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Amending soil with different materials is gaining acceptance as an effective and inexpensive technique for reclamation of salt-affected soils. The main idea of this study was to investigate the effects of biochar, compost of municipal solid waste and different water salinities level on soil physical quality (SDexter) and soil productivity index (SPI). The treatments were as followed: Control: Soil without biochar or compost and irrigated with tap water, S1: Soil without biochar or compost and irrigated with saline water (EC = 4.5 dS m−1), S2: Soil without biochar or compost and irrigated with saline water (EC = 9 dS m−1), B: Soil amended with 1.5%w/w biochar and irrigated with tap water, B+S1: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 4.5 dS m−1), B+S2: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 9 dS m−1), C: Soil amended with 1.5%w/w compost and irrigated with tap water, C+S1: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 4.5 dS m−1), C+S2: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 9 dS m−1). Soil water characteristic curve (SWCC), Field capacity (FC), Plant wilting point (PWP), Plant available water (PAW), Dexter's index of soil physical quality (SDexter) and SPI were examined in a greenhouse experiment. The SPI was calculated by integrating the effects of six soil quality indices: plant available water, organic matter (OM), Electrical conductivity (EC), pH, Bulk density (BD) and Root weighting factor (RF) for all treatments were calculated. The results showed that the B treatment had a slightly higher effect on SWCC. The applied B and C treatments caused insignificant increase in PAW relative to the control. In addition, application of biochar or compost to soil significantly increased the SDexter. The application of C treatment had insignificantly higher value of SDexter compared to other treatments. Compared with the control, SPI was significantly higher for the B and C treatments. Overall, the application of biochar/compost minimized the destructive effects of saline irrigation water and improved the quality of the salt-affected fine-textured soil. [ABSTRACT FROM AUTHOR]

Biochar-based fertilizers (BBFs) agronomic performance depends on its nutrient pools, electrical conductivity (EC) and pH, conventionally assessed by laboratory classical wet methods that are non-environmentally friendly, time-consuming, and costly. However, the nutrient pools and properties of BBFs can be predicted by partial least square regression (PLS) based on Fourier Transform Infrared Spectroscopy (FTIR) analysis. Thus, we aimed to use PLS regression based on FTIR analysis to predict the pH, EC and nitrogen (N), phosphorus (P), and potassium (K) pools in BBFs produced by different routes. Sixteen BBFs were produced by mixing, previously or after the pyrolysis process of low-grade phosphate acidulated with different inorganic acids (sulfuric, hydrochloric and nitric acids), addition or no different sources of Mg (magnesium chloride and serpentinite). PLS models based on the normalized FTIR dataset in BBFs are considered good when R2 during calibration and cross-validation phases are higher than 0.81, values founded in our study to prediction of pH, EC, total, and mineral N, total P, and P soluble in water, citric acid, formic acid, and neutral ammonium citrate, and total K of BBFs. Besides, the difference between R2 of calibration and cross-validation lower than 0.2 founded indicated no overfitting. Furthermore, the PLS models had high prediction capacity (R2 of prediction higher than 0.55) and high accuracy (R2 to y-randomization <0.50). Thus, PLS regression models based on the normalized FTIR dataset in BBFs were models characterized by the good performance, robustness, and nonrandom able to predict the nutrient pools, pH, and EC in BBFs. [ABSTRACT FROM AUTHOR]

Soil salinity is a major challenge in agriculture, particularly in calcareous soils with high calcium carbonate levels. Biochar, produced from biomass pyrolysis, is being considered as a potential solution for mitigating salinity effects. A greenhouse pot experiment was conducted using calcareous soil from a saline field to investigate the effects of sugarcane biochar applied at different rates (0.0%, 2.0%, and 5.0%) on soil properties and wheat (Triticum aestivum L.) growth. Results showed that both Low Rate (2.0% biochar) and High Rate (5.0% biochar) treatments significantly improved soil pH, reduced electrical conductivity (EC), and increased soil organic matter (SOM) content. Plant growth indicators such as plant height, stem diameter, and leaf chlorophyll content also showed significant improvement with biochar application. High Rate had more pronounced effects compared to Low Rate. The analysis confirmed the significant effects of biochar on soil properties and plant growth, indicating its potential as a beneficial soil amendment. Sugarcane biochar has the potential to mitigate salinity stress and enhance crop productivity in calcareous soils. Further research is needed to explore the long-term effects of sugarcane biochar application and its interactions with other soil management practices in different crop systems. These findings highlight the promising role of biochar as a sustainable approach for mitigating salinity stress in agriculture and improving soil quality for crop production. The study's findings highlight the potential industrial applications of sugarcane biochar in addressing soil salinity issues prevalent in calcareous soils, particularly in agriculture. The research underscores the positive impact of biochar on soil attributes, plant growth, and nutrient availability. With its ability to improve soil pH, reduce salinity, increase soil organic matter, and enhance plant growth, sugarcane biochar emerges as a promising soil amendment for agricultural use. This presents an opportunity for industries involved in sustainable agriculture, soil management, and crop enhancement to explore the integration of biochar into their practices. Additionally, the study emphasizes the need for further research and field trials to optimize biochar application rates, assess economic feasibility, and ensure environmental sustainability. The insights gained from this study offer a pathway for industrial stakeholders to explore biochar's role in enhancing soil quality, promoting plant growth, and ensuring sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Sandy and acidic soil conditions are the major factors limiting the production of some vegetable crops in acidic soils. This study aims to examine the effect of various amendments on the growth, yield and mineral nutrients uptake of stem amaranth. Two pot experiments were conducted separately in two generic soils. Six treatments viz. T0 = control (without amendment), T1= lime, T2 = lime + wetland bottom sediment, T3 = lime + vermicompost, T4 = lime + rice straw biochar (RSB) and T5 = RSB were used for both experiments following CRD with four replications. Results revealed that plant heights (45.96 and 50.33 cm) of amaranth grown in alluvial and hill soils, respectively, were the highest in T4 treatment. Similarly, treatment T4 showed the highest fresh (118.53 and 116.11 g pot−1, respectively) and dry biomasses (16.98 and 19.54 g pot−1, respectively) for both soils. For both soils, treatment T4 resulted better nutrient uptake of N, P, K, S, Zn, Fe and Mn by edible stem, while non-amended soil gave the lowest result at all parameters. Analytical values of post-harvest soils indicated that T4 and/or T5 treatments resulted in an improvement in soil pH, organic carbon, total N, exchangeable K and extractable P, S and Zn. Treatment T3 showed elevated concentrations of extractable soils Fe and Mn. The amendment RSB combined with lime can be preferably used in strong acidic soils for cultivation of stem amaranth. [ABSTRACT FROM AUTHOR]

Phaseolus vulgaris is one of the most widely consumed legumes across the globe. It is rich in protein, carbohydrates, fiber, bioactive compounds, and mineral contents. Occurrences of drought under changing climate have posed a challenge to the quality and quantity of the crop yield. Our study, taking Phaseolus vulgaris as a test legume, reports that as a soil amendment, biochar and farmyard manure mitigated drought-induced damage in the plant. The experiment was set up in a greenhouse with 1 m2 blocks together arranged in factorial randomized block design. Water withdrawal was done for 15 days in either vegetative or reproductive stage of the crop to simulate drought conditions. Biochar or Farmyard manure was applied at the rate of 10t ha−1 as soil amendment and each treatment was replicated thrice. Higher photosynthesis (up to 23% and 16%, respectively), leaf protein (41% and 30%, respectively), grain protein (4% and 19%, correspondingly), and in-vitro protein digestibility (60% and 254%, respectively) were noted under application of both the amendments. Grain quality in terms of protein content, in-vitro protein digestibility, and protein fractions of Phaseolus vulgaris was improved under drought due to the addition of biochar and farmyard manure. However, the application of those amendments at the rate of 10t ha−1, especially farmyard manure, had a negative impact on the antinutritional factor (phytic acid) and mineral bioavailability. Between the two amendments studied, farmyard manure proved to be more efficient in promoting the overall grain quality of P. vulgaris, but its inimical effects must be concorded. [ABSTRACT FROM AUTHOR]

Recycling of phosphorus (P) from feedstocks to soils can provide sustainability in agriculture. In our incubation study, we investigated the effects of adding cow manure-derived vermicompost (CMV), cow manure (CM), sugarcane trash biochar (STB), and triple super phosphate (TSP) to extractable P in a sandy loam soil. P was added to the soil at rates of 0, 50, 100, 200, and 300 mg kg−1 based on their total P contents. The amended soils were incubated for 1, 4, 8, and 16 weeks (wk) at room temperature and extractable P samples were measured (by water, Olsen, Mehlich-3 and Bray and Kurtz) and soil pH was monitored. After 1 wk of incubation, the extractable P values were 1.4 mg kg−1 with STB at the smallest while the highest was 79 mg kg−1 with TSP. The corresponding P values in the CMV and CM amended soils were 33 mg kg−1 and 31 mg kg−1. The reductions of extractable P from 1 to 16 wks of incubation were 40%, 35%, and 80% in the CMV, CM and TSP amended soils, respectively, while they increased from 1.43 mg kg−1 to 6.05 mg kg−1 ((320%) in the STB amended soil. Among the amendments, a significant positive relationship was observed between extractable P and the pH in soils amended with STB. The findings revealed that varying P extractability in soils depends on amendment types and duration of incubation. Sugarcane trash biochar did not exhibit an ability to substitute inorganic P fertilizer for assessing bioavailable P. [ABSTRACT FROM AUTHOR]

Soil application of treated sewage sludge is considered a beneficial management option for agriculture and environment. Sludge treated with clay minerals or biochar was evaluated as soil amendment, in comparison with limed or untreated sludge. Bentonite, vermiculite, biochar or lime was added to dewatered sewage sludge at 0 and 15% rates, in three replications and air-dried. Then, the treated and untreated sludge were added to two soils, one acid and one alkaline, at 0 (control), 1 and 3% rates, in three replications. The results showed that the pH of acid soil significantly increased compared to control upon addition of treated and untreated sludge at both rates, but remained acidic (<6.0) in all cases except for limed sludge. Upon addition of 3% treated or untreated sludge to both soils, organic carbon (OC) significantly increased compared to control. The same stands for soil available ammonium nitrogen (NH4-N), phosphorus (P), potassium (K), copper (Cu), zinc (Zn) and boron (B) for both soils and rates. Soil total heavy metals, which regulate sludge's agronomic use, were below the legislative limits. However, the 3% addition rate of all kinds of sludge, especially of untreated, to both soils increased the electrical conductivity of saturation extract (ECse >2 dS m−1) at unacceptable levels for sensitive crops and available P, B and Zn 2–3, 2–4 and 6–12 times above the initial, respectively. Consequently, sewage sludge treated with bentonite, vermiculite or biochar could be used as a soil amendment but at rates lower than 3% (≈120 Mg ha−1). [ABSTRACT FROM AUTHOR]

The addition of organic materials in arid and semi-arid regions not only improves the physicochemical and biological characteristics of the soil but also increases plant growth. In this study, the effect of individual and combined application of humic acid (HA) (150 mg kg−1 soil), wood vinegar (WV) (75-fold dilution), and biochars (corn straw biochar (CSB) and cotton residue biochar (CRB) each at 2% wt.) on the soil Zn chemical fractions and its uptake by Sour Orange (Citrus aurantium L.) seedlings were investigated in a calcareous soil. The results showed the CRB was more effective in increasing the Zn concentration in fractions with high bioavailability (soluble+exchangeable (WsEx) and organic (OM) forms) than the CSB. This may be due to its higher organic carbon content (74%) and electrical conductivity (3.52 dS m−1) than those for the CSB. There was no significant difference between HA and WV in terms of the effect on soil Zn chemical fractions. The CRB+WV and CRB+HA were the best treatments for enhancing the soil Zn bioavailability. The greatest increase in the shoot dry matter yield (2.5-fold) and Zn uptake (29%) was associated with the combined treatment of CRB+HA compared to the control. Furthermore, the shoot dry matter yield of Sour Orange seedlings had a significant and positive correlation with the Zn-WsEx fraction and Zn uptake. It could be concluded that among the treatments, the combined application of CRB+HA was the best in enhancing soil Zn bioavailability, Zn uptake and shoot dry matter yield of Sour Orange seedlings in the calcareous soil. [ABSTRACT FROM AUTHOR]

Jatropha curcas L. plant (Jatropha) has been claimed to grow successfully under low nutrient conditions. This study compared the effects of incorporated poultry litter and its biochar on Jatropha growth in soil. In a greenhouse study, Jatropha plants were grown in sandy-loam soil amended with different rates (0, 15, 30, 60, and 120 g/kg) of poultry litter and its biochar. The biomass yield of Jatropha (root:shoot ratio and dry matter), leaf nutrient content, and soil-plant transfer factors were all evaluated. Incorporating poultry litter and its biochar into soil increased biomass yield and Jatropha leaf nutrient content. The BC600 (Biochar pyrolyzed at 600°C) and PLBC600 (Poultry litter and Biochar pyrolyzed at 600°C) treated plants had a higher root:shoot ratio, whereas the PL treated plants had the highest dry matter content. There was a significant negative moderate to lower negative correlation between dry matter and leaf nutrient content. However, a positive correlation was displayed between leaf nutrient contents. In general, at application rates ranging from 30 to 120 g/kg, BC350 (Biochar pyrolyzed at 350°C) and PLBC350 (Poultry litter and Biochar pyrolyzed at 350°C) improved studied parameters. Finally, adding poultry litter and its biochar to low-nutrient soils is highly recommended for improved Jatropha growth. [ABSTRACT FROM AUTHOR]

Improving soil fertility by adopting several sustainable management practices that are a prime concern for plant growth. Organic waste addition to agricultural soil is becoming a common practice that improves physical, chemical and hydrodynamic properties and minimizes environmental impact. The use of some alternative nutrition sources as biochar and compost has been tested on two-year-old olive varieties 'Chemlali' and 'Koroneiki.' Three treatments were established "Cont" soil didn't amended, "Comp" soil amended with Compost (90% soil+10% compost), and "Bioc" soil amended with biochar (90% soil+10% biochar). All treatments were conducted under deficit irrigation receiving 50% of daily evapotranspiration. We evaluated soil–plant water status and relationships between all studied parameters. Results showed that soil water content was the lowest in non-amended treatments and did not exceed 10%. During experiment, compost amendment induced a better water plant status for both studied varieties less than −2 MPa for mean seasonal leaf water potential, while the biochar amendment induced a weak stress level indicated by the lower potential that reached a minimum value equal to −2.9 MPa. Crop Water Stress Index on biochar-amended soil was more important than that measured on other treatments which confirms the sensitivity of biochar treatment to hard conditions. High negative relationships have been found between soil water statuses and plant water statuses. The highest determination coefficient was between crop water stresss index and leaf water potential was about 0.85. In conclusion, the use of organic amendment is an approach for sustainable olive orchards under low water avaibility. [ABSTRACT FROM AUTHOR]

Soil amendments and critical agronomic practices like biochar (B) and poultry manure (PM) change soil characteristics and have a direct impact on soil sustainability and crop productivity. Hence, a two-year field trial was conducted in the forest-savanna transition zone of southwest Nigeria at two locations (Owo – site A and Obasooto – site B) to examine the impacts of different levels of biochar (B) and poultry manure (PM) on soil physical and chemical qualities, sweet potato (Ipomoea batatas L.) growth, and yield. The experiment consisted of a 2 × 4 × 3 factorial layout with three replicates. The treatments applied at two locations were: four levels of biochar (B) (0, 10.0, 20.0 and 30.0 t ha−1) and three levels of poultry manure (PM) (0, 5.0 and 10.0 t ha−1). The biochar (B) and poultry manure (PM) significantly (p =.05) improved both soil physical and chemical properties, sweet potato growth and yield with their rates of application when compared to the control. In comparison to Owo (site A), Obasooto (site B) had significantly higher sweet potato growth and yield, and better soil properties. Application of 30.0 t ha−1 biochar (B) and 10.0 t ha−1 poultry manure (PM) had the best sweet potato growth and yield parameters of all the biochar (B) combined with poultry manure (PM) treatments. [ABSTRACT FROM AUTHOR]

Various techniques are employed nowadays to lessen the harmful consequences of high soil levels of heavy metals (HMs). In this instance, a relatively novel technique to lessen the toxicity of HMs is the use of biochar. In this study, a pot experiment with a randomized complete block design was carried out to examine the impact of sugarcane bagasse biochar (SBB) on enhancing the development of maize in Cadmium (Cd) and Lead (Pb) polluted soil. The variables included planting maize in sandy clay loam soil, which was done in two separate experiments for Cd and Pb, as well as three levels of SBB (0, 2, and 4% by weight), three levels of Cd (0, 40 and 80 mg kg−1 of soil from CdSO4.8 H2O, and three levels of Pb (0, 400 and 800 mg kg−1 of soil from PbSO4). A single application of SBB in 40 and 80 mg kg−1 Cd-soil significantly increased roots and shoots dry weight by 21.0 and 17.14% and 57.14 and 32.36%, respectively compared to control. A single application of SBB in 400 and 800 mg kg−1 Pb-soil significantly increased roots and shoots dry weight by 39.55 and 12.71% and 57.46 and 26.29%, respectively compared to control. SBB increased chlorophyll index, leaf area, plant height and dry weight of roots and shoots due to a decrease in the concentration of Cd and Pb in the roots and shoots. It can be concluded that SBB addition to HMs-contaminated soils is a suitable remedial action that will enhance plant growth. [ABSTRACT FROM AUTHOR]

Biochar amendment has been known as a promising strategy that improves crop productivity and physio-chemical properties of soil. A pot experiment was conducted to investigate the effect of three biochars: wheat straw, sugarcane bagasse, and rice husk at different levels 2%, 3%, and 5% (w/w) on soil properties and growth of tomato cv. "Money Maker." Results revealed that rice husk at 3% concentration showed significant improvement (+37.4–68.6%) in plant height, number of leaves, fresh and dry shoot weight, fresh and dry root weight and root length compared to control. The physiological parameters like stomatal conductance, photosynthesis, transpiration rate, and water use efficiency were also enhanced (+38–62%) in 3% RH-treated plants while chlorophyll contents were highest in 5% WS, whereas cell membrane stability was maximum in 3% WS-treated plants compared with control. Moreover, 3% RH caused a significant increase (+22.4–81.7%) in electrical conductivity, cation exchange capacity, organic matter, organic carbon, nitrogen, phosphorus, and potassium. Conclusively, 3% RH was found to be the best treatment that improved the soil properties and plant physiological traits that led to enhance overall plant growth. Therefore, RH biochar amendment of soil can be potentially utilized for improving soil properties and plant health. [ABSTRACT FROM AUTHOR]

Biochar has been widely deemed as a soil conditioner to modify the physicochemical and biological properties of soil. In this research, the influence of different biochar application conditions on the effect of heavy metal Cu in soil was detected. In batch experiments, the combinations could definitely enhance the adsorption abilities, and under the combination ratio of 4 wt % biochar, 3 wt % wheat straw, and 5 wt % cow manure compost in the soil, the adsorption rate would be more than 97% in 60 mins. The adsorption kinetics showed the adsorption processes were multiphase diffusion processes and the conversion of activation energy in soil surface was obvious, while the isotherms analysis suggested the adsorption of Cu by the soil under various amendments was mainly monolayer adsorption as well as some other complex reactions. However, in the eluviation experiments, more and more Cu was lost in the leaching solutions when wheat straw and compost were added into the soil as well as biochar. pH values changes indicated that the connections among Cu and solids may be mostly related to the precipitation reaction in the eluviation experiments. FTIR analysis implied that the addition of wheat straw and compost in the biochar could indeed enhance the reaction between heavy metal Cu and soil, however, the reactions were rather complicated, and under the eluviation condition, there was not enough time to form the stable bonds, so more Cu was dissolved into the leaching water. [ABSTRACT FROM AUTHOR]

Studies on the effects of biochar and phosphorus fertilizer on soil productivity and yield of cowpea (Vigna unguiculata) are scarce. Therefore, experiments were conducted in 2019 and 2020 to evaluate the effects of sole and combined application of biochar and phosphorus fertilizer on soil properties, nodulation, growth, and yield of cowpea. The treatments consisted of: biochar at 10 t ha−1 (B10), biochar at 20 t ha−1 (B20), triple super phosphate fertilizer at 60 kg P ha−1 (P), biochar at 10 t ha−1 + P (B10 + P), biochar at 20 t ha−1 + P (B20 + P), and the control. The experimental design was a randomized complete block design with three replications. Results revealed that biochar and P fertilizer applied alone or in combination improved soil properties, growth, nodulation, and yield of cowpea compared with the control. Results also showed that combined applications of biochar with P fertilizer improved these properties most, especially at a higher rate of biochar (B20 + P). B20 + P increased grain yield of cowpea by 155%, 69%, 53%, 69%, and 21% respectively compared with the control, B10, B20, P fertilizer, and B10 + P. This was adduced to raise soil pH and reduced soil bulk density as a result of biochar application which induces P solubility and availability, increased N fixation, and enhanced root growth, increased nodulation leading to improved growth and yield of cowpea. Application of biochar with P fertilizer could therefore be used as a strategy for improving P availability in low pH soils of cowpea growing areas of the tropics. [ABSTRACT FROM AUTHOR]

The transfer of Phosphorus (P) in water draining from agricultural lands to surface and ground waters is regarded as one of the serious agronomic problems in sandy Ultisol soils that occur in the southeastern agricultural plain of the USA. Therefore, enhancement of the P fertilizer use efficiency is considered through the amendment of such soils with organic and inorganic soil amendments. We studied the effect of biochar and coal fly ash amendment on the retention efficiency of soluble fertilizer P added to Ultisols. A sequential P fractionation with a series of acid and alkali extracts was carried out to soil samples added with coal fly ash, bio char and coal fly ash + biochar, applied with soluble P fertilizer, and incubated for 30 days. As per our results, soil amendments reduced the readily leachable fractions of P in soil through a variety of retention and fixation pathways. Coal fly ash converted 41% of P into moderately labile Calcium (Ca) bound P. Biochar could retain 31% of P as less labile organic P and 26% as Ca bound P. The coal fly ash + biochar application significantly reduced the leachable P fraction by converting 93% of the P into labile, moderately labile and residual P pools. Coal fly ash and biochar soil amendments were recommended to reduce the leaching loss of P from acidic sandy Ultisol. [ABSTRACT FROM AUTHOR]

It has been proposed strategy that acidic soil quality can be improved by addition of alkaline byproduct amendments containing silicon, calcium, magnesium and potassium. The effects of amendments and three different forms of nitrogen [(NH2)2CO, NaNO3 and NH4Cl] on quality of acidic soil were investigated in Jiaodong Peninsula of China. A 120-day incubation test was carried out to assess the effect of amendments and nitrogen on soil physicochemical properties, soil carbon (C) mineralization and enzyme activities. The results showed that the addition of alkaline amendments can increase soil pH from 5.93 to 6.99 at the beginning of cultivation, while when amendments combined with urea or NH4Cl, soil pH decreased with incubation time. The response of C mineralization was inversely proportional to soil pH value. The addition of amendments could improve soil C content via decreasing soil C-CO2 emissions, and the mineralization rate was reduced by 26%. Addition of amendments in combination with urea or NH4Cl, which could decrease soil pH, stimulated soil C mineralization and increased soil microbial biomass carbon (MBC) and dissolved organic carbon (DOC) fractions in acidic brown soil. However, when amendments were applied with NaNO3, the soil C mineralization could be inhibited. The addition of amendments or combination of amendments and nitrogen increased the soil invertase and phenol oxidase activities, and inhibited soil urease activity. Therefore, the chemical and biological properties of the acidic brown soil in Jiaodong Peninsula of China might be better improved by combination of amendments and NaNO3. [ABSTRACT FROM AUTHOR]

Through pyrolysis it is possible to transform sewage sludge (SS) into a product called biochar, which can be used safely in agriculture as a soil amendment. Among the advantages of using SS biochar (SSB) are the supply of nutrients and carbon sequestration in the soil. However, there is still a lack of information on the supply of nutrients and the nutritional balance provided by SSB application. The objective of this study was to evaluate the nutritional status of corn plants fertilized with SS biochar by the DRIS method. Soil and plant data from a three-year field experiment were assessed. The field experiment, with four replications, consisted of the following treatments: 1) control, no biochar and no mineral fertilization; 2) mineral fertilization; 3) biochar produced at 300°C; 4) BC300 associated with mineral fertilization; 5) biochar produced at 500°C; 6) BC500 associated with mineral fertilization. In the present study, leaf samples of corn cultivated for three consecutive harvests were used. From the DRIS indexes, it was concluded that potassium is the most limiting nutrient for SSB. Despite that, according to outputs from DRIS, SSB has a good potential as a fertilizer, especially if supplemented with K. [ABSTRACT FROM AUTHOR]

Use of biochars can be effective in increasing the uptake of plant nutrients and stabilizing heavy elements in the soil. The aim of this study was to investigate the effect of biochar application and lead (Pb) levels on some vegetative characteristics and concentrations of micro and macronutrients of Panicum miliaceum grown in rangeland soil under greenhouse conditions. A factorial pot experiment was conducted in a completely randomized design with four replications. The first factor includes biochars (no application of biochar (C), wheat biochar (1.5% w/w) (GB1), wheat biochar (3% w/w) (GB2), corn biochar (1.5% w/w) (ZB1), corn biochar (3% w/w) (ZB2), cotton biochar (1.5% w/w) (PB1) and cotton biochar (3% w/w) (PB2)) and the second factor consisted of Pb levels (0 (Pb0), 150 (Pb150) and 300 (Pb300) mg Pb kg−1 soil). With enhancing the Pb levels from Pb0 to Pb300, the concentration of plant iron (10.46%), manganese (5%), and phosphorus (4.78%) were significantly reduced. While, all the biochars (GB, ZB, and PB) at the level of 3% (w/w) caused a significant increase in the concentration of Fe, Mn, P, and K of plant shoot and decreased the Pb concentration of plant shoot and root. The GB2 treatment was more effective than other biochars in improving the vegetative characteristics, increasing nutrient concentration of the shoot, and reducing the Pb content in the shoot and root. It can be concluded that the use of biochar can be of great help in implementing breeding projects for Pb contaminated pastures. [ABSTRACT FROM AUTHOR]

Essential nutrient concentrations in edible portions of crops can affect human health. Hence, field experiments were carried out for two growing seasons (2019 and 2020) at two degraded sites using a randomized complete block design in a factorial layout with three replications to evaluate the effects of biochar (B), poultry manure (PM), and their combined application on leaf nutrient concentrations and mineral composition of sweet potato. Each year, the experiment consisted of 4 × 3 factorial combinations of biochar (0, 10.0, 20.0, and 30.0 t ha−1) and poultry manure (0, 5.0 and 10.0 t ha−1). The results showed that the sole application of B and PM and their combined application, improved sweet potato leaf nutrient concentrations and mineral composition of sweet potato storage roots. In both years, there were significant interactions of B and PM (B × PM) on leaf nutrient concentrations and mineral composition of sweet potato that were determined, indicating the potential of B in enhancing PM use efficiency and improving better use of the nutrients in the PM. It was found that the highest dosage of combination of 30.0 t ha−1 B and 10.0 t ha−1 PM (B30+ PM10) gave the highest leaf nutrient concentrations and mineral composition of sweet potato at both sites. Lowest leaf nutrient concentrations and mineral composition was obtained for the control. The study indicated that B in combination with PM have the potential to improve sweet potato leaf nutrient concentrations and mineral composition of sweet potato storage roots for human health in severely degraded soils. [ABSTRACT FROM AUTHOR]

The development of canola plant is sensitive to boron (B) and sulfur (S). A constant application of these nutrients is required at all canola stages, especially at the climax vegetative growth, budding, pod formation and seed maturation phases to attain maximum seed yield of canola. Biochar is an essential amendment that makes nutrients available for ‎canola plant for a longer period. Considering the importance of B, S, and biochar to canola crop, a ‎research trial was conducted with four levels of B (0, 0.5, 0.75, and 1 mg B kg−1) and ‎four levels of S (0, 5, 10, and 15 mg S kg−1) were applied, while biochar was applied at 1% (w/w). The results indicated that maximum increase in growth parameters, including shoot length (22%), root length (35%), shoot dry weight (37%) and root dry weight (40%) was obtained with the application ‎of 1 mg B kg−1 + 15 mg S kg−1 and 1% biochar. Yield parameters ‎such as the number of seeds ‎plant−1 (32%), 1000-grain weight (31%) and seed yield (39%) increased significantly by applying the highest level of B and S. Physiological parameters also showed a noteworthy increase as compared to control. Chemical parameters including nitrogen, ‎phosphorous, potassium, and B concentrations in shoots and roots (32, 37, 29, 31, ‎‎42, 34, 38, and 39%, respectively) showed an increasing trend. Therefore, it was ‎concluded that 1% biochar +1 mg B kg−1 and 15 mg S kg−1 performed best for improving the ‎growth and yield of canola. [ABSTRACT FROM AUTHOR]

Application of biochar as an amendment not only improves water retention in soil but also improves overall soil physical environment. To test this hypothesis, a field study was conducted for 2 years, i.e., 2019 and 2020, in an ongoing experiment on maize-based system at the Research Farm, Department of Soil Science, Punjab Agricultural University, Ludhiana, in a sandy loam soil. The parameters tested include soil water-holding capacity, moisture retention, water transmission characteristics, aggregate stability, bulk density, and penetration resistance of soil. Six biochar (B), farmyard manure (fym), and nitrogen (N) combinations were tested, which includes BN1 (biochar @ 7.5 t ha−1 + N @ 75 kg ha−1), BN2 (biochar @ 7.5 t ha−1 + N @ 150 kg ha−1), FN1 (fym @ 20 t ha−1 + N @ 75 kg ha−1), FN2 (fym @ 20 t ha−1 + N @ 150 kg ha−1), N1 (N @ 75 kg ha−1), and N2 (N @ 150 kg ha−1) in main plots and two irrigation regimes IW/CPE ratio 0.6 (I0.6) and 0.9 (I0.9) (irrigation water over cumulative open pan evaporation), i.e., deficit and full irrigation were in subplots. Moisture retention at 0.3 bar was significantly higher under biochar treatment BN1, i.e., 30.0%, while the lowest was recorded under N2, i.e., 25.5% at the end of spring 2020. Biochar and fym-amended soils decreased penetration resistance of soil by 22.57% and 20.85% at 10 cm soil depth as compared to unamended soil. BN1 showed increased mean weight diameter by 43.90% over N1 (control). Deficit irrigation, i.e., I0.6, resulted in 6.11% and 18.78% higher water productivity of both kharif and spring maize, respectively, over I0.9. It is also concluded that biochar as soil amendment may retain more water due to its porous nature and more surface area and also reduce the frequency of irrigation, hence sustaining and optimizing the limited water available for crop production in northwest India. [ABSTRACT FROM AUTHOR]

Phosphorus is one of the key nutrients needed for root initiation, root elongation, root dispersion, roots nodulation and N2 fixation in soybean. Lack of phosphorus limiting soybean growth, productivity and seed setting. Low P availability to plants is a global problem limiting crop production, especially in arid and semi-arid regions of the world. Several agronomic practices have been proposed to enhance P availability and use by crops for higher yield under diverse climatic conditions. Application of organic and inorganic fertilizer with beneficial microbes increases availability of phosphorus in soil and increases its uptake. It is assumed that integration of organic, inorganic and beneficial microbes replenish nutrients in soil, prevent soil declining and degradation, maintain soil functions and increase nutrients availability. These findings confirmed the significant effect of organic sources (biochar, compost and residues) on the reactivity of phosphate. It has been perceived that the release of different organic acids by microflora enhances availability of the indigenous rock phosphate. Extensive usage of organic matter for crop production with chemical and biological fertilizer improves grain yield, plant and soil chemical quality, with the benefit of optimizing economic return. [ABSTRACT FROM AUTHOR]

Soil acidification in the tropics has become a more pressing issue due to its associated aluminum (Al) phytotoxicity. The chemical reactive nature of biochar can alter Al speciation in soils. The study assessed the chemical properties and Al speciation in a Ultisol and an Oxisol amended with corn cob (CC) and rice husk (RH) biochars charred at 300, 450 and 650°C in an incubation study for 120 d. pH was determined periodically while organic carbon (OC), cation exchange capacity (CEC), exchangeable base cations, exchangeable acidity, and exchangeable Al3+ were measured at the end of the incubation period. Dissolved organic carbon (DOC) and pH were also determined in soil solution from each treatment. Throughout the incubation period CC and RH biochars significantly increased soil pH, with CC biochar showing a greater effect. Similar effects were also observed for OC, CEC, and exchangeable base cations (Ca2+, Mg2+ and K+). Soil exchangeable Al3+ and exchangeable acidity, soluble Al and Al3+ activity in soil solution decreased significantly upon biochar application; it was more significant at the 650°C. Biochars at 300–450°C exhibited a more notable increase in soil DOC. At pH ≤ 5.8, Al-DOC and free Al3+ dominated in soil solution while at pH > 5.8, Al species was mainly Al-OH ions (i.e. Al(OH)2+, Al(OH)2+, Al(OH)3, and Al(OH)4−). Biochars at 300–450°C promoted the large formation of Al-DOC while Al-OH ions dominated in 650°C-biochar treatments. Biochar can be used to ameliorate Al phytotoxicity in tropical acid soils, particularly at 300–450°C. [ABSTRACT FROM AUTHOR]

The drought ameliorative effects of poly(acrylic acid) hydrogel (HG), biochar (BC) and plant growth-promoting rhizobacteria (PGPR) were evaluated on soybean exposed to drought stress. Prior to sowing, soybean seeds were soaked for 3–4 h in the broth culture of Planomicrobium chinense (MF616408) and Pseudomonas putida (KX574857), while BC (5 g/kg soil) and HG (2 g/kg soil) were mixed with autoclaved soil. Plants were well watered and grown under natural conditions for 35 d, followed by 4 d of drought exposure. While drought stress negatively impacted plant growth, effects of individual application of BC, HG and PGPR in combating the drought stress were noteworthy and a predominant increase in plant biomass by BC and plant antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) and elevated soil nutrients by PGPR were observed. PGPR assisted HG in retaining the soil moisture content (SMC) and further elevated the leaf relative water content (LRWC) and fresh weight (FW) root. The combined application of HG and PGPR consortium was most effective in improving photosynthetic pigments, FW shoot and soil fertility status. Likewise, the combined application of BC and PGPR had stimulatory effects on plant osmoregulants, with BC combined with Pseudomonas putida significantly improving soil nutrient retention. It is inferred that HG and BC in combination with PGPR isolates and PGPR consortium are effective drought mitigating strategies. [ABSTRACT FROM AUTHOR]

Soil degradation and a global focus on carbon (C) sequestration in soils have resulted in growing societal interest in soil health practices. Biochar has a high C content, porosity, pH, and cation exchange capacity that benefit soil properties. Here we described an incubation study that aims to evaluate the influences of biochar additions on representative forest organic, forest mineral, blueberry, potato, and mixed vegetable soils from Maine, USA. The experiment consisted of amendments of either a lime stabilized industrial byproduct softwood pulp biochar (SPB) or pine wood biochar (PB) at application rates equivalent to 0, 5, 10, 25, 50, and 100 t ha−1. Here we report influences of biochar addition on soil pH, loss-on-ignition (LOI), water-holding capacity (WHC), and exchangeable cations. In general, both SPB and PB increased the value of these soil properties in all mineral soils, with significant increases often being found at a rate of 100 t ha−1. Forest organic soils, however, were more variable attributable to the high organic C concentration of this substrate. Soil response to SPB amendments was strongly influenced by the lime component, although few significant differences were found between SPB and PB amended soils. Analysis of carbon dioxide (CO2) emissions from SPB amendments due to lime dissolution and acid neutralization represented less than 3% of the total carbon added in SPB treated soils, leaving SPB and PB both important potential soil amendments. This suggests that both traditional and industrial byproduct biochars have potential for soil health and C sequestration management goals. [ABSTRACT FROM AUTHOR]

The study was investigated the influence of pyrolysis conditions on the yield and nutrient properties of yak dung-based biochar and its potential of agro-environmental applications. A series of biochars were made by hydrothermal carbonization (HTC) under the different atmospheres, such as Nitrogen (N2) and carbon dioxide (CO2), processing temperatures (200-300 °C) and residence times (1-2 h). The results showed the yield of yak dung-based biochar ranges from 35.33 wt% to 58.29 wt%. The concentration of nitrogen (N), phosphorus (P) and potassium (K) in biochar varied from 28.18 mg·g−1 to 15.54 mg·g−1, 16.23 mg·g−1 to 25.31 mg·g−1 and 0.59 mg·g−1 to 1.02 mg·g−1, respectively. And the contents of micronutrients Zn and Fe varied from 4.6 mg·g−1 to 17.42 mg·g−1, and 15.28 mg·g−1 to 29.22 mg·g−1, respectively. The yield, total carbon (C), N, hydrogen (H) and oxygen (O) content of biochar decreased with increasing processing temperature, while the total P and K content, pH and Brunauer-Emmett-Teller (BET) surface area increased; moreover, the P and K content of biochar produced in N2 increased more compared with CO2. The heavy metal contents of copper (Cu), cadmium (Cd), chromium (Cr), platinum (Pb) and arsenic (As) all were lower in yak dung-based biochar compare with other manures or sewage sludge-based biochar. Biochar produced in N2 had higher nutrient content indicating the potential of application for fertilizer compared with it in CO2; while the biochar produced in CO2 with larger surface area characteristic and more abundant functional groups showing higher potential of application for the soil amendments and nutrient control materials. Our study provides some new insights for biochar production according to its application. [ABSTRACT FROM AUTHOR]

Phosphorus fixation reduces P availability and affects crop yields in tropical soils. The ameliorative effect of biochar and its co-application with mineral P fertilizer on the soil labile inorganic P fractions and crop growth are unknown and hence studied in two soils with contrasting properties. Soils were applied with kunai grass (Imperata cylindrica) biochar at 15 t ha−1, mineral P fertilizer at 64 mg P kg−1 either together or solely to the potted soils under greenhouse conditions and mung bean (Vigna radiata) seeds were planted. Treatments were replicated 3 times and pots were arranged in complete randomized design. Soil samples were collected from the rhizosphere on days 30 and 90 and analyzed for pH, soluble P, inorganic Fe, Al and Ca-bound P fractions. Dry matter content and P uptake by the mung bean was also assessed. Soil pH was unaffected by fertilization regimes in both soils. Sole biochar application as well as co-application with mineral P increased the amount of P in Ca-P, Al-P and Fe-P fractions in both soils. However, co-application of kunai grass biochar with 64 mg P kg−1 of fertilizer significantly (p <.05) increased mung bean crop dry matter in acidic (78.8%) as well as alkaline soil (23.1%). The usage of kunai grass biochar should be combined with mineral P for reaping the synergistic agronomic benefits in the tropical acidic and slightly alkaline soils. [ABSTRACT FROM AUTHOR]

Archeological Dark Earths, known in the Brazilian Amazon as Terra Preta de Índio are fertile and structured soils considered as a potential model for sustainable agriculture. In order to recreate these soils a field experiment, named New Dark Earth, was set up in 2003 in the municipality of Tailândia, state of Pará, northern Brazil. The treatments consisted of the application of organic residues (wastes from local industries) in a loamy sand soil: cattle bones, wood charcoal, shredded wood blades, and the control. The objective of this study was to evaluate the effect of these residues on soil physico-hydrological properties. The results showed that the residues did not significantly increase the soil organic carbon content. Only the wood charcoal resulted in some improvements in soil physico-hydrological properties, such as lower soil bulk density and higher total and microporosity, which was mainly attributed to the high porosity of this material. Consequently, it also presented more available water. For now, it was concluded that despite the three residues are widely available in the region, the use of wood charcoal seems to be the best alternative to bring improvements to the soil physical properties, mainly soil water retention. However, more studies need to be carried out. [ABSTRACT FROM AUTHOR]

Biochar is a solid product obtained by heating of biomass or organic waste in the total or partial absence of oxygen and is applied to improve soil properties, or considered a means of carbon sequestration. Several positive effects of biochar on soil chemical, physical, and biological properties have already been demonstrated. Biochar amendment has also been repeatedly discussed as an effective means to restore saline lands and increase plant tolerance to salt stress. Especially, improved soil cation exchange capacity, water holding capacity, soil nutrient retention, and increased soil enzyme activities and diversity of microbial communities, were reported. However, the underlying mechanisms of such beneficial effects provided by biochar amendment of soils are highly complex. Therefore, more in-depth studies are needed to understand biochar interactions with soil organisms under extreme environments, which will help achieve maximum benefits of biochar under saline soil conditions. [ABSTRACT FROM AUTHOR]

Drought stress adversely affects soil and plant characteristics. The addition of biochar alleviates the adverse impact of drought stress on plants. The plants' morphological, physiological performance and nutrient uptake are highly enhanced after biochar addition (BA) under drought-stress conditions. Biochar improves the water retention and the physical and biological properties of soils. Uptake of sodium (Na+) ions decreased in biochar-amended soil, which leads to makes other cations such as potassium (K+) uptake by plants. Biochar is characterized by high surface area (SA), cation exchange capacity (CEC), high water-holding capacity (WHC), size pore (PS). Those aforementioned properties are subjected to pyrolysis temperature and feedstock of biochar. Studies of biochar suggest that it might progress fertility of soil and maximize crop yields when iapplied to soil with a suitable application rates. This review highlights the capability of biochar in addressing drought stress on plants and its future prospect. [ABSTRACT FROM AUTHOR]

The effects of biochar application on soil properties have been widely discussed in the literature. As its effect is known to weaken over time, its reapplication may be beneficial in ameliorating the soil properties, including soil structure, however, there are several knowledge gaps. Therefore, this work addresses the effects of initial biochar application (0, 10, 20 t ha−1) and its reapplication (0, 10, 20 t ha−1) alone and in combination with N fertilization (40–240 kg N ha−1) on the relationships between the chemical properties of the soil and soil structure in silty loam Haplic Luvisol (Slovakia) during 2017–2019. Results showed that initial application as well as reapplication of biochar improved soil structure, however, more pronounced changes were observed after biochar reapplication when compared to its initial application. In both cases, most of the soil structure parameters were more favorably affected by the application of biochar alone than by its combination with N fertilization and at a higher rather than a lower rate. Due to the initial application of biochar and its reapplication, the stability of the soil aggregates was significantly supported by increasing soil pH and improvement of the soil sorption capacity, while Fe and Al oxides did not improve soil structure. [ABSTRACT FROM AUTHOR]

Biochar (BCH) is one of the most promising amendments to improve soil quality and store carbon in soils. Vast majority of the studies utilized freshly produced materials and assess BCH effects immediately after soil amendment. The aim of this study was to investigate the influence of biochars aged six months with two soil types on soil physicochemical and biological properties along with plant growth. Soils from a protection zone of water sources and from an agricultural area were mixed with three different types of BCH. After six months of aging, lettuce (Lactuca sativa var. capitata) plants were grown on these soils in greenhouse. Plant aboveground and root biomass, soil physicochemical properties [pH, cation exchange capacity (CEC), total nitrogen (TN), soil organic carbon (SOC), and total phosphorus (TP)], and biological activities [fluorescein diacetate activity (FDA) and urease activities, soil respiration, and' humic and nitrogen index] were determined. Studied BCHs had slight influence on soil physicochemical parameters. pH was significantly increased by all BCH amendments: in Luvisol by 12.7% and in Fluvisol by 11.25% (by 1.1 times). SOC was augmented in both soil types with the addition of the third BCH type that corresponded to the initial BCH input. BCH aging in soil had no influence on CEC, TN, TP and soil microbial activities (FDA, urease, and soil respiration). Moreover, two BCHs did not influence plant growth, whereas the third BCH type had a negative impact, decreasing lettuce development by 62% in Luvisol and by 41% in Fluvisol relative to untreated control soils. [ABSTRACT FROM AUTHOR]

Biochar production from organic waste offers an important alternative for waste management, also improves soil properties (bio-physico-chemical) and reduces heavy metal pollution risk caused by the excessive use of chemical fertilizers applied directly to the soils. Biochar is also proposed as an important management strategy to mitigate the negative impacts of greenhouse gases, which are among the most important causes of global climate change. This study aimed to investigate the effects of biochars produced from six different plant wastes on soil enzyme activity, CO2–C emission, total nitrogen (Nt), and nitrate (NO3–N) concentrations. Almond shell (AS), tobacco waste (TW), pomegranate peel (PP), cotton waste (CW), orange peel (OP), and wheat straw (WS) biochars were applied to the soil at the rates of 0.5, 1.0, and 1.5%, and the biochar amended soils were incubated in the laboratory environment (25 ± 2) for 37 weeks. The highest CO2 ̶ C emission was recorded in OP biochar treatment, while the lowest emission was measured in PP treatment, indicating that OP biochar addition tended to decrease C mineralization in the soil. The addition of AS biochar significantly increased the dehydrogenase and urease enzyme activities, while urease activity did not show a significant increase. The results can be attributed to the differences in composition and properties (C: N ratio, pH) of the biochars applied as well as the nature of the feedstocks used in biochar production. Biochar applications increased the Nt and NO3–N concentrations of the soils, and the highest increase was obtained in the WS treatment. The results of the study revealed that PP biochar can be recommended to reduce CO2–C emission from soils, AS biochar has a significant effect on urease and dehydrogenase enzyme activities, and the effect of WS biochar on Nt and NO3–N concentrations of soils were higher than the other five biochar types. [ABSTRACT FROM AUTHOR]

Phosphorus (P) unavailability and lack of organic matter in calcareous soils under semiarid climates are major reasons for low maize productivity grown in these conditions. The hypothesis was tested that integrated use of biofertilizers (BF) and P-sources could improve dry matter (DM) partitioning and yield of hybrid maize (CS-200) in the semiarid climate of Peshawar. A field trial was conducted to investigate the impact of two BF-sources, and eight organic and inorganic P-sources combinations (P) on DM partitioning, yield, and yield components of hybrid maize. The research was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar, during summer 2017. Experiment was laid out in randomized complete block design with split plot arrangement, using four replications. Combination of inorganic-P [single super phosphate (SSP) and rock phosphate (RP)] and organic-P (compost and biochar) sources was used as factor-A, and BF [Phosphate Solubilizing Bacteria (PSB) and Trichoderma (TD)] as factor-B. Phosphorus was applied at the uniform rate of 120 kg ha−1 from different sources (08 treatments). The results revealed that P sources and BF had significantly affected all parameters under study. As compared with TD, application of PSB had significantly increased total plant dry weight (TDW), leaf dry weight (LDW), cob dry weight (CDW), husks dry weigh (HDW), stem dry weight (SDW), and roots dry weight (RDW) at both silking and physiological maturity. The highest ear length (EL), more number of grains per row (NGPR), number of rows per ear (NRPE), number of grains per ear (NGPE), heavy thousand grains weight (TGW), higher total biological yield above ground (BY), grain yield (GY), stover yield (SY), harvest index (HI), and shelling percentage (SP) were obtained with application of PSB over TD. As compared with sole biochar (T3), application of organic-P in the form of sole compost (T4) had significantly increased plant TDW (188.8 g & 312.9 g), LDW (34.3 g & 29.0 g), CDW (41.9 g & 176.1 g), HDW (25.9 g & 21.7 g), SDW (85.4 g & 65.6 g), RDW (26.9 g & 15.2 g) at silking and physiological maturity, respectively. Significantly higher yields (GY, SY, BY, HI & SP) and yield components (EL, NGPE, NRPE & TGW) were recorded with sole compost application (T4) or combined application of compost + SSP (T6). Among all possible interactions of BF and treatments (2 x 8 = 16 combinations), the integrated use of PSB x T4, and PSB x T6 was found to the most beneficial combinations for improving DM partitioning, yield and yield components of hybrid maize in the study area. Interestingly, the integrated use of BF with RP (T7 & T8) had more positive effect on DM partitioning, yield and yield components of hybrid maize than sole application of RP (T2). [ABSTRACT FROM AUTHOR]

Lead (Pb2+) sorption and desorption rates are the most important processes controlling the mobility and availability of this metal in soil. However, information about biochar addition on amounts and rates of Pb2+ sorption and desorption in calcareous soils is limited. In this study, the effect of application of 1% (w/w) walnut leaf biochar produced at 200 (B200), 400 (B400), and 600°C (B600) was investigated on the adsorption and desorption characteristics (isotherm and kinetics) of Pb2+ in a calcareous clay loam soil at two incubation times (30 and 90 days). Results of the isotherm study showed that the maximum adsorption capacity (qm) (2–277 mg kg−1) and the strength of adsorption (KL) (0.010–0.230 l mg−1) increased significantly (P <.05) with an increase in the pyrolysis temperature. The qm and KL decreased significantly (P <.05) in the soils incubated for 90 days compared to the soils incubated for 30 days (except B600). Moreover, rate of Pb2+ adsorption increased significantly (P <.05) with an increase in the pyrolysis temperature, while, available sites and rate of Pb2+ desorption decreased significantly (P <.05) with an increase in the pyrolysis temperature. The rate of Pb2+ adsorption decreased (P <.05) during incubation, while rate of Pb2+ desorption increased (P <.05). Significant correlations (P <.05) were found between isotherm and kinetics coefficients and surface area and P of the biochars. It can be concluded that the application of biochars produced at high temperature contain high P and surface area are suitable for improve Pb-contaminated calcareous soils. [ABSTRACT FROM AUTHOR]

Biochar and compost are important organic amendment materials for modifying the distribution of pore size in soils. The main idea of this study was to investigate the impact of date palm biochar, compost and their combination on soil water parameters, pore size distribution curves and soil aggregates stability at the rates of 1%, 2%, 3% and 4% (10, 20, 30 and 40 g kg-1). In this study, shape (standard deviation (SD), kurtosis and skewness) and location (dmode, dmedian and dmean) parameters, water stable aggregates (WSAs), mean weight diameter (MWD), geometric mean diameter (GMD) and erodibility factor (Kerodibility) were measured and evaluated. Results showed that the indicators of pore size distribution functions for untreated soil (control) were 31.6, 25.8, 23.5, 3.3, −0.16 and 1.14 for dmode, dmedian, dmean, SD, skewness and kurtosis, respectively. While, WSA>0.25 (macro aggregates), MWD, GMD and Kerodibility were 15.94, 0.19, 0.39 and 0.0895, respectively. Here, dmode, dmedian, dmean, SD, skewness and kurtosis were changed due to application rates of biochar, compost and the mixture of biochar–compost, significantly. The application rate of 4% of the biochar–compost mixture had the highest effects, and dmode, dmedian, dmean, SD, skewness and kurtosis were 18.9, 13.3, 11.3, 4.9, −0.21 and 1.15, respectively. Mixing biochar, compost and biochar–compost mixture reduced equivalent pore diameters, dmode, dmedian, dmean, and increased the indicators of WSA>0.25, MWD, GMD and kerodibility. The factors of WSA, MWD, GMD and kerodibility were enhanced. Thus, the application of biochar, compost and biochar–compost mixture could improve water retention and water use efficiency (WUE) of sandy soils. [ABSTRACT FROM AUTHOR]

Current trends in the intensification of olive cultivation including irrigation have dictated a need to reconsider amendment management practices. The addition of organic wastes to agricultural soils is becoming a common practice as a disposal strategy and to improve the physical and chemical soil properties This study examines physiological varieties of young olive trees (Olea europaea L.) grown on deficit irrigation under four different amended soil. We evaluated the short-term effect of different amended soil under deficit irrigation on soil, plant water status, level of soil, and leaf Nitrogen. Water stress was considered to be insignificant or absent with an irrigation amount of 50% of daily evapotranspiration. Leaf relative water content was between 65 and 88% for the Chemlali cultivar, while that of the Koroneiki was between 60 and 70%. Under conditions of water stress, photosynthesis of trees planted in soil amended with biochar decreased from 8.5 to 1.5 μmol.CO2.m−2s−1, compared to the control for both cultivars.To conclude, amendment addition, used as a tool for sustainable agriculture, could improve plant growth, although soil fertility. The type and amount of amendment should receive special attention to be efficient. [ABSTRACT FROM AUTHOR]

Zinc deficiency is a global nutritional problem which is caused by low dietary intake. Wheat is mostly low in bioavailable Zn and is sensitive to zinc deficiency compared with other grain crops and as a result is reflected as cereal with low Zn efficiency. Zn deficiency prevails in arid to semiarid regions of the world for reasons of less solubility and more fixation of Zn in these soil conditions. Biofortification is currently one of the useful approaches to overcome worldwide malnourishment. A pot and two years field trials were conducted on wheat crop with following treatments: control, Zn @ 3 mg kg−1, Zn @ 6 mg kg−1, Zn @ 9 mg kg−1, Compost @ 20 t ha−1, Zn-enriched compost @ 3 mg kg−1, Zn-enriched compost @ 6 mg kg−1, Zn-enriched compost @ 9 mg kg−1, Biochar @ 20 t ha−1, Zn-enriched biochar @ 3 mg kg−1, Zn-enriched biochar @ 6 mg kg−1 and Zn-enriched biochar @ 9 mg kg−1 and treatments for field trial: control, Zn @ 18 kg ha−1, Compost @ 20 t ha−1, Zn-enriched compost @ 18 kg ha−1, Biochar @ 20 t ha−1 and Zn-enriched biochar @ 18 kg ha−1. Results of field trial revealed that maximum grain Zn (29.18 mg kg−1) recorded in Zn-enriched compost @ 9 mg kg−1 and minimum (17.8 mg kg−1) was in control. It is concluded that Zn-enriched organic amendments especially compost found to be appropriate for yield of wheat crop and grain Zn biofortification of wheat that in result increased protein contents and reduced phytic acid concentration. [ABSTRACT FROM AUTHOR]

Date biochar (DB) was obtained by pyrolyzing date residues at four different temperatures (300, 400, 500, and 600°C referred as DB3; DB4; DB5; and DB6). Three experiments were performed: 1) assessment of wheat crop growth 2) water retention in the sandy soil 3) soil physiochemical properties after the application of DB to the soil. Results showed that the low temperature pyrolysis biochar (LTDB; DB3 and DB4) showed that the wheat biomass (by 47 and 29%) and water-holding capacity (by 55% and 32%) was improved when applied along with NPK fertilizer. Moreover, LTDB had positive impacts on soil enzyme activities, i.e., Phosphomonoestrase; Urease; Catalase; Acid Phosphate; Dehydrogenase; and β-glucosidase by 63, 59, 77, 29, 56, and 43%, respectively, over high-temperature DB pyrolysis (HTDB). In the incubation study, LTDB not only improved the physicochemical properties (bulk density, total porosity, pH, electrical conductivity, cation exchange capacity, organic matter, soil aggregation stability), but also improved the water retention. Additionally, carbon dioxide emission was increased in HTDB and the microbial activities are increased in the LTDB. Overall, LTDB improved the soil fertility and productivity over to HTDB in sandy soil. [ABSTRACT FROM AUTHOR]

Sustainable cotton production is under threat due to poor soil health, exhaustive nature of cotton crop in terms of depleting soil fertility and conventional farming practices. Hence, we investigated the role of soil amendments like biochar, poultry and farmyard manures with synthetic fertilizers to improve the soil mineral nutrients uptake, cotton productivity and overall reduction in nutrients losses. Two year field experiments were conducted to evaluate the impact of soil amendment of biochar, poultry and farmyard manures with synthetic fertilizers in improving the soil fertility and cotton productivity under arid climate of South-Punjab, Pakistan in a randomized complete block design (RCBD). Experimental findings showed that highest values of soil available nitrogen (N), phosphorus (P), potassium (K) and soil organic matter (SOM) were recorded with the soil incorporation of 5 Mg ha−1 poultry manure (PM) with 80:45:30 kg ha−1 NPK which was followed by soil incorporation of 10 Mg ha−1 farmyard manure (FYM) with 80:45:30 kg ha−1 NPK and soil incorporation of 3.5 Mg ha−1 biochar (BC) with 80:45:30 kg ha−1 NPK and ultimately improved soil fertility. Similarly, highest values of plant height, leaf area index (LAI), monopodial, sympodial branches and total bolls plant−1, boll weight, seed cotton and biological yield were recorded with amendment of 5 PM Mg ha−1 with 80:45:30 kg NPK ha−1 which was followed by 10 Mg FYM ha−1 with 80:45:30 kg NPK ha−1 and soil incorporation of 3.5 Mg BC ha−1 with 80:45:30 kg NPK ha−1 and ultimately improved cotton productivity. Conclusively, soil incorporation of biochar, poultry and farmyard manures with synthetic fertilizers as integrated nutrient management strategy might be a promising adaptation strategy for improving soil mineral nutrients uptake, cotton productivity and overall reduce the nutrients losses under arid environmental conditions [ABSTRACT FROM AUTHOR]

Both biochar (B) and vermicompost (V) can provide the soil with soluble organic matter. We evaluated the effect of B in reducing nitrate and dissolved organic carbon (DOC) losses from soil via leaching together with the effect of B combined with V solution (vermiwash) in increasing the efficiency of plant nitrogen. Tomato plants (Solanum lycopersicum L.) were cultivated in a greenhouse with soil under three different amendments (B, V and a mix BV). B was applied at a rate of 2% w/w corresponding to 34 t ha−1. V was applied at 25 mg per plant through fertigation. Leachate and soil were monitored in terms of nitrates and DOC throughout the trial (120 days), and plants and fruits were monitored in terms of nitrogen balance index (NBI) and dry matter biomass. B and BV significantly decreased NO3–_N content in the leachate in all recovered times by 66.8% and 71.3%, respectively. In contrast, the absence of biochar in the V treatment led to a 38.1% increase in NO3–_N concentration. Similar results were found for DOC content. The dry biomass of plants increased in B and BV treatments by 19.5 and 28.7%, respectively. The dry biomass of tomato fruits was enhanced by 18.5, 12.1, and 37% in V, B and BV treatments, respectively. Synergisms were found between the char material and complex organic compounds derived from the vermicompost process in terms of safeguarding the quality of the soil, the underground water, and the sustainability of crops. [ABSTRACT FROM AUTHOR]

In Egypt, the total area of agricultural land is 3.36 million acres, which is 3.8% of the country entire territory. One of the main obstacles to agricultural production in Egypt is soil salinization and degradation. Therefore, saline-sodic soil reclamation in arid regions is highly relevant. This study aimed to use Azospirillum inoculation with eco-friendly organic wastes for free remediation of saline-sodic soils. In this work, nine treatments included two levels of spent grain (S1 and S2), two levels of compost (C1 and C2), a mix of both sources (C1S1), Azospirillum (A1), a mix of both sources with Azospirillum (A1S1 and A1C1) and untreated control. The treatments were previously incubated with soil at field capacity for five months under laboratory conditions at 28°C. The most relevant chemical and biological parameters were analyzed every month for five months. Results indicate that Azospirillum inoculation with spent grain increased soil organic carbon (TOC), dehydrogenase and urease enzymes, micro-nutrients iron (Fe2+), zinc (Zn2+), manganese (Mn2+), copper (Cu2+), and boron (B+), and macro-nutrients nitrogen (N), phosphorus (P) and potassium (K); while decreased exchangeable sodium percentage (ESP), pH and EC, by 75%, 12%, and 43% respectively, compared to initial conditions. A significant variation was observed in chemical and biological properties among all treatments in the order of S2 ≥ A1S1> A1 > C2 > C1S1 > A1C1 > C1 > control > initial. In conclusion, the addition of Azospirillum with the spent grain is highly recommended for the saline-sodic soil amelioration. It is more effective than compost to remediate and enhance saline-sodic soils fertility. [ABSTRACT FROM AUTHOR]

A one-time, large application of biochar (charcoal) could increase soil carbon (C) content and improve overall soil quality. It is known that nematodes have effects on soil organic matter and nutrient cycling and are plant diseases; moreover, nematodes affect nutrient mobilization in C-rich soil conditions; however, information is scant on the effect of biochar addition on nematode communities. Therefore, the objective of this field study was to evaluate the influence of sugar maple hardwood biochar on soil nematode communities and assess the relation among soil nematode communities and soil nutrient concentrations. Nematode communities were sampled and identified in soils without biochar application and soil amended with an application of 8% by weight (equivalent to 160 Mg ha−1). The application of 8% biochar did not change the abundance of nematodes but affected some nematode communities. Compared to the unamended soil, biochar-amended soil had lower plant-parasitic nematode populations and higher abundance of predatory nematodes. The Shannon diversity index (H') was lower, and the maturity index (MI) was higher with a mean value of 2.38 with biochar addition compared to 2.21 in unamended plots. Higher soil acidity and addition of substantial amounts of magnesium, calcium, potassium, and manganese in the biochar-amended soils were recorded after biochar application. [ABSTRACT FROM AUTHOR]

A pot experiment was carried out to identify the effect of biochar rates on the performance of Arbuscular mycorrhizal fungi (AMF) Rhizoglomus irregularis and the growth and phosphorus (P) uptake of maize (Zea mays L.) plants under calcareous soil conditions. Eight integration treatments, four biochar rates (zero (control) (B0), 5 (B1), 7.5 (B2), 10 g biochar/kg soil (B3)), and two AMF inoculations (untreated (NM) and inoculated with AMF (M)) were arranged in a randomized complete block design (RCBD) with 5 replicates. The results showed that biochar had a positive effect on the growth of maize, P uptake, and available P in soil. It was also found that this positive effect of biochar increases with increasing rates, but it was found that there were no significant differences between the two highest rates of biochar B2 and B3. Plants treated with AMF had an influential role in the maize growth and its elemental content of P, as well as increasing the availability of P in soil. However, it was found that biochar reduces the effect of AMF but does not completely discourage the activity of AMF. Therefore, it is recommended that under the same circumstances of this experiment, using a rate B2 of biochar and treated with AMF which having the highest maize plant growth and its elemental P content. [ABSTRACT FROM AUTHOR]

The replant disease refers to abnormal crop growth caused by continuous cultivation of the same or related species on the same soil, and often occurring in crops and orchards. Recently, replant disease have become a major factor constraining the sustainable development of global agriculture and fruit trees. The causes of replant disease include biological and abiotic factors, but in the final analysis, they are caused by changes in the soil environment. Soil environment is closely related to soil productivity. A decline of soil quality results in poor crop growth and reduced yield. The causes of soil environment changes mainly include intensive soil tillage, rapid industrialization, soil pollution, destruction of soil micro-ecosystem and substances secreted by plants under replant condition. Biochar, a porous carbon material prepared from pyrolysis of biomass (agricultural waste, etc.), is widely used as an amendment and adsorbent. To understand the role of biochar in alleviating replant disease, we summarized the previous research results of biochar application in replant soil. The following points are summarized: (1) soil problems and their effects on plants; (2) effects of biochar on replant soil environment; and (3) effects of biochar on alleviating replant disease. Overall, the literature suggests that biochar is an effective measure to amendment soil environment and alleviates replant disease. Further studies on biochar will enhance our understanding of biochar–soil interactions, and its long-term impact of biochar on soil environment. [ABSTRACT FROM AUTHOR]

Excess soluble salts in the soil and irrigation water creates difficulties for plant growth and lowers nutrient availability in the soil. Organic ameliorants such as biochar are believed to be one of the effective treatments for soil improvement and salt stress alleviating. To access the response of different types of salt in irrigation water and bamboo biochar amendment on okra growth and nutrient leaching in coastal saline soils, both column and pot experiments were carried out from 2018 to 2019 in Nanjing, China. The experimental results suggested that okra growth and yield were reduced notably under the saline condition in contrast with the control treatment. Anthocyanin accumulation, which is a sign of growth stress, was decreased after the application of different types of salt. Furthermore, the application of different types of salt effectively increases malondialdehyde (MDA) content in sodium sulfate (Na2SO4) and sodium chloride (NaCl) treatments at both 2.0 and 4.0 dS/m. Meanwhile, MDA was reduced in CaCl2 and MgCl2 treatments at both 2.0 and 4.0 dS/m. Nevertheless, bamboo biochar remarkably ameliorated okra seed germination, growth process, and yield due to salt stress. Besides, the leaching of nitrate, total nitrogen and total phosphorus is significantly reduced in the case of biochar application. In conclusion, our study suggested that bamboo biochar is one of the alternatives of ameliorant to improve the productivity of plants in coastal saline soils. [ABSTRACT FROM AUTHOR]

Calcareous and sandy soils generally have soil fertility problems, and these problems have been revealed to be improved by applying compost and biochar produced from the distinct biomass. However, comparing the effects of compost and biochar originating from the same biomass on soil fertility are still not clearly explained. The comparing impacts of compost and biochar both made from the same biomass on soil fertility status in a wind erosion afflicted calcareous and alkaline sandy clay loam (SCL) soil, were explored using a pot experiment. Compost and biochar were produced from a pioneering Oleaster (Oleaster Angustifolia L.) tree through the windrow composting method and pyrolysis process at 450 °C, respectively. The SCL soil used was treated with compost and biochar at rates of 0%, 1%, 2%, and 4% by weight and thereafter incubated for 2 months. The trial layout was in line with a completely randomized plot design with four replicates. Pursuant to the experimental results, the addition of compost and biochar considerably enriched soil fertility by enhancing soil biochemical properties of SCL soil. SCL soil treated with compost yielded the highest available phosphorous (AP), organic carbon (OC), total nitrogen (TN), NH4+-N, NO3-N, active carbon (AC), potential mineralizable nitrogen (PMN), soil microbial respiration (SMR), electrical conductivity (EC), CaCO3, extractable cations (Mg, K, Ca, and Na), cation exchange capacity (CEC), and available micronutrients (Mn, Fe, and Zn), which were significantly higher (P <.001) than the SCL soil amended with biochar, suggesting the recalcitrance of biochar on microbial activities. Furthermore, available micronutrients (Mn, Fe, and Zn) were significantly decreased in SCL soil amended with biochar compared with compost amended SCL soil, indicating the sorption potential of biochar. It was concluded that applying Oleaster tree compost is more effective than biochar in improving soil fertility. However, the effects of biochar on carbon sequestration and the findings of this study need to be proven under field demonstration for more conclusive results prior to recommending farmers to apply either compost or biochar in soil management practices. [ABSTRACT FROM AUTHOR]

Biochar plays an important role in improving soil quality and carbon (C) sequestration. However, the effects of different biochar application rates on soil organic C content and its fractions in the Loess Plateau of northwest China are still unclear. In this work, six biochar treatments were studied, with application rates of 0, 10, 20, 30, 40 and 50 t·ha−1 (CK, T1, T2, T3, T4 and T5, respectively). Soil total organic C (TOC), readily oxidizable C (ROC), water-soluble organic C (WSOC), microbial biomass C (MBC), light fraction organic C (LFOC), heavy fraction organic C (HFOC) and the Carbon pool management index (CPMI) in the 0–30 cm layer were analyzed after 3 years of wheat field trials. The content of soil TOC and its fractions decreased with soil depth but was significantly (p <.05) increased by biochar. TOC, ROC and HFOC showed significant (p <.05) positive correlations with the rate of biochar application, with the highest content of these components in T5. MBC, WSOC and LFOC first increased and then decreased with the increasing rate of biochar application. MBC and WSOC of T3 and LFOC of T4 were the highest of all treatments. When compared with CK, the CPMI of all biochar treatments was >100% in the order of T5 > T4 > T3 > T2 > T1. This study provides scientific support for large-scale biochar application on the Loess Plateau to significantly improve soil quality via increasing the soil organic C fractions and enhancing the inert soil C pool. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the role of biochar properties and application rate in the alleviation of negative impacts of salinity stress on the growth of salt-sensitive common bean (Phaseolus vulgaris L.). The biochar was obtained by slow pyrolysis of olive pruning at 400°C and characterized as high alkaline (9.3) and having a high cation exchange capacity (CEC) and low electrical conductivity (EC) with high porous surface morphology. Plants were grown in the greenhouse and subjected to different amounts of salt (0, 25, 50 mM NaCl) and biochar rate (0, 5, 15 t/ha). Salinity stress reduced shoot growth, biomass accumulation, total chlorophyll and carotenoid content, these parameters were ameliorated by biochar. Adverse effects of salinity on pod settings were also mitigated by biochar supplements. Salinity triggered oxidative stress monitored by increasing hydrogen peroxide (H2O2) content and cell membrane permeability of leaves were mitigated by only 5 t/ha biochar application in contrast 15 t/ha biochar extended oxidative stress level. Our results showed that biochar application may be a promising strategy to increase common bean growth under saline soils due to its specific physicochemical properties, particularly high Na+ adsorption capacity. However, the higher biochar application rate may augment the adverse effects of soil salinity for salt-sensitive bean growth due to its contribution to the cumulative EC level of the soil. [ABSTRACT FROM AUTHOR]