Plant Nutrition, Soil Fertility and Fertilizers
Sepideh Raeisi; Nafiseh Rangzan; Naeimeh Enayatizamir
Abstract
Introduction: Zinc (Zn) is a vital nutrient for plants, needed in small amounts for their reproductive and physiological functions. Zinc deficiency is common in soils with high pH, low organic matter, and high calcium carbonate. Soil salinity is one of the most important and common environmental stresses ...
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Introduction: Zinc (Zn) is a vital nutrient for plants, needed in small amounts for their reproductive and physiological functions. Zinc deficiency is common in soils with high pH, low organic matter, and high calcium carbonate. Soil salinity is one of the most important and common environmental stresses in the world. The impact of salinity on the forms of zinc and its availability in soil has varied. Among the chemical forms of zinc, the soluble and exchangeable forms have the highest mobility and availability for plants; whereas the residual form, associated with the crystalline lattice of soil minerals, appears to be very inactive. Depending on the physical and chemical properties of the soil, the carbonate forms, those bound to iron and manganese oxides, and the organic forms of elements are relatively active and have the potential to be available for plants. Organic materials like carbon black can alter zinc distribution. Zinc-solubilizing bacteria enhance zinc availability by converting insoluble forms into absorbable ones. This study examines the effects of carbon black and growth-promoting bacteria on zinc forms and soil properties under varying salinity levels.Materials and Methods: In this study, to investigate the effect of carbon black and inoculation of a mixture of two bacteria on the distribution of chemical forms of zinc under salinity stress, a pot experiment with four replications was conducted as factorial with three factors: salinity (2, 5, and 8 dS m-1), carbon black (0, 4% by weight), and a mixture of two bacteria (inoculated and non-inoculated). The bacteria included Enterobacter cloacae and Bacillus sp., which were obtained from the microbial collection of the Soil Science Department at Shahid Chamran University of Ahvaz. The experiment was carried out in a completely randomized design in 2023 in the greenhouse of Khuzestan Agricultural Sciences and Natural Resources University. In 5-kilogram pots, 10 corn seeds were planted, which were reduced to 6 plants per pot after ensuring germination. Two months after planting, soil samples were taken from the pots, and after removing the roots and passing through a 2-millimeter sieve, they were transferred to the laboratory to determine the chemical forms of zinc. The sequential extraction method was used to determine the chemical forms of zinc. The fractions—exchangeable, carbonate, iron and manganese oxides, organic, and residual—were determined. The concentration of zinc in the extracts obtained from the various stages of sequential extraction of the soil was read using an atomic absorption device. Some biological properties of soil, such as microbial biomass carbon via fumigation-extraction method, catalase activity via the titration method, and soil respiration by titration of residual NaOH, were measured.Results and Discussion: The interaction effect of carbon black× inoculation× salinity on chemical forms of Zn was significant. The results showed that the inoculation of a mixture of two bacteria and addition of carbon black in soil significantly increased the soluble and exchangeable, carbonate, iron and manganese oxide, and organic forms of zinc. Inoculation of a mixture of two bacteria and carbon black to the soil at a salinity level of 2 dSm-1 resulted in an increase in EXCH-zinc from 1.02 to 1.38 mgkg-1 compared to the control, which is equivalent to a 35% increase. Inoculation of the bacterial mixture and the addition of carbon black to the soil increased all forms of zinc except the residual form. With increasing salinity level, the amounts of soluble and exchangeable, carbonate-bound, and oxide-bound forms increased, while the organic-bound form decreased. The highest amounts of microbial biomass carbon, catalase activity, and soil respiration were measured in the treatment with bacteria, carbon black, and at a salinity level of 2 dS m-1, with values of 19.9 mg-Cmic 100g-1, 0.95 mLKMnO4g-1h-1, and 70.2 mgCO2 100g-1day-1, respectively. There was a positive correlation between soil respiration and all forms of zinc, except the residual form, but the correlation between soil respiration and the residual form of zinc was negative, indicating the influence of microbial activity on different forms of zinc.Conclusion: The addition of a carbon black to the soil and inoculation of a mixture of two bacteria caused zinc to convert from residual form to soluble and exchangeable, carbonate, oxide, and organic forms, increasing the availability of zinc in accessible fractions at various salinity levels. Overall, zinc-solubilizing bacteria offer a promising solution for enhancing zinc availability in saline soils, promoting plant health, and contributing to sustainable agricultural practices.
Zahra Rezaee; Mojtaba Norouzi masir; Abdolamir Moezzi
Abstract
Introduction:Organic matter based on their composition and the C/N ratio can have different effects on nutrient bioavailability, concentration and uptake in soil and plant. Beside that, organic fertilizer can increase the yield of different agricultural products and pave the wey for emergence of sustainable ...
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Introduction:Organic matter based on their composition and the C/N ratio can have different effects on nutrient bioavailability, concentration and uptake in soil and plant. Beside that, organic fertilizer can increase the yield of different agricultural products and pave the wey for emergence of sustainable agricultural . Organic matter is relatively low in majority of soils in Iran, and continuous use of chemical fertilizer would create environmental hazards . Zinc deficiency is a worldwide nutritional constraint in crop production particularly in cereals growing on calcareous soils .Materials and methods:This research was conducted to investigate the effects of organic fertilizers such as bagasse, compost and biochar and chemical fertilizer ZnSo4 on yield of wheat and concentration and uptake of Zn in wheat ,a study based on randomized complete block design with 3 replications was conducted in Greenhouse Faculty of Agriculturar of Shahid Chamran University of Ahvaz during the years1395-96. Treatments included:1-control ,2- ZnSo4 , 3-Bagasse 4- Biochar 5- compost. Some Physical and chemical properties were determined using standard methods (table1).some basic properties of bagasse , compost and biochar were also determined (table 2). after the experiment ,soil and plant properties such as pH, organic matter content(OM), available Zn in soil. and yield , yield components and concentration and uptake of Zn in wheat were determined in samples.After seed ripening grain , yield and component yield were measured from the total pot of each treatment.Statisical analysis of the data was performed using SAS software and comporision using Toki method was also performed.Results: the intial soil was clay loam with organic matter content( om=0.79).Results showed that the treatments had significant effect (p≤ 0.01) on percentage of organic carbon, organic matter, the availability of Zn and pH of soil . Also content of soil micro element affected by treatments and amount of these parameters were increased by using of organic fertilizers .Increase the organic matter in soil by compost improved a must of chemical peroperties and Increase concentration nutrient element in soil. Results showed that pH in the control decreased significantly from 7.74 of soil to 7.53 of soil in the compost. Results showed that the available Zn in the control increased significantly from 0.5 mg kg-1 of soil to 0.71 mg kg-1 of soil in the compost.The results of the experiment showed that all treatments except bagsse increased factors wheat yield . Compost showed greatest yield and bagasse the lowest yield in the the wheat root, grain and shoots (compared to the control). The highest grain yield was obtained from the application of compost. The maximum amount of chlorophylls (a, b, total and SPAD), with application compost. The highest Plant height was obtained from the application of biochar. The results showed that the highest and the lowest of va lue concentration and uptake of Zn in wheat to compos and bagasse respectivity. The maximum amount of chlorophylls (a, b, total and SPAD), with application compost. The highest Plant height was obtained from the application of biochar. The results showed that the highest and the lowest of va lue concentration and uptake of Zn in wheat to compos and bagasse respectivity. Discussion:The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .The obtained result highlight the increased effects of compost on yield and yield components and Zn uptake change in wheat, also in comparison to other treatments, it emphasizes ore on the soil though they were useful too. Therefore, it can be concluded that applying organic fertilizers especially composted form would have, useful effects on plant growth and increasing the concentration of Zn of wheat .
Soil Chemistry and Pollution
Hadi Habiby; Alireza Movahedi; Mojtaba Khoshravesh; Alireza Saberi
Abstract
Introduction Increasing the yield and, consequently, increasing the concentration of macro and micro nutrients in the plant is one of the important aspects of agriculture. The improvement of the quality and quantity of some elements, such as potassium, zinc, and iron in the soil can cause an increase ...
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Introduction Increasing the yield and, consequently, increasing the concentration of macro and micro nutrients in the plant is one of the important aspects of agriculture. The improvement of the quality and quantity of some elements, such as potassium, zinc, and iron in the soil can cause an increase in the yield of the crop and the concentration of these elements in plant tissues. The increase in the concentration of these elements in plants can be effective in the health of livestock and consequently the health of humans. One of the new approaches that can be used in this field is the use of magnetic water. Magnetic water is obtained by passing water from a magnetic field. An externally applied magnetic field causes changes in the atomic, molecular, and electronic structure of the treated water, such as changes to its solidifying and boiling points, viscosity and the dielectric constant, the formation of clustering structures from linear and ring hydrogen-bound chains of molecules, the magnetic interaction between these clustering structures, and increasing the polarization effects of water molecules. The biological effects of magnetic field or electromagnetic field treatments depend on the strength and exposure period of water conditioning, in particular, the ion content, quality, and the volume of water. Materials and Methods For this purpose, a field experiment was conducted in a factorial arrangement with two main treatments, adding and without adding potassium and zinc fertilizers, and five sub-treatments (magnetic field strengths, including a 0.4 Electromagnetic Coil (EC), 0.3 magnet, 0.3 EC, 0.1 EC, and the control treatment) in four replications at Research Station of Goran University of Agricultural and Natural Resources. The size of each experimental plot was 2 m × 2.5 m. Corn was planted in each plot with the distances of 15 cm from each other and rows with distances of 70 cm from each other. An electromagnetic coil and a permanent magnet were used to create a magnetic field. Water was passed from the middle of this magnetic field through a hose and the plots were irrigated with this magnetic water. The irrigation was conducted based on soil moisture content and continued until the harvest and drying of the plants. Soil and plant samples were taken at two flowering and harvesting stages and were transferred to the laboratory for analyzation. Concentrations of Zn and Fe in the soil and plant tissues were measured. Statistical analysis was performed using the SAS software. Results and Discussion The results of this study showed that all the plots that were irrigated by magnetic water had corn plants with greater height and more yield was obtained than the control treatments. This could be due to the ease of absorbing water from the soil. Magnetic water has lower surface tension than untreated water, so the plant needs less force to absorb water from soil particles. Also, the plants that were irrigated by magnetic water had higher concentrations (P <0.01) of elements such as zinc and iron in their cobs. Magnetic water can increase the availability of the elements in the soil. So, more concentration of elements can be absorbed by the roots and transferred to the aerial parts of the plants. Among the magnetic water treatments, 0.4 Tesla strength treatment had the highest effect on the yield and corn height, as well as zinc and iron concentration in cobs (P <0.01). Higher strengths of the magnetic field (0.4 T) had more effect on the availability of elements in the soil and their absorption by the plants. The yield of corn in 0.4 EC, 0.3 M, 0.3 EC, and 0.1 EC treatments that potassium and zinc fertilizers were added to them increased as compared to the control. So, increasing the strength of the magnetic field had more effects on some soil properties. The treatments that K and Zn fertilizers were added to them had more yield than other treatments that these fertilizers were not added to them. This could be attributed to the fact that magnetic water has increased the solubility of K and Zn fertilizers. In fact, magnetic water has been able to increase the uptake of Zn from the soil. Conclusion These results indicate that the magnetization of water can be used as an appropriate approach to increase the quantity and quality of product yield and the concentration of the elements in the crops.
Plant Nutrition, Soil Fertility and Fertilizers
banafsheh rezaee niko; Naeimeh Enayatizamir; mojtaba norozi masir
Abstract
Introduction Zinc is one of the imperative micronutrients required relatively in small concentrations in tissues for healthy growth and reproduction of plants. Zinc deficiency in plants leads to reduced membrane integrity and synthesis of carbohydrates, auxins, nucleotides, cytochromes, and chlorophyll ...
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Introduction Zinc is one of the imperative micronutrients required relatively in small concentrations in tissues for healthy growth and reproduction of plants. Zinc deficiency in plants leads to reduced membrane integrity and synthesis of carbohydrates, auxins, nucleotides, cytochromes, and chlorophyll and develops susceptibility to heat stress. The solubility of Zn is highly dependent upon soil pH and moisture and hence arid and semiarid areas are often zinc-deficient. The use of microorganisms with the aim of improving nutrients availability for plants is an important practice and necessary for agriculture. Zinc-solubilizing microorganisms can solubilize zinc from inorganic and organic pools of total soil zinc and can be utilized to increase zinc availability to plants. Therefore, the present study was carried out to isolate and characterize native zinc-solubilizing bacteria from Zea mays rhizosphere and evaluate their zinc-solubilizing potential and the effect of zinc solubilizing isolate on Zea mays growth.Materials and Methods: In vitro zinc solubilization assay of isolates was done using 0.1% zinc from zinc oxide in both plate and broth assays. Actively growing cultures of each isolates were spot-inoculated (7 µL) onto the agar and plates were incubated at 28°C for 48 h. The clearing zone around colony was recorded. Quantitative study of zinc solubilization was studied in 150 mL conical flasks containing 50 mL of liquid mineral salt medium. The broth was inoculated with 10 µL of overnight grown bacterial inoculum and incubated for 72 h at 160 rpm in an incubator shaker at 28°C. After incubation, the culture broth was centrifuged and the concentration of Zn in the supernatant was estimated in atomic absorption spectrophotometer. Among these isolates, 18 isolates with a solubility index of 1 and higher were selected based on morphological, biochemical and physiological characteristics for further studies. An isolate with more ability to dissolve zinc, phosphorus, potassium and auxin production were selected for investigation the effect of isolate on Zea mays growth. Maize seeds of cultivable variety were surface sterilized with 1% sodium hypochlorite for 5 min and washed several times with sterile distilled water. Seeds were treated with inoculum containing 108 cfu•g−1 of isolate. A factorial experiment in a completely randomized design with five replications was conducted. The treatments included two levels of bacteria B1 (control), B2 (Stenotrophomonas) and zinc sulfate fertilizer at three levels of Zn0 (control), Zn20 (20 kg/ha) and Zn40 (40 kg/ha). After 60 days of sowing, plants were removed from the tubes carefully and biometric parameters like root length, shoot length and dry mass of plants were recorded as the indicative of plant growth. Results and Discussion: A total of 50 bacterial isolates were isolated from corn rhizosphere. Of all, sixteen isolates showed solubilization halo on plate agar medium. Among the cultures, Z1, Z3, Z16 and Z12 showed the highest solubilisation zone in ZnO amended medium with maximum solubility index (1.3). Quantitative assay for zinc solubilisation revealed that Z14 were able to dissolve 44.8 ppm from ZnO in liquid medium. While solubility index of this isolate was lower that above mentioned isolates (1). Of all, the isolate Z14 with highest zinc solubilisation by broth assay was characterized and identified as Stenotrophomonasspecies based on Gram-negtive reaction and other biochemical and physiological properties. This isolate was able to produce auxin and dissolve insoluble phosphorus and potassium from the source tricalcium phosphate and vermiculte, respectively. One of these strains (Z14), Stenotrophomonas was used as inoculum in corn culture. Seed bacterization of maize with zinc solubilising Stenotrophomonas enhanced the plant growth significantly after 15 days. Results indicated a significant interaction effect of bacterium and fertilizer on shoot dry weight and chlorophyll content (p < 0.01). The maximum spad index and wet weight of aerial part obtained at present of bacterium and without using of zinc sulfate. The main effect of bacterium on wet and dry weight of root and wet weight of aerial part, root length and shoot height was significant (p < 0.01). َApplication of bacterium in all treatments caused to increased all measured parameters in th eperesence of zinc fertilizer or absence of zinc fertilizer.Conclusion: PGPR is known as a group of useful rhizospheric bacteria that increase plant growth. Today, the increasing use of PGPRs in agriculture as an alternative to chemical fertilizers to prevent environmental contamination.
