Poultry Litter Biochar Research Articles

Changes in Total and Available K Contents in Feldspar and Mica Co-pyrolyzed with Poultry Litter at Different Temperatures

Plant available potassium (K) content is very low in K-bearing mineral ores present in Sri Lanka and that restrict their use in crop production as K fertilizer sources. Heating of minerals can increase their plant available forms of nutrients. The objective of this experiment was to study the effect of direct heating of K-bearing minerals at different temperatures and co-pyrolyis with poultry litter (PL) at different rates on their total and available K contents. Poultry litter was co-pyrolyzed with 0, 1 and 5% (w/w) of feldspar and mica at 350, 500, 650 and 900 ℃. K-bearing minerals were also directly heated at these temperatures. With direct heating the mineral, total K contents of feldspar (6.2%) and mica (4.5%) were significantly (p<0.001) increased by 10% and 18%, respectively at 500 ℃ and then decreased by 33 and 65%, respectively at 900 ℃. Available K contents in feldspar (0.05%) and in mica (0.03%) either decreased significantly (feldspar) or did not change (mica) upon direct heating. Increasing pyrolysis temperature up to 650 ℃ increased both total (4.2 to 6.4%), and available K (3.2 to 6.1%) contents in poultry litter biochar (PLB). Co-pyrolysis of PL with feldspar or mica at 1 or 5% rates did not improve the total or available K contents in PLB at these temperatures. We concluded that heat treatment of locally available feldspar and mica or co-pyrolyzing them with PL are not effective technologies to increase their utilization in agriculture.

The Effect of Temperature and Treatment Regime on the Physical, Chemical, and Biological Properties of Poultry Litter Biochar

The Effect of Temperature and Treatment Regime on the Physical, Chemical, and Biological Properties of Poultry Litter Biochar

Qualities and Quantities of Poultry Litter Biochar Characterization and Investigation

Excessive land application of poultry litter (PL) may lead to surface runoff of nitrogen (N) and phosphorus (P), which cause eutrophication, fish death, and water pollution that ultimately have negative effects on humans and animals. Increases in poultry production in the Delmarva Peninsula underscore the need for more efficient, cost-effective, and sustainable disposal technologies for processing PL instead of direct land application. The pyrolysis conversion process can potentially produce nutrient-rich poultry litter biochar (PLB), while the pyrolysis process can change the N and P to a more stable component, thus reducing its runoff. Pyrolysis also kills off any microorganisms that would otherwise trigger negative environmental health effects. This study is to apply an integrated method and investigate the effect of pyrolysis temperature (300 °C, 500 °C), poultry litter source (different feedstock composition), and bedding material mixture (10% pine shavings) on PLB qualities and quantities. Proximate and ultimate analysis showed PL sources and bedding material addition influenced the physicochemical properties of feedstock. The SEM and BET surface results indicate that pyrolysis temperature had a significant effect on changing the PLB morphology and structure, as well as the pH value (7.78 at 300 °C vs. 8.78 at 500 °C), extractable phosphorus (P) (18.73 ppm at 300 °C vs. 11.72 ppm at 500 °C), sulfur (S) (363 ppm at 300 °C vs. 344 ppm at 500 °C), and production yield of PLBs (47.65% at 300 °C vs. 60.62% at 500 °C). The results further suggest that adding a bedding material mixture (10% pine shavings) to PLs improved qualities by reducing the content of extractable P and S, as well as pH values of PLBs. This study also found the increment in both the pore volume and the area of Bethel Farm was higher than that of Sun Farm. Characterization and investigation of qualities and quantities of PLB using the integrated framework suggest that PL from Bethel Farm could produce better-quality PLB at a higher pyrolysis temperature and bedding material mixture to control N and P runoff problems.

Impact of Pyrolyzed and Unpyrolyzed Animal Manures on Soil Properties, Carbon Sequestration, and Clover Productivity in Andisol

The use of organic waste in agricultural soil can enhance crop yields, improve waste management, and boost soil carbon (C) sequestration. However, more field data are required to fully understand the impacts of pyrolyzed and unpyrolyzed animal manures. The objectives of this study were (i) to analyze the impact of two pyrolyzed and unpyrolyzed manures on soil properties, soil C storage, and clover productivity and (ii) to examine the biochar’s movement through the soil profile. Poultry litter (PL), dairy manure (DM), poultry litter biochar (PLBC), and dairy manure biochar (DBC) were applied at rates of 8 t ha−1 in a field experiment with red clover (Trifolium pratense L. var. Quiñequeli) in an Andisol. We monitored changes in soil chemical properties, foliar properties, and crop yield after three clover cuttings. To examine the movement of biochars through the soil profile, we set up a lab experiment where field conditions were simulated. PLBC, DBC, and PL increased soil pH by 0.5 (6.44), 0.28 (6.22), and 0.25 (6.19) units, respectively. Soil available P increased in both pyrolyzed and unpyrolyzed PL treatments (by 8.53 mg P kg−1, on average). Clover yields only increased in treatments with amendments that provided more available P and increased the pH. The addition of DBC increased soil total C (30.3%). Both biochars added to the soil surface exhibited little movement through the soil profile (2 to 4 cm). In this study, the pyrolysis of manures emerged as an option for reducing waste volume from the farming industry. Manure biochars proved useful at low rates for enhancing crop yields (PLBC) and storing C in the soil (DBC).

Biochar facilitated Biological CO2 conversion to C2-C6 alcohols and fatty acids

Microbial CO2 utilization reduces the carbon footprint, providing economic potential. Biochar, rich in minerals and trace metals, can enhance microbial activity. This study investigates poultry litter and switchgrass biochars produced at 350 and 700 °C (PLB350, PLB700, SGB350 and SGB700, respectively) affect CO2 conversion to C2–C6 alcohols and acids by Clostridium muellerianum P21, C. ragsdalei P11 and C. carboxidivorans P7. Fermentations were in 250-mL bottles containing H2:CO2:N2 (60:20:20) shaken at 125 rpm and 37 °C. SGB350 increased alcohol titers by 1.1–2.1 fold, and PLB350 enhanced acid concentrations by 1.2–1.7 fold compared to the control without biochar. About 2.0–3.3 fold more ethanol was formed by strain P11 compared to strains P7 and P21 with SGB350. However, strain P21 produced 2.4-fold more butanol than strain P7 with SGB350, including unique hexanol production. These results highlight the potential of biochar in enhancing C2–C6 alcohol production from CO2, thereby boosting process feasibility.

Effect of Biochar Type and Amendment Rates on Soil Physicochemical Properties: Potential Application in Bioengineered Structures

Abstract Biochar has recently gained attention as a potential soil amendment for its usage in bioengineered structures, e.g., landfill cover system, green slopes, green corridor, etc., that usually comprises compacted soil with vegetation. In literature, many studies have explored the effect of biochar sourced from plant (agri-residues, wood)- and animal-based biomass on physicochemical properties of soil suitable for agricultural application. However, systematic study rarely has been conducted for soil suitable for bioengineered structures, and contradictory results have been reported. The objective of the present study is to explore the effects of biochar produced from different feedstock types (poultry litter, water hyacinth, and sawdust) on physicochemical properties of soil for bioengineered structures application. The results revealed that the amendment of biochar increased the liquid limit (14–52 %), plastic limit (PL, 2–66 %), optimum moisture content (OMC, 4–50 %), pH (29–59 %), cation exchange capacity (20–428 %), and water absorption capacity (12–94 %), whereas it decreased the maximum dry density (7–17 %), specific gravity (3–17 %), and shrinkage area ratio (SAR, 22–57 %) of the soil. Among the different biochar types tested, water hyacinth biochar (WHB) exhibited the highest increase in PL, OMC, and pH, and decrease in specific gravity and SAR of the soil after amendment, whereas poultry litter biochar showed the lowest variation of the same. These changes in the soil physicochemical properties after biochar amendment are likely attributed to the presence of intrapores and active chemicals in biochar, which are highly dependent on feedstock types. The findings of the present study could be useful in understanding the hydro-mechanical and plant interaction of biochar-amended soil (BAS), and potential implementation of BAS in bioengineered structures.

Poultry litter biochar soil amendment affects microbial community structures, promotes phosphorus cycling and growth of barley (Hordeumvulgare)

Phosphorus (P) is a non-replaceable, finite component of fertilizers. The imbalanced resource distribution and possible depletion of P impose challenges on current crop production worldwide. The aim of this study was to assess the impact of poultry litter biochar on plant growth and P mobilizing capability of the microbiome in comparison to a mineral fertilizer application. Spring barley (Hordeum vulgare) was grown in microcosms using a P-limited soil, fertilized with 0 (control), 50 (fertilizer) kg P ha−1 or a poultry litter biochar amendment (biochar, 2% w/w). Biochar amended rhizospheres had significantly higher phosphonate-utilizing bacteria, phoC and phoD gene (acid and alkaline phosphatase) copy numbers and improved P availability. Spring barley dry matter yields were significantly higher for biochar and fertilizer over control; however, P uptake with biochar was higher than with fertilizer. Furthermore, biochar had higher arbuscular mycorrhizal colonization and significantly raised soil pH. Fingerprint-analysis showed significant differences between all treatments for bacterial and fungal communities. 16S rRNA gene-based sequencing analysis revealed increased relative abundance of the phyla Actinobacteriota and Chloroflexi in biochar compared to control, potentially contributing to the ameliorated plant growth conditions. Pearson correlations of both phyla was positive with a range of P cycling variables as well as Morgan's P but negative with acid phosphatase activity. FAPROTAX analysis revealed positive correlations of aromatic compound degradation with phoC and phoD gene abundance, highlighting a possible link between biodegradation and P release. In conclusion, poultry litter biochar could potentially replace mineral P fertilizer for sustainable plant growth in P depleted soil environments.

Revitalizando fertilidade dos solos globais: Meta-análise sobre benefícios do biochar de cama de frango na saúde do solo

ABSTRACT This study aimed to conduct a meta-analysis (MA) of systematic review data on poultry litter biochar (PLB) to answer the following questions: (i) What are the major studies regarding this worldwide? (ii) Which soil chemical attributes are the most affected? and (iii) Does PLB improve soil quality and crop productivity? MA revealed that the application of PLB significantly changed several key soil attributes, including pH, cation exchange capacity (CEC), and nitrogen, carbon, potassium, calcium, magnesium, and aluminum content. Specifically, MA showed that PLB decreased Al3+ in the soil by 71% while increasing pH, N, C, and CEC by 16, 20, 36, and 82%, respectively. This significant increase in CEC was associated with the addition of Ca2+, Mg2+, and K+ cations by 43, 202, and 636%, respectively. It was verified that PLB serves a dual function: it corrects soil acidity and pH while also enhancing the content of key nutrients, such as C and N. This study broadens the understanding of the potential of reusing poultry litter in biochar production, offering valuable data for developing strategies to improve both soil health and fertility.

Magnesium activation affects the properties and phosphate sorption capacity of poultry litter biochar

Biochars with a high affinity for phosphorus (P) are promising soil amendments for reducing P in agricultural runoff. Poultry litter (PL) is an abundant biochar feedstock. However, PL-derived biochars are typically high in soluble P and therefore require chemical modification to become effective P sorbents. This study investigated the effect of magnesium (Mg) activation on extractable P (EP) and P sorption capacities of PL-derived biochars. Biochar was produced at 500–900 °C from PL activated with 0–1 M Mg. Three differentially aged PL feedstocks were evaluated (1-, 3–5-, and 7–9-year-old). Increased Mg activation level and pyrolysis temperature both resulted in EP reductions from the biochars. Specifically, biochars produced at temperatures ≥ 700 °C from PL activated with ≥ 0.25 M Mg had negligible EP. X-ray diffractograms indicated that increased Mg loading favored the formation of stable Mg3(PO4)2 phases while increasing temperature favored the formation of both Mg3(PO4)2 and Ca5(PO4)3OH. Maximum P sorption capacities (Pmax) of the biochars were estimated by fitting Langmuir isotherms to batch sorption data and ranged from 0.66–10.35 mg g−1. Average Pmax values were not affected by PL age or pyrolysis temperature; however, biochars produced from 1 M Mg-activated PL did have significantly higher average Pmax values (p < 0.05), likely due to a greater abundance of MgO. Overall, the results demonstrated that Mg activation is an effective strategy for producing PL-derived biochars with the potential ability to reduce P loading into environmentally sensitive ecosystems.

Poultry litter and cow dung biochar as P sources for cowpea cultivation in two Ghanaian soils

Poultry litter and cow dung biochar as P sources for cowpea cultivation in two Ghanaian soils

Influence of Poultry Litter Biochar on Some Properties and Carbon Mineralization in Acidic Soil

During the last years, biochar (BC) from various organic wastes and its application to soil to improve soil properties have been a very common treatment in agricultural soils. While many studies have been conducted on the effects of biochar on the improvement of alkaline soils, studies on acid soils are limited. An incubation experiment was conducted to investigate the effects of poultry litter biochar (PLBC) on acidic soil properties and C mineralization. Biochar derived from poultry litter (PLBC) through slow pyrolysis was mixed with soil in three different doses (0, 2, and 5%) and subjected to a 120-day incubation period. pH increased from 4.38 to 5.31 at the end of the incubation. Electrical conductivity (EC) values also increased. Carbon dioxide (CO2) emission reached its maximum on the 30th day of the incubation in control and with PLBC applied to the soil. PLBC increased the organic matter (OM) content of the soil. Values were 3.51%, 4.70%, 6.27% for control, PLBC 2% and 5% treatments, respectively. PLBC does have an increasing negative priming effect on the carbon (C) mineralization of the soil. Particulate organic matter (POM) increased the storage of organic carbon (OC) in the POM fraction for both PLBC applications. It is revealed that PLBC showed soil conditioning effect as well as C storage in the soil. This study was on the short-term incubation under controlled conditions, varying results would be obtained in field conditions.

Pine Chip and Poultry Litter Derived Biochars Affect C and N Dynamics in Two Georgia, USA, Ultisols

Some biochars produced by pyrolysis of biomass have the potential to sequester C and enhance nutrient supplies in agricultural soils. A 28-day lab incubation was used to assess the potential effects of biochars derived from pine chips (PC) or poultry litter (PL) applied at five application rates (0, 22.5, 45.0, 67.5, and 90 Mg ha−1 equivalent). Biochars were applied to two acidic Ultisols, a Cecil sandy loam and a Tifton loamy sand, found in Georgia, USA. Cumulative basal soil respiration was measured over the 28-day incubation. Other soil properties measured before and after incubation were soil pH, total soil organic carbon (SOC), total soil N, soluble organic C (OC), soil mineral nitrogen (NH4+-N and NO3−-N), and microbial biomass C (MBC). Before incubation, addition of both PC and PL biochars increased soil pH, total SOC, and C:N ratio in both soils. Addition of the PL biochar increased total soil N, soluble OC, and NO3−-N in both soils, MBC in Tifton soil, and NH4+-N in Cecil soil. Addition of the PC biochar decreased NO3−-N in Cecil soil but increased it in Tifton soil. After the 28-day incubation, averaged across soils, pH increased in the 22.5 Mg ha−1 PC and 22.5 and 67.5 Mg ha−1 PL treatments, total SOC declined in the 45 and 67.5 Mg ha−1 PC treatments, and the C:N increased in soil controls and decreased in the 67.5 Mg ha−1 PC treatment. In Cecil soil, the MBC declined in PL treatments except at 90 Mg ha−1, and NH4+-N declined in the 90 Mg ha−1 PC treatments. In Tifton soil, MBC increased in the 45 Mg ha−1 PL treatment, and NH4+-N increased in all but the 22.5 Mg ha−1 PL treatments. Total N and NO3−-N did not change with incubation. Basal respiration was not affected by biochar, thought it was generally greater in Cecil than Tifton soil. Net SOC loss and the initial increase in soluble OC and MBC indicated potential C priming from adding both biochars. Increased NH4+-N with time in Tifton PL treatments indicated potential N priming. In Cecil soil, the PC biochar may have immobilized NH4+-N, but PL biochar likely supplied it. In Tifton soil, PC biochar appeared to be generally inert, but PL biochar supplied soluble OC and NH4+-N, although it might have inhibited nitrification.

Biochar and Polyhalite Fertilizers Improve Soil’s Biochemical Characteristics and Sunflower (Helianthus annuus L.) Yield

Biochar (BC) applications have multiple impacts on crops’ nutrient availability, growth and yield depending on the feedstock type and pyrolysis conditions. Pot and field experiments were conducted to examine the effects of biochars (BCs) prepared from three different feedstocks, Acacia modesta wood biochar (AWB), Dalbergia sissoo wood biochar (DWB) and poultry litter biochar (PLB), on soil’s nutrient availability, uptake by wheat (Triticum aestivum) and sunflower (Helianthus annuus) crops and their yield attributes. All BCs were applied at the rate of 10t ha−1 in each treatment in both experiments, and pot and field trials were designed according to a two-factor factorial completely randomized design (CRD) and two-factor factorial randomized complete block design (RCBD), respectively. The concentration of soil NO3-N, NH4-N, Olsen P and extractable K increased by 98.5, 296, 228 and 47%, respectively, in the pot experiment with the application of PLB+polyhalite (PH) treatments. Similarly, in field experiments, NO3-N, NH4-N and Olsen P contents increased by 91, 268 and 156% under the PLB+PH treatment, respectively. However, in both experiments, soil’s microbial biomass phosphorus (MBP) was significantly higher after AWB+PH treatment, and the increments were 127 and 109% while microbial biomass nitrogen (MBN) contents were 16 and 14% higher than the control under DWB+PH and AWB+PH treatments, respectively, in the field experiment. Similarly, combined PLB+PH increased the total organic carbon (TOC) of soil by 193%. Moreover, PLB+PH co-applications with PH significantly increased sunflower grain yields by up to 58% and the harvest index by 45%. Overall, no negative impact with respect to BCs was observed on the soil’s nutrient content and plant growth. Hence, for immediate crop benefits and soil health, using nutrient biochar (PLB) alone or in combination with chemical fertilizers is recommended.

Effectiveness of mixing poultry litter compost with rice husk biochar in mitigating ammonia volatilization and carbon dioxide emission

Nitrogen-rich materials such as poultry litter (PL) contributes to substantial N and C loss in the form of ammonia (NH3) and carbon dioxide (CO2) during composting. Biochar can act as a sorbent of ammonia (NH3) and CO2 emission released during co-composting. Thus, co-composting poultry litter with rice husk biochar as a bulking agent is a good technique to mitigate NH3 volatilization and CO2 emission. A study was conducted to evaluate the effects of composting the mixtures of poultry litter with rice husk biochar at different ratios on NH3 and CO2 emissions. Four mixtures of poultry litter and rice husk biochar at different rate were composted at 0:1, 0.5:1, 1.3:1 and 2.3:1 ratio of rice husk biochar (RHB): poultry litter (PL) on a dry weight basis to achieve a suitable C/N ratio of 15, 20, 25, and 30, respectively. The results show that composting poultry litter with rice husk biochar can accelerate the breakdown of organic matter, thereby shortening the thermophilic phase compared to composting using poultry litter alone. There was a significant reduction in the cumulative NH3 emissions, which accounted for 78.38%, 94.60%, and 97.30%, for each C/N ratio of 20, 25, and 30. The total nitrogen (TN) retained relative was 75.96%, 85.61%, 90.24%, and 87.89% for each C/N ratio of 15, 20, 25, and 30 at the completion of composting. Total carbon dioxide lost was 5.64%, 6.62%, 8.91%, and 14.54%, for each C/N ratio of 15, 20, 21, and 30. In addition, the total carbon (TC) retained were 66.60%, 72.56%, 77.39%, and 85.29% for 15, 20, 25, and 30 C/N ratios and shows significant difference as compared with the initial reading of TC of the compost mixtures. In conclusion, mixing and composting rice husk biochar in poultry litter with C/N ratio of 25 helps in reducing the NH3 volatilization and CO2 emissions, while reducing the overall operational costs of waste disposal by shortening the composting time alongside nitrogen conservation and carbon sequestration. In formulating the compost mixture with rice husk biochar, the contribution of C and N from the biochar can be neglected in the determination of C/N ratio to predict the rate of mineralization in the compost because biochar has characteristic of being quite inert and recalcitrant in nature.

Characterization of Poultry Litter Biochar and Activated Biochar as a Soil Amendment for Valorization

Biochar applications to soils may enhance soil quality, hydrological properties, and agronomic productivity. Modification of biochar by activation via introduction of heteroatoms at different pyrolysis conditions can alter physical and chemical characteristics, which may enhance soil properties, although the extent of this is unknown. The objective of this study was to investigate the impacts of pyrolysis temperature (400, 500, 600, and 700 °C) on activated (activated with methanesulfonic acid) and unactivated biochar produced from poultry litter to identify optimum production conditions for end use as a soil amendment. Physical, chemical, and surface properties of biochars were determined using wet chemistry and spectroscopic analyses. Results showed that activation with methanesulfonic acid increased biochars’ oxygen content, while decreasing its point of zero charge and electrical conductivity. Conversion of raw poultry litter to activated and unactivated biochar increased concentration of P (3-fold), K (1.8-fold), Ca (3-fold), Mg (2.3-fold), and S (4.8-fold), with concentrations increasing with increasing temperatures (p &lt; 0.05) except for C and N. Activated biochar had lower recovery of C and N, but greater water-holding capacity than unactivated biochar. Concentrations of NH4-N, NO3-N, and water-soluble P were greater in unactivated biochar (p &lt; 0.05). Among all biochars, activated biochar produced at 400 °C had the lowest bulk density, total P, K, Ca, and Mg, and greatest water-holding capacity, water-soluble P, Ca, and Mg concentrations, thereby suggesting improved soil amendment characteristics and subsequent soil health under poultry litter biochars produced under these conditions.

Impact of biochar-compost derived from thermal pyrolysis of poultry litter and woodchips on N mineralization and maize growth in contrasting tropical dryland soils

A soil incubation and a greenhouse pot study was set up to determine the effects of biochar-compost mix on N transformation and availability and maize seedling performance on an alkaline and an acidic dryland soil. Urea fertilizer (F), sole application of poultry litter and woodchip biochar plus urea (PB + F & WB + F), biochar-compost mixture (1:1) plus urea derived from poultry litter (PB + C + F), woodchip (WB + C + F), and no amendment or urea application treatments were tested for N mineralization and soil properties. Results indicate that despite the unequal and high total N input, PB + C + F and WB + C + F mineralized less N of the total N input compared to urea (F), in the alkaline and acidic soil type. WB + C without F addition enhanced total N uptake comparable with F, and increased maize biomass in the alkaline soil. Addition of compost to WB (WB + C) enhanced maize P uptake and performed similarly as F.

Combined application of poultry litter biochar with NPK fertilizer mitigates the effects of stress in wheat (Triticum aestivum L.) grown on chromium contaminated soil

Combined application of poultry litter biochar with NPK fertilizer mitigates the effects of stress in wheat (Triticum aestivum L.) grown on chromium contaminated soil

The effects of biochar aging on rhizosphere microbial communities in cadmium-contaminated acid soil.

Biochars are widely used in the remediation of Cd-contaminated soils. However, changes in the bacterial communities in the rhizosphere contaminated with Cd in response to biochar aging are poorly studied. Addressing this gap in knowledge is important to improving micro-ecological services on healthy growth of plants with mitigation strategies against Cd contamination. An aging experiment (270 days) was conducted with biochars derived from poultry litter and sugar-gum wood added to a Cd-contaminated acid soil. Bacterial communities in the rhizosphere of Brassica rapa and bulk soils were investigated after 1, 90 and 270 days of biochar aging. There was no significant difference (P>0.05) in bacterial Shannon and Simpson indices between the control and biochar treatments. However, compared to the no-Cd control, the addition of Cd decreased the relative abundances of Firmicutes, Chloroflexi and Acidobacteriota but increased those of Actinobacteriota and Proteobacteria. Poultry-litter biochar had the largest effect on bacterial community composition, especially in the rhizosphere. Aging of poultry-litter biochar increased the abundance of Armatimonadota over time more than the sugar-gum-wood biochar, which was attributed to a lower pH and higher bioavailability of Cd in the sugar-gum-wood biochar treatment. The addition of poultry-litter biochar to the contaminated soil mitigated the bioaccumulation of Cd by increasing soil pH and restoring soil bacterial ecology in contaminated acid soils over time.

Biochar Amendments for Reducing Nitrate Leaching from Soils of Different Textural Classes in the Nigerian Savanna

This study was carried out with the aim of assessing the effectiveness of four biochar materials; in reducing nitrate leaching from soils of three different textural classes in the Nigerian Savanna region. Soil samples (0-20 cm depth) were collected from three different soil types and three different locations each in the Nigerian Savanna using stratified random sampling. Two hundred and fifty (250) g of soil samples were amended with 0, 2.5, 5, 7.5 and 10 tonha-1 of Maize cob biochar (MCB), rice husk biochar (RHB), cow dung biochar (CDB) and poultry litter biochar (PLB) and were subjected to laboratory leaching experiment. Sixty (60) ml of nutrient solutions containing 300 mgl-1 nitrate using ammonium nitrate (NH4NO3) was applied to each of the laboratory biochar-incubated soil columns to study biochar effect on nutrients retention and transport. The experiment was laid in a Randomize Complete Block Design (RCBD) replicated three times. Leachates were collected and nitrate concentration was determined using a dual beam UV/VIS spectrophotometer. The data collected were analysed using the Generalized Linear Model (GLM) procedure and the means were separated using Tukey’s honest significant difference (SAS version 9.4). Results obtained revealed that there were no significant differences among the biochar treatments on nitrate leaching from Clay loam. However, highest nitrate leaching from Loamy soil of 30.53% was recorded by the application of 2.5 tonha-1 PLB and was significantly different from the application of 2.5 and 5-ton ha-1 RHB and 5-ton ha-1 MCB. Similarly, highest nitrate leaching from Sandy loam of 32.18 % was recorded by the application of 5-ton ha-1 MCB and was significantly higher than 5.94, 2.40 and 7.12 % recorded by the application of 2.5 and 5-ton ha-1 RHB and 7.5 tonha-1 CDB respectively. Therefore, application of 2.5, 5-ton ha-1 RHB and 7.5 tonha-1 CDB can effectively reduce nitrate leaching from Sandy loam. While 2.5, 5, 7.5 tonha-1 CDB and 2. 5 and 5 tonha-1 RHB reduced nitrate leaching from Loamy soils.

Biochar-graphene oxide composite is efficient to adsorb and deliver copper and zinc in tropical soil

Highly weathered soils have low micronutrient availability and very low efficiency for most soluble fertilizers . In this article the effect of poultry litter biochar-graphene oxide composite (PLB-GO) as a novel adsorbent for copper (Cu) and zinc (Zn) was evaluated, as well as its fertilizing effects on plant growth, nutrient use efficiency and soil fertility . In order to do so, poultry litter biochar (PLB) and PLB-GO were produced, characterized and evaluated by isotherm adsorption and kinetics studies regarding their Cu and Zn sorption and desorption properties. Cu and Zn loaded on PLB and PLB-GO as biochar-based fertilizers (BBF) were also evaluated. PLB-GO showed 16.2% and 17.7% higher Cu and Zn adsorption capacity , respectively, than pristine PLB, and in both cases <0.5% of the sorbed metal content was released in water. Plant effects on growth and nutrient uptake were, in general, higher or similar to the results obtained for sulfates . The application of PLB increased Cu availability while PLB-GO increased Zn availability after cultivation, even after increasing nutrient uptake and being little soluble in water. Addition of small amounts (≤0.5%) of GO in biochar has potential to increase its properties to retain micronutrients and enhance the fertilizer use effectiveness in highly weathered soils. • Biochar enrichment with graphene oxide increased metals adsorption from 16.2% to 17.7%. • Copper and zinc adsorbed by graphene oxide-biochar showed low water solubility (<0.5%). • Biochar-based micronutrient fertilizer increased grain production from 8% to 17%. • Biochar-based micronutrient fertilizer showed enhanced efficiency in highly weathered soil.