Hamed Rajabi; Sedigheh Safarzadeh Shirazi; abdolmajid ronaghi
Abstract
Introduction: Application of chemical fertilizer is one of the methods to supply nutrient elements for plants and it is an effective method to meet plants nutrients demands; but organic fertilizers such as biochar application can be used as a proper solution to decrease gases resulted from agricultural ...
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Introduction: Application of chemical fertilizer is one of the methods to supply nutrient elements for plants and it is an effective method to meet plants nutrients demands; but organic fertilizers such as biochar application can be used as a proper solution to decrease gases resulted from agricultural activities, increase soil's organic matters and to manage soil fertility. Biochar can increase soil fertility of some soils, increase agricultural productivity, and provide protection against some foliar and soil-borne diseases. Biochar is a high-carbon charcoal used as a soil amendment and it is made of plant biomass and produced during pyrolysis process in the absence of oxygen. The ability of biochar to store C and improve soil fertility will depend on its physical and chemical properties, which can be varied in the pyrolysis process (pyrolysis temperature) or through the choice of raw materials.
Materials and methods: In order to study the effect of pistachio residue biochar produced in two different temperatures and chemical fertilizer on macronutrients concentration and growth of spinach (viroflay) (Spinacia oleracea), a greenhouse experiment was conducted in a factorial (2×3×3) arranged in a completely randomized design with three replications. Treatments consisted of three biochar levels (0, 3, and 6% by weight) prepared at two temperatures (200 and 400 °C), and three fertilizers level [0 (blank), (Nitrogen=80 and Phosphorous=15 mg kg-1 soil) and (Nitrogen =150 and Phosphorous =30 mg kg-1 soil)]. Bulk soil sample was collected from the surface horizon (0–30 cm) in Bajgah Agricultural Station of Shiraz University, Iran. Pots contained 2 kg dry soil. Treatments were added to all pots uniformly and were mixed. Then soil samples incubated in 25 ̊C for 30 days; and soil moisture was kept at about field capacity (FC). Following incubation time, based on soil analysis nutrients were added to all pots uniformly. Ten seeds were sown in each pot, and soil moisture was kept at about field capacity. Spinach seedlings were thinned to five uniform plants per pot 15 days after emergence. The pots were then maintained under FC. Plants were harvested after 8 weeks after emergence. Aerial parts of spinach plants were separated and oven dried and were weighed and ground. Total nitrogen (N), phosphorous (P) and potassium (K) in plants were measured. Statistical analysis was performed using SAS and Excel statistical software packages.
Results and discussion: Results showed that biochar prepared at 200 and 400 ̊C had no significant effect on spinach dry weight (DW). Chemical fertilizer significantly increased average of spinach DW. Chemical fertilizers improved N and P concentration in plant, therefore increase growth of spinach than control. Biochar prepared at 200 and 400 ̊C significantly increased shoots N, P and K concentration of spinach compared to that of control; but biochar prepared at 400 ̊C had significant effect on shoots N and P concentration. Biochar might be direct nutrition resources for plant and supply many nutritional elements such as N, P and K for plant and increase concentration of these elements in plant. Application of chemical fertilizer significantly increased N and P and significantly decreased K concentration in spinach shoot. Several studies showed that application of biochar improved efficiency of nitrogen fertilizer in several soils and finally more nitrogen absorbed by plant. Biochar prepared at two temperatures had no significant effect on DW and shoot N concentration of spinach. However, addition of biochar prepared at 400 ̊C significantly decreased shoot P concentration and significantly increased shoot K concentration in spinach, as compared to biochar prepared at 200 ̊C.
Conclusion: Results indicated that application of biochar prepared at 200 and 400 ̊C improve composition of spinach but had no effect on its DW, probably because of short term of plant growth, kind of biochar, and biochor levels. Applications of biochar, increased shoot N and P concentration; it might be due to improving physical, chemical and biological properties of soil with addition of biochar. Also, biochar supplied nutritional elements and improve efficiency of chemical fertilizer; therefore it is appropriate that biochar applied with chemical fertilizers. Our results showed that 6% biochar level was the best suggested levels that in three chemical fertilizer levels increased shoot N and P concentration of spinach. With increasing temperature for preparing biochar, pH of biochar increased; so, it might be concluded that biochar prepared at low temperature was appropriate than biochar prepared at high temperature for application to calcareous soils.
Mahshid Shafigh; reza ghasemi; abdolmajid ronaghi
Abstract
Introduction: Plants can uptake, bioaccumulate and immobilize different metals in their tissues. Phytoremediation technique has been used to remove hazardous substances including heavy metals from the environment. Assisted phytoremediation is usually the process of applying a chemical additive to heavy ...
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Introduction: Plants can uptake, bioaccumulate and immobilize different metals in their tissues. Phytoremediation technique has been used to remove hazardous substances including heavy metals from the environment. Assisted phytoremediation is usually the process of applying a chemical additive to heavy metal contaminated soils to enhance the metal uptake by plants. The main objective of present study was to investigate the effectiveness of plant growth regulators (PGRs) and a humic substance (HS) on Ni phytoremediation by maize in a Ni-pollutrd calcareous soil.
Materials and Methods: The experiment designed as a 5×3 factorial trial arranged in a completely randomized design with three replicates. Three kilograms of soil was placed in plastic pots and pots were watered with distilled water to field capacity and maintained at this moisture level throughout the experiment by watering the pots to a constant weight. The soils were polluted with 250 mg Ni Kg-1 as Ni-nitrate Ni (NO3)2. Six maize (Zea mays L.) seeds were planted 2 cm deep in soil and thinned to three uniform stands 1 week after emergence. Treatments consisted of three levels of soil application of commercially humic substance, HS, (0, 3, and 6 mg kg as Humax 95-WSG containing about 80% humic acid, and about 15% fulvic acid) and five levels of PGRs (0 or 10 µM GA3, IAA, BAP and SA). The HS was applied as split doses in three times at 15 day intervals along with irrigation water. The seedlings were exposed to aqueous solutions of HS 16 days after sowing for the first time. Prepared solutions of PGRs were sprayed three times at 15 day intervals from emergence. Seven weeks after planting, shoots were harvested and roots were separated from soil carefully, both parts were rinsed with distilled water and dried at 65°C for 72 h, weighed, ground, and dry meshed at 550°C. Root and shoot dry matter and Ni concentration and uptake and phytoremediation criteria were considered as plant responses. Data were statistically analyzed using SAS and SPSS software packages. Application of different PGRs had no considerable effect on phytoextraction or translocation efficiencies. Among the four PGRs studied application of SA and BA significantly increased mean uptake efficiency.
Results and Discussion: Among four PGRs evaluated, application of GA3 increased mean shoot dry matter yield and application of SA increased mean root dry matter yield. Application of the highest HS level (6 mg kg-1) decreased both mean root and shoot dry weight. Application of SA increased Ni concentration in both maize root and shoot. Application of BA only increased Ni concentration in maize root. Although application of the highest HS level (6 mg kg-1) caused an increase in Ni concentration in maize shoot, this effect was attributed to the influence of HS on the decrease in decreasing dry weight of maize shoot. Application of all PGRs except GA3 increased leaf greenness criterion. Addition of HS had no significant effect on leaf greenness. Application of PGRs enhanced root concentration factor (RCF) and decreased translocation factor (TF). Among PGRs evaluated, BA was the most effective on TF, and SA or BA was the most effective on RCF. However HS were not significantly influenced these phytoremediation criteria, as compared with control. The efficiency of PGRs in root Ni uptake was in the order of SA > BA > GA3 > IAA. Application of BA had a significant effect on Ni distribution among root and shoot, in comparison with other PGRs, and caused an increase and a decrease in root and shoot uptake of Ni, respectively. However HS had a negative effect on tolerance index and its application decreased root and shoot dry weights. Results showed that the values of Ni in maize root was considerably higher than that of maize shoot demonstrated that phytostabilization was the main mechanism involved in the phytoremediation of Ni by maize and application of PGRs was effective on this mechanism.
Conclusion: Results reported here indicated that although the addition of HS did not cause a significant effect on Ni phytoremediation, application of most studied PGRs had a positive effect on Ni phytoremediation by maize. Application of SA and BA increased uptake efficiency and RCF and application of GA3 increased shoot dry matter and tolerance index. The fact that Ni uptake by roots was significantly higher than that of shoots demonstrated that phytostabilization was the main mechanism involved in the phytoremediation of Ni by maize. According to results reported herein the addition of PGRs especially SA is likely to be promising in phytostabilization of Ni in calcareous soils polluted with this metal.
leila zare; abdolmajid ronaghi; Seyed Ali Akbar Moosavi; Reza Ghasemi
Abstract
Introduction: Vermicompost is one of the important bio-fertilizer which is the product of the process of composting different organic wastes such as manures and crop residues using different earthworms. Vermicomposts, especially those are derived from animal wastes,contain the large amounts of nutrients ...
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Introduction: Vermicompost is one of the important bio-fertilizer which is the product of the process of composting different organic wastes such as manures and crop residues using different earthworms. Vermicomposts, especially those are derived from animal wastes,contain the large amounts of nutrients compaired with the composts prepared from crop residues. Vermicomposts contain plant available form of nutrients such as nitrate nitrogen, exchangeable phosphorus and potassium, calcium and magnesium. Nowadays, the use of vermicompost in sustainable agriculture to improve the growth and quality of fruits and crops is very common. Drought occurs when the amount of moisture in soil and water resources and rainfall is less than what plants need for normal growth and function. Two thirds of farm lands in Iran have been located in arid and semi-arid regions with annual rainfall less than150 mm that has been distributed irregularly and unpredictable during growth season imposing water stress in most crops. It indicates the importance of water management and proposing different strategies for mitigating detrimental effect of water stress in croplands. Due to the fact that crops nutrient management under drought and water stress using organic fertilizers is an effective method in reaching to high yields in sustainable agriculture, the objective of the present study was to investigate the influence of vermicompost application on reducing the adverse effects of water stress on the growth and chemical composition of corn in a calcareous soil.
Materials and Methods: In order to study the influence of water stress and application of vermicompost on corn dry matter yield and nutrients concentration of corn shoot, a greenhouse factorial experiment (4×3) in completely randomized design with three replications was conducted in college of agriculture, Shiraz university, Shiraz, Iran. The factors consisted of four vermicompost levels (0, 10, 20 and30g kg-1soil equal to 0, 20, 40 and 60 Mg ha-1) and three moisture levels(100, 80and 60%of field capacity(FC)). The soil samples were collected (0-30 cm depth) from a calcareous soil (Fine, mixed, mesic, Typic, Calcixrepts), located at Bajgah, Shiraz, Iran. Soil samples were mixed thoroughly with different levels of vermicompost and transfred to plastic pots. Six corn seeds were planted in each pot and were thinned to three uniform plants, one week after germination. Eight weeks after germination, corn shoots were harvested, dried and recorded. Plant samples were grind using a portable grinder and transferred to the laboratory for chemical analysis. The collected data were statistically analysed using SAS software (9.1.3) package.
Results and Discussion: The results indicated that with increasing the levels of vermicompost, dry matter yield and concentrations of total nitrogen (TN), phosphorus (P), iron (Fe), copper(Cu) and zinc (Zn) in corn shoots were significantly increased. But, due to the antagonistic relationship between manganese (Mn) and Zn or Fe,concentrations of Mn were significantly decreased. However, the concentration of Mn was in the sufficiency range. The highest dry matter yield and concentrations of nitrogen and phosphorus in corn shoot was observed at 30 g kg-1 vermicompost treatment, with 19, 10 and 20 % increase (compared to the control), respectively. The application of 30 g kg-1 vermicompost increased the concentrations of Zn, Cu and Fe by 41%, 90% and 75%, respectively and concentration of Mn decreased by 11.88%, compared to the control. Increasing the levels of water stress increased significantly the concentration of nutrients in corn shoot due to the reduction of corn biomass. The highest increase in nutrient concentrations was observed at 60% FC moisture level. Nitrogen and phosphorus concentrations in corn shoots by 12.5and 22.5% and Zn, Cu, Fe and Mn by 25, 83, 43and29% were higher compared to those of control (100% FC), respectively. The interaction effects of water stress and vermicompost on the concentrations of shoot N and Cu were significant and both were incresead by simultanoeus application of vermicompost and levels of water stress. The applicaion of 30 g kg-1 vermicompost (about 60 ton ha-1) under 60% FC moisture level increased significantly dry matter yield and the concentrations of nitrogen, phosphorus, zinc, copper and iron in corn shoot by 29%,5.5%, 23, 110, 41 and 71 percent compared to the control, respectively. However, because of the antagonistic relationships,the iron or manganese concentrations were reduced, but were yet in the sufficiency range. The use of 30 g kg-1 vermicompost under 80% FC moisture level Also increased significantly the concentrations of nitrogen, phosphorus, zinc, iron and copper by 9, 23, 24, 59 and 43 percent compared to the control, respectively.
Conclusion: The applicaion of 30 g kg-1 vermicompost increased significantly dry matter yield and the concentration of nitrogen, phosphorus, zinc, copper and iron in corn shoot under water stress treatments. In conclusion, the application of vermicompost mitigated the detrimental effects of water stress on corn dry matter yield and concentration of nutrients due to the positive effects of compost on physical, chemical and biological properties of the calcareous soil.
M. Bahraminia; M. zarei; abdolmajid ronaghi; R. Ghasemi
Abstract
A greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of zinc contaminated calcareous soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design (CRD) with three replications. Two factors consisted ...
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A greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of zinc contaminated calcareous soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design (CRD) with three replications. Two factors consisted of Zn levels (10, 150, 300 and 600 mg kg-1 as ZnSO4.7H2O) and AM fungi (control, Glomus intraradices, Glomus versiforme). Shoot and root dry weights decreased as Zn levels increased. Mycorrhizal inoculation increased those plant measured parameters compared to those of control. With increasing Zn levels, and mycorrhizal inoculation, Zn uptake of shoot and root increased. Root colonization with mycorrhizal inoculation increased, but decreased as Zn levels increased. Mycorrhizal inoculation increased zinc extraction, uptake and translocation efficiencies. Zinc translocation factor decreased as Zn levels increased, however inoculation with AM fungi increased it. Zinc extraction and uptake efficiencies of G. intraradices were more than G. versiforme,while zinc translocation efficiency and factor were vice versa.
M. Zarei; Z. Paymaneh; abdolmajid ronaghi; A.A. Kamgar Haghighi; A. Shahsavar
Abstract
Rootstocks are of primary importance to the citrus industry. Rough lemon (Citrus jambhiri L.) is one of major and widely used rootstocks in Citrus production. The experiment was a completely randomized design in a factorial arrangement with three replications. The factors were mycorrhizal treatments ...
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Rootstocks are of primary importance to the citrus industry. Rough lemon (Citrus jambhiri L.) is one of major and widely used rootstocks in Citrus production. The experiment was a completely randomized design in a factorial arrangement with three replications. The factors were mycorrhizal treatments at two levels (inoculation with Glomus mosseae and control) and irrigation treatments in 4 irrigation intervals (2, 4, 6 and 8 days). Water deficit decreased shoot and root dry weights and decreasing effect was more on the shoot. As water deficit levels increased, root colonization, leaf water potential and chlorophyll content decreased, but leaf temperature increased. Arbuscular mycorrhizal fungus increased root colonization, shoot and root dry weights, chlorophyll content and leaf water potential, while decreased leaf temperature in comparison with non mycorrhizal treatments.
H. R. Boostani; abdolmajid ronaghi
Abstract
Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse ...
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Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse experiment (5 × 3 factorial) arranged in a completely randomized design with three replicates was conducted. The first factor included SS levels (0, 10, 20, 40 and 80 gr kg-1 soil) and the second factor was soil textural classes (clay loam, sandy loam and sandy). A chemical fertilizer treatment was also used to compare its affect with that of SS application levels on growth and chemical composition of corn. For comparison of applied SS levels (one factor) with chemical fertilizer treatment in each soil textural classes was used from a completely randomized design with six treatment and three replicates. The results indicated that addition of SS significantly increased DMY of corn in all textures. Application of SS significantly increased N, P, Fe, Zn, Cu and Mn concentration in corn aerial parts and nutrients deficiencies symptoms disappeared. Nutrients concentrations in corn plants did not reach to toxic levels even at high rates of SS application and concentration of Cd and Pb were negligible and not detectable in shoot corn. Based on nutrient deficiency in calcareous soils especially Zn and Fe, application of SS for contrasting with shortage of these elements can be effective way to eliminate these nutrients shortage. In general, application of SS was superior to chemical fertilizer treatment in increasing concentration of nutrients and DMY of corn. Prior to any SS recommendations the results of this experiment needs to be verified under field conditions.
M. Zahedifar; N. Karimian; A.M. Ronaghi; J. Yasrebi; Y. Emam
Abstract
Abstract
In order to determine the time of maximum demand of winter wheat (Triticum aestivum L.) to phosphorous fertilizers and P and zinc (Zn) distribution in different parts of wheat at various growth stages and study their relation to the contents of these elements in soil P and Zn under field conditions, ...
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Abstract
In order to determine the time of maximum demand of winter wheat (Triticum aestivum L.) to phosphorous fertilizers and P and zinc (Zn) distribution in different parts of wheat at various growth stages and study their relation to the contents of these elements in soil P and Zn under field conditions, samples were collected from different parts of the plants at seven growth stages (i.e., the end of tillering to the complete seed ripening) and analyzed for P and Zn. Soil under the plants were also sampled, simultaneously, and analyzed for the same nutrients. The experimental plots consisted of three 5-ha fields located at Bajgah Experiment Station, College of Agriculture, Shiraz University, Shiraz, Iran (52 32 E, 29 36 N, 1810 m above mean sea level). Samples were taken during 2007-2008. Shoot P and Zn concentrations decreased as the growth proceeded from the end of tillering to the complete seed ripening stage. Phosphorus and Zn concentrations of flag leaf and stem increased from milk development toward complete seed ripening (stages 7 to 9), whereas those of spickle increased. Certain relation between soil and plant P or Zn was not found in the present study. The similarity of the P and Zn changes in flag leaf and stem suggests that flag leaf concentration of P and Zn (i.e., an almost non destructive analysis) can be used for evaluation of nutritional status of winter wheat plants under the field conditions.
Keywords: Flag leaf analysis, Wheat growth stages, Zadoks decimal codes, Spickle analysis
