Biochar From Agricultural Byproducts For Improved Soil Quality And Carbon Sequestration

Soil carbon sequestration has emerged as an innovative approach that may offer a low-risk and an efficient way to mitigate climate change and replenish soil fertility. In various agricultural production systems, byproducts are produced in significant amounts from crop residues such as pecan shells (PC), peanut shells (PS), and cotton gin (CG) that can be used to produce biochar and applied to agricultural soil first to sequester C and second to enhance plant growth by supplying and retaining nutrients, improving soil physical and biological properties

Biochars From Solid Organic Municipal Wastes For Soil Quality Enhancement

The overall municipal organic waste in Qatar accounts for 57% of municipal waste generated annually. Organic solid wastes such as food, newspapers, packaging, furniture woods and wood from building demolition have traditionally been placed in landfill, which create issues of sustainability for a country like Qatar with small land mass. While the recently opened Doha solid waste treatment facility contributed to alleviating the pressure on Landfill sites through composting and incineration, new value-added use of solid organic waste are needed for environmental and economic sustainability. Fortunately, biochars from mixed organic solid wastes can be used in soil amendment for food security and long term carbon sequestration for environmental sustainability. We hypothesize that deficiencies in depleted Qatari soils can be remedied by the application of biochars that are custom-designed to possess the right physicochemical characteristics suitable to improve soil fertility. Hence, this study was conducted to (1) Optimize production of biochars from mixed organic waste for desired physicochemical characteristics as soil enhancers. (2) Produce and characterize designer biochars using optimum production conditions for testing in soil incubation experiments. Select municipal organic wastes (newspaper, cardboard, woodchips and landscaping residues) individually and in a 25% blend were used as a precursor for biochar preparation. These residues were chosen due to their commonality in municipal solid waste streams. A complete 5 × 3 × 3 factorial design was used in this study with five biochar precursors (the 4 solid waste materials and a 25% blend/mixture), 3 sets of pyrolysis temperatures (350, 500, and 750°C) and 3 sets of pyrolysis residence time (2, 4 and 6 hrs). Data obtained showed that biochar yield was in the range of 21- 62% across all feedstocks and pyrolysis conditions. The highest yield was observed in newspaper-based biochars pyrolized at 350°C for 2 hrs. Key parameters such as pH, electrical conductivity bulk density and surface area, which positively improve water and nutrient-holding capacity in biochar-amended soil, varied depending on the precursors and production conditions. Bulk density was high in woodchips-based biochars but was similar among all other biochars, irrespective of precursors and pyrolysis conditions. The total surface area of biochars was low but showed dramatic increase in all feedstocks at 700°C pyrolysis temperature. The highest electrical conductivity observed in cardboard-based biochars pyrolized at 700C. Biochars produced from selected waste precursors were acidic except those produced at 700°C temperature where pH became alkaline. The wide range of biochar pH suggests potential tailoring to remediate the specific soil acidity. Cumulatively, biochars showed promising results for improving soil fertility parameters such as better water holding capacity, pH stabilization, and increased electrical conductivity of soil for better aggregation. These findings indicate that solid organic municipal wastes hold promising potential as precursors for manufacturing of value-added biochars with varied physicochemical characteristics allowing them to be used not only as an alternative to bio-waste management and greenhouse gas mitigation but also as means to improve depleted Qatari soil as the country embarks on its ambitious goals of ensuring food security and environmental sustainability.qscienc

Switchgrass Biochar Effects Two Aridisols

The use of biochar has received growing attention with regards to improving the physico-chemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on effects in Aridisols. The objective of this study was to investigate the effect of either low or high temperature (250 or 500C) pyrolyzed switchgrass biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to either a Declo loam (Xeric Haplocalcids) or a Warden very fine sandy loam (Xeric Haplocambids) and then incubated at 15% moisture content (by weight) for 127 days; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized water on days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO3-N, NO2-N, and NH4-N concentrations were quantified. After the incubation experiment had terminated, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO3-N, and NH4-N, total C, inorganic C, organic C, and pH. As compared to the 250C, the 500C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250C switchgrass biochar likely due to binding by biochar’s functional group sites. Both biochars caused an increase in leachate K, while the 500C biochar increased leachate P. The 500C biochar reduced leachate NO3-N concentrations as compared to the control; however, the 250C biochar reduced NO3-N concentrations to the greatest extent. Easily degradable C, associated with the 250C biochar’s structural make-up, likely stimulated microbial growth which caused NO3-N immobilization. Soil extractable K, P, and NO3-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential

Biochars impact on soil moisture storage in an Ultisol and two Aridisols

Droughts associated with low or erratic rainfall distribution can cause detrimental crop moisture stress. This problem is exacerbated in the USA’s arid western and southeastern Coastal Plain due to poor rainfall distribution, poor soil water storage, or poorly-aggregated, subsurface hard layers that limit root penetration. We hypothesized that soil physical deficiencies may be improved by biochar applications. Research indicates a single biochar will not serve as a universal supplement to all soils; consequently, biochars may need to be designed with physico-chemical properties that can ameliorate specific soil physical deficiencies. We conducted a laboratory study that examined the effect of biochar on soil moisture retention and aggregate formation. Eight biochars were made from four feedstocks at two different pyrolysis temperature classes (500°C; 932°C) and were characterized for their physical and chemical properties. In addition, we included a biochar made using fast pyrolysis of hardwood wastes. All biochars were mixed at 2% w/w with either a Norfolk loamy sand (Fine-loamy, kaolinitic, thermic Typic Kandiudults), a Declo silt loam (Coarse-loamy, mixed, superactive, mesic xeric Haplocalcids), or a Warden silt loam (Coarse-silty, mixed, superactive, mesic xeric Haplocambids). Amended soils were laboratory incubated in pots for up to 127 days. About every 30 days, bulk density was measured and then each pot was leached with 1.2 to 1.3 pore volumes of deionized water. Gravimetric and volumetric soil moisture contents were determined after free drainage had ceased and again 2 and 6 days after leaching. The Norfolk-treated soils were later dry-sieved, and the sum by weight of their 0.5- to 1.0-mm aggregates was determined. In general, the biochar surface area and surface tension increased when produced under higher pyrolytic temperatures (>500°C). After leaching, Norfolk soils treated with switchgrass biochars had the most significant increase in soil moisture capacities. Similar increases were found in the Declo and Warden soils. Formation of 0.5- to 1.0-mm aggregates in the Norfolk loamy sand varied with biochar. Biochars enhanced the moisture storage capacity of the Ultisol and Aridisols thereby potentially reducing the on-set of crop moisture stress; however, the effect varied considerably with biochar feedstock and pyrolysis temperature

Short-term greenhouse emission lowering effect of biochars from solid organic municipal wastes

Qatar economy has been growing rapidly during the last two decades during which waste generation and greenhouse gas emissions increased exponentially making them among the main environmental challenges facing the country. Production of biochar from municipal solid organic wastes (SOWs) for soil application may offer a sustainable waste management strategy while improving crop productivity and sequestering carbon. This study was conducted to (1) investigate the physicochemical parameters of biochars for SOW, (2) select the best-performing biochars for soil fertility, and (3) evaluate the potential benefits of these biochars in lowering greenhouse gases (GHGs) during soil incubation. Biochars were produced from SOW at pyrolysis temperatures of 300�750��C and residence times of 2�6�h. Biochars were characterized before use in soil incubation to select the best-performing treatment and evaluation of potential GHG-lowering effect using CO2 emission as proxy. Here, soil�biochar mixtures (0�2%w/w) were incubated in greenhouse settings for 120�days at 10% soil moisture. Soil properties, such as pH, EC, TC, and WHC, were significantly improved after soil amendment with biochar. Two biochars produced from mixed materials at 300�500��C for 2�h and used at 0.5�1% application rate performed the best in enhancing soil fertility parameters. A significant decrease in CO2 emission was observed in vials with soil�biochar mixtures, especially for biochars produced at 500��C compared the corresponding raw materials which exhibited an exponential increase in the CO2 emission. Hence, application of biochar to agricultural soils could be beneficial for simultaneously improving soil fertility/crop productivity while sequestering carbon, thereby reducing anthropogenic emissions of GHGs. 2017, Islamic Azad University (IAU).Acknowledgements This research project was made possible by grant # NPRP -5 - 1020 - 4 � 011 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The authors would like to express sincere gratitude to the Central Labs Team, Qatar University, for providing assistance with the characterization of biochar and soil samples analysis

Physico-chemical characterization of biochars from solid municipal waste for use in soil amendment

The fast economic and demographic growth lead to generation of large amounts of solid wastes placing Qatar on top of most nations with a per capita solid waste generation of nearly 2.5 milliontons/year of which 60% is organic. A substantial amount of this solid waste ends up in landfills generating greenhouse gases that contribute to global warming. At the same time, the soil in most of the country is depleted and/or naturally poor. These issues can be addressed through conversion of this waste into biochar to improve soil quality and act as carbon sink. The objectives of this study were to (1) produce biochar from 4 different groups (paper, soft materials, hard wood, and mixed materials) at 3 different pyrolysis temperatures (300, 500, and 750°C) and residence times (2, 4, and 6h), and (2) evaluate biochars⿿ properties relevant to soil applications, namely physico-chemical properties [yield, pH, bulk density, ash, total surface area (TSA), surface charge (SC), and electrical conductivity (EC)] and elemental composition. Feedstocks were ground and pelleted then pyrolyzed under N2 using a Lindberg furnace equipped with a retort using the above conditions. Results showed that biochars⿿ pH, TSA, and ash content increased with temperature while the yield recovery and SC were higher at low temperature, with 94% biomass recovery observed for hard wood at 300°C versus 23% at 750°C. The pH of the four types of biochar increased from 5.7 at 300°C for hard wood to 12 at 750°C for mixed materials which make them suitable for a range of pH remediation in both acidic and alkaline soils. The TSA was limited in all biochars produced at 300°C but reached 241m2g⿿1 and 163m2g⿿1 for hard wood and mixed materials produced at 750°C, respectively. This suggests that biochars produced at high temperature can provide an internal surface area for soil microbiota while contributing to retention of water and nutrients. The C content increased as the temperature increased to reach 97% and 62% at 750°C for HW and mixed materials, respectively, suggesting that biochars obtained at high temperature could increase the soil CEC and sequester carbon in the soil for long term. SEM analysis clearly showed the development of well-defined pores as the temperature increases. This study suggests that solid waste-based biochars have the potential to enhance soil properties, if produced under careful selection of precursor and pyrolysis conditions.NPRP grant # NPRP - 5 -1020 - 4-011 from the Qatar National Research Fund (a member of Qatar Foundation)

Mixed Solid Municipal Waste-Based Biochar for Soil Fertility and Greenhouse Gas Mitigation

Municipal solid waste management is one of the major challenges facing Qatar with more than 2.5 million tons of municipal solid waste each year, a very high waste generation rate in a country with small land mass. Solid waste in Qatar consists mostly of organic materials (60%) with the remaining made up of recyclables, such as glass, metals and plastics. Qatar's ambitious development strategy targets environmental sustainability and invests in research on key grand challenges including water/food security. Fortunately both can be addressed through value-added conversion of solid organic waste into biochars. Solid municipal wastes such as newspaper, cardboard, woodchips and plant residues from landscaping can be converted to biochar for mitigation of their environmental impact and value-addition. On the other hand, agricultural soils have significant deficiencies in a range of essential trace elements and macronutrients and often exhibit low water holding capacity. These deficiencies impact both the yield and the nutritional quality of edible crops with direct consequences cost-effectiveness and human health. Fortunately, these challenges can be advantageously addressed by production of biochars from organic sources such as mixed organic solid waste from municipalities as well as agricultural and landscaping operations. The landfill and composting of these solid municipal wastes generate greenhouse gases that contribute to climate changes. Biochars prepared from solid municipal wastes can greatly benefit the carbon content of soil. Additionally, biochar may interact with fertilizers to deliver indirect improvements in plant growth and reduce the emission of greenhouse gases from native organic matter. Biochars can also be custom-designed to increase/decrease native soil pH to bring it closer to the optimum range for microbial and plant growth. These applications give solid organic municipal wastes promising potential as precursors for value-added biochars with varied physicochemical characteristics allowing them to be used not only as an alternative to bio-waste management and greenhouse gas mitigation but also as means to improve depleted soil. We hypothesize that soil deficiencies in soil can be remedied by the application of biochars that are custom-designed to possess the right physicochemical characteristics suitable to improve soil fertility. The aim of this study was to: (1) produce biochars from mixed solid organic waste for use in soil quality enhancement, (2) investigate the effect of biochar addition to soil on plant germination and growth and (3) evaluate the potential of biochars in mitigating green house gas (GHGs) emissions. Select solid organic municipal wastes (newspaper, cardboard, woodchips and landscaping residues) were used as a precursor for biochar preparation. A blend of 25% of each precursor was used and pyrolyzed at 700°C for 2 hrs under N2 gas at a flow rate of 0.1 mL min− 1 using a Lindberg box programmable furnace equipped with an air-tight retort. Soil fertility parameters such as pH, water retention and macro and micronutrients were analyzed. Fine sandy clay loam soil from the Ap horizon (0-15 cm deep) was amended with biochar at the rate of 2% (w/w). To test the germination rate in soils, with and without biochars (produced from municipal solid waste precursors of 25% blend of four types of waste materials), hybrid savoyed spinach seeds were sown in germination trays (3 seeds/well) for two weeks in climate controlled greenhouse settings. Trays were watered twice daily to maintain moisture level between 10 and 12 percent. The percentage of seed germination was calculated and the plant growth measured as dry biomass. Incubation experiments were conducted to measure GHGs production in sealed glass vials containing soil with and without biochar or raw materials from which this biochar was produced. Greenhouse gases emission differential between the biochars and their corresponding raw feedstocks in treated soil was used as indicator of GHGs emission by biochars during the incubation period Biochars prepared from blends produced at 700°C pyrolysis temperatures and used at 2% application rate to soil showed higher pH (6.8), increased water retention, and high K and NO3-N content. The net effect of these changes in soil properties positively impacted both seed germination and biomass yield of the plants (up to two folds in soil amended with biochars). At the same time, conversion of solid organic wastes into biochar enabled 14% reduction in GHGs emission compared to the solid waste precursors, as indicated by lower CO2 emission. Biochar amendment in soil significantly reduced the CO2 emission (14%), which would otherwise have increased greenhouse gas due to solid waste decomposition in soil. This differential is mainly due to respiration controlled by microbes. Soil amended with biochar closely followed the trend of soil treatment signifying no additional contribution to CO2 efflux. The increase in CO2 efflux seen in feedstock-amended soil can be attributed to the decomposition of feedstock during the time incubation period. In summary, biochars from mixed solid organic wastes at 2% carbon to soil ratio improved seed germination, increased plant biomass yield, and reduced GHGs emission compared to precursors. To reach the maximum benefits, pyrolysis conditions and feedstock selection are critical steps to produce biochars with desirable properties for specific soil amendment. From the present study, it is clear that constituents of municipal solid organic wastes hold promising potential as inexpensive precursor for value-added biochar manufacturing with varied and customizable physicochemical characteristics that would be beneficial in soil amendments while alleviating the problem of solid waste disposal and contributing to mitigation of GHGs. Further studies are need needed to confirm the reported advantages in natural field settings.qscienc

Conversion of Organic Municipal Wastes into Biochars and their Effect on Fertility Parameters of Normal and Sabkha Soils of Qatar

Qatar is undergoing rapid economic growth fueled by its ambitious national vision 2030 which specifically aims to achieve sustainable development. To achieve the latter, durable and sustainable alternatives for municipal solid waste management are needed, especially since Qatar tops most nations in terms of per capita solid waste generation with nearly 2.5 million tons/year of which 60% consists of organic waste. Current disposal methods include incineration, composting, and land filling which generate greenhouse gases that contribute to global warming. At the same time, the soils in most of the country are poor with weak aggregation, low in organic matter, and low water holding capacity. Hence, it makes economic and environmental sense to convert solid organic wastes generated by municipalities into biochars that improve soil quality and act as carbon sink. The suitability of biochar as an effective soil amendment has been related to but not limited to boosting soil fertility by raising soil pH, increasing water holding capacity (WHC) and retention of nutrients in soil, providing a habitat for beneficial fungi and microbes, improving Cation Exchange Capacity (CEC), and reducing nutrients leaching. In addition, biochar has the ability to reduce the emission of the most potent greenhouse gases such as methane (CH4) and nitrous oxide (N2O). The objectives of this study were to: (1) produce and characterize biochars from solid organic wastes commonly found in Qatar municipal waste streams, (2) determine the effects of solid waste-based biochars on major soil fertility characteristics of normal and sabkha soils of Qatar, (3) select the best performing biochars for use in plant growth experiments. Four feedstocks [paper, landscape waste, wood, and a mixture of all three) were pelletized, dried, and used as precursors for the production of biochars following a 4 × 3 × 3 factor factorial design consisting of the type of precursor (four different municipal solid organic precursors), pyrolysis temperatures (300, 500, and 750°C) and residence time (2, 4, and 6 hours). Feedstocks were pyrolyzed under N2 gas at a flow rate of 0.1 mL min− 1 using a Lindberg box furnace equipped with an air tight retort. Yields, surface area, and chemical properties [ash content, pH, surface charge, Electrical Conductivity (EC), Total Carbon (TC), and elemental analysis] of biochars with relevance to soil applications were determined. Qatari sandy soils (Normal and Sabkha) from the Ap horizon (0–15 cm deep) were collected, air dried, and 2-mm sieved. The incubation experiment was conducted in greenhouse pots. To each pot, sufficient amount of 0.25-mm sieved biochar was mixed with soil to yield carbon to soil ratios of 0, 1, and 2% (wt/wt). Box-Behnken experimental design was used instead of the full factorial to decrease the number of treatments to a manageable level (126 treatments) with three replications at the center. The biochar-amended soils (Normal sandy and Sabkha soils) were incubated for 120 days in a greenhouse at a 10% (wt/wt) moisture level. Samples of incubated soils were collected at time 0 (T0: after 8hrs) and at time120 (T120: after 120 days of incubation) for evaluation of soil fertility characteristics (pH, EC, WHC, aggregate stability, TCN content, macro, and micronutrients composition). In addition, pots were leached at days 60 and 120 and their leachates weighed, filtered, and analyzed for total organic carbon (TOC), pH, EC, micro, and macronutrients. The application of biochars from different precursors to normal soil at different application rates showed a slight increase in pH of treated soil compared to the soil control at T0 and T120, particularly for biochars produced at high temperature and application rate. The increased soil pH is attributable to buffering effect of biochars pH which typically increases as the pyrolysis temperature increases. The same trend was observed for EC where the pyrolysis temperature of biochars seems to be the most influential on the normal soil EC, especially as it ages. The aggregate stability for the normal soil did not increase as the biochar application rate increases, except for hard wood-based biochar produced at high temperature which had a positive effect on the aggregate stability. However for sabkha soil, the pyrolysis temperature and biochar rate significantly increased the aggregate stability of this soil regardless of the precursor. This can be explained by the accumulation of organic matter that was favored by the binding of organic biochar compounds to abundant soil minerals through cation bridging and the formation of microaggregates that would then form large soil aggregates. The addition of biochars has significantly increased the total carbon (TC) of both soil types compared to the control soils. The total carbon increased with both application rate and pyrolysis temperature. Biochar pyrolysis temperature and application rates favored increased TC with variation depending on the type of precursor, soil type, and duration of incubation. This may be attributed to the oxidation and microbial activity processes that speeded up the process of mineralization in the soil. Overall, the TC in normal soil was higher compared to the sabkha soil which may be due to the fact that the starting carbon concentration in the normal soil was higher than that of sabkha soil. In terms of water holding capacity, it significantly increased in both soil types following biochar amendment, especially those produced at high pyrolysis temperature. The positive effect of soil amendment with biochars on WHC was most pronounced in the sabkha soil which exhibited markedly increased ability to absorb and retain water after biochar addition. This is likely due to the high surface area and porosity of the biochars combined with the effect of the polarity of compounds on the surface of biochars which physically retain water and/or improve soil aggregation thereby retaining more water in the soil. The addition of biochars to soil had a positive effect on the pH of normal soil leachates but less so on leachates from sabkha soil. Some pH variations were also observed within the pH of the same soil leachates as a function of the type of precursors used to produce biochars, most likely due to difference in initial composition of the precursors. This implies that biochars with greater liming capacity can provide greater benefit to arable soils that require liming. The results of cluster analysis were used to determine the group of biochar-amended soils which are the most significantly different from the control treatment in terms of soil fertility parameters (pH, EC, TC, WHC, aggregate stability, leachate pH, micro and macronutrients). From the four precursors, only two (soft and mixed materials) were found to be most effective for normal soil and all improved sabkha soil. To further narrow the selection, a secondary selection was carried out based on the biochars precursor type, yield, and energy required for biochar production. Two biochars emerged as the best performing biochars for normal and sabkha soils. Biochars produced from mixed materials pyrolyzed at 500–750°C for 4–6 hours of pyrolysis time and used 2% application rate are best for amendment of normal soil while soft and mixed materials pyrolyzed at 300–500°C for 4 hours and used at 0.5–1% application rates as most suitable for the amendment of sabkha soil. These biochars were found to improve all soil fertility parameters, especially in terms of pH and WHC. From the above discussion, it is clear that Biochar characterization and short-term soil incubations can provide insights into the potential effectiveness of biochar as soil fertility enhancer and aid in the selection of potential biochars that can improve crop productivity. Overall, normal soil seems to require mixed material produced at high temperature and longer time and applied at high rate while sabkha soil required softer materials produced at lower temperature and shorter time and applied a low application rate. This is encouraging results for carbon depleted soil in Qatar where the application of biochar to agricultural soils has the potential to greatly improve soil physical and chemical conditions while serving as a long term carbon sink. These best performing biochars are being tested in plant growth experiments designed to assess their impact on plant biomass and productivity as indicator or their potential in field agriculture in Qatar.qscienc

A Review of the Neutrophil Extracellular Traps (NETs) from Cow, Sheep and Goat Models

This review provides insight into the importance of understanding NETosis in cows, sheep, and goats in light of the importance to their health, welfare and use as animal models. Neutrophils are essential to innate immunity, pathogen infection, and inflammatory diseases. The relevance of NETosis as a conserved innate immune response mechanism and the translational implications for public health are presented. Increased understanding of NETosis in ruminants will contribute to the prediction of pathologies and design of strategic interventions targeting NETs. This will help to control pathogens such as coronaviruses and inflammatory diseases such as mastitis that impact all mammals, including humans. Definition of unique attributes of NETosis in ruminants, in comparison to what has been observed in humans, has significant translational implications for one health and global food security, and thus warrants further study

Switchgrass Biochar Effects Two Aridisols

The use of biochar has received growing attention with regards to improving the physico-chemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on effects in Aridisols. The objective of this study was to investigate the effect of either low or high temperature (250 or 500C) pyrolyzed switchgrass biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to either a Declo loam (Xeric Haplocalcids) or a Warden very fine sandy loam (Xeric Haplocambids) and then incubated at 15% moisture content (by weight) for 127 days; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized water on days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO3-N, NO2-N, and NH4-N concentrations were quantified. After the incubation experiment had terminated, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO3-N, and NH4-N, total C, inorganic C, organic C, and pH. As compared to the 250C, the 500C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250C switchgrass biochar likely due to binding by biochar’s functional group sites. Both biochars caused an increase in leachate K, while the 500C biochar increased leachate P. The 500C biochar reduced leachate NO3-N concentrations as compared to the control; however, the 250C biochar reduced NO3-N concentrations to the greatest extent. Easily degradable C, associated with the 250C biochar’s structural make-up, likely stimulated microbial growth which caused NO3-N immobilization. Soil extractable K, P, and NO3-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential