Plant Nutrition, Soil Fertility and Fertilizers
Narges Sousaraei; Mojtaba Barani Motlagh; Seyed Alireza Movahedi Naeini
Abstract
Introduction: When the supply of micronutrients needed by the plant is insufficient, not only the yield of the product but also the quality of plant products are affected. Application of organic amendments is one of the ways to increase the nutrients such as zinc uptake by plants for. Biochar can be ...
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Introduction: When the supply of micronutrients needed by the plant is insufficient, not only the yield of the product but also the quality of plant products are affected. Application of organic amendments is one of the ways to increase the nutrients such as zinc uptake by plants for. Biochar can be used as a raw material for the preparation and synthesis of mineral or metal composites due to its high specific surface area, porous structure and oxygen bonding groups on its surface. In these composites, biochar is used as a good porous structure to support and host metals. Biochar can have a significant impact on soil properties, the availability of nutrients, and the dynamics of the nutrients in arid and semi-arid soils, Depending on the feedstock and pyrolysis conditions However, very limited studies have examined biochar use as a nutrient carrier in the synthesis of organic-mineral compounds. Therefore, the present study was done to investigate the efficiency of zinc-enriched biochar pellets using two pre-pyrolysis and post- pyrolysis methods, and their effect on some physiological traits (chlorophyll a, b and total) and bioavailability of zinc in soil and plant.Materials and Methods: A zinc deficiency Soil was collected from 0-30 cm depth under arable lands of Seyed Abad located in Azadshahr township, Golestan Province, Iran. To achieve the objectives of this study, a factorial experiment in a completely randomized design with three replications and 18 treatments (54 pots in total) was performed in the greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. Factors included three types of zinc fertilizers (zinc sulphate, zinc-rich biochar prepared using pre-pyrolysis and post-pyrolysis methods) in three levels (0, 10 and 20 mg kg-1 zinc) and foliar spraying (distilled water and 3:1000 zinc). Zinc foliar spraying was done during the 6-10 leaf stage in the early hours of the morning before sunrise. Irrigation and weeding operations were performed manually. At the end of the growing period (vegetative and reproductive), some physiological traits (chlorophyll a, b, total and carotenoid), concentration and zinc uptake in shoots in the two stages of flag leaf emergence and seed maturity, and available concentration of zinc in the soil after wheat plant harvest were measured. The statistical results of the data were analyzed using SAS software and LSD test (at 5% level) was used for comparing the mean values.Results and Discussion: Based on the results, the interaction of type and levels of treatments was significant on all the studied traits at P<0.01, except for carotenoid. The means comparison showed that both zinc-enriched biochar pellets and zinc sulfate increased physiological traits in wheat plants. The highest amount of chlorophyll a, b, and total was obtained with an average of 4.99, 3.36, and 8.35 mg g-1 of fresh weight of the plant from the treatment of a pre-pyrolysis pellet with a concentration of 20 mg kg-1 with zinc sulfate foliar spraying, respectively. The highest zinc uptake in both the flag leaf emergence and seed maturity stages was obtained with an average of 120.33 and 86.62 mg kg-1 of dry weight of the plant from the pre and post-pyrolysis pellet treatment with a concentration of 20 mg/kkg with zinc sulfate foliar spraying, which had an increase of 20 mg kg-1 of zinc sulfate foliar spraying, respectively, equivalent to 27.69 and 30%. The pre-pyrolysis pellet treatment with 20 mg kg-1 zinc and zinc sulfate foliar spraying gave the most zinc extracted with DTPA, at an average of 3.41 mg kg-1. This was compared to the 10 mg kg-1 and 0 mg kg-1 pre-pyrolysis biochar pellet treatments, which gave an average of 2.39 mg kg-1 and 0.92 mg kg-1, respectively, which is an increase of 29.91 and 73.02 percent. The amount of DTPA extractable Zn with the amount of chlorophyll a (r = 0.87**), chlorophyll b (r = 0.81**), total chlorophyll (r = 0.87**), and carotenoids (r = 0.89**) had a positive and significant correlation. The results showed that between DTPA extractable Zn with zinc concentration (r = 0.91**) and zinc uptake (r = 0.90**) in the stage of flag emergence and zinc concentration (r = 0.87**) and zinc uptake (r = 0.86**) in the stage of seed maturity in the wheat plant, there was a positive and significant correlation.Conclusions: In general, the results showed that the positive role of biochar-zinc pellets in increasing the concentration and zinc uptake in wheat plants. Nevertheless, supplemental zinc foliar application with biochar pellets rich in zinc in the amount of 20 mg kg-1 in the form of post-pyrolysis had the greatest effect on the physiological characteristics and Zn bioavailability for wheat plants.
Naser Rashidi; Abdolamir Moezzi; Afrasyab Rahnama
Abstract
Introduction Salinity is one of the growth-limiting factors for pistachio (Pistacia vera L.) crop production in semiarid and arid soils of Iran. Salinity poses two major threats to plant growth: osmotic stress and ionic stress. In addition, it also manifested an oxidative stress. The deleterious effects ...
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Introduction Salinity is one of the growth-limiting factors for pistachio (Pistacia vera L.) crop production in semiarid and arid soils of Iran. Salinity poses two major threats to plant growth: osmotic stress and ionic stress. In addition, it also manifested an oxidative stress. The deleterious effects of salinity affect different physiological and metabolic processes of plants. The uptake of high amounts of salt by the plant leads to the increase of the osmotic pressure in the cytosol. Under this condition compatible osmoprotectant, such as proline and soluble sugars, is produced to protect the cells against the adverse effects from salt stress. High accumulation of proline is associated with tolerance to stress. Na+ and K+ homeostasis plays a vital role in the growth and development of higher plants under salt conditions owing to potassium–sodium (K+–Na+) interaction and is often associated with K+ deficiency. Application of potassium fertilizer affect plants growth and tolerance under salinity stress. The potassium is indispensable for several physiological processes, including the maintenance of membrane potential and turgor, enzyme activation, stomatal movement, regulation of osmotic pressure. Therefore the objective of this study was to evaluate the effect of potassium sulfate fertilizer application on growth, photosynthetic pigments, proline, soluble sugar and Na and K Uptake by Badami-riz Zarand P. vera L. (the main pistachio rootstock in Iran’s pistachio plantation area) seedlings under salinity stress. Materials and methods This study carried out in greenhouse condition as a factorial experiment based on a completely randomized design and in three replications. Experimental factors was salinity of irrigation water (in three levels including 0.65, 5 and 10 dS m-1) and potassium sulfate fertilizer application )in three levels including without application or control, 150 and 250 mg kg-1 soil). Pistachio (Pistacia vera L. cv. Badami-riz Zarand) seeds were surface sterilized with solution of sodium hypochlorite in distilled water. Seedlings were transplanted in plastic potscontaining 10 kg of soil. The pots were maintained in the greenhouse under 25 ± 4 ◦C temperature and under natural light. The mean relative humidity was 40 %. At the end of growth period (six mounth), the plants were harvested and leaf area, root dry weight, shoot dry weight, chlorophyll a and b, total chlorophyll, carotenoids, proline, spluble sugar, root and shoot K and Na concentration were measured. In addition, the K and Na uptake in shoot and root, as well as K/Na ratio were calculated. Analysis of variance (ANOVA) was performed using SAS program version 9.4 (SAS Institute, Cary, NC). Significant differences of the mean values (P <0 .05 for F-test) were determined by Duncans’s Multiple Range Test. Results and Discussion Results indicated that with increasing salinity stress, leaf area, root, and shoot dry weight, chlorophyll content and shoot and root K uptake decreased, while carotenoids and shoot and root Na concentration increased. The highest and lowest value of leaf area, root, and shoot dry weight, chlorophyll content and shoot and root K uptake were observed in control and high salinity levels (10 dS m-1) treatments respectively. Application of potassium sulfate fertilizer at both levels (150 and 250 mg kg-1) led to a significant increase in leaf area (8.1 and 8.7 % respectively), root dry weight (21.2 and 20.0 %), shoot dry weight (21.3 and 19.9 %), total chlorophyll (10 and 7.8 %), carotenoids (32.2 % and 35.7), proline (21.1 and 14.4 %), root K concentration (44.1 and 56.2 %), shoot K concentration (11.0 and 26.9 %) and K uptake in root and shoot. in high salinity treatment seedlings showed higher Na+/K+ ratio in the roots than that of the shoots. In addition, application of potassium sulfate fertilizer decreased Na uptake in shoot and root. Moreover, the addition of potassium fertilizer increased K/Na ratio in the shoot and root. The results also indicated there were no significant difference between potassium sulfate fertilizer levels (150 and 250 mg kg-1) effects on investigated traits. Conclusion It could be concluded that application of potassium sulfate fertilizer results in reduce the negative effects of salinity stress and subsequently enhance tolerance to salinity stress and improved P. vera L. seedlings growth. Therefore, nutrient management of potassium can be considered for decline of negative effects of salinity in P. vera L. v. Badami-riz Zarand seedlings.