Soil Application Of Biochar Research Articles

Global meta-analysis and machine learning reveal the critical role of soil properties in influencing biochar-pesticide interactions

Biochar application in soils is increasingly advocated globally for its dual benefits in enhancing agricultural productivity and sequestering carbon. However, lingering concerns persist regarding its environmental impact, particularly concerning its interactions with pesticide residues in soil. Previous research has fragmentarily indicated elevated pesticide residues and prolonged persistence in biochar-amended soil, suggesting a potential adverse consequence of biochar application on pesticide degradation. Yet, conclusive evidence and conditions for this phenomenon remain elusive. To address this gap, we conducted a comprehensive assessment using meta-analysis and machine learning techniques, synthesizing data from 58 studies comprising 386 observations worldwide. Contrary to initial concerns, our findings revealed no definitive increase in pesticide concentrations in soil following biochar application. Moreover, a significant reduction of 66 % in pesticide concentrations within soil organisms, such as plants and earthworms, was observed. The quantitative analysis identified soil organic matter content as a key factor influencing biochar-pesticide interactions, suggesting that applying biochar to soils rich in organic matter is less likely to increase pesticide persistence. This study provides a critical assessment of the environmental fate of pesticides under biochar application, offering valuable guidance for the optimal utilization of both pesticides and biochar in sustainable agricultural practices.

Co-application of silicon and biochar affected anatomical and biochemical properties of corn leaf (Zea mays L.) under soil nickel toxicity

Soil pollution with heavy metals is a threat to crop production. Practically, application of silicon (Si) with biochar can be a cost-effective approach to immobilize metals in contaminated soils. Investigation of the anatomical and biochemical changes of corn leaf is important for describing the mechanisms of Si and biochar soil application in alleviating the negative effects of nickel (Ni) toxicity. A factorial pot experiment was conducted to investigate the effect of Si (0, 250 and 500 mg Si kg-1 soil) in combination with rice husk biochar (RHB) or sheep manure biochar (SMB) prepared at two pyrolysis temperatures (300 and 500 °C) on anatomical and biochemical properties of corn leaves in a Ni-polluted soil. The length, width, area and weight of third-leaf, and metaxylem and protoxylem of midrib improved by application of Si250 with RHB more than SMB. At Si250, RHB300 and RHB500 improved the stomatal area by 31.7 and 27.7% compared to control (without biochar), respectively. The leaf membrane stability index was increased by increasing Si application level and reached 69% in RHB300. In contrast to total chlorophyll, the highest carotenoid content, catalase and peroxidase was obtained by control (without Si and biochar) followed by SMB. At Si250, the highest relative water content (RWC) was observed in RHB300 by 34.8% increase. Also, RHB300 had the highest total dry matter, with increases of 82.2, 120.0 and 83.1% at Si0, Si250 and Si500, respectively. By increasing the Si level and biochar application, the shoot Ni decreased between 42.1 to 133.3%. Combined application of Si250 with RHB300 resulted in the highest dry matter through improving the leaf dimensions, metaxylem and protoxylem areas of midrib, membrane stability index, total chlorophyll, and RWC, while Ni uptake was reduced.

Impact of biochar on the degradation rates of three pesticides by vegetables and its effects on soil bacterial communities under greenhouse conditions

A 28 days pesticide degradation experiment was conducted for broccoli (Brassica oleracea L. var. italica Planch) and pakchoi (Brassica chinensis L.) with three pesticides (chlorantraniliprole (CAP), haloxyfop-etotyl (HPM), and indoxacarb (IXB)) to explore the effects of biochar on pesticide environmental fate and rhizosphere soil diversity. Rice straw biochar (RB) was applied to soil at a 25.00 t ha−1 dosage under greenhouse conditions, and its effects on the degradation of three pesticides in vegetables and in soil were investigated individually. Overall, RB application effectively facilitated CAP and HPM degradation in broccoli by 13.51–39.42% and in broccoli soil by 23.80–74.10%, respectively. RB application slowed the degradation of CAP, HPM and IXB in pakchoi by 0.00–57.17% and slowed the degradation of CAP in pakchoi by 37.32–43.40%. The results showed that the effect of RB application on pesticide degradation in crops and soil was related to biochar properties, pesticide solubility, plant growth status, and soil characteristics. Rhizosphere soil microorganisms were also investigated, and the results showed that biochar application may be valuable for altering bacterial richness and diversity. The effect of biochar application on pesticide residues in crops and soil was influenced by the vegetable variety first, and the second was pesticide characteristics. RB applied to soil at a 25.00 t ha−1 dosage under greenhouse conditions is recommended for broccoli production to ensure food safety. Our results suggested that biochar application in soil could reduce pesticide non-point source pollution, especially for highly soluble pesticides, and could affect soil microorganisms.

Biochar alters maize growth, mycorrhizal associations and fall armyworm performance

Abstract Background and aims Biochar is a carbon source employed to improve soil properties, promoting plant health and nutrition in agroecosystems. Root associated microorganisms such as arbuscular mycorrhizal fungi (AMF) are also used as bioinoculants in combination with biochar to provide eco-friendly alternatives for crop production under unfavorable growth conditions. However, information on the effects of biochar on multitrophic interactions of plants with herbivorous insects is limited. Therefore, the objective of this work was to evaluate the effect of biochar and arbuscular mycorrhizae on plants and herbivorous insects. Methods We established a multifactorial experiment with maize plants, AMF (two strains, Rizhophagus irregularis and a native consortium) and the Fall Armyworm Spodoptera frugiperda with and without soil application of biochar. Variables of biomass, plant nutrition, mycorrhizal colonization and performance of herbivorous insects were measured. Results We found that biochar reduced insect herbivory and promoted mycorrhizal association in maize. However, plant growth was reduced. Additionally, AMF increased the weight of fall armyworm larvae. Conclusion Our results show that biochar influences maize plant development, AMF, and fall armyworm performance, but did not affect interactions between these below- and above ground components.

How much biochar is safe? Exploring potential ecotoxicological consequences for soil invertebrates and plants

The application of biochar in soil has shown promising potential for mitigating the toxicity of contaminated soils due to its unique properties. However, the understanding of its adverse effects on soil biota remains limited. This study aimed to investigate the potential ecotoxicological effects of incorporating sugarcane straw biochar into clay and sandy soils. This research assessed three biochar dosages (2 %, 5 %, and 10 %) and their effects on four species: the springtails Sinella curviseta and Proisotoma minuta, the worm Enchytraeus crypticus, and the plant Eruca sativa L. The results revealed that biochar incorporation had positive effects on plant growth, increasing biomass, and shoot and root length in E. sativa, with more pronounced effects in clay soil. However, the effects on the survival, reproduction, and growth of springtails varied depending on the species and soil type, with a reduction in the survival of P. minuta in both soils (2,2 and 2,9 times lower in clay soil and sandy soil respectively) and S. curviseta only in clay soil (24 % to 36 % decrease). The reproduction of P. minuta decreased in both soils (34 % - 48 % in sandy soil and 50 % - 80 % in clay soil), while the reproduction of S. curviseta decreased only at the lowest proportion of biochar in the clay soil (18 % decrease). For E. crypticus, biochar improved both survival and reproduction, especially in sandy soil (1.9 and 11 times greater respectively). Therefore, biochar has positive effects on worms and plants, indicating the potential to improve soil health and support ecosystem resilience, but it has deleterious effects on springtails at certain dosages. The effects of biochar amendments on soil characteristics and the effects of biochar-induced toxicity should be considered to avoid potential risks to representative species. The findings presented herein address lacunae in ecotoxicology by delineating safe concentrations of biochar for various soil species, thus paving the way for subsequent validation of optimal application doses.

Recycling of Mulberry Stalk as Biochar and its Effect on Uptake of Nutrients by Mulberry

A field experiment was conducted in the mulberry crop to know the effect of soil application of mulberry stalk biochar on nutrients uptake by mulberry at farmer’s field at Sidlaghatta (Tq), Chikkabalapura District. A randomized block design was employed with eight treatments and three replications. A randomized block design was employed with eight treatments replicated thrice. Results revealed that, Combined soil application of biochar @ 10 t ha-1 and FYM @ 10 t ha-1 (T8) recorded higher leaf yield per hectare (13.07 t ha-1) and it was on par with T7 (12.61 t ha-1) which received soil application of biochar @ 7.5 t ha-1 and FYM @ 10 t ha-1. The lowest leaf yield of 10.45 t ha-1 was recorded in control which was devoid of biochar. Among different treatments, significantly higher uptake of primary nutrients (Nitrogen, phosphorus and potassium of 90.68, 9.07 and 47.10 kg ha-1, respectively) secondary nutrients (calcium, magnesium and sulphur of 44.48, 17.26 and 9.75 kg ha-1, respectively) and micronutrients (iron, manganese, zinc, copper and boron of 748.20, 153.22, 139.34, 60.92 and 54.25 g ha-1, respectively) by mulberry were recorded in the treatment (T8) which received soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1 and followed by T7 which received biochar @ 7.5 t ha-1 + FYM @ 10 t ha-1 and found superior over other treatments. The control with no biochar application recorded lower nutrients uptake by mulberry crop. The findings revealed that utilization of mulberry stalk as a biochar has positive effect on nutrient uptake by mulberry crop and it could partly replace chemical fertilizers and promote organic farming in a circular economy concept.

Effect of Mulberry Stalk Biochar on Soil Nutrients Status and Productivity of Mulberry (Morus alba L.)

Biochar as an organic amendment improves soil attributes, with a potentially significant effect on soil fertility. The main objective of this study was to quantify the effect of biochar addition on nutrients status in mulberry cultivated soil. A field experiment was conducted in the mulberry crop to know the effect of soil application of mulberry stalk biochar on nutrients build up in soil at farmer’s field at Sidlaghatta (TQ), Chikkaballapura District during 2020-2021 (rabi2020, summer and kharif-2021). A randomized block design was employed with eight treatments replicated thrice T1: Control (NPK375:140:140 kg ha-1 alone) T2: POP (FYM (25 t ha-1) + NPK 375:140:140 kg ha-1) T3: Soil application of biochar @ 5 t ha-1T4: Soil application of biochar @ 7.5 t ha-1 T5: Soil application of biochar @ 10 t ha-1T6: Soil application of biochar @ 5 t ha-1 + FYM @ 10 t ha-1T7: Soil application of biochar @7.5 t ha-1 + FYM @ 10 t ha-1T8: Soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1NPK is common for all the treatments. Combined soil application of biochar @ 10 t ha-1 and FYM @ 10 t ha-1 (T8) increased the leaf yield (13.07 t ha-1) by 21 % over control (10.45 t ha-1 Significantly higher soil primary, secondary and micronutrients were recorded in T8 (soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1) followed by treatment T7 which received soil application of biochar @ 7.5 t ha-1 + FYM @ 10 t ha-1. The lower soil primary, secondary and micronutrients were recorded in T1 which is devoid of biochar. The findings revealed that utilization of mulberry stalk as a biochar has positive effect on the improvement of nutrient status and it could partly replace chemical fertilizers and promote organic farming in a circular economy concept.

Insights into CO2 and N2O emissions driven by applying biochar and nitrogen fertilizers in upland soil

Biochar and soil carbon sequestration hold promise in mitigating global warming by storing carbon in the soil. However, the interaction between biochar properties, soil carbon-nitrogen cycling, and nitrogen fertilizer application's impact on soil carbon-nitrogen balance remained unclear. Herein, we conducted batch experiments to study the effects and mechanisms of rice straw biochar application (produced at 300, 500, and 700 °C) on net greenhouse gas emissions (CO2, N2O, CH4) in upland soils under different forms of nitrogen fertilizers. The findings revealed that (NH4)2SO4 and urea significantly elevated soil carbon dioxide equivalent emissions, ranging from 28 to 61.7 kg CO2e/ha and 8.2 to 37.7 kg CO2e/ha, respectively. Conversely, KNO3 reduced soil CO2e emissions, ranging from 2.2 to 13.6 kg CO2e/ha. However, none of these three nitrogen forms exhibited a significant effect on CH4 emissions. The pyrolysis temperature of biochar was found negatively correlated with soil CO2 and N2O emissions. The alkaline substances presented in biochar pyrolyzed at 500–700 °C raised soil pH, increased the ratio of Gram-negative to Gram-positive bacteria, and enhanced the relative abundance of Sphingomonadaceae. Moreover, the co-application of KNO3 based nitrogen fertilizer and biochar increased the total carbon/inorganic nitrogen ratio and reduces the relative abundance of Nitrospirae. This series of reactions led to a significant increase in soil DOC content, meanwhile reduced soil CO2 emissions, and inhibited the nitrification process and decreased the emission of soil N2O. This study provided a scientific basis for the rational application of biochar in soil.

RHIZOSPHERE MICROBIOME, SOIL ENZYMES AND GROUNDNUT YIELD AS INFLUENCED BY ADDITION OF BIOCHAR AND FERTILIZERS IN IRRIGATED ALFISOL OF NORTH COASTAL ANDHRA PRADESH

The field experiment was conducted in irrigated Alfisols of North coastal Andhra Pradesh tostudy the effect of biochar and chemical fertilizers on rhizosphere microbiome, soil enzymes andyield performance of groundnut crop (variety K-6) during rabi, 2018-19. Biochar application tosoil significantly increased soil bacterial, fungal and actinomycetes population. At pod developmentstage, the highest number of bacterial count (39.0 x106 CFU g-1 soil) was observed in T5 (100%RDF + biochar @ 6 t ha-1) which was on par with all the biochar applied treatments (T3, T4, T6, T7,T8). The Biochar applied @ 6 t ha-1 (T5 & T8) significantly increased the bacterial population ascompared to non-biochar applied treatments (T1 & T2). Fungal and actinomycetes populationfollowed the similar trend of bacterial count. Soil urease activity was significantly superior inbiochar applied treatments (T3, T4, T5, T6, T7, T8) compared to non biochar applied treatments (T1and T2). With increased rates of biochar application the urease activity markedly increased insoil. Similar trend was noticed with respect to dehydrogenase, acid phosphatase and alkalinephosphatase enzymes in soil in response to addition of biochar. At pod development stage, thehighest leaf area index (3.16) was recorded with 100% RDF + biochar @ 6 t ha-1(T5) which wassignificantly higher than T1 (control), T2 (100% RDF) and T6 (75% RDF + biochar @ 2 t ha-1). Thehighest drymatter accumulation of 2951 kg ha-1 at peg penetration and 6428 kg ha-1 at poddevelopment was observed in T5 (100% RDF + biochar @ 6 t ha-1) which was on par with T3(100% RDF + biochar @ 2 t ha-1), T4 (100% RDF + biochar @ 4 t ha-1), T8 (75% RDF + biochar @6 t ha-1) treatments. Groundnut pod yield was highest (4019.58 kg ha-1) in treatment received100% RDF + biochar @ 6 t ha-1, which was on par with T4 (100% RDF + biochar @ 6 t ha-1) and T8(75% RDF + biochar @ 6 t ha-1).

Effect of Mulberry Stalk Biochar, FYM and Humic Acid on Growth, Yield and Quality of Mulberry (Morus alba L.)

A field experiment was conducted in a mulberry crop to investigate the impact of soil application of mulberry stalk biochar with FYM and foliar spray of humic acid on the growth, yield and quality of mulberry at a farmer's field in Mylandlahalli Village, Chintamani Taluk, Chikkaballapura District. The experiment was set up in a randomized complete block design with eight treatments, each replicated thrice. Result of the experiment revealed that among the various treatments applied, the combined application of biochar with FYM and humic acid (T8: Soil application of biochar @ 10 t ha-1 + FYM @10 t ha-1 + 2% Humic acid foliar spray) had significant effect on plant height (196.10 cm), number of shoots per plant (15.06), number of leaves per shoot (31.78), leaf yield (26.22 t ha-1), crude protein (20.28%) and lower crude fibre (1.56%). The next best treatments were T7 (Soil application of biochar @ 7.5 t ha-1 + FYM @10 t ha-1 + 1% foliar spray of humic acid) and T6 (Soil application of biochar @ 5 t ha-1 + FYM @10 t ha-1 + 0.5% Humic acid foliar spray) and these treatments were statistically comparable but significantly superior to the package of practice (POP).

Toxicity and Behavioral Effects of Amending Soils with Biochar on Red Imported Fire Ants, Solenopsis invicta.

Solenopsis invicta, often known as the red imported fire ants (RIFAs), is a well-known global invasive ant species that can be found in agricultural, urban, and natural environments worldwide. Simultaneously, it also inhabits the soil. Biochar is generated by the pyrolysis of organic matter under high-temperature anoxic environments and widely used in agricultural ecosystems and soil amendment. However, to date, it remains unknown as to whether soil application of biochar has a negative effect on RIFAs. In our study, we investigated the toxicity and irritability effects of different amounts of biochar (0%, 1%, 2%, 5%, 10%, and 20%) introduced into the soil on red fire ants; upon comparison with the control soil (0% biochar), the application of 1%, 2%, and 5% biochar did not result in significantly different results. But the utilization of biochar at a concentration over 10% effectively repelled the RIFAs, resulting in their departure from the treated soils. High doses of biochar were able to cause death of red fire ants; the mortality rate of red fire ants reached 55.56% after 11 days of 20% biochar treatment. We also evaluated the effects of biochar on four behaviors of red fire ants, namely aggregation, walking, grasping, and attacking; 20% of the biochar treatment group reduced aggregation by 64.22% and this value was 55.22%, 68.44%, and 62.36% for walking, grasping, and attacking. Finally, we measured the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) enzyme activity and malondialdehyde (MDA) content in red fire ants; the results showed that the activities of the three enzymes increased with the increase in biochar addition, which indicated that a high dose of biochar induced oxidative stress in red fire ants. Our results indicate that biochar has the potential to cause toxicity and repel red imported fire ants (RIFAs) in a manner that is dependent on the concentration. We propose that biochar could be utilized in the control and manufacturing of baits for red fire ant management. This work establishes a foundation for the prevention and management of red fire ants and the logical utilization of biochar.

Producing, Characterizing and Quantifying Biochar in the Woods Using Portable Flame Cap Kilns.

One of the biggest challenges in utilizing non-commercial forest biomass is its widely distributed nature. The best solution to the biomass problem, to avoid expensive and carbon-intensive processing (chipping) and transportation costs, is to process it onsite. However, conventional burn piles have destructive impacts on forest soil and provide no benefits other than fuel reduction. Converting forest slash to biochar onsite has many ecological advantages over the current practice of slash disposal by incineration in burn piles, including reduced soil heating and particulate emissions, along with multiple benefits of the biochar to forest soil health and water holding capacity when left in place. Making biochar onsite in the woods is a way to return a pyrogenic carbon component to forest soils that has been missing due to the recent history of fire suppression. Biochar is also a leading method of carbon removal and sequestration for climate change mitigation. In this study, we document a method for making biochar using a portable biochar kiln. This low-cost method utilizes hand crews equipped with water for quenching kilns before the biochar burns to ash. Simple techniques for quantifying and characterizing the biochar produced are incorporated into the method for the purpose of measuring impact and qualifying for carbon removal certificates to help pay for the cost of the work. We describe the CM002 Component Methodology that provides standardized procedures for the quantification of GHG benefits during three stages of the process: waste biomass sourcing, biochar production, and biochar soil application. The CM002 Methodology is based on international best practices, including the most recent VCS methodology VM0044 Standards and EBC C-Sink Artisan Standards. Reliable quantification methods utilizing appropriate safety factors are the first essential step toward eligibility for carbon removal finance.

Experimental investigation of moisture influence on biochar and biochar-soil blends thermophysical properties

Biochar is a carbonaceous and porous material obtained through pyrolysis or gasification. It can be extremely valuable as soil amendment since it increases the organic matter content and fertility, the microbial activity, the water retention, and the crop yields. Moreover, biochar soil application has the potential for long-term carbon sequestration which makes its application to soil interesting even outside agricultural crops. In recent years, the study of the variation of the thermophysical properties of the soil induced by mixing with biochar has attracted interest.In this work, the effect of the water content on thermal conductivity of biochar was investigated by means of the guarded hot plate apparatus λ-Meter EP500e. The same procedure was applied to various mixtures of biochar and soil. Furthermore, the specific heat was measured in order to obtain the thermal diffusivity in the various conditions through a calorimeter. Solar reflectance was also measured following the ASTM C1549 using a solar spectrum reflectometer SSR-ER. The obtained thermophysical properties can be used for the evaluation of the temperature trend of soil at different depths during the seasonal variations.

Biotoxicity attenuation and the underlying physicochemical mechanism of biochar aged under simulated natural environmental conditions

Biochar (BC), with the benefits of enhancing soil fertility, absorbing heavy metals, carbon sequestration, and mitigating the greenhouse effect, has been extensively used for soil remediation. However, the long-term changes in the biotoxicity of BC under complex environmental conditions, which are the key factors influencing the sustainable application of BC in soil, are still unclear. Herein, the biotoxicity of BC aged with various processes, including dry‒wet cycle (DW) aging, freeze‒thaw cycle (FT) aging, ultraviolet irradiation (UV) aging, and low molecular weight organic acid (OA) aging, was systematically investigated by Escherichia coli (E. coli) culture experiments. The toxicity attenuation rate (%·week−1) was proposed to more concisely and clearly compare the influence of different aging methods on BC toxicity. The results indicated that after 5 weeks of aging, the toxicity attenuation rate during the four aging modes followed the order OA aging > FT aging > UV aging > DW aging. BC was nontoxic after 1 week of OA aging, 4 weeks of FT aging, 7 weeks of UV aging, and 14 weeks of DW aging. Spectroscopic characterizations revealed that humic acids in the dissolved organic matter of BC were the main reason for the biotoxicity. In addition, the attenuation of environmentally persistent free radicals on BC during aging was also an important factor for reducing environmental toxicity. This work provides insight into the detoxification mechanism of the BC aging process under ordinary environmental conditions and guidance for the safe application of BC in soil.

Three-year field experiments revealed the immobilization effect of natural aging biochar on typical heavy metals (Pb, Cu, Cd)

Biochar has been widely used for the remediation of heavy metal contaminated soil, while the long-term field aging on its properties and the performance in the ability of metal immobilization must not be overlooked. In this study, the stability of immobilized heavy metals (Cd, Cu, Pb) on biochar during a 3-year remediation for soil in the field was investigated through desorption experiments. The results indicated that the application of biochar and its aging in the field both remarkably increased the immobilization of the 3 metal ions in the field under 3-year remediation. The cumulative desorption of the 3 metals decreased with biochar aging, and the desorption rate of Pb2+, Cu2+ and Cd2+ in T3 (Application of 30 t·hm−2 of biochar) for the third year was 0.08 %, 0.20 % and 13.15 %. Meanwhile, both the desorption rates and extents exhibited significant difference with the order of Pb2+ < Cu2+ < Cd2+. The increased soil pH, the enhancement of O/C ratio (Increase from 0.30 for fresh BC to 0.61 for aged BC(S3)) and oxygen-containing functional groups in biochar, and the accretion of organo-mineral micro-agglomerates on biochar surfaces and in pores during field aging process jointly contributed the immobilization of metals in soils mainly through co-precipitation and complexation. Our results provide new insights into the practical application of biochar in soils contaminated with multiple heavy metals from the perspective of long-term effects, which suggests that the potential release risk of metals become slighter over time.

Impacts of Biochar Treatments on Some Soil Properties and Micronutrient Availability

The application of biochar as a soil amendment has been recognized as an environmentally friendly and highly efficient strategy for restoring the fertility of the soil and increasing agricultural productivity. In this study, the impacts of Senna tora biochar treatments on soil properties and micronutrient availability in the farmlands of Misau, Bauchi State, Nigeria, were investigated. A complete randomized design replicated three times, which included control soil (no biochar/0 day), 30 days, and 60 days of biochar treatments, was adapted based on the fact that incubation time affects biochar application in soil. After treatments, the biochar was removed and the soil samples from each treatment were analyzed for pH, soil bulk density (BD), cation exchange capacity (CEC), organic carbon (OC) and micronutrient levels using various analytical methods. The results of the analysis show pH, OC and CEC values increased significantly (p ≤ 0.05) from 6.66 to 7.89, 3.40 to 3.90 g/kg and 5.16 to 7.29 cmol/kg respectively, while BD decreased significantly from 1.56 to 1.48 g/cm3 after 60 days of biochar treatment. The levels of Mn, Cu and Zn increased from 188.25 to 286.12 mg/kg, 14.38 to 41.88 mg/kg and 68.63 to 140.19 mg/kg respectively, while levels of Fe decreased from 9460.00 to 4782.73 mg/kg after 60 days of biochar treatments. Application of Senna tora biochar has generally led to a significant improvement in the fertility of the soil. It is therefore recommended that Senna torabiochar be used in the field to demonstrate its practical application.

Impact of Interaction between Biochar and Soil Microorganisms on Growth of Chinese Cabbage by Increasing Soil Fertility

We investigated the improvement of cabbage growth through the interaction of biochar, which can promote microbial activity, with the microbes in the soil. An increase in cabbage growth could be detected in soil with biochar or soil microbes, but the fresh weight of cabbage in soil supplemented with both biochar and microbes was 8.8% and 5% higher, respectively, than that with either microbes or biochar alone. The phosphorus content in Chinese cabbage was also increased by 36.3% when compared with the control without the addition of biochar and microbes. Such an improvement on cabbage growth is closely related to the soil amelioration. The application of biochar in soil significantly stimulated the growth of soil microbes and further altered the microbial community structure in soil. When 2% biochar and microbes were simultaneously applied in soil, the content of the organic matter and available phosphorus content in soil was 36.7% and 45.5% higher, respectively, than that in soil with or without biochar. The maximal increment in the available potassium content was observed in the soil supplemented with both 5% biochar and soil microbes, which was 46.4% higher than that in soil without the addition of biochar and microbes. Both phosphatase and urease activity in soil were also increased by 61.2% and 49.4%, respectively, by applying 2% biochar in soil together with microbes, as the interaction of biochar with the microbes could promote the activity of soil microbes and enzymes which resulted in an improvement in soil fertility. The interaction of biochar with microbes in soil could promote the plant growth of Chinese cabbage by increasing the soil fertility.

Biomass Waste Conversion Technologies and Its Application for Sustainable Environmental Development—A Review

With the global population continuing to increase, the demand for food and energy has escalated, resulting in severe environmental pressures. Traditional methods of food and energy production have left a significant footprint on the environment, primarily due to the emission of greenhouse gases and a notable surge in waste production. Nevertheless, scientists have recently focused on developing sustainable solutions by managing biomass waste and converting it into useful products. Various biomass conversion technologies, including pyrolysis, gasification, and fermentation, have emerged to transform waste materials into valuable commodities like biofuels, fertilizers, and chemicals. These technologies present an alternative to conventional energy production methods and decrease reliance on non-renewable resources. Furthermore, the by-products generated through biomass conversion, such as biochar, possess utility as valuable soil amendments. This review emphasizes the potential of biomass conversion technologies in providing sustainable solutions for waste management, food and energy production, and reducing negative environmental impacts while providing valuable by-products for agricultural use. The focus is on Lebanon, which is facing a waste and energy crisis, with an aim to encourage and promote sustainable practices by highlighting different green waste management technologies. Focusing on the application of biochar in soil, our goal is to provide cost-effective and eco-friendly solutions to various agricultural and environmental challenges in Lebanon. This includes using biochar from biomass waste as a soil amendment to boost crop yields, remediate soil pollution, reduce soil drought stress, and address other related issues.

Densified biochar capsules as an alternative to conventional seedings

The application of biochar in soil provides various benefits that can vary in intensity as the pyrolysis temperature increases. However, its low density makes this material easily transportable and prone to being removed from the system. The objective of this study was to investigate the pyrolysis temperatures and compression pressure of densified biochar carrier capsules on the physiological quality of Schizolobium parahyba var. amazonicum seeds. Produced at three final pyrolysis temperatures (300, 600, and 900 °C), the biochar was characterized through bulk and true density analyses, immediate composition, pH, electrical conductivity, cation exchange capacity, water-soluble carbon, characterization of organic structures by FTIR, and PAH analysis. Subsequently, the biochar was compacted by briquetting at two compression pressures (50 and 200 psi) with one seed per capsule, and germination, emergence, and quality of generated seedlings were evaluated. After verifying residue normality and variance homogeneity, analysis of variance was conducted following a completely randomized design in a 3 × 2 factorial arrangement, with four replications per treatment and two additional control treatments. Upon identifying significant differences, regression model adjustments were performed. Cluster-based multivariate analysis was used to identify similarities among the studied treatments, both for capsules and controls. Pyrolysis temperature and compression pressure influenced seed germination, emergence, and initial seedling growth. Lower pressure favored shoot development, while higher pressure favored root development and generated seedlings of higher quality. The benefits of biochar to soil, combined with the implementation of seeds, make the production of densified biochar capsules an alternative to conventional seedings, potentially reducing high energy and financial costs and enabling the recovery of degraded areas, even in difficult-to-access regions.

Biochar addition reduces N2O emissions in fertilized soils under energy cane cultivation

N2O emissions resulting from the application of nitrogen (N) fertilizers and vinasse represent the main sources of greenhouse gases (GHG) emissions in sugar-energy sector. Conversely, the application of biochar in soils has been worldwide recognized as an strategy to mitigate N2O emissions, although little is known about their effects on soils under energy cane production. The study aimed to evaluate the effects of biochar addition as a strategy to mitigate soil N2O emissions in soil under energy cane cultivation, as well as to quantify the abundance of N2O-producing and N2O-reducing microbial guilds. A greenhouse experiment was conducted in a completely randomized design, with five treatments and four replications. The treatments were: i) no N fertilization (control); ii) N fertilization; iii) N fertilization plus vinasse; iv) N fertilization plus biochar; v) N fertilization plus vinasse plus biochar. All treatments (except control) were balanced to receive the same amount of nutrients. Biochar was added at a rate of 5 g kg−1 of soil. Soil N2O emissions were quantified by static chambers for 78 days, and soil sampling were performed to determine chemical and microbiological attributes, including functional genes of the nitrogen cycle (AOA, AOB, nirK, nirS, nosZI and nosZII) by real-time PCR. Results indicated that vinasse addition increased N2O emissions. Conversely, the application of biochar reduced N2O emissions associated with the application of N fertilizer (56 %) and N fertilizer + vinasse (41 %). The high N2O emissions observed in vinasse treatment were directly correlated with nitrifier microorganisms (AOB and AOA), indicating that nitrification should be the main pathway of N2O emissions in this treatment. The production of energy cane biomass was similar between N fertilizer treatments. High N2O emission intensities (mg N2O g biomass−1) were obtained in treatments with vinasse application. This study concluded that biochar is an effficient strategy to mitigate N2O emissions, providing the first insights into how biochar affects the microbial community associated with N2O emissions from soil under energy cane cultivation.