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The mitigation of greenhouse gas (GHG) emissions and water usage optimization in rice cultivation is challenging for many agricultural countries, including Thailand, who have set goals of reaching net zero emissions and coping with droughts caused by climate change. Alternate wetting and drying (AWD) and biochar application are possible practices for achieving cleaner rice production through reduction of GHG emissions and water consumption. However, these methods' potential varies by site, especially in areas with limited control of water levels. This study assessed the effects of AWD at different drying levels (10, 15, and 20 cm below the soil surface) and rice straw biochar on GHG emissions, yield production, water use, soil characteristics, and economic aspects. This study was conducted over two rice cultivation seasons: a major season in 2022 and a second season in 2023 at a field in Kalasin Province, northeastern Thailand. Using AWD and biochar reduced annual GHG emissions by 48.2% and 8.01%, respectively. Deeper drying levels of AWD showed greater mitigation potential than shallow levels. The combination of AWD and biochar had additional potential for GHG mitigation, however, this impact did not show statistical change as compared to their separate potentials. The adoption of AWD and biochar could also maintain the amount of rice yield compared to traditional practice. All levels of AWD saved irrigation water consumption by an average of 16.8% per season; the highest potential was observed in AWD at 10 cm below the soil surface. Biochar improved soil health after two seasons by enhancing soil pH and organic carbon sequestration. The combination of AWD and biochar did not additionally augment the capacity in water saving of AWD or soil improvement of biochar. The AWD water regime also did not increase net profits, while biochar decreased net profits due to the required investment in biochar production. Using AWD is a feasible way to mitigate GHG emissions and save water without affecting rice productivity and net profits in northeastern Thailand. [Display omitted] • Alternate wetting and drying (AWD) mitigated greenhouse gas emissions by 48.2%. • AWD reduced irrigation water use by an average of 16.8%. • AWD at 15 cm of drying level without biochar is suggested as a mitigation tool. • Rice straw biochar showed the significant impact on soil organic carbon stock. [ABSTRACT FROM AUTHOR]

This study examines the conversion of durian peel to biochar and pyrolysis liquid via slow pyrolysis. The central composite design was utilized to optimize the conditions of three independent variables, namely pyrolysis temperature, cooling temperature, and holding time. Analysis of variance revealed that only pyrolysis temperature had a significant effect on biochar and pyrolysis liquid yields. The biochar and pyrolysis liquid yields fit by a second-order polynomial model agreed well with experimental results. As the pyrolysis temperature increased, the solid product yield decreased, while the pyrolysis liquid yield increased. The highest biochar and pyrolysis liquid yields were 56.11% and 38.53% that derive at 300 and 600 °C of pyrolysis temperature, respectively. The validation of both prediction models showed over 96% agreement. Biochar of high heating value (26.55 MJ/kg) was obtained at 600 °C pyrolysis temperature and 30 min holding time. According to the Van Krevelen plot, the molar ratios of the H/C and O/C of the biochar obtained at 600 °C of pyrolysis temperatures were similar to coal material. The high-quality biochar was of carbon storage class 4 according to the IBI classification; and the characteristics of pyrolysis liquid met community product standards of Thailand. An economic analysis was performed to assess the feasibility of converting 60 tons/year of durian peel into biochar and pyrolysis liquid. An internal project rate of return (IRR) of 25.91% with a payback period of 1.58 years was estimated. The findings of this study indicate the economic viability of immediately deploying large-scale pyrolysis utilizing a waste stream from agriculture. [Display omitted] • Pyrolysis temperature mainly determined biochar and pyrolysis liquid yields. • Maximum biochar (56%) and pyrolysis liquid yields (38%) were determined. • The biochar is rated as a high-class 4 of carbon storage by the IBI. • The durian peel pyrolysis liquid met community product standards of Thailand. • In an economic study IRR is 25.91% with a payback period of 1.58 years. [ABSTRACT FROM AUTHOR]

• A paddy field in Thailand contaminated with Cd (41.02 mg kg−1) was restored. • BZVI decreased Cd accumulation in rice grains by 83 %. • BZVI as soil amendment enriched Fe and Zn accumulation in rice grains by 10 %. • ZVI corrosion enhanced by biochar is the key to BZVI success. • This technique is suitable for community-driven soil restoration. Consuming rice grown in contaminated soil that has an elevated level of cadmium (Cd) is a health risk. This study revealed that using a combination of biochar and zerovalent iron (BZVI) reduces the concentration of Cd and enhances that of the essential elements zinc (Zn) and iron (Fe) in rice. The Cd concentration in brown rice grain cultivated in an untreated paddy was 0.84 ± 0.20 mg kg−1, double the acceptable level (0.4 mg kg−1). Soil amendment with BZVI successfully decreased Cd in brown rice by 83 % compared to the untreated field presumably due to the Cd sorption on biochar (BC) and enhanced ZVI corrosion by-products while ZVI and BC alone achieved only 40 % and 74 % reduction, respectively. Moreover, while using ZVI or BC alone decreased Fe in rice grain by 8–14 %, BZVI enhanced the Fe concentrations in rice grain by 11 % because of Fe2+/Fe3+ release from BC-enhanced ZVI corrosion. Similarly, the presence of BC in BZVI enhanced Zn accumulation in rice grain by 8% due to competitive sorption of Cd2+ on BZVI, which may desorb Zn2+, promoting Zn translocation to rice. Using ZVI alone decreased Zn in rice by 19 %. [ABSTRACT FROM AUTHOR]

Durian peel is a type of biomass derived from agricultural residues, which are found in abundant in Thailand. This study aims to investigate the thermal and chemical properties of three indigenous durian peels, namely Monthong (MDP), Puangmanee (PDP), and Bacho (BDP), as well as the characteristics of biochar and pyrolysis liquid derived from slow pyrolysis of the durian peel. MDP had the greatest volatile matter and fixed carbon content, with 73.97 and 18.43 wt%, respectively. MDP was applied for further research in order to produce biochar and pyrolysis liquid at pyrolysis temperatures of 400 and 600 °C. The maximum biochar yield was 36.01% at 400 °C, while the maximum pyrolysis liquid yield was 37.25% at 600 °C. The largest high heating value of biochar (24.48 MJ kg−1) was obtained at 600 °C more than the high heating value of feedstock (14.32 MJ kg−1). Biochar obtained at 400 °C can be categorized as fertilizer class 4, while biochar obtained at 600 °C can be classified as carbon storage class 2 using the IBI biochar classification tool. The quality of the pyrolysis liquid was determined to be of 3.14 pH and 1.052 g mL−1 specific gravity at a pyrolysis temperature of 600 °C, which meets Thailand standards. As a result, both 400 °C and 600 °C pyrolysis liquids produced significant chemicals that are employed in a variety of industries. Consequently, this research is strongly recommended to be expanded to produce high-quality durian peel biochar and pyrolysis liquid. [Display omitted] • Comprehensive physical, chemical, thermal properties of durian peels were explored. • Durian peel biochar can be categorized by the IBI as carbon storage class 2. • The biochar can be classified by the IBI as a high fertilizer class 4. • Pyrolysis liquid derived from the durian peel meet Thailand standards. • 81 main compounds with essential chemicals were detected in the pyrolysis liquids. [ABSTRACT FROM AUTHOR]

In agricultural studies, estimating and testing differences between treatment regimes in a designed experiment usually determines the subsequent success or failure of inputs or management practices. Fine-scale soil variability of the experimental site can reduce statistical power and should be determined in order to optimize the experiment design. Although randomization is often performed, there is a probability that such randomization does not cover for fine scale soil variability. To determine the effect of this fine scale soil variability, a well characterized test system comprising of biochar's effects on soil microbial communities were studied, in conjunction with Electrical Resisitivity Tomography (ERT) to identify its role on biochar's differential interaction with soil microbial communities. Two main soil profiles were identified by the ERT survey and soil characteristics and soil microbial communities were differently affected by the biochar application with regards to soil profile. Fungal communities (mycorrhization intensity and fungal richness in particular) seemed to be more strongly affected than bacterial communities, however, these effects didn't show a similar trend in between the two studied soil profiles. Consequently, most of the effects of biochar application were masked by the soil variability of the experimental site when analysed in a nested design with randomization. Our results support the relevance of taking fine scale soil variability into account prior to the establishment of a field trial to optimize experimental design. [ABSTRACT FROM AUTHOR]

The in-field burning of sugarcane leaf residues presents a major environmental and health burden in Thailand. In this study, sugarcane leaves were converted into a biochar-based slow release phosphorus (P) fertilizer via pyrolysis at 600 °C, and the influence of pre- and post-pyrolysis treatment on the P loading and release was investigated. The sugarcane leaves were pre-treated with an alkaline (diammonium phosphate, DAP) or an acidic P source (phosphoric acid, PA), with or without addition of MgO. Additionally, the biochar was post-treated with DAP to increase the P loading. Extraction of P in DI water and 2% formic acid were used as indicators for potential slow release. The microporous biochars had a specific surface area of 69–333 m2 g−1 and pre-treatment resulted in a P content of 34–82 g kg−1. When MgO was included in the pre-treatment, XRD analysis confirmed formation of crystalline Mg 2 P 2 O 7 , irrespective of the P source. This Mg 2 P 2 O 7 was responsible for slow P release in DI water over 240 h via a dissolution-controlled process. Post-treatment with DAP increased the P loading to 156 g kg−1 in the form of water-soluble monoammonium phosphate (MAP), which did not contribute to slow release. The tunable P release via combinations of pre- and post-pyrolysis treatment makes these engineered biochars attractive as P sources for crops and presents an attractive solution to mitigate in-field sugarcane residue burning. [Display omitted] • P-loaded biochar was prepared by co-pyrolysis of sugarcane leaves with P + MgO. • Addition of MgO in pre-pyrolysis treatment results in slow release of P. • The slow P release is controlled by dissolution of Mg 2 P 2 O 7. • Post-treatment with DAP increases water-soluble P but not slow-release P. [ABSTRACT FROM AUTHOR]

Production of biofuels via biomass pyrolysis has received a strong emphasis since it may produce a wide variety of renewable fuels in liquid (bio-oil), solid (biochar), and gas (syngas) forms. Sugarcane bagasse, waste from the sugar-alcohol industry, is largely produced in Brazil, India, and Thailand and appears as a great biomass option for pyrolysis due to its properties, abundance, and current underutilization. However, sugarcane bagasse properties and pyrolysis operating conditions may directly affect the product properties, distribution, and further application as fuels and chemicals. Thus, it is necessary a thorough study of these subjects. This review brings an overview of biomass and pyrolysis concepts, as well as a collection of improvements in the production of products (bio-oil, biochar, and gas) via sugarcane bagasse pyrolysis. In addition, this review discusses the interaction between process operating conditions and this biomass type to address how the products' properties and yields are affected. • Fast Pyrolysis: an efficient thermochemical process for bio-oil, biochar, and gas production. • Fast Pyrolysis concepts, operational conditions, and reactor configurations were reviewed. • Bio-oil, biochar, and gas production as an alternative for renewable energy world matrix. • Focus on sugarcane bagasse as a raw material for bio-oil, biochar, and gas production. • Upgrading methods for bio-oil, challenges, and future works in the pyrolysis field. [ABSTRACT FROM AUTHOR]