EFFECT OF ZINC NUTRITION ON GROWTH,YIELD, AND QUALITY OF FORAGE SORGHUM IN RESPECT WITH INCREASING POTASSIUM APPLICATION RATES

A two-year field study was conducted to determine the effect of two zinc (Zn) levels [0 and 10 kg zinc sulfate (ZnSO₄) ha^?1] in respect with four potassium (K) levels (0, 20, 40 and 60 kg K₂O ha^?1) on growth, yield and quality of forage sorghum. The soil of the experimental field was loamy sand (Inceptisol), carrying 70, 08, 77, and 0.51 mg nitrogen (N), phosphorus (P), K, and Zn kg^?1 soil, respectively. Increasing K levels significantly improved most of the growth, yield, and quality attributes gradually irrespective of the Zn levels. Zinc applied at 10 kg ZnSO₄ ha^?1 proved significantly better than no zinc application at various K application rates. The benefit of zinc application increased progressively with increasing K rates for most of the parameters studied, indicating significant response of the crop to positive K × Zn interaction in plants in respect with K and Zn application to the soil. Accordingly, 60 kg K₂O ha^?1 applied with10 kg ZnSO₄ ha^?1 boosted most of the attributes maximally. It resulted in about 20–40% increase in growth attributes, 25% increase in fresh matter yield, 36–38% increase in dry matter yield, and 38% increase in protein yield compared to the comparable K level applied without zinc. It also enhanced N uptake by 38%, P uptake by 5–19%, K uptake by 40–42%, and Zn uptake by 114–144%. Across the K rates, application of 10 kg ZnSO₄ surpassed no zinc application by 30–35% in N uptake, by 8–15% in P uptake, by 33–36% in K uptake, by 120–140% in Zn uptake, by 19–21% in fresh matter yield, by 29–31% in dry matter yield, and by 30–34% in protein yield.     

Effect of Mycorrhiza,Organic Sources,Lime, Secondary and Micro-nutrients on Soil Microbial Activities and Yield Performance of Yam Bean (Pachyrhizus erosus L.) in Alfisols

Effect of integrated use of mycorrhiza, lime, inorganic fertilizers, and organic manures on microbial activities and yield performance of yam bean (Pachyrhizus erosus L.) was studied for two consecutive kharif (rainy) seasons during 2013–14 and 2014–15 in an acid Alfisol. The experiment was laid out with 16 treatments consisting of graded doses of soil test–based nitrogen, phosphors, and potassium (NPK); lime; mycorrhiza; organic sources, that is, farmyard manure (FYM), vermicompost, and green manure; secondary magnesium sulfate (MgSO₄) and micronutrients zinc sulfate (ZnSO₄ and borax). Significantly highest mean tuber yield (29.61 t ha^?1) was recorded due to integrated application of lime + FYM + NPK + ZnSO₄. Graded doses of NPK showed a mean yield response of 65%, 134%, and 191% due to addition of 50%, 100%, and 150% of NPK over control, respectively. Inoculation of vesicular–arbuscular mycorrhiza (VAM) combined with NPK and FYM recorded a mean tuber yield of 25.14 t ha^?1. Highest mean dry matter (18.85%) was recorded due to application of 150% NPK, whereas highest starch content on fresh weight basis was recorded due to integrated use of lime + FYM + NPK + MgSO₄ (11.11%). Application of 150% NPK has recorded highest dehydrogenase activity (2.018 µg TPF h^?1 g^?1) and fluorescein diacetate hydrolysis assay (2.012 µg g^?1 h^?1). Fungal inoculation of VAM in combination with lime + FYM + NPK recorded highest acid and alkaline phosphatase activities (82.20 and 67.02 µg PNP g^?1 soil h^?1, respectively). Soil biological activities and phosphatase activities had highly significant relationship with tuber yield and biochemical constituents of yam bean. The study emphasized the conjunctive use of soil test–based inorganic fertilizers, lime, and organic manures to enhance the enzymatic activities and to realize higher crop yields of yam bean in acid Alfisols.     

Symbiotic parameters,growth, nutrient accumulation,productivity and profitability as influenced by integrated nutrient management in lentil (Lens culinaris)

Field experiments evaluated the effects of integrated nutrient management on symbiotic parameters, growth, nutrient accumulation, productivity and profitability of lentil (Lens culinaris Medikus). Application of recommended dose of nutrients (RDN, 12.5 kg N ha^?1 + 40 kg P₂O₅ ha^?1) + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers [Rhizobium + phosphate solubilizing bacteria (PSB) + plant growth promoting rhizobacteria (PGPR)] + 1.0 g ammonium molybdate kg^?1 seed recorded the highest number & dry weight of nodules, leghaemoglobin content, root & shoot dry weight, plant height, number of pods plant^?1 and 100-seed weight. The next best treatment was RDN + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed. On the basis of mean of three-year data, the treatment of RDN + 25 kg ZnSO₄ ha^?1 + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg^?1 seed proved the best in realizing the highest grain yield (34.0%), gross returns (34.0%) and net returns (54.8% higher over control). Nitrogen, phosphorus and potassium in the grains and straw were significantly improved where RDN was applied in combination with seed inoculation, basal application of ZnSO₄ and seed treatment with 1 g ammonium molybdate than their single applications.     

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.     

Availability of Cadmium and Zinc as Affected by the Use of Reactive Phosphate Rock,Lime, and Chicken Manure on an Indonesian Acidic Upland Soil under Field Conditions

We assessed cadmium (Cd) and zinc (Zn) availability when applying reactive phosphate rock (RPR) in combination with lime and chicken manure on Indonesian acidic upland soils. Maize plants were grown on unamended soil and soils treated with several combinations of 2 tons dolomite ha^–1, 2 tons of chicken manure ha^–1, 1 ton ha^–1 of RPRL (reactive phosphate rock containing 4 mg Cd kg^–1 and 224 mg Zn kg^–1), and 1 ton ha^–1 of RPRH (RPR containing 69 mg Cd kg^–1 and 745 mg Zn kg^–1). In addition to its positive effect on plant yield, application of RPR in combination with chicken manure did not result in toxic Cd concentrations. Although liming is effective to reduce plant Cd concentrations, it results in more soil Cd accumulation and more plant Zn deficiency. Cadmium and Zn concentrations in shoots and grains can be predicted well from amounts extracted from the soil by 0.5 M ammonium (NH₄) acetate + 0.02 M ethylenediaminetetraacetic acid (EDTA) at pH 4.65.     

Appraisal of Some Soil Tests for Zinc Availability to Late‐Sown Wheat Grown in Mollisols

Abstract

Five soil extractants, namely, 0.005 M diethylene triamine pentaacetic acid (DTPA) (pH 7.3), 0.005 M DTPA+1 M ammonium bicarbonate (pH 7.6), Mehlich 3, 0.01 M ethylene diamine tetraacetic acid (EDTA)+0.05 M ammonium carbonate (pH 8.6), and 1 M magnesium chloride (MgCl₂) (pH 6.0), were evaluated to predict the response of wheat to zinc (Zn) application in Mollisols. These extractants could be arranged in the following decreasing order of their Zn extracting power: Mehlich 3>0.005 M DTPA+1 M ammonium bicarbonate>0.01 M EDTA+0.05 M ammonium carbonate>0.005 M DTPA>1 M MgCl₂. The critical limits of Zn in soil, below which the yield response to late sown wheat (var. UP‐2338) to Zn application could be expected, were 0.57 mg 0.005 M DTPA (pH 7.3) extractable and 1.72 mg Mehlich 3–extractable Zn kg^?1 soil. The critical limit of Zn in whole shoot at 60 days after emergence was found to be 26.1 mg Zn kg^?1 plant tissue. The DTPA and Mehlich 3–extractable soil Zn also correlated significantly and positively with Zn concentration in whole shoot at 60 days after emergence and total Zn uptake by wheat at harvest.     

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.     

Evaluation of Various Zinc Extractants in Lowland Rice Soil under the Influence of Zinc Sulfate and Chelated Zinc

Field experiments were conducted on rice (cv ‘IET 4094’) in an Aeric endoaquept (pH 7.2) to evaluate the various zinc (Zn) extractants in lowland rice soil under the influence of Zn sulfate and chelated Zn. The diethylenetriaminepentaacetic acid (DTPA), 0.1 N hydrochloric acid (HCl), and 0.05 N HCl‐extractable Zn concentrations in soil increased initially up to the Z29 stage of crop growth when Zn was applied as a single basal source, being greater with Zn ethylenediaminetetraacetic acid (Zn‐EDTA) compared to zinc sulfate (ZnSO₄) application. Among the various extractants, the performance of 0.1 N HCl in extracting Zn was better than the other two extractants and followed the trend 0.1 N HCl > 0.005 M DTPA > 0.05 N HCl. The greatest increase in grain and straw yield of rice was 37.8 and 20.4%, respectively, over the control in the treatment T₇ (1 kg Zn ha^?1 as Zn‐EDTA at basal).     

Growth,Mineral Composition,and Biochemical Changes of Broad Bean as Affected by Sodium Chloride and Zinc Levels and Sources

Plants grown in salt‐affected soils may suffer from limited available water, ion toxicity, and essential plant nutrient deficiency, leading to reduced growth. The present experiment was initiated to evaluate how salinity and soil zinc (Zn) fertilization would affects growth and chemical and biochemical composition of broad bean grown in a calcareous soil low in available Zn. The broad bean was subjected to five sodium chloride (NaCl) levels (0, 10, 20, 30, and 40 m mol kg^?1 soil) and three Zn rates [0, 5, and 10 mg kg^?1 as Zn sulfate (ZnSO₄) or Zn ethylenediaminetetraaceticacid (EDTA)] under greenhouse conditions. The experiment was arranged in a factorial manner in a completely randomized design with three replications. Sodium chloride significantly decreased shoot dry weight, leaf area, and chlorophyll concentration, whereas Zn treatment strongly increased these plant growth parameters. The suppressing effect of soil salinity on the shoot dry weight and leaf area were alleviated by soil Zn fertilization, but the stimulating effect became less pronounced at higher NaCl levels. Moreover, rice seedlings treated with ZnSO₄ produced more shoot dry weight and had greater leaf area and chlorophyll concentration than those treated with Zn EDTA. In the present study, plant chloride and sodium accumulations were significantly increased and those of potassium (K), calcium (Ca), and magnesium (Mg) strongly decreased as NaCl concentrations in the soil were increased. Moreover, changes in rice shoot Cl^?, Na⁺, and K⁺ concentrations were primarily affected by the changes in NaCl rate and to a lesser degree were related to Zn levels. The concentrations of Cl^? and Na⁺ associated with 50% shoot growth suppression were greater with Zn‐treated plants than untreated ones, suggesting that Zn fertilization might increase the plant tolerance to high Cl^? and Na⁺ accumulations in rice shoot. Zinc application markedly increased Zn concentration of broad bean shoots, whereas plants grown on NaCl‐treated soil contained significantly less Zn than those grown on NaCl‐untreated soil. Our study showed a consistent increase in praline content and a significant decrease in reducing sugar concentration with increasing salinity and Zn rates. However, Zn‐treated broad bean contained less proline and reducing sugars than Zn‐untreated plants, and the depressing impact of applied Zn as Zn EDTA on reducing sugar concentration was greater than that of ZnSO₄. In conclusion, it appears that when broad bean is to be grown in salt‐affected soils, it is highly advisable to supply plants with adequate available Zn.     

Integration of Soil pH with Soil‐Test Values of Zinc for Prediction of Yield Response in Rice Grown in Mollisols

Seventeen Mollisols having pH_(1:2) in the range of 6.00 to 8.42 were analyzed with five extractants, and the extractable zinc (Zn) ranges were 0.84 to 2.75 mg Zn kg^?1 soil for diethylenetriaminepentaacetic acid (DTPA) (pH 7.3), 0.91 to 2.72 mg Zn kg^?1 soil for DTPA + ammonium bicarbonate (pH 7.6), 1.82 to 7.18 mg Zn kg^?1 soil for Mehlich 3, 1.22 to 3.83 mg Zn kg^?1 soil for ethylenediaminetetraacetic acid (EDTA) + ammonium carbonate, and 0.88 to 1.18 mg Zn kg^?1 soil for 1 mol L^?1 magnesium chloride (MgCl₂) (pH 6.0). Zinc extracted by DTPA (pH 7.3) and Mehlich 3 showed significant positive correlation with sand content, whereas only Mehlich 3 showed negative correlation with soil pH. All extractants showed significant positive correlation with each other except for 1 mol L^?1 MgCl₂‐extractable Zn, which had significant positive correlation with only Mehlich 3– and EDTA + ammonium carbonate–extractable Zn. A greenhouse experiment showed that Bray's percentage yield of rice was poorly correlated to extractable soil Zn but had a significant and negative linear correlation with soil pH (r = ?0.662, significant at p = 0.01). Total Zn uptake by rice had a significant positive correlation with 1 mol L^?1 MgCl₂– and Mehlich 3–extractable Zn. A proposed parameter (p extractable Zn + p OH^?) involving both soil extractable Zn and pH terms together showed significant and positive correlation with Bray's percentage yield and total Zn uptake of rice. The calculated values of critical limits of soil Zn in terms of the proposed parameter were 14.1699 for DTPA (pH 7.3), 13.9587 for DTPA + ammonium bicarbonate, 13.7016 for Mehlich 3, 13.9402 for EDTA + ammonium carbonate, and 14.1810 for 1 mol L^?1 MgCl₂ (pH 6.0). The critical limits of Zn in rice grain and straw were 17.32 and 22.95 mg Zn kg^?1 plant tissue, respectively.     

Water Use and Soil Fertility under Rice–Wheat Cropping System in Response to Green Manuring and Zinc Nutrition

ABSTRACT

Soil fertility and water use are two important aspects that influence rice productivity. This study was conducted to evaluate the performance of in-situ (sesbania and rice bean) and ex-situ (subabul) green manuring along with zinc fertilization on water productivity and soil fertility in rice under rice–wheat cropping system at Indian Agricultural Research Institute, New Delhi, India. Sesbania incorporation recorded higher total water productivity (2.20 and 3.24 kg ha^?1 mm^?1), available soil nutrients, organic carbon, alkaline phosphatase activity, microbial biomass carbon and increased soil dehydrogenase activity by 39.6 and 26.8% over subabul and rice bean respectively. Among interaction of green manures and zinc fertilization, subabul × foliar application of chelated zinc-ethylenediaminetetraacetic acid at 20, 40, 60 and 80 days after transplanting recorded highest total water productivity (2.56 and 3.79 kg ha^?1 mm^?1). Foliar application of chelated Zn-EDTA at 20, 40, 60 and 80 days after transplanting recorded significantly higher water productivity than other Zn treatments, however it was statistically similar with foliar application of zinc at active tillering + flowering + grain filling. Sesbania × 5 kg Zn ha^?1 through chelated Zn-EDTA, recorded highest available nitrogen, phosphorus, potassium, zinc, manganese, copper and iron than other green manure and Zn fertilization interactions, although it was statistically similar with rice bean × 5 kg Zn ha^?1 through chelated Zn-EDTA as soil application. Sesbania × foliar application of 5 kg Zn ha^?1 through chelated Zn-EDTA as soil application recorded highest soil enzymatic activities and microbial biomass carbon.     

Turkey Manure Ash Effects on Alfalfa Yield,Tissue Elemental Composition,and Chemical Soil Properties

A power plant that utilizes turkey manure as fuel to produce energy was built in Benson, Minnesota, and started full energy production in 2007. The plant was built to meet legislative requirements governing the use of renewable sources to generate energy in Minnesota. Although the use of turkey manure as biofuel generates energy, it also results in turkey manure ash (TMA) as a by‐product that contains phosphorus (P), potassium (K), sulfur (S), and zinc (Z) as well as other essential and nonessential elements. A 2‐year study was conducted to compare TMA with triple‐superphosphate and potassium chloride fertilizers as a source of nutrients for alfalfa (Medicago sativa) at three locations: Lamberton, Morris, and Appleton, Minnesota. The soils at Lamberton and Appleton were acidic with P and K concentrations ranging from medium‐high to very high, whereas the soil at Morris was alkaline with high concentrations of P and K. The experiment consisted of a control (0 P and 0 K) and annual and split applications of TMA and fertilizer. Annual TMA and fertilizer rates were 84 kg P₂O₅ ha^?1, 118 kg K₂O ha^?1, and 34 kg S ha^?1. Split rates were 42/42 kg P₂O₅ ha^?1, 59/59 kg K₂O ha^?1, and 17/17 kg S ha^?1. However, because of an overestimation of citrate‐soluble P in 2005 for the TMA, the total amount of available P applied with the TMA for the 2‐year study was 168 kg P₂O₅ ha^?1 compared with 286 kg P₂O₅ ha^?1 for the fertilizer. In the first year, fertilizer resulted in greater alfalfa biomass yield than TMA and the control, whereas in the second year, alfalfa yields with TMA and fertilizer were similar and both more than the control. In 2005, TMA resulted in more copper (Cu) and S tissue concentrations than the fertilizer. In 2006, application of both sources increased tissue P and S concentrations compared with the control. The TMA increased tissue Cu concentration and Zn plant uptake compared with fertilizer. Bray P1–extractable soil P concentrations were less with TMA and control treatments than with the fertilizer treatments. Ammonium acetate–extractable soil sodium (Na) concentrations were greater with TMA than with fertilizer and the control. By the second year, both ash and fertilizer treatments resulted in more K uptake than the untreated control with no difference in K uptake between the two sources or time of application. Both sources were effective in increasing P uptake compared with the untreated control. TMA was shown to be an effective source of nutrients for alfalfa production.     

Spatial variability of soil properties and wheat yields in an irrigated field

Abstract

An irrigated farmer's field at Hafizabad village in Dera Ismail Khan District of Northwest Frontier Province of Pakistan was sampled at a regular grid spacing of 50x15 m from surface (15 cm) to study the spatial variability of soil properties and wheat yield. The farm measured 250x75 m. Soil samples collected were analyzed for soil pH, lime content, organic matter, mineral nitrogen (N), ammonium bicarbonate (AB)‐DTPA‐extractable phosphorus (P) and potassium (K), and soil texture. A uniformly trial on wheat with a uniform rate of 120 kg N ha^‐1, 90 kg P₂O₅ ha^‐1, and 60 kg K₂O ha^‐1 was laid out. The results showed that the soil P had the highest coefficient of variation (CV 46%) followed by organic matter (36.20%) and clay content (33.81%). Grain yield had also a considerable variation in the field (CV=31.84%). Geostatistical technique of semivariogram analysis showed that mineral N, AB‐DTPA‐extractable K, sand, silt, and clay content had the strong spatial structure. Maps of soil fertility and crop productivity of the farm was prepared using modern geostatistical technique of kriging. The farm was divided into different management zones based on these maps for fertility management.     

Effect of elemental sulphur and sulphur containing waste in a calcareous soil in Turkey

The effect of elemental sulphur (S) and S containing waste applications on soil pH treated with 0–2,000 kg ha^‐l elemental S, and 0–100 tons ha‐¹ of waste was determined in the field and the pots. Sorghum (Sorghum bicolor L.) was grown in a Lithic Xerorthent soil which was taken from where the field experiment was conducted in pots receiving 5 kg soil. Plants were harvested 20 weeks after planting or 30 weeks after the applications for determination of dry matter yield and phosphorus (P), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) uptake by shoots. EC, NaHCO₃‐extractable P, and DTPA‐extractable Fe, Zn, Mn, Cu also were measured in pot soil at the 5th, 10th, and 30th weeks. All treatments led to a decrease in soil pH though pH tended to increase again during course of time in both field and pot experiments. The both elemental S and waste applications in pot experiment caused an increase in dry matter yield and P, Fe, zinc (Zn), Mn and Cu uptake (mg pot^‐1) by shoots in sorghum plant. There was also an increase in EC of soil due to both applications of S. The concentration of available P extracted by NaHCO₃ in the pot soil, though not significantly different, was slightly higher compared with the control. Waste applications increased DTPA‐extractable Fe content of the soil, DTPA‐extractable Mn and DTPA‐extractable Cu. DTPA‐extractable Zn content, however, was reduced by the same applications.     

Influence of Liming on Soil Chemical Properties and Plant Growth of Pineapple (Ananas Comusus L.Merr.) On Red Acid Soil,Lampung, Indonesia

ABSTRACT

Red acid soil is generally distributed in humid tropical areas under high rainfall. The main constraint is usually the extremely low pH of the soil due to the very intensive leaching of the bases from the soil. At the same time, however, the soluble micro elements, such as iron, are high. This can cause plant toxicity. The liming of acidic soils is normally performed to reduce the iron toxicity as the first step toward providing a balanced nutrition for cultivated plants. The objective of this study is to determine the effects of liming on the soil pH, on the decrease of iron in the soil and on the growth of the pineapple. The research was done in the Greenhouse of the Research and Development Department, PT Great Giant Pineapple, Lampung, Indonesia, from November 2015 to April 2016. The design of the experiment was arranged as a completely randomized design with seven treatments and three replications, consisting of: No dolomite (D0), dolomite 1 t ha^?1 (D1), dolomite 2 t ha^?1 (D2), dolomite 3 t ha^?1 (D3), dolomite 4 t ha^?1 (D4), dolomite 5 t ha^?1 (D5) with added Fe-EDTA and for the control treatment, no dolomite and no Fe-EDTA (C0). The results showed that an increase in the dolomite dose can increase the pH, potassium (K), calcium (Ca) and magnesium (Mg) in the soil and can decrease the iron (Fe) in the soil significantly. Increasing the pH, K, Ca and Mg and decreasing the Fe in the soil were seen to influence the growth of the pineapple. In particular, the leaf area of the pineapple plant increased considerably. The other parameters also increased, but not significantly.     

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.     

Effects of Forms and Rates of Zinc Fertilizers on Cadmium Concentrations in Two Cultivars of Maize

Abstract

A pot experiment was conducted to investigate the effects of three soluble zinc (Zn) fertilizers on cadmium (Cd) concentrations in two genotypes of maize (Zea mays): Jidan 209 and Changdan 374. Zinc fertilizers were added to soil at four levels: 0, 80, 160, and 240 mg kg^?1 soil as nitrate [Zn(NO₃)₂], chloride (ZnCl₂), and sulfate (ZnSO₄). Cadmium nitrate [Cd(NO₃)₂] was added to all the treatments at a uniform rate equivalent to 10 mg kg^?1 soil. The biomass of maize plants was increased with the application of three zinc fertilizers, of which Zn(NO₃)₂ yielded more than others. Under ZnCl₂ treatment, plant growth was promoted at the lower level and depressed at the higher one. All the three fertilizers decreased Cd concentration in shoots in comparison with treatments without Zn, but there were variations with different forms, especially in plants treated with Zn(NO₃)₂, which had the minimal value. The orders of average Cd concentration in shoots with different zinc fertilizers were ZnSO₄>ZnCl₂>Zn(NO₃)₂ for Jidan 209 and ZnCl₂>ZnSO₄>Zn(NO₃)₂ for Changdan 374, respectively (P<0.001). There was no significant difference between ZnSO₄ and ZnCl₂ treatments. The lowest Cd concentration in shoots was found in the 80‐mg‐kg^?1 soil or 160‐mg‐kg^?1 soil treatment. Cadmium concentration in roots in the presence of ZnCl₂ was the lowest and under ZnSO₄ the highest. The mechanism involved needs to be studied to elucidate the characteristics of complexation of Cl^? and SO₄ ^2? with Cd in plants and their influence on transfer from roots to shoots.     

Zinc Sulfate Foliar Application Effects on Some Physiological Characteristics and Phenolic and Essential Oil Contents of Lavandula stoechas L. Under Sodium Chloride (NaCl) Salinity Conditions

Lavandula stoechas L. plant is a perennial evergreen used as a fragrant ornamental and medicinal plant. In order to study the effect of foliar spray of zinc sulfate (ZnSO₄) (0, 1000, and 2000 mgL^?1) and sodium chloride (NaCl) salinity (0, 75, and 150 mM) on some physiological characteristics of Lavandula stoechas L. plants, a pot experiment was carried out at the Research Greenhouse of Azarbaijan Shahid Madani University, Iran. Physiological characteristics [root and leaf dry weights, total soluble solids (TSSs), total anthocyanins, chlorophyll b, Zn²⁺, potassium (K⁺) contents, and K⁺/Na⁺ ratio] were significantly affected by the interaction effects of ZnSO₄ foliar application and salinity levels. The highest root dry weight, chlorophyll b, anthocyanin, and Zn contents as well as TSS were found in the plants with NaCl₀ × ZnSO_{4 2000} mgL^?1. For Na⁺, the greatest value was recorded with NaCl ₁₅₀ × ZnSO₄₀. The highest K⁺/Na⁺ ratio was found in the control plants. Foliar application of ZnSO₄ promoted the total phenolic content, especially at 2000 mgL^–1. The highest amounts of flower dry weights were recorded at NaCl₀. Chlorophyll a, total flavonoids, stem dry weight, and essential oil content were affected with ZnSO₄ treatment and salinity levels. The highest values for the essential oil content, chlorophyll a content, and stem dry weight were attained by the nonsaline treatment. Both foliar application levels positively influenced the essential oil and flavonoid contents of the plants. The results reveal that zinc application had marked effects on the physiological characteristics of Lavandula stoechas L. plants growing under salinity stress conditions.     

Zinc Application Effects on Yield and Seed Oil Content of Sunflower Grown on a Saline Calcareous Soil

ABSTRACT

Two field experiments (2000–2001 and 2001–2002) were conducted at two nearby fields in the Qanavat region of Qom province, central Iran, to investigate the effects of zinc (Zn) fertilization on production of sunflower. The experiment was conducted in a randomized complete block design with six treatments in three replicates. Treatments were: Zn₀ (non-Zn fertilized), Zn₁₀, Zn₂₀, Zn₃₀, and Zn₆₀ (soil application of 10, 20, 30, and 60 kg Zn ha^?1, respectively), and Zn_Spray (foliar spraying of 0.5 kg Zn ha^?1 using ZnSO₄). Seeds of sunflower (Helianthus annuus cv. ‘Record’) were planted on June 20, 2000 and June 15, 2001. At harvest, shoot and seed yields as well as concentration of Zn, iron (Fe), manganese (Mn), sodium (Na), and chloride (Cl) in leaves of sunflower were determined. Addition of 20 kg Zn ha^?1 significantly increased seed production and shoot dry-matter yield of sunflower, while other Zn treatments had no significant effect on shoot dry-matter yield, or decreased it. The thousand-seed weight was the yield component most affected by Zn fertilization, while plant height and head diameter did not change. The maximum content of seed oil was achieved under the Zn₁₀ treatment, then decreased at higher rates of soil-applied Zn such that oil content of seed under the Zn₃₀ and Zn₆₀, treatments was significantly lower than that of the control. Seed oil content was unaffected by foliar spraying of Zn. The concentration of Zn in sunflower leaves was increased with an increase in soil-added Zn of from 0 to 60 kg Zn ha^?1. The highest leaf concentrations of Zn (162 and 175 mg kg^?1 day matter (DM) in the first and second year, respectively) were achieved by foliar application of ZnSO₄. Leaf concentration of Fe was significantly increased in the Zn₂₀ treatment compared with the control but decreased at the higher rates of soil-added ZnSO₄. Soil addition of different levels of ZnSO₄ decreased concentration of Na and Cl in leaves. The lowest concentration of Na and Cl in leaves was observed under Zn₂₀. The results of this study suggest that soil application of a suitable amount of Zn has a positive effect on both quantitative and qualitative yield of sunflower in saline, calcareous soils.     

Influence of pH on Productivity,Nutrient Use Efficiency by Dry Bean,and Soil Phosphorus Availability in a No‐Tillage System

Abstract

Low pH is one of the most yield‐limiting factors for crop production in Cerrado soils. The objective of this study was to determine influence of soil pH on grain yield and its components, and use of nutrients by dry bean in a no‐tillage system in an Oxisol (Typic Haplorthox) of the Cerrado region of Brazil. Five field experiments were conducted for three consecutive years. The pH levels were low (5.3), medium (6.4), and high (6.8), created by applying lime at the rates of 0, 12, and 24 Mg ha^?1. Grain yield and its components were significantly influenced by soil pH. Adequate pH for grain yield and its components was 6.4. Maximum variation in grain yield was measured by shoot dry weight, and minimum variation was due to 100‐grain weight. Nutrient utilization efficiency was in the order of magnesium (Mg) > phosphorus (P) > calcium (Ca) > potassium (K) > nitrogen (N) > copper (Cu) > manganese (Mn) > zinc (Zn) > iron (Fe). Soil extractable P increased linearly with increasing pH in the range of 5.3 to 7.3. These results show that adequate soil pH is an important soil acidity index in improving bean yield in Brazilian Oxisols.