جستجوی مقالات مرتبط با کلیدواژه « زغال زیستی » در نشریات گروه « آب و خاک »

reenhouse conditions, the use of biochar on yield and yield components of cucumber and to determine the effect of water stress and biochar on cucumber yield components in Birjand region. Application of biochar in soil increases the yield of cucumber (Cucumis sativus) of Storm cultivar and the combined effect of water stress and biochar modulates the effect of water stress on reducing crop yield.

Due to the conditions in the greenhouse and the type of cultivation (stacks), this study was selected as a factorial in a randomized complete block design with three dehydration treatments and four biochar treatments. Drought stress has three levels of 100, 75, 50% water requirement. And biochar levels of zero, 2, 4, 6 grams per kilogram of soil are selected The type of cultivation is in the form of a stack or a stack in which a stack is selected and divided into equal plots. Based on the number of treatments and replications selected, 36 plots are required, each plot being 80 cm long and 40 cm wide. After preparing a suitable culture medium, two seeds were planted in each plot with a distance of 2 cm because if the seed did not germinate or was destroyed, another one could be used as an alternative. Then, all plots were irrigated automatically until the plants became four-leafed, and pest control operations were carried out equally and equally among all plots.

The results show that biochar had a significant effect on cucumber height, cucumber diameter, cucumber weight, plant height, number of leaves and stem diameter at 1% level. It can be seen that water stress at the level of 1% had a significant effect on cucumber height, cucumber weight, number of leaves and stem diameter. But its effect on cucumber diameter index and plant height was not significant. In this experiment, the interaction effect of biochar and water stress at 1% level had a significant effect on cucumber height and cucumber weight and at 5% level on cucumber diameter and stem diameter, but its effect on plant height and number of leaves was not significant.

Drought stress was significant on cucumber height, cucumber weight, number of leaves and stem diameter at 1% level and had no effect on cucumber diameter and plant height indices. • The best performance in plant height, cucumber weight, number of leaves and stem diameter at I100 level. Consumption of 6 grams of biochar per kilogram of soil at the level of water stress, 100% water requirement had the highest yield on growth indices (cucumber height, cucumber weight) and at the level of 5% on stem diameter and cucumber diameter indices. The use of biochar on the indices of stem diameter, cucumber diameter, cucumber weight, cucumber height, number of leaves and plant height was positive and significant and the use of 6 g of biochar per kg of soil in all indicators has the highest yield for cucumber plant. The interaction effect of water stress and biochar was significant on cucumber height and cucumber weight indices at 1% level and on cucumber diameter and stem diameter indices at 5% level, but the interaction effect of stress and biochar on plant height and leaf area indices was not significant.

Phosphorus (P) is one of the most important components and a limiting factor for the growth of plants due to its low mobility and availability in soil. Application of organic materials such as biochar is one of the main choices to increase the availability of P in soil. Biochar is a carbon-rich material derived from pyrolysis of organic feedstocks under limited or no oxygen conditions. Biochar can influence the availability of P by improving the physicochemical, biological, and enzymatic conditions of soil, in addition to directly increasing the concentration of nutritional elements, particularly P. Soil pollution by heavy metals such as Cadmium (Cd) has been one of the environmental concerns in the last several decades. Cadmium alters the activity and diversity of soil microbial communities, and it also lessens soil function by decreasing the activity of enzymes related to nutrient cycling. Application of organic materials such as biochar in contaminated soil can reduce the availability of heavy metals in the soil, and as a result, increase the biological properties. It is hypothesized that application of biochar in heavy metal-contaminated soil influences the availability of P not only directly but also indirectly by improving microbial and enzymatic activity. This issue depends on the type of biochar and soil. Therefore, this study was conducted to investigate the interaction effect of biochar (cow manure and wheat straw) and Cd on microbial respiration, acid and alkaline phosphatase activity and available P in two soils with different physicochemical characteristics. A factorial experiment was conducted using a completely randomized design with three replicates. The experimental factors included 4 levels of Cd contamination (0, 5, 10 and 20 mg kg-1), 3 levels of biochar (control, wheat straw and cattle manure biochar) and 2 types of soil (corck sofla and research center). Two types of soil contaminated with different amounts of Cd from CdCl2, were amended with 2.5% of the biochar, then were incubated for 14 and 90 days at laboratory temperature and 70% field capacity. At the end of each incubation time, available Cd and P, basal respiration and acid and alkaline phosphatase activity were measured. The application of cattle manure and wheat straw biochar in soil reduced the available Cd by 70-86% and 61-85%, respectively. At all levels of Cd contamination, the amount of available Cd in the research center soil with sandy loam texture was higher than that of the Kark Sefala soil with clay texture. Higher concentrations of Cd also reduced the microbial respiration and the enzyme activities in the research center (31-46%) more than in the corck sofla (21.5-35.5%) soil. The decrease in microbial respiration and enzyme activities due to Cd contamination in the soil without biochar (10-41.5%) was more than the soil amended with wheat straw (5-39.8%) and cow manure (0.8-37.9%) biochar. The results also showed that available P increased with biochar addition and decreased with increasing Cd concentration in soil, so that the highest amount of available P was observed in the soil amended with cow manure biochar and without Cd contamination. Positive and significant correlation between available P with microbial respiration (r=0.385-0.604), alkaline (r=0.764-0.879) and acid (r=0.761-0.883) phosphatase activity was obtained, indicating that microbial activity and the enzymes involved in P cycling, play a significant role in the availability of P in the soil. These findings indicated that the application of biochar in Cd-contaminated soils can increase the bioavailability of P in the soil by decreasing the availaility of Cd and increasing microbial activity and alkaline and acid phosphatase activity. This issue was affected by the biochar and soil type.

Widespread entry of effluents, which are toxic and non-biodegradable, from factories and various industries into the environment, and accordingly, pollution of water and soil resources lead to many dangers for humans and other organisms. Therefore, modification of these resources is important. Currently, multiple technologies from the physical, chemical, and biological perspectives have been established for the remediation of contaminated water. However, most of them involve energy consumption, high-cost instruments, low efficiency, complicated implementation, or secondary pollution. Therefore, it is critical to develop more convenient, economic, and environmentally harmonious strategies for the decontamination of polluted water. Biochar is an emerging material that is manufactured by the decomposition of carbon-rich biomass under oxygen-limited pyrolysis. Remarkable progress has been made in the understanding of biochar as an environmentally friendly and low-cost material for carbon sequestration, energy recovery, contamination relief, and nutrient supplementation. In recent decades, biochar has gained significant attention in the remediation of contamination in terrestrial and aquatic environments. However, biochar only has limited adsorption ability to anionic contaminants in water. This is because biochar often has a negative surface charge, hindering it to absorb negatively charged compounds such as Cr(VI) and Direct Blue71. Various modification methods thus have been developed to improve its affiliation to anionic contaminants by introducing metal oxides onto the carbon surface within its pore networks. Studies showed that the application of biochar and metal-coated biochar, effectively leads to the removal of significant amounts of contaminants from water and soil, but so far the impact of metal-carbon composite on the removal of contaminants, especially anionic contaminants has not been reviewed. Therefore, the purpose of this research is to produce different types of biochar-metal composites, to investigate the effectiveness of different types of composites in removing Direct Blue 71 and chromium from aqueous solution, and also to compare the composites with: plant biomass, metal-coated biomass, biochar, and metal coated biochar.

In this study, the effect of plant biomass, metal-coated biomass, biochar, metal-coated biochar, and metal-biochar composite at two temperatures (300 and 600  ̊C) on the removal of Direct Blue 71 and Chromium contaminants from the water was investigated. The biochar used in this experiment was produced from the thermal decomposition of rice straw, which is abundant in the region. At first, the sample was passed through a 2 mm sieve, then they pyrolyzed at 300 and 600  ̊C for three hours. Metal-coated biochars and metal-biochar composites were prepared from the combination of metals (manganese, zinc, copper, iron, and aluminum) with a concentration of 10,000 mg L-1 with agricultural residues (rice straw) as a raw material or biochar. The samples were mixed with metals with a ratio of 1:50 (1 gram of sample, 50 mL of metal solution) and shaken for 24 hours. Then the samples were filtered and oven dried at 70  ̊C. After the preparation of adsorbents, a specific amount of adsorbents and pollutants with a concentration of 20 mg L-1 were combined and shaken for three hours until they reached equilibrium. All the samples were centrifuged for 5 minutes at 6000 rpm. After filtration, the final concentration of pollutants was determined and the removal percentage of Direct Blue 71 and chromium was calculated.

Based on our results, the application of different adsorbents has a significant effect on the removal percentage of Direct Blue 71 and chromium from the water. Our data showed that high-temperature adsorbents were more efficient in removing Direct Blue 71 and chromium. For example, by increasing the biochar pyrolysis temperature from 300 to 600 °C, the Direct Blue 71 removal percentage has increased from 10.733 to 63.695 %. According to the results of the current study, it can be observed that covering the agricultural residues and biochars with metals has been able to increase the efficiency of the adsorbents in pollutant removal due to the creation of a cationic bridge. In general, the results of this study showed that the application of aluminum and iron composite and aluminum and iron coated biochar produced at 600°C was beneficial in the remediation of contaminated water and these adsorbents could remove 98.303, 88.847, 98.302 and 96.777 % of Direct Blue 71 and 97.983, 78.733, 96.75 and 92.167 % of chromium pollutant from the aqueous solution, respectively. Therefore, the application of these adsorbents can be useful to modify water polluted with these contaminants.

According to the results of this research, it can be observed that the addition of metal-coated biochar and biochar-metal composite to water has reduced the amount of direct blue 71 and chromium pollutants, so their use in water contaminated with these pollutants can be beneficial. Organic materials and biochar are among the adsorbents that are widely used to reduce pollutants from water and soil, but anionic pollutants are not well absorbed due to the dominant negative surface charge of these adsorbents. Therefore, it seems that for more effective use of organic adsorbents, it is necessary to combine these materials with metals or other materials so that their absorption capacity increases and they can be effective in removing anionic pollutants. The composite has a new physical and chemical nature compared to Biomass which is pyrolyzed alone (biochar). Even composite can be significantly different from metal-coated biochar.

 Wind erosion is one of the important processes of soil degradation in arid and semi-arid regions. Increased soil surface resistance is a key factor to prevent wind erosion. Mulch can increase the resistance of soil surface against erosive agents by creating a coating on the soil surface. The effectiveness of mulch on wind erosion control is on the quantity, type, and durability of the used in dust sources of Iran for stabilizing soil surface against wind erosion. In recent decades, petroleum mulch has been broadly used for stabilizing soil surface against wind erosion in dust sources of Iran. Bio-polymers (e.g. cellulose hydrogel and biochar) and naturally accessible materials (e.g. nanoclay) as environment-friendly mulches can be an alternative to chemical polymers and petroleum mulches. In arid and semi-arid regions, wetting-drying cycles play a crucial role in soil aggregate formation and strength. However, there have been limited studies assessing the impact of wetting-drying cycles on the durability of applied mulches. The main objective of this study was to assess the effectiveness of different types of mulches, including inorganic montmorillonite nanoclay, chemical polyvinyl acetate polymer, and biological biochar and cellulose hydrogel, at various time intervals. The study aimed to improve the physical and mechanical properties of soil, as well as control wind erosion in a loamy sand soil using a wind tunnel. Additionally, the durability of these mulches was evaluated over time after subjecting them to four wetting-drying cycles.

 A factorial experiment was conducted based on completely randomized design with three replications. The factors including mulch type (four levels: nanoclay montmorillonite, polyvinyl acetate polymer, biochar and cellulose hydrogel), mulch concentration (Nanoclay montmorillonite: 0, 16 and 32, Polyvinyl Acetate polymer: 0, 8, and 16, biochar and cellulose hydrogel: 0, 65 and 200 g/m2) and duration (21, 42, 63 and 126 days). The soil used in the wind tunnel experiments was collected from a dust source in the southeast of Ahvaz (Site Number 4). Trays measuring 50×30×5 cm were filled with this soil. The soil surface was then uniformly sprayed with an emulsion of Nanoclay and Polyvinyl Acetate. Additionally, biochar and cellulose hydrogel were mixed uniformly with the soil. Water was sprayed on the soil surface to maintain a constant moisture content of 75% of field capacity. After a specified period, soil properties such as mean weight diameter of aggregates, fractal dimension, penetration resistance, and shear strength were measured. The trays were then placed in a wind tunnel, and a wind erosion test was conducted at a wind speed of 20 m/s for a duration of 5 minutes. The amount of soil loss was measured using the weight method. Then, at each time, the best treatment from each mulch (in terms of reducing wind erosion) was selected and subjected to wet and dry cycles (four cycles).

 The results showed a significant interaction effects (p<0.01) of mulch type, mulch concentration and time factors on soil aggregate stability and fractal dimension, penetration resistance, shear strength were significant (p<0.01). Soil loss decreased in soils amended with biochar and cellulose hydrogel and increased in the case of montmorillonite and polyvinyl acetate polymer over the time. The amount of soil loss in soil amended with cellulose hydrogel decreased by 99.3%. The highest amount of soil penetration resistance and shear strength was observed in cellulose hydrogel mulch at the fourth time which were equal to 1038 and 123 kPa, respectively. Over time, the mean weight diameter of aggregates increased in the soil treated with cellulose and biochar hydrogels, but decreased in the polyvinyl acetate and montmorillonite nanoclay treatments. There was a negative correlation between aggregate stability and the fractal dimension of aggregates. In terms of soil loss, at the fourth measurement time, soils modified with cellulose hydrogels, biochar, polyvinyl acetate, and montmorillonite nanoclay experienced reductions of 99%, 71%, 84%, and 85% respectively, compared to the control. After four wet and dry cycles, the soil loss further decreased by 98%, 64%, 76%, and 81% in the respective treatments, compared to the control.

 In general, it can be concluded that cellulose hydrogel presented the greatest effect on reducing soil loss and controlling wind erosion. In the soils amended with biochar and cellulose hydrogel, the effect of mulches on reducing soil loss increased over the time. However, the opposite results were found in the case of polyvinyl acetate and montmorillonite nanoclay polymers. Therefore, biochar and cellulose hydrogel in the long term and polyvinyl acetate polymer and montmorillonite nanoclay in the short term can control wind erosion. Wet and dry cycles at all durations increased soil loss. But their effect remained on soil loss reduction until the end of the fourth cycle. The results revealed that environmentally friendly biopolymers synthesized from biomass components can be considered as sustainable sources to reduce wind erosion. Bio-polymers are a new window into the use of sustainable biomaterials instead of synthetics in wind erosion control.

The application of organic matter and soil conditioners is essential to maintain soil efficiency and achieve sustainable agriculture. The aim of this study was to investigate the effect of application of biochar and wood vinegar on penetration resistance and stability of soil aggregates under forage corn cultivation.

For this purpose, a study was conducted in greenhouse conditions at ShahreKord University. The experiment was performed as a factorial experiment in a completely randomized design with 30 treatments in 3 replications. The studied treatments included wood vinegar in 6 amounts of zero (W0), 0.02 (W1), 0.04 (W2), 0.1 (W3), 0.2 (W4) and 0.4 (W5) g/Kg (first factor) and conditioner including raw material (pomegranate and plum wood) in 2 levels 1 (B01) and 2 (B02) weight-weight percentage and biochar in 2 levels 1 (B1) and 2 (B2) weight-weight percentage (second factor) was applied. Soil penetration resistance of the undisturbed samples at 0, 10, 50, 100, 500, 1000 and 1500 Kpa matric suctions by penetrometer and mean weight diameter of aggregates by dry sieving was measured.

The results showed that the main effect of wood vinegar and conditioner (raw material (pomegranate and plum wood) and biochar) application and the interaction effect of wood vinegar and conditioner (raw material (pomegranate and plum wood) and biochar) application on bulk density and aggregate stability and soil penetration resistance at 0,10, 50, 100 and 500 Kpa matric suctions were significant at the level of 1%. The application of wood vinegar and raw material increased bulk density and aggregate stability that the highest aggregate stability was related to W2B2 treatment, which increased the stability of aggregates by150% of the control. Also the application of wood vinegar and raw material increased the reduction of soil penetration resistance. So that at 0, 10, 50, 100 and 500 Kpa matric suctions, the greatest decrease in penetration resistance was related to W5B2 treatment, which soil penetration resistance was observed in 81.7, 82.89, 86.89, 78.65 and 78.65% of the control.

Wood vinegar and biochar has high organic carbon, which is effective in increasing the aggregates stability and creating larger aggregates and increasing mean weight diameter of aggregates and the cause can be attributed to the increase of the bonding force between the aggregates by the compounds in organic matter. Also, biochar and wood vinegar reduced soil penetration resistance by increasing soil organic carbon and reducing soil bulk density.

Increasing population and water consumption in agriculture and industry sectors enhanced the entry of various pollutants into the environment and water resources. In this study, the removal of lead from water by three adsorbents, sepiolite clay, corn biochar, and corn biochar-clay complex were investigated. For this purpose, the adsorption isotherms and kinetics were performed by the three studied adsorbents. By increasing the concentration in lead from 50 to 1500 mg L-1, the absorption capacity of the adsorbents increased, but the absorption percentage decreased. The results showed that the lead highest absorption capacity is related to the corn biochar adsorbent, while the clay-biochar complex had a higher absorption capacity than the clay adsorbent. To study the absorption process, Langmuir and Freundlich's isotherms were checked for each adsorbent and it was found that the absorption of lead follows both models, but the Langmuir model with the highest coefficient of explanation (R2) and the lowest sum of squared standard error (SSE) has the best fit. The effect of contact time with the adsorbent on the absorption rate was investigated and it was found that the absorption efficiency increased with increasing contact time. The pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion kinetic models were fitted for lead at concentrations of 600, 1000 and 1500 mg L-1 in 30 to 1440 min. The Elovich model at the concentration of 500 mg/L and the pseudo-second order model at the concentrations of 1000 and 1500 mg/L showed the best fit with the laboratory data. At low concentrations, the clay-biochar complex showed better absorption performance, but biochar was a better absorber with increasing lead concentration than the other two adsorbents.

Different agricultural policies tend to minimize the environmental risks caused by the continuous use of pesticides and other synthetic chemicals and look for alternative methods. Wood vinegar and biochar can be used in organic agriculture as soil conditioners. This study aimed to investigate the effect of biochar and wood vinegar on some chemical and microbiological properties of soil under forage corn cultivation.

For this purpose, a research was carried out in greenhouse condition. The experiment was a factorial experiment in a completely randomized design in 3 replications. The studied treatments include wood vinegar in 6 amounts of zero (W0), 0.02 (W1), 0.04 (W2), 0.1 (W3), 0.2 (W4), and 0.4 (W5) g/Kg (first factor) and soil conditioner including raw material (wood of pomegranate and plum trees) in 2 levels 1% (B01) and 2% (B02) amounts and biochar (biochar prepared from pomegranate and plum trees at temperature 4500C) was applied at 2 levels of 1% (B1) and 2% (B2) amounts (second factor). The chemical properties of the soils such as soil acidity (pH), electrical conductivity (EC), soil organic carbon (OC), total nitrogen (TN), soluble sodium (Na+), soluble potassium (K+), soluble calcium (Ca+2), soluble magnesium (Mg+2) and available phosphorous (P); and the soil microbiological properties including basal respiration and microbial biomass carbon and the physical characteristics of forage corn such as height, stem diameter, dry weight, and wet weight were measured.

The results showed that co-application of conditioner and wood vinegar increased soil acidity (5.3%), electrical conductivity (EC), soluble calcium (Ca+2), soluble magnesium (Mg+2), organic carbon (OC), basal respiration, and microbial biomass carbon. The most significant increase in electrical conductivity (EC), soluble calcium (Ca+2), soluble magnesium (Mg+2), and organic carbon (OC) were observed in W5B2 treatment, which were 5.3, 3.9, 2.2, 3.6, and 7.2 times more than the control. Also, the basal respiration with the highest amount of emitted CO2 during one month of incubation in all three times intervals was observed in W5B2 treatment. So that in the first, second, and third ten days, the rate of soil microbial respiration in W5B2 treatment was observed 6.91, 6.54, and 6.4 times more than the control, respectively. The co-application of wood vinegar and biochar led to increase in the stem diameter, dry weight, and wet weight of the plant. In contrast, the co-application of wood vinegar and the soil conditioner decreased the plant's stem diameter, wet and dry weight compared to the control. Addition of conditioner material alone increased soluble sodium (Na+), soluble potassium (K+), Fe, Cu, Zn, and Mn, while decreasing total nitrogen (TN) and available phosphorous (P).

The results illustrated that the effect of using biochar and wood vinegar on increasing, the concentration of elements and improving the qualitative characteristics of soil and plants depends on the amount of nutrients, organic carbon in biochar and wood vinegar, soil acidity and their consumption. Considering the positive effect of biochar and wood vinegar on increasing soil organic carbon, increasing the availability of nutrients, stimulating soil microbial activity and increasing plant growth, it is recommended to use biochar and wood vinegar in calcareous soils of Iran.

The purpose of incorporating organic modifiers such as biochar with soil is stabilizing carbon, improving fertility, absorbing pollutants, and consequently increasing crop production. Biochar is a biofuel and the resultant of organic matters thermocouples. Biochars are produced in high temperature ovens and are commonly alkaline and so suitable for the acidic soils. However, if the raw materials are heated at low temperatures, the resulting biochar can be acidic and useful for modifying calcareous soils. The aim of this study was to investigate the effect of two types of acidic biochars of rice husk and pine cone for modifying the physical properties of two calcareous soils of Isfahan province.

Based on a preliminary experiment, rice husk biochar (pH=5.64) and pine cone biochar (pH=6.56) produced at 300°C were selected for this study. The experiment was performed in a completely randomized factorial design with three replications. Treatments included two types of biochar (pine cone and rice husk) mixed with soil at one, three and six percent (g/g), two types of soil (a sandy loam, Tiran and a clay loam, Lavark), and two incubation periods of one and six months, with 4 controls and a total of 28 pots. The treated soils were kept in an incubator at 25°C and 60% of field (pot) capacity. At the end of the incubation periods, the soil moisture contents at field capacity and the permanent wilting point were measured respectively using sand-kaolin box and pressure plate devices and then soil available water contents was calculated.

The results showed that the addition of biochars improved some physical properties of soils. The treatment of the soils with 3% and 6% of biochars caused significant increases in the available water (AW) in the sandy loam soils compared to the control. The physical quality index of Dexter (SDexter) fitted by van Genuchten–Mualem was significantly increased in the sandy loam soil amended with 6% of the biochars and in the clay loam soil amended with 3% and 6% of the biochars. The use of biochars also improved the physical quality of the soil, described by the Dexter index, from poor to very good.

The results of this study showed that addition of 6% rice husk biochar to the clay loam soil and at the 30 days incubation period, could improve soil properties. Therefore, according to these findings, the biochars produced from pine cones and rice husk can be suggested as a suitable conditioner for improving physical properties of the regional calcareous soils.

With increasing population and water consumption in agriculture and industry, the entry of various contaminants into the environment and soil and water resources has been increased. Cadmium heavy metal is known as one of the polluting elements. In addition to toxicity, it has adverse effects on the health of living organisms, too. In this study, the adsorption method was investigated by the three adsorbents of sepiolite clay, corn biochar, and clay and corn biochar complex on the removal of cadmium metal from water. For this purpose, experiments related to adsorption isotherms and adsorption kinetics were performed by the three adsorbents. Parameters affecting the adsorption process include type of adsorbent, change in initial concentration of cadmium solution, and changes in adsorbent contact time were investigated. The adsorption capacity of the adsorbents increased with increasing cadmium concentration from 150 to 800 mg/l, but the adsorption percentage decreased with increasing concentration. The results showed that the highest adsorption capacity in cadmium was related to corn biochar, while the clay-biochar adsorbent had more adsorption capacity than clay adsorbent. Langmuir and Freundlich isotherms for each element and adsorbent were investigated to study the adsorption process. It was found that the adsorption of cadmium by the adsorbents follows both models. Freundlich model with the highest coefficient of determination (R2) and the lowest sum of squares of standard error (SSE) showed the best fit with laboratory data. The effect of adsorbent contact time on the adsorption rate was investigated and found that the adsorption efficiency increased with increasing contact time. Fitting quasi-first-order, quasi-second-order, Elovitch, and intra-particle dispersion models for cadmium at concentrations of 150 and 600 mg/l was performed at 30 to 1440 min. The Elovich model at concentrations of 150 and 600 mg/l cadmium showed the best fit with laboratory data. At concentrations of 150, clay-biochar complexes showed better adsorption performance, but at other concentrations of cadmium, biochar was a better adsorbent than the other two adsorbents. Based on the results inferred from adsorption experiments, it can be stated that the corn biochar compared to clay and biochar and clay and biochar complex compared to clay has a high ability to remove heavy metals from contaminated water, which can be used as a cheap and practical material used to remove contaminants such as cadmium.

The present study was intended to improve the chemical properties of a saline-sodic soil using the individual application of alfalfa residue and two biochars produced from sugarcane bagasse and walnut shell, at the weighting ratio of 5%; their concomitant application with gypsum, aluminum sulfate and the mixture of these two chemical amendments was considered. The experiment was conducted in three replications using the factorial experiment in a completely randomized design. After four months of incubation, the soil samples were measured for their main chemical properties. The results showed that alfalfa residues were the most effective treatment to reduce the soil pH; so the concomitant application of this organic amendment with gypsum lowered the soil pH from 9.13 in the control (untreated soil) to 7.24. It was also observed that the addition of gypsum and/or aluminum sulfate to the soil led to the increase of the soil electrolyte concentration and consequently, the increase of soil electrical conductivity to three times greater than control, through an increase of ions, like calcium and sulfate in the soil solution. Increasing the soluble sodium concentration by replacing exchangeable sodium by other similar ions showed that the studied treatments enhanced the sodium adsorption ratio (SAR), which could be regulated by washing. Concomitant application of the walnut-shell biochar with gypsum had the most increasing effect on the soil SAR, enhancing it from 22.6 in the control to 54.3. Potassium was released from organic amendments, improving the soil general conditions; addition of chemical amendments elevated soil exchangeable potassium contents; however, the elevated soil available phosphorus contents were less influenced by chemical amendments application. As the conclusion, it seems that the positive impacts of the applied chemical and organic amendments would supplement each other; as a result, the concurrent use of both treatments not only improves the bad soil chemical properties, but also enhances the soil fertility.

Drought and the resulting stress are one of the most important and common environmental stresses which limit agricultural production. Researchers have used organic amendments such as biochar to improve soil properties and reduce the effects of the undesirable stresses. The purpose of this study was to investigate the effect of using the provided biochar of walnut wood and walnut green shell on retention curve and hydraulic parameters of a sandy soil in completely randomized design. For this purpose, the biochar were produced at 400 0C for 2 h. The amendments (walnut wood and walnut green shell and their biochar) at 1 and 2 w/w% ratios (36 and 72 t ha-1, respectively) were mixed with soil sample in three replications and were incubated for 120 days in greenhouse conditions. The retention curve of the incubated soils was measured using sandbox and pressure plates apparatus. Statistical analysis showed that the applied biochar had significant effects on bulk density, porosity, stability of aggregates in wet sieving, and van Genuchten’s parameters (except residual moisture parameter). Application of 2% walnut green shell biochar led to 17% reduction in bulk density (17%) compared to the control and increased the total soil porosity. Application of 2% biochar had the highest effect on the soil water retention curve. Also, the addition of biochar significantly increased soil water retention at low tension and decreased the difference in soil moisture content between treatments. Since water retention curve in lower tension is affected by coarse soil pores and soil structure it could be concluded that addition of biochar improved soil structure and increased coarse soil porosity. Application of appropriate biochar as an amendment in agricultural soil can partially improve the physical and hydraulic properties of sandy soils in semiarid region.

The aim of this study was to recognize the transformation of soil organic matter fractions in burned and unburned pasture lands. The study area was a pasture land located in Alvand hillslope (toposequence), near the village of Haidara, Hamadan. The low-intensity wildfire occurred in the hillslope in autumn (October) 2015, in such a way that half the toposequence was burned up to the bottom symmetrically. Soil samples were gathered from three locations (up, mid, and down) of burned and unburned parts of toposequence 2 (December, 2015-autumn) and 9 months (June, 2016-spring) after wildfire occurrence. In each location, soil sampling was carried out in two parts; between the bushes and under their canopies and in two depths; 0-5 (upper) and 5-10 cm (lower) layers, respectively. Litter samples were also gathered in a 30*30 cm2 plot for each burnt and unburnt parts of toposequence. All sampling was carried out in three replications. The light fraction of organic matter (LF), cold and hot water extractable organic carbons (CWEOC and HWEOC), biomass carbon (BC), total organic carbon (TOC), and basal respiration (BR) were measured. The data analyzed in split-split plot design for each layer (upper and lower) and each season (autumn and spring) of sampling separately. In the mentioned statistical design, sampling location on toposequence (up, mid, and down) was regarded as the main plot, fire impacted area (burnt and unburnt) as a subplot, and sampling location related to bushes (between and under canopy) as sub-sub plot. Soil OC and BR were higher in the upper layer and under the bush's canopy rather than the lower layer and between bushes. In general wildfire increased TOC (42%), LF (41%), and BC (52%) in the sampled soils. In contrast, CWEOC, HWEOC, and BR in burnt soils were 61, 52, and 48% lower compared to those in unburnt soils, respectively. Although in autumn the litter content was lower on burnt soils compared to those in unburnt soils (50%), in spring it significantly increased on burnt soils. The increases in litter on burnt and unburnt soils were 4.5 and 2 times, respectively. The study showed that wildfire and burning of plant cover by producing biochar on the pastures can improve carbon sequestration in soil.

Application of Mycorrhizal Fungi (MF) and biochar can increase water and nutrient uptake in the rooting zone and thus improve crop production. A factorial experiment with completely randomized design with three replications was conducted to investigate the effects of biochar (0, 2 and 4% w/w) and MF (non-inoculation and inoculation with MF) on the morphophysiological characteristics and concentration of elements in calendula (Calendula officinalis L.) in greenhouse condition. The biochar was passed through a sieve of 2 mm and mixed with soil. The application of mycorrhizal fungi was done by direct contact with the root of plant. After six months, the morphophysiological characteristics and the concentration of some macro and micro elements in shoot were measured. The results showed that with simultaneous application of 4% biochar and mycorrhizal fungi increased chlorophyll, flower diameter, plant height, leaf area, stem diameter, plant dry weight and concentration of P, K, Ca and Fe compared to control, significantly. Zn concentration increased in 4% biochar treatment and simultaneous use of 4% biochar and mycorrhizal fungui compared to the control significantly (13.7 and 19.5% respectively). The application of 4% biochar caused a significant increase in Mn concentration compared to the control (91.3 against 86.6 mg.kg-1), while the application of 2% biochar has not a significant difference with control and 4% biochar treatments. The results of the effect of adding biohar to soil after plant growth period showed that available K, Ca, Mg and Mn increased with addition of 4% biochar by 22.2, 18.2, 43.6 and 15.2%, respectively. However, 2% biochar treatment had no significant effect on these soil parameters compared to control. It seems that application of these materials can improve availability of nutrients and plant growth parameters by improving plant growth conditions and affect crop production.

Due to the calcareous nature of our country's soils, the plant phosphorus availability is low.  In order to study the effects of soil microorganisms and biochar application on the phosphorous availability, growth and yield of sorghum and some soil chemical characteristics, a pot experiment as factorial in completely randomized design were conducted. In this research, effects of two treatments of inoculation and non-inoculation of phosphate solubilizing bacteria and two biochar consumption treatments (0 and 1.5% by weight) on the four levels of zero, 25, 50 and 75 mg .kg-1 of P2O5 as triple superphosphate source, in three replications were studied. The results showed that phosphate solubilizing bacteria inoculation and biochar application had a significant increase on the volumes, fresh and dry weight of roots, fresh forage yield and phosphorous, nitrogen, potassium and zinc uptake. Using phosphorus increased the forage weight by increasing the height and diameter of the stems. Phosphorus application also increased soil salinity and decreased soil organic carbon, but bacteria inoculation increased the amounts of organic carbon and decreased soil salinity while biochar application increased both of organic carbon and salinity amounts. None of them had a significant effect on soil acidity. Data showed that although single application of the biochar and or bacteria had significant effects on the phosphorus uptake increases, but combined use of biochar and phosphorus and bacteria with phosphorus and also combination of these three treatments caused sorghum yield increases by increasing of phosphorus uptake. In other words, biochar or bacterial had a positive effect on the phosphorus effectiveness so that the highest plant height, fresh and dry forage, and the highest phosphorus, nitrogen, potassium and zinc uptake were obtained from the combined use of phosphorus solubilizing bacteria, biochar and 50 mg P2O5 per kg of soil.

Iron deficiency is one of the most important nutritional disorders in plants, particularly in calcareous soils and deeply affects the yield and quality of the product. Due to the major role of iron in the synthesis of chlorophyll, chlorosis occurs in young leaves in deficiency conditions. In such condition, biochar can help to increase OM, soil fertility level, and iron use efficiency and, to reduce iron chlorosis. The aim of this study was to investigate the effect of iron- impregnated biochar on the availability of iron and the elimination of soybean iron chlorosis in a calcareous soil.

 Calcareous soil with iron deficiency (0-30 cm) was collected from the east of Golestan province and prepared for cultivation. Two types of biochar were produced from wheat straw and particleboard through slow pyrolysis (increasing 5 °C/min) at 300 °C for 2 hours under restricted oxygen conditions in an electric furnace, and then impregnated with iron sulfate solution. FTIR spectra and SEM images of biochars surfaces were also provided. A pot experiment was conducted as a factorial based on a completely randomized design with four replications. Factors were biochars (wheat straw biochar (WB) and particleboard biochars (PB) each one with 2.5% w/w), iron impregnated biochars (Fe impregnated wheat straw biochar 2.5% w/w (Fe- IWB1) and 5% w/w (Fe-IWB2), 2.5% w/w (Fe-IPB1) and 5% w/w (Fe-IPB2) Fe impregnated particleboards, Fe- Sequestrene (S) and control without Fe and biochar (C), and two soybean cultivars (Williams and Saman). The sown pots were maintained near the field capacity for 12 weeks. Then, SPAD numbers, concentration and uptake of active iron in young and senile leaves and active iron content in soil were determined after harvest.

 With increasing application of iron impregnated biochar, active iron content increased in the soil. SPAD numbers of the upper leaves of both soybean cultivars in Fe impregnated biochars were significantly higher than those of non-impregnated biochars and control treatments (P ≤ 0.05). Iron chlorosis symptoms in soybeans decreased following the increased application of Fe impregnated biochars, consequently, there were no iron chlorosis symptoms in 5% Fe impregnated biochar treatments. Also, the active iron concentration of the upper leaves and the amount of leaf active iron uptake significantly increased as a result of Fe impregnated biochars application in both soybean cultivars compared to control and non-impregnated biochars (P ≤ 0.05). The highest concentration of active iron in upper leaves was observed in 5% w/w Fe impregnated biochars treatments, but its value for cultivar Williams in Fe impregnated wheat biochar was higher than that in Fe impregnated particleboard biochar. The results of the SEM images indicated that wheat biochar had more quantity of and fine pores (also CEC) than that of the particleboard biochar, and the surface areas of both biochars were rough and dark after impregnation with iron, indicating the adsorption or accumulation of iron at their surfaces. Also, there was a significant positive correlation between the active iron concentration with SPAD numbers in the upper leaves (r = 0.88 **) and dry weight of soybean shoots (r = 0.87 **). Cultivars responses to Fe impregnated biochars showed that iron uptake and active iron concentration in the upper leaves of Williams variety were significantly less than those of Saman variety at both levels of Fe impregnated biochars (P ≤ 0.05), which indicates that cultivar Williams is more susceptible to the iron chlorosis. The results of this experiment and reports from other studies show that the application of impregnated biochars from nutrients besides increasing SOM, permeability and soil moisture, CEC and soil fertility level, also increases the acquisition and use efficiency of iron in the plant.

 The results of this study showed that due to the strong adsorption of soil iron, non-impregnated biochar application in the level of 2.5% had no significant effect on the concentration and uptake of active iron and spad numbers of the plant. However, using Fe impregnated biochar and increasing their application in calcareous soils with iron chlorosis resulted in a significant increase of active soil iron content, concentration and uptake of active iron and SPAD numbers of the plant, and, conversely, a decrease of leaf chlorosis. Therefore, besides improving the physical, chemical and biological properties of the soil, the application of Fe impregnated biochar can also be a promising approach to eliminate iron chlorosis in sensitive plants, particularly soybeans in calcareous soils.

Nowadays, extensive application of antibiotics in medicine for treating people and in agriculture and veterinary caused soil and water contamination and also have negative impacts on soil microorganisms and biological processes rate. In the present study, the effect of releasing the mostly used antibiotic in soil (gentamicin, oxytetracycline, and penicillin) and different concentrations (50, 100 and 200 mg/kg dry soil) with and without organic and mineral conditioner (cow manure, biochar, and nano-zeolite) on total soil fungi, total cultivable bacteria and coliforms and their resistance and resilience indices at three time periods including 1-7, 7-30 and 30-90 days during a 90-day incubation time was evaluated in a split-factorial design which soil conditioners were considered as main plots and antibiotic types and concentration were as experimental factors. Resistance and resilience indices were calculated for microbial groups, as well. The addition of antibiotics, including gentamicin, reduced the abundance of microorganisms. Based on the results, cow manure had the highest total fungi count at 1-7 days which had no significant difference with biochar application. At 7-30 days, total bacteria count in antibiotic-treated soil significantly increased which the increase rate for gentamicin and oxytetracycline, especially at higher concentrations was more than penicillin. At 7-30 and 30-90 days, the application of cow manure and gentamicin and oxytetracycline at 100 and 200 mg/kg soil resulted in the highest total coliforms count. Generally, the results of the present study showed that the application of conditioners, especially cow manure, could decrease the toxic effects of antibiotics in soils and causes an increase in resistance and resilience indices of soil microorganisms.

Biochar is a carbon-rich product which is produced using pyrolysis of carbon-containing organic residues under anaerobic or oxygen-limited conditions. Due to unique properties such as high organic carbon, specific surface area and cation exchange capacity, application of biochar leads to increase in adsorption and holding capacity of water and nutrients. This, in turn, results in improved soil fertility. The aim of this study was to investigate the effect of iron impregnated biochr on iron uptake and growth of soybean grown in calcareous soil.

An iron deficient calcareous soil (0-30 cm) was collected from east of Golestan province and after air drying, it was passed through a 2 mm sieve. Two types of biochar were produced from wheat straw and particleboard (at 300○C) and impregnated with iron sulfate (Fe2SO4.7H2O). A pot experiment was conducted as a factorial arrangement in a completely randomized design with four replications. Factors were biochars (wheat straw biochar (WB) and particleboard biochars (PB) with 2.5% w/w), iron impregnated biochars (Fe impregnated wheat straw biochar 2.5% w/w (Fe- IWB1) and 5% w/w (Fe-IWB2), 2.5% w/w (Fe-IPB1) and 5% w/w (Fe-IPB2) Fe impregnated particleboards, Fe- Sequestrene (S) and control (C), and two Soybean cultivars (Williams and Saman). The sown pots were maintained in field capacity by weighing method for 12 weeks. Then, height, fresh and dry weights, total iron concentration and uptake of shoot and soil available iron contents were determined after the harvest.

The application of Fe impregnated biochar increased iron availability in the soil. Also, SEM images showed that iron was adsorbed or accumulated on biochars surfaces. Height, fresh and dry weights of both soybean cultivars in Fe impregnated biochars were significantly higher than those of bichars and control treatments (P ≤ 0.01), but there were no significant differences among them with treatment Fe- Sequestrene. Furthermore, with the application of Fe impregnated biochars, the iron concentration and uptake amount of shoots in both soybean cultivars increased significantly compared to control and non-impregnated biochars treatments (P <0.01). Cultivars responses to Fe impregnated biochars showed that shoot dry weight and iron uptake of the Saman variety were significantly higher than those of Williams variety in both levels of Fe impregnated biochars.

The application of Fe impregnated biochar in calcareous soils with iron chlorosis increased iron availability. Therefore, in addition to improving the physical, chemical and biological properties of soil, Fe impregnated biochars like Fe- Sequestrene can effectively remove the iron deficiency of the plant.

Wind erosion is one of the most important environmental challenges in arid and semiarid regions which cause soil loss and dust storm. In recent decades, the potential of soil erosion has been recognized as serious threat against soil sustainability. In addition, accelerated soil erosion has led to harmful environmental effects. Therefore, focus on soil erosion outcomes is necessary in order to mitigate its environmental impacts. Understanding interactions between land use management and topographical properties of landscape are important in order to effectively control soil erosion through implementing best management practices (BMPs). Application of mulch is one of the most prevailing scenarios to prevent the erosive soil against wind as an erosive factor in the hotspots. In this regard the type of much is really important because the environmental aspects and the mulch consistency are important factors for production and selection of mulch between several options. Nowadays, sustainable management is one of the most important scopes in order to achieve the aims of human healthy. In this regards the Bagasse of sugarcane and Conocarpus were selected as feedstocks to produce biochars. Biochar is the by-product of anaerobic process which called pyrolysis. The biogases, energy and so on are other outputs of pyrolysis. Another treatment which evaluated in this study was Zeoplant. Zeoplant is a super absorptive material which is able to hold the water in the soil therefore is capable to enhance the water holding capacity of the soil.      

In this study the effects of biochar of Bagasse from sugarcane, biochar of Conocarpus and Zeoplant in three levels (0, 2 and 4 percentage) and two moisture levels (25 and 50 percentage of FC) and 3 replications in randomized completely design with factorial on physical and mechanical properties of soil as indices of soil erodibility was studied. Soil sampling accomplished from Horalazim marshes and after application of treatment, incubated in tray with the size of 70×30×10 cm for 90 days. After incubations the trays located in wind tunnel in order to simulate wind erosion process under a wind with 15 m/sec speed and 2 m from soil surface. The main measured soil physical and mechanical parameters include mean weight diameter (MWD), penetration resistance (PR), tensile strength (TS), friability index (FI), shear strength, crusting index (CI), soil textural index and organic matter. The statistical analysis was performed using SAS 9.2 software and the mean comparison was accomplished with Duncan test (5 %). In order to draw the graphs Origin 2017 software was used.  

The soil texture was silty loam (SiL) including 62% silt, 26% clay and 12% sand, therefore the soil was sensitive to wind erosion. Soil organic matter before application of biochars and Zeoplant was around 1.93% and after application increased to 3.78%. Application of these treatments and the period of incubation, enhanced the soil porosity. Generally increasing soil organic matter and soil porosity and decreasing of bulk density are the main factors to increase the soil aggregation. Our results showed that all three treatments in two moisture levels significantly increased soil porosity, tensile strength and field capacity and decrease soil crusting index (P<0.01). Biochar of bagasse and Zeoplant (2%) also significantly increased shear strength whereas biochar of Conocarpus has no significant effect on shear strength. Overall the applied treatments with armoring effect (AE) and increase the soil aggregate stability, diminished the wind erosion.

Our study illustrated that application of biochar is able to improve soil physical and mechanical properties. The main aspect of this positive effect is the specific characteristics and the structure of biochar which showed with SEM (Scanning electronic microscope) images. Moreover, Zeoplant is organic-inorganic treatment and including high potential to absorb the water in the soil. Indeed, the mulching is an effective management strategy to maintain and preserve the soil against wind (as erosive agent) however afterwards a vegetation cover must be grow on the surface. Therefore some treatments such as Zeoplant are essential to hold the water in the soils of arid and semiarid regions because in those areas the water scarcity is one of the main challenges. Based on our results and evaluation of these treatments we found two main processes which are effective to mitigate wind erosion. The first is aggregation process because of organic carbon and organic matter in the soil and the binding between organic and inorganic components. The second one is an armoring effect which is originating from amendments especially biochar lumps on the surface. Finally our results confirmed the application of evaluated treatments to preserve the erosive soil against wind.

Biochar is a carbon-rich solid material produced by heating biomass and agricultural residues in an oxygen-limited environment. However, effects of biochar in soil depend on pyrolysis temperature and type of the raw material used in its production. In order to determine the effect of biochars prepared from agricultural residues at different temperatures on soil characteristics, soil cations and anions and Na and K concentrations of corn, a factorial experiment was conducted in a completely randomized design in four replications under greenhouse condition. Treatments included biochar type (rice, cotton and canola), pyrolysis temperatures (350 and 700 °C) and two application rates (0, 2 and 5 w/w). The results showed that all types of biochar increased soil EC values. The lowest and highest values of soil pH were observed at biochar prepared from rice and cotton residues, respectively. The soil pH was significantly increased with increasing pyrolysis temperature from 350 to 700 °C. The highest values of soil Na+, Ca++, Mg++, Cl- and HCO3- was observed at 350 °C. The results showed that between each three biochars type produced from crop residues (rice, cotton and canola), the highest Na concentrations of leaf and stem were recorded with addition of biochar prepared from rice residues, however, the biochar prepared from canola residues lead to the highest amount on K concentrations of leaf and stem. The pyrolysis temperature only affected the Na concentration of leaf at 5% probability level. The results showed that pyrolysis temperature and the type of feedstock material are important factors that influence the chemical properties of biochars and subsequently the soil characteristics.

Little is known about the effects of biochar on earthworms and their interactions on soil biological properties. The purpose of this study was to investigate the effects of earthworm and cow manure biochar (compared to cow manure) on some biological properties of soil. For this purpose, the soil was treated with cow manure or its biochar in 4 levels (0, 1, 2 and 5%) in the absence and presence of earthworm and incubated for 30 and 90 days. The results showed that the number of earthworm decreased in soil treated with cow manure biochar in 30 days of incubation. After 90 days of incubation, application of 1, 2 and 5% cow manure increased the number of earthworm by 26, 91 and 104%, respectively. Application of 1% biochar resulted no significant effect on the number of earthworm, but the 2 and 5% biochar decreased the number of earthworms by 43 and 48%, respectively. The results showed that the earthworm led to considerable increase on the basal respiration, substrate induced respiration and microbial biomass carbon in soils treated with cow manure compared to cow manure biochar. Also, application of both amendment improved the soil biological properties compared to the control. On the other hand, earthworm increased and decreased the metabolic quotient in 30 and 90 days incubation, respectively. The addition of cow manure and its biochar reduced the metabolic quotient in 90 days of incubation. In addition, the soil treated with 5% cow manure and earthworm (in 90 days) had the lowest metabolic quotient. Overall, cow manure improved soil biological quality better than cow manure biochar. However, application of 1% cow manure biochar in the soil which has no negative effect on earthworm, can be also beneficial to improve soil biological quality.