under Zinc Defficient Condition

A field experiment conducted at the Indian Agricultural Research Institute, New Delhi, India showed that oats (Avena sativa L.) responded (grain yield increase) to zinc (Zn) fertilizer and coating of oat seeds with Zn sulfate or Zn oxide is the best practice. Zinc fertilizer applied to soil, deep placement (5 cm below the seed placement) was superior for growth and yield than soil surface (broadcast) application. Delaying Zn application to 25 days after sowing (first irrigation) was inferior to Zn application at sowing. Partial factor productivity (PFP) of applied Zn varied from 700–2,024 kg grain kg Zn^?1, agronomic efficiency (AE) varied from 62–428 kg grain increase kg^?1 Zn (applied) and physiological efficiency (PE) of Zn varied from 1,822–3,221 kg grain kg^?1 Zn (absorbed). The crop recovery efficiency (CRE) varied from 3.1–17.7%. Thus, adequate Zn fertilizer of oats can lead to higher grain yield and higher Zn concentration in grain (improved quality for human nutrition) under Zn deficient soil.     

Effect of different foliar zinc application at different growth stages on seed zinc concentration and its impact on seedling vigor in rice

This study evaluated how zinc (Zn) concentration of rice (Oryza sativa L.) seed may be increased and subsequent seedling growth improved by foliar Zn application. Eight foliar Zn treatments of 0.5% zinc sulfate (ZnSO₄?·?7H₂O) were applied to the rice plant at different growth stages. The resulting seeds were germinated to evaluate effects of seed Zn on seedling growth. Foliar Zn increased paddy Zn concentration only when applied after flowering, with larger increases when applications were repeated. The largest increases of up to ten-fold were in the husk, and smaller increases in brown rice Zn. In the first few days of germination, seedlings from seeds with 42 to 67?mg Zn?kg^?1 had longer roots and coleoptiles than those from seeds with 18?mg Zn?kg^?1, but this effect disappeared later. The benefit of high seed Zn in seedling growth is also indicated by a positive correlation between Zn concentration in germinating seeds and the combined roots and shoot dry weight (r?=?0.55, p?相似文献   

Effect of Zinc Humate on Growth of Soybean and Wheat in Zinc‐Deficient Calcareous Soil

Abstract

Humic acids have many benefits for plant growth and development, and these effects may be maximized if these materials are combined with micronutrient applications. In the present study, pot experiments were conducted to evaluate the effects of zinc (Zn) humate and ZnSO₄ on growth of wheat and soybean in a severely Zn‐deficient calcareous soil (DTPA‐Zn: 0.10 mg kg^?1 soil). Plants were grown for 24 (wheat) and 28 days (soybean) with 0 or 5 mg kg^?1 of Zn as either ZnSO₄ or Zn humate. Zinc humate used in the experiments was obtained from Humintech GmbH, Germany, and contained 5% of Zn. When Zn was not supplied, plants rapidly developed visible symptoms of Zn deficiency (e.g., chlorosis and brown patches on young leaves in soybean and necrotic patches on middle‐aged leaves in wheat). Adding Zn humate eliminated Zn‐deficiency symptoms and enhanced dry matter production by 50% in soybean and 120% in wheat. Zinc‐humate and ZnSO₄ were similarly effective in increasing dry matter production in wheat; but Zn humate increased soybean dry matter more than ZnSO₄. When Zn was not supplied, Zn concentrations were 6 mg kg^?1 for wheat and 8 mg kg^?1 for soybean. Application of Zn humate and ZnSO₄ increased shoot Zn concentration of plants to 36 and 34 mg kg^?1 in wheat and to 13 and 18 mg kg^?1 in soybean, respectively. The results indicate that soybean and wheat plants can efficiently utilize Zn chelated to humic acid in calcareous soils, and this utilization is comparable to the utilization of Zn from ZnSO₄. Under Zn‐deficient soil conditions, plant growth and yield can be maximized by the combined positive effects of Zn and humic acids.     

Response of Wheat Plants to Zinc,Iron, and Manganese Applications and Uptake and Concentration of Zinc,Iron, and Manganese in Wheat Grains

This experiment was conducted at Zahak Agricultural Research Station in the Sistan region in southeast Iran. A factorial design with three replications was used to determine the effects of zinc (Zn), iron (Fe), and manganese (Mn) applications on wheat yield, Zn, Fe, and Mn uptakes and concentrations in grains. Four levels of Zn [soil applications of 0, 40, and 80 kg ha^?1 and foliar application of 0.5% zinc sulfate (ZnSO₄) solution], two levels of iron sulfate (FeSO₄; 0 and 1%) as foliar application, and two levels of Mn (0 and 0.5%) also as foliar application were used in this study. Results showed that the interactive effects of Zn and Mn were significant on the number of grains in each spike. The highest number of grains resulted from the application of 80 kg ZnSO₄ ha^?1 and foliar Mn. The interactive effects of Zn and Fe were significant on weight of 1000 grains. The highest weight of 1000 grains resulted from application of 80 kg Zn and foliar Fe. Application of 80 kg ZnSO₄ ha^?1 alone and 80 kg ZnSO₄ ha^?1 with foliar application of Mn significantly increased grain yield in 2003. The 2‐year results showed that foliar application of Zn increased Zn concentration and Fe concentration in grains 99% and 8%, respectively. Foliar application of Fe resulted in a 21% increase in Fe concentration and a 13% increase in Zn concentration in grains. The foliar application of Mn resulted in a 7% increased in Mn concentration in grains.     

CUMULATIVE AND RESIDUAL EFFECTS OF ZINC SULFATE ON GRAIN YIELD,ZINC, IRON,AND COPPER CONCENTRATION IN CORN AND WHEAT

Re-application of zinc (Zn) sulfate for corn (Zea mays L.) production in rotation of wheat-corn has varied effects on yield of crops grown in Zn deficient soils. Therefore, this study was done as split plots in a complete randomized block design (CRBD) where the main plots were control with and without Zn application in wheat (Triticum aestivum L.) production. Sub-plots were of control, without Zn fertilizer, base application of 75 kg per hectare (kg Zn ha^?1), 25% and 50% less than base application and as foliar spray in combination with the 4 soil Zn treatments for corn production. Effect of previous Zn application on grain Zn concentration of corn was significant (P < 0.01). Zinc concentrations in treatments of without previous Zn (nil Zn) application and with Zn application were 28.1 and 31.8 mg kg^?1, respectively. Soil application of 75 kg ha^?1 and foliar application of Zn sulfate gave the highest yield (8853 kg ha^?1) showed an increase of 25 percent in compared with nil-Zn. Although re-application of Zn has small effect on yield, but resulted in was the highest grain concentration.     

RESPONSES OF COOL-SEASON GRAIN LEGUMES AND WHEAT TO SOIL-APPLIED ZINC

The yield and zinc (Zn) content response of faba bean (Vicia faba L.), chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.) and wheat (Triticum aestivum L.) to applications of Zn fertilizer was compared in a glasshouse experiment using two alkaline soils from southwestern Australia. Comparative Zn requirements were determined from yields of 46-day-old dried shoots when no Zn fertilizer was applied, the amount of Zn required to produce the same percentage of the maximum (relative) yield of dried shoots, and the Zn content of dried shoots (Zn concentration multiplied by yield of dried shoots). The concentration of Zn in youngest tissue and in dried shoots was used to determine critical concentrations for Zn in tissue. Faba bean used indigenous soil Zn more effectively than chickpea, followed by wheat and then lentil. The Zn requirement was lowest for faba bean, and increased in the order faba bean < chickpea < wheat < lentil. Zinc concentration in dried youngest tissue and in dried shoots increased with an increase in the amount of added Zn. The critical Zn concentration in the youngest tissue, associated with 90% of the relative yield, was (mg Zn kg^?1): 25 for lentil, 18 for faba bean, 17 for chickpea and 12 for wheat; corresponding values for dried whole tops (mg Zn kg^?1) were: 30 for lentil, 19 for faba bean, 17 for chickpea, and 20 for wheat. Information on comparative responses of the grain legumes to Zn additions relative to wheat, and critical tissue test values, will aid in the fertilizer management of Zn in cool-season grain legumes in the southwestern Australian farming systems.     

Zinc fertilization of lentil for grain yield and grain zinc concentration in ten Saskatchewan soils

Fertilization of grain legumes with zinc (Zn) can affect both marketable yield and Zn content of the grain, which is important in addressing human nutritional deficiencies in certain regions of the world. A pot experiment was conducted to determine the response of three different market classes of lentil to Zn fertilization using ten surface soils from Saskatchewan (Canada). The distribution of Zn among labile and stable fractions chemically separated from the soil was also determined in the ten prairie soils and related to the lentil responses observed. The three market classes of lentils (large and small green, small red) were grown without Zn (control), and with 2.5 and 5 kg Zn ha^?1 added as zinc sulfate to each soil prior to planting. Zinc fertilizer application significantly influenced grain yield and was soil dependent. A significant increase in grain yield over the control was observed from application of Zn on some low organic matter, high pH Brown Chernozem soils whereas a decrease in grain yield over control was observed in other soils such as a Black Chernozem of high organic matter content and low (<7) pH. Lack of positive yield response to addition of Zn were related to measured high diethylene triamine pentaacetic acid (DTPA) extractable and plant root simulator (PRS) resin membrane probe Zn, and large amounts of native Zn in exchangeable and iron/manganese (Fe/Mn) oxide bound fractions. Application of Zn fertilizer generally increased the grain concentration of Zn. For example, an increase of ～20% in Zn concentration over control was observed when 5 kg Zn ha^?1 was added to a loamy textured low organic matter Brown Chernozem soil. Overall, small green lentil was more consistent in producing a positive response to Zn fertilizer application on soils with low plant available Zn compared to large green lentil and small red lentil.     

Variability in Response to Zinc Application in 10 High-Yielding Wheat Varieties

A pot culture experiment was conducted to study the effect of zinc (Zn) on biofortification of 10 wheat (Triticum aestivum L.) varieties in the Zn-deficient soil of Lucknow. Treatments consisted of 0 and 20 mg Zn kg^?1 as a basal dose and 20 mg Zn kg^?1 basal dose with two foliar sprays of zinc sulfate (ZnSO₄) 0.5%. Foliar sprays of Zn were applied twice at the preflowering stage and 7 days after flowering. Results from the present study revealed that poor growth of plants grown in soil without Zn applications (0 mg Zn kg^?1) were improved by applications of Zn (20 mg Zn kg^?1) more when Zn was applied with two foliar sprays. Application of Zn (20 mg Zn kg^?1) with two foliar sprays also proved beneficial for maximizing Zn concentrations of grains and other plant parts. Wheat varieties NW 1076, K 3827, NW 2036, and UP 262 appeared highly responsive to the treatments.