Enrichment of lithium in lettuce plants through agronomic biofortification

Abstract

Biofortification of crops with lithium (Li) is a new trend in agriculture and researches on this subject still scarce, therefore, this work aims to evaluate the accumulation potential and the effects in agronomic characteristics of lettuce (Lactuca sativa L.) submitted to foliar application of two Li chemical sources and different concentrations. The experiment was conducted in a greenhouse and the applications of lithium hydroxide (LiOH) and lithium sulfate (Li₂SO₄) were done via foliar spray at concentrations ranging from 0 to 40?mg dm^?3. The applications were divided into three applications distributed at 15, 25, and 35?days after transplanting. Positive and promising results were observed in agronomic characteristics and Li in accumulation. High concentrations of Li (40?mg dm^?3) may compromise the development of lettuce plants, however, lower concentrations applied (16 to 26?mg dm^?3 of Li) promoted an increase in dry weight of roots and shoot/root ratio, both chemical forms, and stem diameter and specific leaf area, Li₂SO₄, suggesting beneficial effect of this element. Li accumulation in shoots depend on the concentrations of this element in the applied solution of Li but not on its chemical form.     

Low efficiency of Zn uptake and translocation in plants provide poor micronutrient enrichment in rice and soybean grains

Abstract

Recent research has shown the need for an in-depth knowledge of zinc biofortification of cereal and oilseed grains due to its importance to human nutrition. However, little is known about the Zn dynamics in plant–soil system. In this work, we evaluated the effect of soil-applied Zn on the absorption, translocation, and compartmentalization of Zn in rice (Oryza sativa L.) and soybean (Glycine max L. Merrill) plants. The soil used in the greenhouse experiment was fertilized with zinc chloride (ZnCl₂) at rates of 0, 1, 2, 4, and 8?mg Zn kg^?1. The source of Zn was labeled by ⁶⁵Zn with specific activity of 185.5 kBq mg^?1 Zn. The amount of Zn derived from fertilizer and its use in each plants compartment was determined by direct method in isotopic calculations. Rice and soybean plants presented low efficiency in the absorption from soil-applied Zn. The accumulated Zn in the panicle, pod, and grains was not modified, due to its low translocation in the plant. The Zn uptake in rice plants was from 1.34 to 4.60?mg pot^?1 in shoots and just 0.81 to 1.43?mg pot^?1 translocated to panicles. Soybean plants presented Zn uptake between 2.36 and 4.68?mg pot^?1 in shoots, out of which 0.19 to 0.34?mg.pot^?1 and 0.48 to 0.57?mg pot^?1 translocated to grains and pods, respectively. The nutrient utilization from fertilizer was low, with mean values of 12 and 8.7% for rice and soybean plants, respectively. Soil-applied Zn showed low capacity for enriching rice panicle and soybean pod or grain probably due low Zn uptake and translocation.     

Effect of sulfur source and rates on yield and yield components of soybean in subtropical soils

Abstract

The supply of sulfur (S) fertilizers, such as phosphogypsum, to new agricultural frontiers has been hindered by the high cost of freight. However, this problem could be resolved by utilizing deposits of rock in the affected regions. Accordingly, a greenhouse study was designed to evaluate the effect of S source and rate on soybean yield. Five S rates (0, 50, 100, and 200?mg kg^?1) and five S sources (S-phosphogypsum, S-Niquelândia rock, S-Araripina rock, S-Grajaú rock, and S-Sulfurgran [90% S0?+?10% bentonite]) were applied to soybean grown in two soil types (Typic Ultisol and Typic Oxisol), which differ in clay content. Regardless of soil type, the application of P-phosphogypsum resulted in a higher grain yield. However, application of the other S sources also improved grain yield as well as total dry weight; S application, in general, improved soybean yield components (number of grains per pod, number of pods per pot, and weight of pods per pot), photosynthetic rate, chlorophyll content, and the S levels of leaves and grains as well as the available sulfate (SO₄^2-) levels in the soil. Therefore, for soybean grown in Typic Ultisol and Typic Oxisol, different S sources effectively improve a variety of variables that ultimately improve grain yield.     

Evaluation of the sulphur status of some soils from Portugal

Total S, extractable SO₄, and SO₄^? retention capacity were determined in a range of soils covering the dominant soil groups in Portugal which are expected to show S deficiency. Total S was relatively low (83–435 mg S kg^?1) in all soils and KH₂PO₄^? extractable SO₄ was, in general, low for plant growth, ranging from 0.9 to 32.2 mg S kg^?1. SO₄^? retention capacity ranged from ?33.1 to 64.7 mg S kg^?1 and was negative in many (14 out of 20) of the soils. Most of the soils are expected to be S deficient and show extensive leaching of SO₄. Other selected soil properties that may affect the chemistry of SO₄ were determined. A highly significant simple correlation was obtained between SO₄ adsorbed and extractable Al by the Mehra and Jackson method (CDB-Al) (r = 0.74; P < 0.001). A multiple regression which included silt improved the correlation of SO₄ adsorbed with CDB-Al (r = 0.79; P < 0.001).     

Inoculation of arbuscular mycorrhizal fungi can substantially reduce phosphate fertilizer application to Allium fistulosum L. and achieve marketable yield under field condition

The effects of inoculating arbuscular mycorrhizal (AM) fungi on the growth, phosphorus (P) uptake, and yield of Welsh onion (Allium fistulosum L.) were examined under the non-sterile field condition. Welsh onion was inoculated with the AM fungus, Glomus R-10, and grown in a glasshouse for 58?days. Non-inoculated plants were grown as control. Inoculated and non-inoculated seedlings were transplanted to a field with four available soil P levels (300, 600, 1,000, and 1,500?mg P₂O₅?kg^?1 soil) and grown for 109?days. AM fungus colonization, shoot P concentration, shoot dry weight, shoot length, and leaf sheath diameter were measured. Percentage AM fungus colonization of inoculated plants was 94% at transplant and ranged from 60% to 77% at harvest. Meanwhile, non-inoculated plants were colonized by indigenous AM fungi. Shoot length and leaf sheath diameter of inoculated plants were larger than those of non-inoculated plants grown in soil containing 300 and 600?mg P₂O₅?kg^?1 soil. Shoot P content of inoculated plants was higher than that of non-inoculated plants grown in soil containing 300 and 600?mg P₂O₅?kg^?1 soil. Yield (shoot dry weight) was higher for non-inoculated plants grown in soil containing 1,000 and 1,500?mg P₂O₅?kg^?1 soil than for those grown in soil containing 300 and 600?mg?P₂O₅ kg^?1 soil. Meanwhile, the yields of inoculated plants (200?g plant^?1) grown in soils containing the four P levels were not significantly different. Yield of inoculated plants grown in soil containing 300?mg P₂O₅ kg^?1 soil was similar to that of non-inoculated plants grown in soil containing 1,000?mg P₂O₅?kg^?1 soil. The cost of AM fungal inoculum for inoculated plants was US$ 2,285?ha^?1 and lower than the cost of superphosphate (US$ 5,659?ha^?1) added to soil containing 1,000?mg P₂O₅ kg^?1 soil for non-inoculated plants. These results indicate that the inoculation of AM fungi can achieve marketable yield of A. fistulosum under the field condition with reduced application of P fertilizer.     

伴随阴离子对马铃薯种植冲击土中钾素固持与淋溶的影响

A column study was carried out to assess the influence of accompanying anions on potassium (K) leaching at potato growing sites with different soil textures (sandy loam and clay loam) in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg^-1 through different sources having different accompanying anions (Cl^-, SO₄^2-, NO₃^- and H₂PO₄^-). Maximum K was retained in the top 0--15 cm layer with a sharp decrease in K content occurring in 15--30 cm layer of the soil column. The trend was similar for both levels of applied K as well as frequency of leaching and soil type. The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg^-1, indicating higher potential of clay rich soil to adsorb K. In general, the K leaching in presence of the accompanying anions followed the order of SO₄^2- ≤ H₂PO₄^2- < NO₃^- = Cl^-. Highest 1 mol L^-1 CH3COONH4-extractable K was retained when K was applied along with SO42- and H2PO4- anions, and the least was retained when accompanying anion was Cl^-1. The influence of anions was more pronounced in the light textured soil and at high amounts of K application. Higher levels of K application resulted in higher losses of K, especially in sandy loam soil as observed from the leachate concentration. Among the different K sources, the maximum amount of K leaching was noticed in the soil column amended with KCl. After four leachings, the maximum amount of K leached out was 6.40 mg L^-1 in Hundowal clay loam and 9.29 mg L^-1 in Khanaura sandy loam at 60 mg K kg^-1 of soil application through KCl. These concentrations were lower than the recommended guideline of the World Health Organisation (12.00 mg L^-1).     

Soybean response to copper applied to two soils with different levels of organic matter and clay

Abstract

Increasing the amount of soil organic matter (OM) alters the availability of copper (Cu) for plants under tropical and subtropical conditions. With the aim of evaluating the effects of the OM/Cu interaction on the soybean crop, a trial was conducted with a fully randomized 2?×?5 factorial design and four replicates. The treatments consisted of five Cu rates (0, 1, 2, 4 and 8?mg kg^?1) and two soil types: Typic Oxisol and Typic Ultisol. The soybean responded to fertilization with Cu, producing the highest estimated grain yield at a rate of 4.1?mg kg^?1. Similarly were also observed for shoot dry weight, number of pods and root length. The soil chemical properties and nutrient levels in the leaves and grain were influenced only by the soil type, whereas physiological components were affected in terms of photosynthetic rate and intercellular CO₂ concentration.     

Manganese foliar supplementation impacts rice yield in tropical lowlands

Abstract

The aim of this work was to evaluate manganese (Mn) sources and levels effects in irrigated rice production in central Brasil (tropical lowlands of Tocantins state). The experiment was conducted in a 5x5?+?1 factorial scheme, five Mn sources and five levels (0.5; 1.0; 1.5; 2.0; and 2.5?kg ha^?1), applied in induction of tillering of rice plants, plus a control without treatment, and Mn content in leaves (mg kg^?1), number of panicles per area (m²), hundred grains weight (g), intact grains (%), and grain yield (kg ha^?1) were analyzed. Treatments with Mn-carbonate source got the best results and this source at the level of 1.5?kg ha^?1 provided the highest yield: 7,375?kg ha^?1. Higher values were obtained with the application of 1.0 to 1.5?kg ha^?1 of Mn, except for the intact grains where the best means were obtained at 2.5?kg ha^?1.     

RESPONSE OF SOYBEAN TO SOIL APPLIED SULFUR AND BORON IN A CALCAREOUS SOIL

A greenhouse experiment with soybean grown on sulfur (S) and boron (B) deficient calcareous soil was conducted for two years in northwest India to study the influence of increasing sulfur and boron levels on yield and its attributing characters at different growth stages (55 days, maturity). The treatments included four levels each of soil applied sulfur viz. 0, 6.5, 13.4, 20.1 mg S kg^?1 and boron viz. 0, 0.22, 0.44, 0.88 mg B kg^?1 at the time of sowing. The highest dry matter yield at 55 days after sowing, DAS (19.3 g pot^?1) and maturity (straw yield ?25.2 g pot^?1 and grain yield ?7.3 g pot^?1) was recorded with B_0.44 S_13.4 treatment combination. The combined applications of sulfur and boron yielded highest oil content with B_0.44S_13.4 (21.7%) treatment level. Chlorophyll ‘a’ and ‘b’ increased significantly with successive levels of sulfur and boron addition at 55 DAS. The mean sulfur and boron uptake in straw and grains increased significantly with increasing levels of sulfur and boron up to 13.4 mg kg^?1 and 0.44 mg kg^?1 and decreased non-significantly thereafter. At both the growth stages, a synergistic interactive effect of combined application of sulfur and boron was observed with B_0.44 S_13.4 treatment level for sulfur and boron uptake in straw and 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.     

AGRONOMIC EFFICIENCY AND PROFITABILITY OF P-FERTILIZERS APPLIED AT DIFFERENT PLANTING DENSITIES OF MAIZE IN NORTHWEST PAKISTAN

The use of appropriate source of phosphorus (P) fertilizer at different planting densities has considerable impact on growth, grain yield as well as profitability of maize (Zea mays L). Field experiment was conducted in order to investigate the impact of P sources [(S₀ = P not applied, S₁ = SSP (single super phosphate) S₂ = NP (nitrophos), and S₃ = DAP (diammonium phosphate)] on maize growth analysis, yield and economic returns planted at different planting densities (D₁ = 40,000, D₂ = 60,000, D₃ = 80,000, and D₄ = 100,000 plants ha^?1) at the New Developmental Agricultural Research Farm of Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan, during summer 2006. This paper reports the profitability data with two objectives: 1) to compare agronomic efficiency and profitability of P-fertilizers, and 2) to know whether plant densities affect agronomic efficiency and profitability of P-fertilizers. Application of DAP and SSP resulted in higher partial factor productivity (PFP) (63.58 and 61.92 kg grains kg^?1 P), agronomic efficiency (AE) (13.01 and 13.71 kg grains kg^?1 P) and net returns (NR) (Rs. 16,289 and 16,204 ha^?1), respectively, while NP stood at the bottom in the ranking with lower PFP (57.16 kg grains kg^?1 P), AE (8.94 kg grains kg^?1 P) and NR (Rs. 4,472 ha^?1). Among the plant densities, D₃ stood first with maximum PFP (69.60 kg grains kg^?1 P), AE (18.21 kg grains kg^?1 P) and NR (Rs. 21,461 ha^?1) as compared to other plant densities. In conclusion, the findings suggest that growing maize at D₃ applied with either SSP or DAP is more profitable in the wheat-maize cropping system in the study area.     

Alleviation of salt stress by increasing potassium sulphate doses in four medicinal and aromatic plants

In this study, the effects of potassium doses (control, 150, 300 and 450?mg K₂SO₄ kg^?1) and salt stress (control, 100?mM NaCl) on the yield and some element content of four medicinal and aromatic (Coriandrum sativum, Anethum graveolens, Ocimum basilicum and Foeniculum vulgare) plants were investigated in climate chamber. Both salinity and K fertiliser levels affected the fresh and dry weight of all evaluated plants. Anethum graveolens, Ocimum basilicum species are more sensitive to salinity, particularly at the vegetative productive stages. The highest fresh and dry weights of leaves, stems, roots and herb in Coriandrum sativum and Foeniculum vulgare species was observed in 300?mg?kg^?1 fertiliser applications. In general, there was a relatively consistent and positive correlation between root element content and aerial parts element content. The result of the present study showed that NaCl treatment caused an increase in Na⁺ concentration, and a decrease in K⁺ and Ca⁺² concentration in Coriandrum sativum, Anethum graveolens, Ocimum basilicum and Foeniculum vulgare. There was an interaction between K₂SO₄ application and salinity effects on Na⁺ concentration in the all evaluated plants. Given the experimental results, especially Foeniculum vulgare and Coriandrum sativum species were the most resistant to salt stress.     

Determining critical limit of boron in soil for wheat (Triticum aestivum L.)

Abstract

Critical values of boron (B) for wheat nutrition in soil and plant were determined through a pot experiment with twenty-one surface soils of Alluvial flood plain and Red-latertic belt comprising three major soil orders (Entisols, Alfisols, Inceptisols) with four levels of boron. Application of boron significantly increased the dry matter yield as well as uptake of B by plants. Critical concentration of hot calcium chloride (CaCl₂) extractable B in soil for wheat was found to be 0.53?mg?kg^?1. The critical plant B concentration varied with growth stages and values were 7.4?mg?kg^?1 at panicle initiation and 4.18?mg?kg^?1 at maturity, respectively. The findings of this investigation also recommend the application of 2?kg?B^?1?ha^?1 for ensuring B sufficiency to wheat in Indo-gangetic alluvial and Red-Lateritic soils.     

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.     

Quantification of Inorganic Anions in Tea (Camellia Sinensis (L) O. Kuntze) Tissues and Soil Using Ion Chromatography Coupled with Conductivity Detector

A simple ion chromatographic method is proposed for the simultaneous quantification of five inorganic anions in samples derived from tea system with a suppressed conductivity detector. For this purpose extracts of leaves, roots and soils of tea obtained at room temperature yielded chromatographic profiles with substantial differences in the relative contents of fluoride (F^?), chloride (Cl^?), nitrate (NO₃^?) and sulfate (SO₄ ^2-). Although Cl^? and SO₄^2- were common to each extracted sample in different categories and accounted for the majority of the anions present, one additional anion peak was detected in root and leaf tissues. Irrespective of the clone and sample investigated the average F^? content varied from 253 to 1664 mg kg^?1, Cl^? varied between 60 and 1789 mg kg^?1, NO₃^? varied from 119 to 188 mg kg^?1 and SO₄^2- varied between 55 and 6779 mg kg^?1. The anionic load was at its crest in clone UPASI – 3 in all the three categories of samples with few exceptions. Among the samples investigated, tea roots contained a considerable amount of major anions, while tea soils had the lowest amount of the detected anions. The recovery of all the quantified anions was above 95%. The correlation coefficient for all anions where above 99.50%. The concentration of nitrite (NO₂^?) was below the limits of detection based on the analytical technique adopted. Anion nitrate was not detected in tea root and tea leaf extracts.     

Micronutrient availability in soils of Northwest Bosnia and Herzegovina in relation to silage maize production

Maize (Zea mays L.) is the most widely grown crop in Bosnia and Herzegovina especially in Northwest part of the country. Considering that, the maize is extremely sensitive to micronutrient deficiency the main aim of this study was to asses: (1) micronutrient availability in soil, (2) micronutrient status in silage maize; and (3) the relationship between micronutrient soil availability and maize plant concentration. Soil samples for micronutrient availability (n?=?112) were collected from 28 farms in 7 municipalities. Plant available micro- and macro- nutrients in soil were extracted using Mehlich-3, except plant available Se was extracted using 0.1M KH₂PO₄. Result showed that on average there was no significant difference between different soil types regarding their potential in plant available nutrients. P deficiency was present both, in soil and plants in whole region. Soil extractable P was ranging from 0.003–0.13?g?kg^?1 and total plant P was ranging from 0.79–4.95?g?kg^?1. Zinc deficiency was observed in two locations both in soil (0.71?mg?kg^?1; 0.79?mg?kg^?1) and plant (11.5?mg?kg^?1; 15.8?mg?kg^?1). Potential Se soil deficiency was observed on some locations, while Se plant status is not high enough to meet daily requirements of farm animals. Extractable soil nutrients could be used as relatively good predictor of potential soil and plant deficiencies, but soil nutrient interactions and climate conditions are highly effecting the plant uptake potential.     

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.     

Yield enhancement and biofortification of chickpea (Cicer arietinum L.) grain with iron and zinc through foliar application of ferrous sulfate and urea

Abstract

This study investigated effects of iron (Fe) and nitrogen (N) foliar application on Fe and zinc (Zn) content in chickpea grain, grain yield, and protein content. Application of FeSO₄ at 0.5% at flowering?+?pod formation stages resulted in the highest Fe (73.50 and 75.34?mg Fe kg^?1 grain in first and second year) and Zn (35.08 and 34.21?mg Zn kg^?1 grain) content in grain followed by the application of FeSO₄ at 0.5% at flowering stage alone (68.27 and 69.97?mg Fe kg^?1 grain and 32.44 and 32.27?mg Zn kg^?1 grain) and control (54.63 and 55.69?mg Fe kg^?1 grain and 29.48 and 29.07?mg Zn kg^?1 grain). Urea spray at 2% at flowering as well as at flowering?+?pod formation stages also improved the Zn and Fe content in the grain. Combined use of Fe and urea improved the grain Fe and Zn content over sole application of Fe.     

Multiple element concentration in the grain of spring barley (Hordeum vulgare L.) collection

Multiple element analyses were carried out to investigate variation in element concentrations in barley grains of 336 genotypes. Of 13 elements analyzed, Ba ranged from 0.2 to 8.9?mg kg^?1, Ca from 186.4 to 977.5?mg kg^?1, Cu from 1.5 to 9.8?mg kg^?1, K from 353.2 to 7721.5?mg kg^?1, Mg from 1049.8 to 2024.2?mg kg^?1, Mn from 8.1 to 22.9?mg kg^?1, Na from 55.9 to 627.9?mg kg^?1, P from 2272.9 to 5428.8?mg kg^?1, S from 880.7 to 1898.0?mg kg^?1, Si from 19.1 to 663.2?mg kg^?1, and Sr from 0.35 to 2.62?mg kg^?1 in the barley grain. The least square means showed high Zn, Fe, Mg, P, and S concentration in AM-64 and AM-228 genotypes. The principal component analysis of element concentration showed four PCs explained 64.3% total variance. Strong positive correlations (p?<?0.001) of Fe-Mn, Fe-S, S-Mn, Zn-P, Zn-Mg, Mg-P, Mg-Mn, and Ca-Sr were found. The identification barley genotypes that showed high elements concentration furnish valuable genetic resources for biofortification in future.     

Evaluation of Extractants and Quantity–Intensity Relationship for Estimation of Available Potassium in Some Calcareous Soils of Western Iran

Accurate estimation of the available potassium (K⁺) supplied by calcareous soils in arid and semi‐arid regions is becoming more important. Exchangeable K⁺, determined by ammonium acetate (NH₄OAc), might not be the best predictor of the soil K⁺ available to crops in soils containing micaceous minerals. The effectiveness of different extraction methods for the prediction of K‐supplying capacities and quantity–intensity relationships was studied in 10 calcareous soils in western Iran. Total K⁺ uptake by wheat grown in the greenhouse was used to measure plant‐available soil K⁺. The following methods extracted increasingly higher average amounts of soil K⁺: 0.025 M H₂SO₄ (45 mg K⁺ kg^?1), 1 M NaCl (92 mg K⁺ kg^?1), 0.01 M CaCl₂ (104 mg K⁺ kg^?1), 0.1 M BaCl₂ (126 mg K⁺ kg^?1), and 1 M NH₄OAc (312 mg K⁺ kg^?1). Potassium extracted by 0.01 M CaCl₂, 1 M NaCl, 0.1 M BaCl₂, and 0.025 M H₂SO₄ showed higher correlation with K⁺ uptake by the crop (P < 0.01) than did NH₄OAc (P < 0.05), which is used to extract K⁺ in the soils of the studied area. There were significant correlations among exchangeable K⁺ adsorbed on the planar surfaces of soils (labile K⁺) and K⁺ plant uptake and K⁺ extracted by all extractants. It would appear that both 0.01 M CaCl₂ and 1 M NaCl extractants and labile K⁺ may provide the most useful prediction of K⁺ uptake by plants in these calcareous soils containing micaceous minerals.