Field Burning Research Articles

No Field Evidence of Grass Fuel Structure effects on Postfire Tree Mortality in Juniperus virginiana

Prescribed fires are an important management tool for containing woody plant encroachment in rangeland ecosystems. Grasses are the dominant fuel type in rangelands. Past work has shown that grass canopy architecture, which varies among grass species, can influence flammability. Whether variation in grass fuel structure can influence postfire plant responses has not yet been tested. To bridge this gap, we set up field burning experiments with different fuel treatments and examined postfire mortality of Juniperus virginiana L. in a tallgrass prairie in southwestern Missouri. We sampled 60 trees and measured tree height and diameter at breast height before the fire. Fuels surrounding each tree were manipulated to vary independently in both fuel load and fuel structure. Flame temperatures were measured during the fire, and both stem and canopy injuries were evaluated 1 d after the fire. We surveyed tree mortality 7 mo after the fire. We found no effects of either fuel load or fuel structure on postfire mortality or on canopy injury in J. virginiana. Canopy injury was a critical fire severity measurement determining postfire mortality in J. virginiana, and taller trees are more fire resilient. Despite laboratory-observed fuel structure effects on flammability, this study finds no evidence for the importance of grass fuel load and canopy architecture in influencing postfire tree response. This result might arise from the low crown depth and low canopy water content of J. virginiana, which can promote canopy fire and result in a high mortality rate across fuel treatments. Notwithstanding the negative results, testing laboratory-based findings in field settings is important for further examining laboratory observations and upscaling individual-level processes to ecosystems to help identify the key ecological processes determining population dynamics and community assembly. Our study also suggests that prescribed fire is an effective tool to remove encroaching J. virginiana in tallgrass prairies at an early stage.

Preparation of porous biochar from fusarium wilt-infected banana straw for remediation of cadmium pollution in water bodies

The problem of cadmium pollution and its control is becoming increasingly severe issue in the world. Banana straw is an abundant bio raw material, but its burning or discarding in field not only causes pollution but also spreads fusarium wilt. The objective of this paper is to utilize biochar derived from the wilt-infected banana straw for remediation of Cd(II) pollution while to eliminate the pathogen. The activity of wilt pathogen in biochar was determined by PDA petri dish test. The Cd(II) adsorption of the biochar was determined by batch adsorption experiments. The effects of KOH concentration (0.25, 0.5 and 0.75 M) on the physicochemical characteristics of the biochar were also observed by BET, SEM, FTIR, XRD and XPS. Results showed that pristine banana straw biochar (PBBC) did not harbor any pathogen. The specific surface area (SSA) and Cd(II) adsorption capacity of 0.75 M KOH modified banana straw biochar (MBBC0.75M) were increased by 247.2% and 46.1% compared to that of PBBC, respectively. Cd(II) adsorption by MBBC0.75M was suitable to be described by the pseudo-second-order kinetic model and Freundlich isotherm. After Cd(II) adsorption, the CdCO3 were confirmed by XRD and observed through SEM. The weakness and shift of oxygen-containing functional groups in MBBC0.75M after Cd(II) adsorption implied that those groups were complexed with Cd(II). The results showed that pyrolysis could not only eliminate banana fusarium wilt, but also prepare porous biochar with the wilt-infected banana straw. The porous biochar possessed the potential to adsorb Cd(II) pollutants.

Temporal Variation and Sources of Particulate Matter in Kannur: Insights from a Coastal City in South India

In this study, particulate matter (PM) variation has been analyzed to address the dearth of scientific research on air pollution in a coastal city from south India. Mean PM2.5 and PM10 concentrations were 61.6 ± 26.4 and 87.3 ± 35.4 μg/m3. The highest (lowest) seasonal concentration was observed during winter (monsoon). Increase in PM from September to February is attributed to low relative humidity, biomass burning in nearby paddy fields, and continental air mass from the east and north-easterly direction. The mean PM2.5/PM10 ratio was 0.71, with the seasonal ratio ranging between 0.64 (summer) and 0.76 (monsoon), indicating the dominance of anthropogenic PM fraction. PM exhibited typical characteristic of the urban region, i.e., a two-peak diurnal trend during all seasons except monsoon. PM10 (PM2.5) concentrations decreased by ∼7–24.2% (∼11–21%) on the weekends, with the highest reduction in winter seasons. Regarding correlation analysis among PM, CO, and ozone; a negative correlation between PM10 and O3 and a positive correlation between PM and CO was observed. Wind speed and PM10 showed a positive quadratic linear, whereas wind speed and PM2.5 showed a negative linear relationship. The primary sources of particulate matter in Kannur town are motor vehicle emissions, dust from construction work in surrounding zones, and nearby industrial units.

Development and performance evaluation of paddy straw based insulating block composite for low temperature storage application

The study focuses on the conversion of crop residues into thermal insulation materials, to gain better utility with value addition. Such applications will divert the paddy straw to useful purposes, leading to reduction in the open field burning of paddy straw in various developing countries. The process was optimized for manufacturing of insulating block composite and evaluating the mechanical and thermal performance of the same. Properties like compressive strength, internal bonding strength, density, porosity, and thermal conductivity were studied for the block. The optimum physical and mechanical properties were observed as moisture content 8–10 %, a block density 450–500 kg/m3, porosity 70 % with particle size of 8–15 mm. The mixture ratio of block was optimized as paddy straw 574.9 g, clay 840 g, and seed lac 260 g with thermal conductivity, compressive strength, bonding strength, and porosity as 0.08 W/m K, 1.19 MPa, 0.028 MPa, and 70.7 %, respectively, using Response Surface Methodology. An eco-friendly, economical and sustainable technological value addition for paddy straw was obtained and used for insulation purposes in cold storages as well as drying chambers. Paddy straw insulating block can also be utilized in combination with conventional insulation materials.

Morphological and Elemental Classification of Freshly‐Emitted Individual Particles From Field and Laboratory Residential Biomass Burning

AbstractResidential biomass burning significantly contributes to air pollution in developing countries. However, the microscopic properties of individual particles in their emissions have not been well understood. In this study, individual primary particles from 14 kinds of biomass fuels (including firewood, crop residue, and animal dung) were collected in laboratory and field measurements, and their morphology, composition and mixing state were acquired using transmission electron microscope. These results constitute a source profile database of individual primary particles from residential biomass burning. The database reveals that different types of biomass fuels exhibit different emission characteristics, that is, residential firewood burning mainly emits pure carbonaceous particles (including organic matter (OM) and soot particles), crop residue burning mainly emits K‐containing particles (including OM‐K, soot(‐OM)‐K, and K‐rich particles), and animal dung burning mainly emits pure carbonaceous particles and K‐containing particles. Moreover, our results indicate that the emission characteristics obtained from laboratory and field measurements are different. Field measurements conducted in two selected villages in North China Plain exhibit a higher presence of soot particles compared to laboratory measurements, owing to their higher combustion temperatures. In contrast, field measurements conducted in one selected village in Qinghai‐Tibet Plateau contain less soot particles than those from laboratory measurements in plain areas, due to the deficient oxygen supply during combustion process in the high‐altitude regions. These results warn us that the emission estimation from residential biomass burning should notice the large emission differences among different biomass types and between field and laboratory measurements.

Opportunities for mitigating net system greenhouse gas emissions in Southeast Asian rice production: A systematic review

Southeast Asia (SEA) is a key producer and exporter of rice, accounting for around 28% of rice produced globally. To effectively mitigate greenhouse gas (GHG) emissions in SEA rice systems, field methane (CH4) and nitrous oxide (N2O) emissions have been intensively studied. However, an integrated assessment of system-level GHG emissions which includes other carbon (C) balance components, such as soil organic carbon (SOC) or energy use, that can positively or negatively influence the net capacity for climate change mitigation is lacking. We conducted a systematic review of published research in SEA rice systems to synthesize findings across four main components of net system emissions: (1) field GHG emissions, (2) energy inputs, (3) residue utilization beyond the field, and (4) SOC change. The objectives were to highlight effective mitigation opportunities and explore cross-component effects to identify tradeoffs and key knowledge gaps. Field GHG emissions were the largest contributor to net system emissions in agreement with existing scientific consensus, with results showing that practices such as floodwater drainage and residue removal are sound options for CH4 mitigation. On the other hand, increasing SOC potentially provides a large GHG mitigation opportunity, with long-term continuous rice cropping and practices such as residue incorporation and biochar application promoting SOC increase. A reduction in energy inputs was mainly achieved by optimizing agrochemical use, especially N fertilizers. For residue utilization beyond the field, GHG emission mitigation mainly came from preventing open field burning through residue removal. Removed residue can subsequently be used for producing energy that offsets GHG emissions associated with conventional fuel sources (e.g. fossil fuel-based electricity generation) or substituting material used in other production systems. Integrating all four components of net system emissions into one analysis underscores the following two main takeaways. First, the components of field GHG emissions and SOC change are the biggest opportunities for reducing net system emissions and need to be considered for effective climate change mitigation. Second, the reduction of C inputs through residue removal and increased soil aeration through multiple drainage will lower CH4 emissions but may also potentially decrease SOC stocks over time. Hence, we argue that future research needs to consider cross-component effects to optimize net system emissions, specifically the “stacking” of best management practices for mitigation related to field GHG emissions or SOC change in long-term experiments.

Agricultural burning in Imperial Valley, California and respiratory symptoms in children: A cross-sectional, repeated measures analysis

Burning of agricultural fields is an understudied source of air pollution in rural communities in the United States. Smoke from agricultural burning contains air toxics that adversely impact respiratory health. Imperial County in southeastern California is a highly productive agricultural valley that heavily employs agricultural burning to clear post-harvest crop remnants. We related individual-level exposure to agricultural burns to parent-reported respiratory symptoms in children.We leveraged the Children's Assessing Imperial Valley Respiratory Health and the Environment (AIRE) cohort of 735 predominantly Hispanic low-income elementary school students in Imperial County. Parents reported children's respiratory health symptoms and family demographic characteristics in questionnaires collected at enrollment and in annual follow-up assessments from 2017 to 2019. Permitted agricultural burns in Imperial County from 2016 to 2019 were spatially linked to children's geocoded residential addresses. We used generalized estimating equations to evaluate prevalence differences (PDs) in respiratory symptoms with increasing exposure to agricultural burning within 3 km in the 12 months prior to each assessment.Nearly half of children (346, 49 %) lived within 3 km of at least one agricultural burn in the year prior to study enrollment. In adjusted models, each additional day of agricultural burning in the prior year was associated with a one percentage point higher prevalence of wheezing (PD 1.1 %; 95 % CI 0.2 %, 2.0 %) and higher bronchitic symptoms (PD 1.0 %; 95 % CI -0.2 %, 2.1 %). Children exposed to four or more days of burning had an absolute increased prevalence of wheezing and bronchitic symptoms of 5.9 % (95 % CI -0.3 %, 12 %) and 5.6 % (95 % CI -1.8 %, 13 %), respectively, compared to no burn exposure. Associations with wheezing were stronger among children with asthma (PD 14 %; 95 % CI -1.4 %, 29 %).To our knowledge, this is the first U.S. study of agricultural burning and children's respiratory health. This work suggests that reducing agricultural burning could improve children's respiratory health.

Aerosol emission from soil during field burning

Soil is heated or burned during field biomass burning, including forest fires, grassland fires, and open straw burning. The characteristics of the aerosols released from the high-temperature heated soil have not been reported, according to our knowledge. In this work, three types of soil were heated at different temperatures in a tubular furnace to mimic the heating process during field burning. The particulate emission factors (EFPM), particle size distributions, organic carbon (OC) contents, and organic compositions of the emitted aerosols were investigated in detail. It was found that the particulate matter (PM) produced by soil at high temperature (≥300 °C) cannot be neglected. The PM emission flux of the shallow surface of soil (with depth less than 5 cm) could be dozens of times higher than those from biomass burning when the surface temperature rises to 500 °C. The soil heated at higher temperatures emitted more particles with smaller sizes. These aerosols also contain toxic and harmful substances such as aromatics, heterocycles and nitriles. Therefore, the results strongly suggest that aerosol emissions from the heated soil during the field biomass burning cannot be ignored and could have significant environmental impacts.

Thermochemical Characterization of Rice-Derived Residues for Fuel Use and Its Potential for Slagging Tendency

Rice is the most important cereal in Asia. However, it also results in the generation of large quantities of rice-derived residues (i.e., rice straw and rice husk). Due to the residues richness in lignocellulosic components, they potentially have considerable value in material and/or energy production without illegal burning in open fields. This work focused on investigating the thermochemical properties and inorganic/metal element contents of rice straw and rice husk. The former included proximate analysis, calorific value, thermogravimetric analysis (TGA) and energy dispersive X-ray spectroscopy (EDS). The latter covered the ten elements most relevant to their slagging/fouling indices. The results showed that they are suitable for energy use as biomass fuels, but rice husk was superior to rice straw because of the high silica content in the rice husk and the significant contents of potassium, sulfur and phosphorus in the rice straw. Using several slagging and fouling indices, the evaluation results were also consistent with their contents of inorganic elements or oxides. To increase the fuel properties of rice-derived residues, they could be pretreated with alkaline leaching, thus causing lower emissions of particulates and reduced slagging tendency when co-firing them with coal in industrial boilers.

Residue removal and nitrogen cycling in burn and non‐burn Kentucky bluegrass seed production systems

AbstractKentucky bluegrass (Poa pratensis L.) postharvest residue in northern Idaho has historically been burned to maintain stand life and profitability. Alternatives to open field burning are necessary to reduce adverse impacts of burning on air quality and several have been proposed. However, limited information is available on the impact of residue management on residue removal and nitrogen cycling. In this study, the impact of residue management on residue nutrient dynamics and nitrogen availability was evaluated within replicated full load burn (FLB), bale then burn (BB), bale then mow then harrow (BMH), and system (SYST) (BMH year 1, BB year 2, and FLB year 3) plots in Kootenai County, ID from 2002 to 2006. Standing and non‐standing residues were measured immediately following grass seed harvest and periodically thereafter in each plot. Averaged across years, non‐standing residue (thatch) removal ranged from −13% in BMH to 61% in FLB, and removal of standing biomass ranged from 6% in BMH to 92% in FLB. The combined removal of both non‐standing and standing residue was 18% with BMH, 57% with SYST, 69% with BB, and 75% with FLB. Plant N uptake ranged from 53 kg N ha−1 in FLB in 2006 to 131 in SYST (BMH) in 2003 and nitrogen use efficiency, calculated using partial factor productivity formula, ranged from 0.6 to 5.8 kg bluegrass seed per kg N fertilizer. Mean NO3−–N concentrations from lysimeters 10‐cm deep were 14 mg NO3−–N L−1 in FLB, 12 mg NO3−–N L−1 in BB, and 6 mg NO3−–N L−1 in BMH treatments for years 2003–2006. Greater concentrations of NO3−–N in burn treatments were available for plant uptake or leaching compared to the BMH treatment. The data indicate that the efficacy of any residue management system will vary from year to year and impact seed production in the following year. Nitrogen availability varied across residue management systems, suggesting N fertilizer product, rate, and timing to optimize N use efficiency may also need to vary.

Low Cost Zero till In situ Green Manuring for Kharif Rice-A Success Story

Low cost zero till in situ green manuring using plant species like dhaincha (Sesbania aculeata) and sunnhemp (Crotalaria juncea) will eliminate the age old problems of large scale adoption of green manuring across the farming community. These two species germinated and grown well when sown before (as paira crop during last irrigation) or after rice harvest under zero till condition, with assured nor western rain/monsoon rain or with one post sowing irrigation (7.5 cm). The zero till paira dhaincha green manuring process opened up the scope of producing green manuring at lower cost and saves up to Rs.15000/ha over conventional rain fed green manuring system. Green manuring by dhaincha produced 50-60 tonnes of biomass at 35-40 DAS in alluvial (North 24 PGS), lateritic (Purulia) and clay soils (Paschim Medinipur), produced 30-50 q raw rice /ha and saved 20-27 kg (30 per cent) chemical nitrogen/ha. This green manure will help in quicker decomposition of rice straw left after combined harvest (3.5- 6,0 t/ha), minimise its field burning, sequester enough carbon to the soil. Fifty tonnes green biomass of dhaincha/sunnhemp, has the potential to absorb 15 tonnes CO2 from the atmosphere, sequesters 2 tonnes of carbon in soil, minimise environmental pollution, improve soil health, its structure and water holding capacity. This technique can be adopted in rice growing countries across the globe without difficulty. Seed production dhaincha and sunnhemp is possible by growing it as paira crop (40 kg/ha) within kharif rice which grows up to 45 cm height, produces healthy pods and matures by 70 days which otherwise takes 5-8 months in normal season. If the seed crop is not harvested in rice fallows, from shattered seeds, self-seeded zero till and rain fed dhaincha manure can be obtained in rice fallows.

Post-fire recovery of soil organic carbon, soil total nitrogen, soil nutrients, and soil erodibility in rotational shifting cultivation in Northern Thailand

The hill tribes in Thailand traditionally depend on rotational shifting cultivation (RSC). However, insufficient understanding remains on post-fire soil properties and soil erodibility (k-values) with fallow years. To address this gap, the levels of soil organic carbon (SOC), soil total nitrogen (STN), soil nutrients, and soil erodibility after fire in RSC were investigated. Topsoil (0–10 cm) samples from sites with 4 (RSC-4Y), 5 (RSC-5Y), and 7 (RSC-7Y) fallow years in Chiang Mai Province, northern Thailand, were taken at four time points: before burning, 5 min after burning, 9 months after burning, and 2 years after burning. Soil pH, electrical conductivity, and soil nutrient (available P, K, and Ca) levels were increased after burning and remained higher than the pre-burning levels for at least 2 years. The SOC stock decreased after burning in all fallow fields. At 2 years after burning, the SOC stock in RSC-4Y was higher than before burning, whereas in RSC-5Y and RSC-7Y, the levels had not reached the pre-fire levels. The STN stocks of all studied fields significantly decreased after burning and had not reached the pre-burning levels after 2 years. After burning, the topsoil of RSC-4Y was most susceptible to erosion. However, only in RSC-4Y, the k-value was unchanged at 2 years after burning. Three different approaches are recommended for post-fire land management: 1) farmers should not cut and remove the weeds and grasses at the soil surface, 2) burning should be performed around late winter or early summer (November–February) to inhibit complete combustion, and 3) contour-felled log erosion barriers should be made by using the trunks remaining after the fire to trap the sediment and slow down surface runoff.

Trends of source apportioned PM2.5 in Tianjin over 2013–2019: Impacts of Clean Air Actions

A long-term (2013–2019) PM2.5 speciation dataset measured in Tianjin, the largest industrial city in northern China, was analyzed with dispersion normalized positive matrix factorization (DN-PMF). The trends of source apportioned PM2.5 were used to assess the effectiveness of source-specific control policies and measures in support of the two China's Clean Air Actions implemented nationwide in 2013–2017 and 2018–2020, respectively. Eight sources were resolved from the DN-PMF analysis: coal combustion (CC), biomass burning (BB), vehicular emissions, dust, steelmaking and galvanizing emissions, a mixed sulfate-rich factor and secondary nitrate. After adjustment for meteorological fluctuations, a substantial improvement in PM2.5 air quality was observed in Tianjin with decreases in PM2.5 at an annual rate of 6.6%/y. PM2.5 from CC decreased by 4.1%/y. The reductions in SO2 concentration, PM2.5 contributed by CC, and sulfate demonstrated the improved control of CC-related emissions and fuel quality. Policies aimed at eliminating winter-heating pollution have had substantial success as shown by reduced heating-related SO2, CC, and sulfate from 2013 to 2019. The two industrial source types showed sharp drops after the 2013 mandated controls went into effect to phaseout outdated iron/steel production and enforce tighter emission standards for these industries. BB reduced significantly by 2016 and remained low due to the no open field burning policy. Vehicular emissions and road/soil dust declined over the Action's first phase followed by positive upward trends, showing that further emission controls are needed. Nitrate concentrations remained constant although NOX emissions dropped significantly. The lack of a decrease in nitrate may result from increased ammonia emissions from enhanced vehicular NOX controls. The port and shipping emissions were evident implying their impacts on coastal air quality. These results affirm the effectiveness of the Clean Air Actions in reducing primary anthropogenic emissions. However, further emission reductions are needed to meet global health-based air quality standards.

Chemical composition and potential sources of PM2.5 in Hanoi

The chemical composition of PM2.5 was monitored simultaneously at two sites, one in a general area of the city center and one at a roadside, in Hanoi, Vietnam, during August 2019–July 2020 using 220 daily (24 h) filter samples. PM mass, water soluble ions, trace elements, organic and elemental carbon and sugar anhydrides were measured. The annual average PM2.5 concentrations, 49 and 46 μg m−3 at the traffic and the general urban site, respectively, exceeded the national (25 μg m−3) and 2021 WHO limit values (5 μg m−3). Daily PM2.5 concentrations were the highest in winter when stagnant meteorological conditions prevailed. On average, half of the resolved mass was organic matter, of which about 40% was attributable to biomass burning, most likely rice straw field burning and domestic fuel combustion. One third of PM2.5 was secondary inorganic aerosol which was dominated by sulphate hence indicating a high contribution of stationary sources like coal combustion. The elemental carbon level was higher at the traffic site, except in April 2020 during the COVID-19 restrictions. Zinc was the most common trace element with high daily variations and large differences between the sites, and it often peaked with Cd, Cl− and Pb indicating contribution of industrial sources and/or coal combustion. The highest zinc concentrations appeared on a few days and likely originated from open burning of municipal solid waste. It appeared that scattered open waste and biomass burning, as well as coal combustion, are important sources causing spikes of PM2.5 pollution in Hanoi above the general levels caused by routine industrial and traffic sources, especially during stagnant winter days. Source contributions were further studied with positive matrix factorization producing six source factors: traffic (12%), local secondary inorganic aerosol (SIA, 18%), biomass burning (19%), industry (9%), long-range transported SIA (25%) and dust (17%).

A sustainable approach for soil amendment; available plant nutrients in rice straws

The main aim of this study is to estimate the potential of mitigating the soil degradation by the utilization of rice straws, In every crop huge quantity of crop residue is generated along with the food grains. Only small part of the crop residue is used as cattle feed and other applications, significant quantity of these crop residues are either left unutilized or disposed by means of open field burning by the farmers, because other disposal options are not economically viable for the farmers. Consequences of open field burning of crop residues in India are, contribution of particulate matter in the atmosphere, emission of CO2, CO, NH3, NOx, SOx, and smog. On burning of crop residue heat produced is also accounted for the damage of microbes and other nutrients also present on the top layer of the soil, loss of organic carbon; it adversely affects soil fertility and productivity. It has a great economic potential as it contains high carbon content and significant amount of other essential plant nutrients which are required for plant growth. Sun dried rice straw samples were collected and analysed for primary nutrients (C, H, S, N, P2O5 and K2O) required for plant growth. Moisture content was 11.70%, Elemental analysis of paddy straw on dry basis was found C = 36.04%, H = 5.25%, S = 0.28% & N = 0.69% P2O5 = 0.43% and K2O = 0.64% in the kharif season 2021. These elements were quantified by using different advanced analytical techniques.

Recent Trends, Opportunities and Challenges in Sustainable Management of Rice Straw Waste Biomass for Green Biorefinery

Waste rice straw biomass and its burning in open fields have become a serious issue of greenhouse gases emission and air pollution, which has a negative impact on public health and the environment. However, the environmental impact of burning this agro-waste can be mitigated by diverting it towards green biorefinery through the sustainable production of energy, biofuels, organic chemicals, and building blocks for various polymers. This will not only help to reduce the reliance on limited fuels and various chemicals derived from petroleum, but also help in the restoration of the environment in a sustainable manner through its complete utilization. To maximize the inherent conversion potential of rice straw biomass into valuable products, this agriculture waste biomass requires a comprehensive analysis and a techno-economic review for its sustainable management. This review article focuses on the sustainable management of rice straw waste biomass via innovative valorization approaches, as well as the opportunities and challenges encountered in this sector for meeting the demand of current and future green biorefineries.

Feasibility of 10 MW Biomass-Fired Power Plant Used Rice Straw in Cambodia

This study investigates the feasibility of rice straw for energy production in Cambodia. The potential areas for a 10 MW biomass-fired power plant installation are estimated based on rice straw availability displayed in a graphic information system (GIS). The discounted cash flow (DCF) method on the profitability index (PI) was executed by Mathlab software, which was used to determine the period of the power plant profitability. The reduction of CO and CO2 emissions from the proposed rice straw biomass-fired power plant with 10 MW capacity was calculated and compared with the coal-fired power plant and open field burning. Prey Veng, Takeo, and Battambang are potential provinces that have an estimated rice straw source of 804,796 t/annum, 720,040 t/annum, and 603,273 t/annum, respectively. Within a 20-year project, the biomass-fired power plant can reach profitability between six and ten years with the operation of the rice-straw price of 20 USD/t to 40 USD/t. The total energy produced by these potential areas is 1251 GWh/annum, with a CO2 emission avoidance of 1.06 million t/annum compared to the coal-fired power plant operation. Simultaneously, the emission savings of the biomass-fired power plant compared to open-field burning are 0.61 million t/annum of CO2 and 0.02 million t/annum of CO in the study site. The findings are prospectively essential for further designing of a small-scale biomass-fired power plant in Cambodia.

Paddy Straw Management Practices

Paddy straw is one of the organic materials and natural residues obtained from the paddy crop. It is the third largest crop remanant obtained from the agriculture after sugarcane bagasse and maize straw. Storage of the surplus paddy straw, removal of entire straw from the field and very little time between the cultivation of the next crop are the major issues associated with paddy straw. Thus, stubble burning is a quickest, cheapest and easiest way to prepare field for the next crop. Burning of paddy straw results in extensive impact on both on and off farm, e.g., killing of useful microflora and fauna of the soil, losses of soil organic matter and contribution to harmful greenhouse gases including their harmful effects on human and animal health. Therefore, paddy straw burning is a major issue of environmental pollution also. Hence, need of the hour is to provide environment friendly alternatives to paddy straw instead of burning in open field. Paddy straw can be used as a source of energy, mulching material, biofuel, industrial raw material, fodder for animals, etc.

Utilization of Rice Straw into Bioethanol through Biological Pathways

The increasing burning of fossil fuels and changes in land use and forestry increase the CO2 in the earth's atmosphere. This condition increases the earth's global temperature, thus causing climate change. In addition, the volume of rice straw waste is very abundant, and the most popular treatment is burning in rice fields. This process also contributes to air pollution and an increase in CO2 gas. Meanwhile, straw is lignocellulosic biomass containing cellulose and hemicellulose as a source of sugar to be converted into bioethanol. Lignocellulosic biomass conversion consists of three main stages, pretreatment, hydrolysis, and fermentation. The process of converting rice straw into bioethanol has been developed. However, the current obstacle is that the conversion process requires high energy, produces chemical waste, and is not environmentally friendly. A biological approach is preferred so that the rice straw conversion process becomes more sustainable. This paper reviews the pretreatment, hydrolysis, and fermentation processes in biologically converting rice straw into bioethanol. Thus it is expected to be able to respond to existing challenges through a biological and more environmentally friendly approach.

Забруднення угідь унаслідок бойових дій: огляд рішень для подолання кризи

The purpose of this work is to analyze the types of pollution on the lands that have undergone hostilities and to review scientific research on this topic in order to find rational technological solutions to overcome the crisis. Methods and materials. The study is aimed at reviewing open scientific literary sources regarding the contamination of agricultural lands affected by the conduct of military operations. The research focuses on physical and chemical disturbances in the soil caused by military actions (bombing of land, land contamination by shrapnel remains, soil compaction by military equipment, chemical pollution by heavy metals, etc.) and land restoration methods. Research results. The primary task in eliminating the consequences of hostilities is the demining of land areas. There is a wide range of types of means for finding mines and machines for demining, in which the working body can be a reactive explosive device or a mechanical system in the form of a bucket, rollers of a rotating rotor, etc. Reclamation of lands disturbed as a result of military operations is carried out in two stages: technical and biological. The essence of the technical stage is to prepare the territories for the next target use. It consists in planning, as well as applying soil or fertile rocks to a leveled surface. The biological stage is a set of measures to restore the fertility of disturbed lands. It covers agrotechnical and reclamation measures aimed at restoring flora and fauna. To overcome the consequences of soil pollution by oil products and to compensate for nitrogen losses on land due to burning of fields, it is advisable to use active oil-oxidizing and regenerating soil microorganisms, by applying them with tillage and seeding units equipped with devices for applying liquid and dry complex fertilizers. Conclusions. Among the practical agrotechnical approaches to soil restoration after rough reclamation of land, the following can be distinguished: cultivation of bioenergy crops on damaged lands; application of minimal tillage technologies using organic waste and microbiological preparations; biotechnologies of soil remediation. In view of the technical and technological solutions of soil treatment for land restoration, each of the following consequences requires a special approach. Reclamation of damaged lands is advisable when experts estimate the terms of restoration of economic activity at no more than 15 years. If the soil cover needs a longer period for recovery, land conservation is carried out. Key words: soil pollution, hostilities, reclamation, remediation, land reclamation, soil treatment.