Impact Of Biochar Amendment Research Articles

Impact of biochar amendments on soil water and plant uptake dynamics under different cropping systems

AbstractApplication of biochar amendments in agricultural systems has received much attention in recent years. In this study, we assess the 5‐year impacts of biochar application on soil water and plant interactions for an irrigated fresh market tomato (Solanum lycopersicum) and a rainfed pasture (Poaceae) cropping system. In particular, we focus on three varieties of locally produced biochar from agricultural waste materials—almond shell, walnut shell, and almond pruning residues that are pyrolyzed using a mobile pyrolysis unit. We used the soil hydrological model HYDRUS‐1D to explicitly track seasonal and annual soil water fluxes through changes in water retention, drainage, evaporation, and plant water uptake under biochar application. Modeling results show that the application of biochar at 5% increased soil water availability within the top 20 cm for a rainfed system, irrespective of biochar amendment type. This is clearly indicative of higher plant water uptake and greater water use efficiency (WUE) under biochar application. In contrast, a similar biochar amendment for the irrigated system did not affect WUE, instead reducing seasonal soil evaporation loss and thereby reducing irrigation demand. In both cropping systems, year‐to‐year variability in precipitation significantly impacted the total amount of water saved under biochar application with certain amendments retaining more water than others. Given that biochar application increased water retention irrespective of cropping systems, we further used a simple approach to determine yield trade‐off, if any, between control and biochar treatments. Our economic balance clearly demonstrates that the water saved by amending soil with biochar does not offset the yield disparity if compensated with carbon credits and therefore, application of biochar should be actively considered for both its direct and indirect benefits to potential greenhouse gas mitigation (e.g., diverting orchard waste from open burning), water savings, and soil health.

Impact of biochar amendments on copper mobility, phytotoxicity, photosynthesis and mineral fluxes on (Zea mays L.) in contaminated soils

Soil copper (Cu2+) contamination is a source of phytotoxicity and biochar incorporation is a possible mitigation strategy for improving plant performance and avoiding Cu2+ contamination. This study evaluated the effect of biochar (0, 1 and 2% BC) and/or copper (0 and 100 ppm) on growth, photosynthesis, Cu2+ accumulation, and mineral content of maize grown under controlled greenhouse conditions. Biochar application increased water holding capacity (WHC), while the addition of Cu2+ improved electric conductivity (EC) in soil samples. The sole copper treatment enhanced Cu-accumulation, mineral uptake (K+, Na+, Ca++ and Mg++), dark respiration and light dependent electron flux in PSII. However, it also led to a reduction of growth and net CO2 assimilation rate and caused an enhanced ETR/Pg, indicating a threat of ROS production. The sole addition of biochar to the soil had a positive impact on the total macronutrient content but a negative impact on growth, leaf CO2/H2O gasexchange. However, the combined application of BC and Cu2+ led to a reduced tissue Cu2+ levels, higher shoot growth CO2/H2O gasexchange (Pn, WUE, COE) and finally a reduced ETR/Pg ratio. Plants treated with biochar and higher Cu2+ levels decreased about 30% ETR/Pg which is associated with the optimum growth and photosynthetic efficiency of Photosystem II. Hence, it could be clearly shown that BC and Cu2+ achieved together, and contrary to their individual mode of action, an improvement of Pn, WUE, COE and Rd. We assume that BC application in the studied soil highly restricted the availability of added Cu promoting Cu-stable forms thus reducing the environmental risk and phytotoxicity at soils high in copper (2%BC, 100 ppm Cu2+). The study proposes that BC as a suitable amendment for restoring degraded soils with toxic trace elements but not for soils with limited supply of this micronutrient or copper deprivation

Impact of biochar amendment on antibiotic removal and ARGs accumulation in constructed wetlands for low C/N wastewater treatment

Constructed wetlands (CWs) amended with biochar to stimulate antibiotic and antibiotic resistance genes (ARGs) removal from carbon restricts wastewater holds particular application prospect due to high efficiency and good stability. In this study, we conducted biochar amended constructed wetland (BCW) and non-biochar amended constructed wetland (NCW) to explore the feasibility and mechanisms for sulfamethoxazole (SMX) and ARGs removal from low C/N wastewater. Results showed that biochar-amended considerably stimulated the biological oxidation and reduction process in CW, as evidenced by higher chemical oxygen demand (COD), nitrogen, and SMX removal performance (7.1 ± 2.6 %, 19.8 ± 3.6 %, 36.8 ± 6.2 %) than that in NCW. The accumulation of ARGs was negatively associated with SMX removal efficiency, where the int and sul genes performed lower concentration in BCW due to the higher SMX removal efficiency. The biochar’s dissolved organic carbon release in CWs indicated that water and alkaline media portray the optimum conditions for SMX and ARGs removal. Microbial community analysis exposed that more functional consortia capable of SMX metabolism (e.g., Arthrobacter, Ramlibacter, Flavobacterium, and norank_f_JG30-KF-CM45) were enriched in BCW. This study demonstrated the feasibility and mechanism of biochar-amended CWs for regulated SMX removal and ARGs accumulation, which provides new insights for enhancing the depuration ability of CWs.

Can biochar application improve the net economic benefits of tea plantations?

Biochar applied to the soil can contribute to the sustainability of agriculture by promoting ecosystem services. Tea production contributes to addressing hunger and poverty in developing countries. However, little is known about the impact of biochar amendment on ecosystem services in tea plantations. We evaluated ecosystem services from an economic assessment perspective to better understand the effects of biochar on ecosystem services and dis-services. We conducted field experiments in two subtropical tea plantations with three treatments: no fertilizer and compound fertilizers applied without and with biochar. Results showed that biochar increased the net ecosystem carbon budget by 17-fold through direct carbon addition, thus increasing regulating services. Compared to compound fertilizer alone, biochar application reduced total reactive nitrogen loss by an average of 1.8 % due to an average reduction of 16.2 % and 21.5 % in nitrous oxide and nitric oxide emissions, respectively. However, the high cost of biochar, the low environmental benefits due to the low carbon price, and the fact that biochar did not provide additional economic profit made the net ecosystem economic benefits unsatisfactory. For comparison, we set up an optimistic scenario based on the increased carbon price ($160/ton CO2-equivalent) and the documented effects of biochar on yield (+9.6 %), nitrogen leaching/runoff (−24 %), and ammonia volatilization (+14 %). The scenario analysis showed that increased yields and higher carbon prices could contribute to the increase in net ecosystem economic benefits. Taken together, our findings suggest that the impact of biochar on yield benefits is the key to biochar application and that a market-regulated carbon price accompanied by appropriate ecological compensation is necessary to effectively promote biochar application by farmers.

Impact of biochar amendment on soil hydrological properties and crop water use efficiency: A global meta‐analysis and structural equation model

AbstractThe regulation of soil water retention by biochar amendment has been concerned especially in cropland ecosystem. However, the quantification of biochar's effects on soil hydrological properties and crop water use efficiency (WUE) is still limited, and the factors driving the biochar effect need to be investigated. Based on a database with 681 observations, meta‐analysis and structural equation model (SEM) were employed to reveal how biochar amendment affects water supply capacity and WUE. The results showed that biochar application increased available water content (AWC) and WUE by 26.8% and 4.7% on average, respectively. According to the SEM of AWC (R2 = 0.70–0.96), the increase of soil organic carbon (+36.1%) by biochar application can not only directly improve AWC but also indirectly improve AWC by affecting permanent wilting point (−1.0%) and mean weight diameter (+11.1%). The SEM of WUE (R2 = 0.74) indicated that soil moisture and porosity were increased by 10.8% and 7.0% under biochar amendment, which was the reason why biochar improved WUE. This study emphasized that biochar can improve soil hydrology and crop yield by increasing soil water supply conditions. And a rational rate of biochar is the precondition to obtaining the benefits of soil hydrology, otherwise, the excessive use of biochar may lead to the decline of WUE.

Impact of Biochar Amendment on Soil Properties and Organic Matter Composition in Trace Element-Contaminated Soil.

The application of biochar as an organic amendment in polluted soils can facilitate their recovery by reducing the availability of contaminants. In the present work, the effect of biochar application to acid soils contaminated by heavy metal spillage is studied to assess its effect on the quantity and composition of soil organic matter (SOM), with special attention given to soil humic acids (HAs). This effect is poorly known and of great importance, as HA is one of the most active components of SOM. The field experiment was carried out in 12 field plots of fluvisols, with moderate and high contamination by trace elements (called MAS and AS, respectively), that are located in the Guadiamar Green Corridor (SW Spain), which were amended with 8 Mg·ha−1 of olive pit biochar (OB) and rice husk biochar (RB). The results indicate that 22 months after biochar application, a noticeable increase in soil water holding capacity, total organic carbon content, and soil pH were observed. The amounts of oxidisable carbon (C) and extracted HAs in the soils were not altered due to biochar addition. Thermogravimetric analyses of HAs showed an increase in the abundance of the most thermostable OM fraction of the MAS (375–650 °C), whereas the HAs of AS were enriched in the intermediate fraction (200–375 °C). Spectroscopic and chromatographic analyses indicate that the addition of biochar did not alter the composition of the organic fraction of HAs, while Cu, Fe, and as were considerably accumulated at HAs.

Impact of biochar amendment on soil nematode communities in a West African rain-fed rice cropland

Summary Nematode population and diversity in a West African rain-fed rice cropland amended with biochar (B), biochar plus inorganic fertiliser (B + NPK), inorganic fertiliser (NPK) and control (CK) without amendments were investigated in a 3-year field study. Results demonstrated that significant differences exist between treatments and years of study for total nematode population and nematode trophic groups. Total nematode density, nematode trophic group (bacterivore and plant-parasitic) density were increased and dominant in B + NPK compared with CK after 3 years. Relative abundance of nematode genera according to trophic group across treatments showed Hirschmanniella (23%) as the dominant plant parasites in NPK, and Heterocephalobus (27%), Aphelenchoides (22%) and Eudorylaimus (9%) as dominant bacterivores, fungivores and omnivores-predators, respectively, in B + NPK. Trophic group indicators showed that the fungivore plus bacterivore to plant-parasitic ratio (73%) was significantly increased by B + NPK treatment in comparison to CK. Conversely, treatments exerted no significant effect on the fungivore to bacterivore ratio (F/B) throughout the period of study, which implies less disturbance and adverse impact of biochar on nematode communities. Apart from treatments and environmental factors, changes in nematode trophic groups were strongly related to soil chemical properties, such as soil pH, total nitrogen and available phosphorus, which shows their influence on soil nematode community. Our result shows the positive effect of integrated addition of biochar and inorganic fertiliser in balancing nematode diversity and building a resilient soil ecosystem in a low input rain-fed rice cropping system.

Vegetated roofs for managing stormwater quantity in cold climate

Vegetated roofs, i.e. green roofs, were continuously measured for runoff to quantify their capacity to manage stormwater in a field experiment in southern Finland, with distinct seasonality and varying weather conditions. Attention was paid to heavy storms to study the potential in mitigating urban flooding. In addition, the impact of biochar amendment (10% v/v) on rainfall retention was studied. Meadow vegetation was established on crushed brick based substrate either by introducing plants as seedlings and seeds or by using pre-grown readymade mats. Annual retention varied from 40% to 70%. The highest retention, ca. 80%, was found in summer even though it was the rainiest season. Wintertime retention was 30–40%. The coarse substrate enabled infiltration even when frozen and, thus, the roofs operated also in winter. Heavy storms occurred mainly in summer, the season with the highest hydrologic performance of the roofs, resulting in >80% peak attenuation and slow release of runoff. In individual rain events, runoff from meadow roofs was largely a function of rainfall depth. However, retention was weakly explained by the amount of rainfall or by other variables, such as rainfall intensity or antecedent dry period, indicating the difficulty in capturing the complex phenomena behind variable weather conditions. Biochar improved retention only slightly, at maximum by ca. 10%. The empirical evidence of this study highlights vegetated roofs as a feasible technology to be applied in urban runoff management even in cold climate.

Reproduction and biomarker responses of Eisenia fetida after exposure to imidacloprid in biochar-amended soil

Terrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.

Impact of biochar amendment on soil aggregation varied with incubation duration and biochar pyrolysis temperature

Impact of biochar amendment on soil aggregation varied with incubation duration and biochar pyrolysis temperature

Changes in soil water retention following biochar amendment

ABSTRACT To mitigate water runoff from arable land, a variety of measures can be applied. One of them is the amendment of highly porous biochar to increase the water retention capacity of soils and store the runoff water. Various types of biochar are made under variable production conditions and amended to soils of different quality in a wide range of quantities. Since reported data show ambiguities due to various feedstock, pyrolysis parameters, soil characteristics, and a highly variable change in water retention capacity (WRC), robust statistical methods were applied to compare the reported data from previous studies. The results revealed that biochar increased WRC by 0.26% t ha−1 of biochar added on average. In terms of WRC, biochar produced at lower pyrolysis temperatures functioned surprisingly better than that produced at higher temperatures, which was confirmed by a decision tree made by J48 algorithm. The increase of WRC was higher with sandy soils, whereas silty and loamy soils did not show a significant increase. Biochar made from easily biodegradable, post-harvest residues such as straw or rice husk showed higher impact than others made from wood that is appreciated for its high porosity. This is a groundbreaking argument for stopping the usage of biochar for energy purposes. The high organic content in soils was the major driver damping the WRC increase. The most effective measure for increasing WRC is the application of 90 t ha−1 biochar, preferably made of an easily biodegradable phytomass that is pyrolyzed at low temperatures. The presented study compares 166 specific combinations of various biochar and soil properties, shows the effectivity of biochar amendments for WTR increment, and reviews the impact of biochar amendment in terms of water retention in agricultural landscapes.

Impact of biochar amendment on the uptake, fate and bioavailability of pharmaceuticals in soil-radish systems

Crops grown in soils receiving wastewaters, biosolids, or manures can accumulate pharmaceuticals in edible parts, raising concerns over potential human exposure to multiple pharmaceuticals. Nonetheless, viable mitigation options for minimizing plant uptake of pharmaceuticals are limited. This study evaluated how biochar amendment could influence the uptake of 15 pharmaceuticals by radish (Raphanus sativus) grown in a sandy loam at two amendment rates (0.1 and 1% w/w). Comparing with that in the unamended soil, the accumulation of acetaminophen, carbamazepine, sulfadiazine, sulfamethoxazole, lamotrigine, carbadox, trimethoprim, oxytetracycline, tylosin, estrone, and triclosan in radish grown in the soil amended with 1.0% of biochar was significantly decreased by 33.3–83.0%. However, the concentration of lincomycin in radish was increased by 36.7–48.2% in the soil amended with 1% biochar. While the soil amended with 1.0% of biochar had increased sorption of all 15 pharmaceuticals, the persistence of 7 pharmaceuticals in the soil were prolonged, including caffeine, sulfadiazine, sulfamethoxazole, lincomycin, estrone, 17 β-estradiol and triclosan. The reduced plant uptake of pharmaceuticals was mainly due to their lowered concentrations in pore water by the presence of biochar. Overall, the estimated daily intake data suggest that biochar amendment could potentially decrease total human exposure to a mixture of pharmaceuticals.

Impact of biochar amendment on the abundance and structure of diazotrophic community in an alkaline soil

Biological nitrogen (N) fixation contributes to the pool of plant-available N in soil and helps to minimize the use of inorganic N fertilizer in agricultural ecosystems. Although diazotrophs play an important role in the biological fixation of atmospheric N2 in a range of soil types, the knowledge of their response to biochar amendment is still limited. Here, using the nifH gene as a molecular marker, we investigated the short-term effect of biochar application on the abundance, community composition and activity of diazotroph in an alkaline soil. A field trial was established before soybean sowing in 2017 and five treatments were included: inorganic NPK fertilizer (CK); inorganic NPK fertilizer + wheat straw (CS); inorganic NPK fertilizer + low rate of biochar (B4); inorganic NPK fertilizer + high rate of biochar (B20); biochar compound fertilizer (BCF). The field trial was lasted for one crop season and samples were collected by soybean harvest. The results showed that biochar addition generally increased the concentration of soil organic carbon (SOC) and available phosphorous (AP), while B20 treatment significantly increased the total nitrogen (TN) and available potassium (AK). Biochar addition treatments increased the nifH gene abundance and altered the community structure of soil diazotrophs. The abundance of nifH gene was positively correlated with SOC, indicating that increasing SOC potentially affected diazotrophic population in the alkaline soil. Community structure of diazotrophs in the CS treatment was similar with the CK treatment; thus, there was no effect of crop straw on diazotroph community structure. In contrast, the application of biochar and biochar compound fertilizer altered the diazotroph community structure with shifts in the dominant genus, with higher Sinorhizobium in the biochar-amended treatments. SOC, C/N and AP were the key factors correlated with change in diazotroph community structure. Overall, our results suggest that the addition of biochar or biochar compound fertilizer could increase the abundance and alter the community structure of diazotrophs, which may benefit N fixation in alkaline agricultural soil. Conversely, the direct straw return had no effect on the abundance and community structure of diazotrophs.

Biochar amendment alters the relation between the Pb distribution and biological activities in soil

In the present investigation, the impact of biochar amendments on the Pb fractionation pattern and soil enzymatic activities in soil was evaluated. Two spiking concentrations of exogenous Pb, two application rates (2% and 4%) of biochar and three plants such as Withania somnifera, Andrographis paniculata and Bacopa monnieri were taken for the study. Three experiment sets were designed for each plant. Distribution of Pb (in acid soluble, reducible, oxidizable and residual fractions), physicochemical and biological properties (β-glucosidase, acidic and alkaline phosphatases, urease and microbial biomass) of soil were examined. Several chemometric techniques were applied to this huge data to evaluate the association of soil microbial activities with Pb fractionation. The results revealed that biochar amendments altered the fractionation of Pb by shifting from mobile fraction (acid soluble) to immobile fraction (oxidizable and residual). The correlation analysis suggested that this could be attributed to the increase in cation exchange capacity, organic carbon and available phosphorus content in the soil after biochar amendments. The results clearly demonstrated that biochar amendments in Pb-contaminated soil improved the enzymatic activities in the soil. The multidimensional scaling, correlation and sequential equation modeling imply that biochar has a shielding effect on soil microbial activity against Pb stress from each fraction of soil.

Impact of Biochar Amendment on Soil Quality and Crop Yield in a Greenhouse Environment

Impact of Biochar Amendment on Soil Quality and Crop Yield in a Greenhouse Environment

Influence of biochar on volatile fatty acids accumulation and microbial community succession during biosolids composting

The impact of biochar amendment on volatile fatty acids (VFAs) and odor generation during the biosolids-wheat straw composting was investigated. Five treatments were design using the same mixture of biosolids-wheat straw with different dosage of biochar blending (2%, 4%, 8% and 12% on dry weight basis) and without biochar applied treatment served as control. The results of VFAs and Odour Index (OI) profile designated that compost with 8–12% biochar became more rapidly humified with less quantity of VFAs and OI generation content compared to control. Consequently, the VFAs degrading and total bacterial abundance are also significantly higher recorded in 8–12% biochar than 2% biochar and control. In addition, 8–12% biochar applied treatment has significantly maximum close correlation among the all physicochemical and gaseous emission parameters. Finally, results designated that higher dosage of biochar (8–12% biochar) was more feasible approach for biosolids composting.

Impacts of biochar addition on soil dissolved organic matter characteristics in a wheat-maize rotation system in Loess Plateau of China

Biochar amendment in soil has the potential to sequester carbon, improve soil quality and mitigate greenhouse gas (GHG) emission in agriculture, but the impact of biochar amendments on dissolved organic matter (DOM) properties of soils in the fertilized agro-ecosystem has received little research attention. This study performed a long-term field experiment to assess the influence of biochar amendments (different addition rate: 4 t ha−1 and 8 t ha−1) on DOM characteristics in soils in wheat-maize rotation system in Loess Plateau of China by exploiting fluorescence excitation-emission spectrophotometry and parallel factor analysis (EEM-PARAFAC). Our results showed that the content of soil DOM was significantly influenced by the addition of biochar, and the higher biochar addition markedly increased the mean concentration of dissolved organic carbon (DOC) (from 83.99 mg kg−1 to 144.27 mg kg−1) in soils under the same fertilizer application. Three identified fluorescent components (fulvic acid-like, humic acid-like and tryptophan-like) were found, and fluorescence intensity of those components (especially humic-like material) was enhanced with the increasing DOC in the biochar treatments but the composition of DOM was not changed. These findings would be beneficial to understand the biochar's effects and processes in decreasing GHG emissions from soils.

Impact of biochar amendment on soil water soluble carbon in the context of extreme hydrological events

Biochar amendments to soil have been promoted as a low cost carbon (C) sequestration strategy as well as a way to increase nutrient retention and remediate contaminants. If biochar is to become part of a long-term management strategy, it is important to consider its positive and negative impacts, and their trade-offs, on soil organic matter (SOM) and soluble C under different hydrological conditions such as prolonged drought or frequent wet-dry cycles. A 52-week incubation experiment measuring the influence of biochar on soil water soluble C under different soil moisture conditions (wet, dry, or wet-dry cycles) indicated that, in general, dry and wet-dry cycles increased water soluble C, and biochar addition further increased release of water soluble C from native SOM. Biochar amendment appeared to increase transformation of native SOM to water soluble C, based on specific ultraviolet absorption (SUVA) and C stable isotope composition; however, the increased amount of water soluble C from native SOM is less than 1% of total biochar C. The impacts of biochar on water soluble C need to be carefully considered when applying biochar to agricultural soil.

Dissipation of fomesafen in biochar-amended soil and its availability to corn (Zea mays L.) and earthworm (Eisenia fetida)

Purpose Biochar application has been shown to be effective in improving soil fertility and sequestering soil contaminants. However, the impact of biochar amendments on the environmental fate of pesticides and the bioavailability of pesticides to living organisms in the soil environment is still not fully understood.

Impact of biochar amendment on enzymatic resilience properties of mine spoils

Soil enzymes are crucial for soil nutrient cycling function. Understanding of the factors that control their response to major disturbances such as dumping of environmentally toxic acidic waste remains limited. We evaluated the effect of dumping of overburden (OB) and their amendments using biochar, on the resistance and resilience of soil enzyme activities involved in phosphorus, nitrogen, sulphur and carbon cycling (acid & alkaline phosphatase, urease, arylsulphatase, dehydrogenase, phenol oxidases, cellulase and β-glucosidase). For investigation the soils treated with OB and with the mixture of OB and biochar were used for the cultivation of bacopa were used. We assessed 0day, 45day and 90days activities of the target soil enzymes, available phosphorus, nitrogen, sulphur, soil organic carbon and microbial identification. The resilience and resistance index of all the treatments were calculated. We found that phyto-remediated OB-contaminated soil has its own resilience power. However, biochar addition enhanced the enzyme resistance and resilience of OB contaminated soil. In silico study indicates that biochar–Fe complex play a significant role in enzymatic activities. Overall, the results indicate a significant influence of phytoremediation and biochar addition on soil enzymatic activity that is extremely resistant to OB. This study provides insight on how biochar addition modulates soil biochemical and microbiological response to OB affected soils.