Agricultural Crop Residues Research Articles

Influence of activation conditions on the physicochemical properties of activated biochar: a review

The biochar produced from agricultural crop residues through thermochemical processes helps in crop waste management. Biochar has paid more attention due to its distinctive features such as high organic carbon content, stable structure, large surface area, and cation exchange capacity. The biochar obtained from crop residues can be readily converted into activated biochar. This review paper systematically summarised the preparation of activated biochar, characterisation, and analytical techniques of activated biochar based on more than 150 literatures published in the last 10 years. The physicochemical properties of activated biochar varies according to the type of feedstock, pyrolysis condition, and mode of activation. The selection of the activation method mainly depends on its further end environmental application. Physical activation or steam purging at high temperature creates pores inside biochar. Gas purging increases the surface area and pore volume, although steam activation is not much suitable to improve the BC surface functionality as compared to chemical and impregnation activation. Sulphuric and oxalic acid–modified biochar was found to be most suitable for the soil amendment. Alkaline activation enhances the surface area and oxygen-containing functional group in activated biochar. Metal oxide–modified biochar had better surface functionalities than did physical- and chemical-activated biochar and better sorption of organic and inorganic contaminants from potable water and waste water. In summary, activated biochar has a wide environmental prospect in remediation.

Agricultural crop residue burning and its environmental impacts and potential causes – case of northwest India

This study aims to examine the adverse environmental impact and potential causes of the dubious agricultural practice of agricultural crop residue (ACR) burning which prevails in the northwest region of India. It also evaluates the alternatives for sustainable management of ACR and investigates the associated policy as well as functional challenges against the widespread adoption of these alternatives. To achieve the research purpose, a field study was conducted at the Panipat district of Haryana. As a part of this three-month-long field study, the outlook of state and local administration responsible for regulating ACR burning practices was obtained through semi-structured interviews. Additionally, farmers’ viewpoints were gathered through focus group interviews. The estimates of atmospheric emissions from ACR burning in Panipat were calculated using the United Nation (UN)’s Intergovernmental Panel on Climate Change (IPCC) guidelines. Strategies for mitigating the environmental impact of ACR burning are recommended.

Supply of agricultural biomass residues for on-farm composting: a cross-analysis of relevant data sets for the most sustainable management combination

ABSTRACT Agricultural crop production can generate significant residues and their management is generally a disposal problem. Composting can be a solution. It is essentially an efficient bioconversion technique to process organic wastes (manure, food, crop and forestry residues, solid digestate) into humus-like substances destined to different uses (soil amendment, organic fertilization, plant nursery substrates). Life Cycle Assessment, Energy Analysis, and Life Cost Costing were used to perform a cross-analysis aimed to assess the environmental, economic, and energy sustainability of some procurement systems of compostable materials (bulking agents and agricultural crop residues) to be allocated to composting on the farm. The procurement systems were characterized by different mechanization levels in order to explore the possible scenarios related to the availability of vehicles within the farm and increasing transport distances. Our findings underline that the most sustainable option for the environment it was not often the most cost-effective choice. Therefore, the cross-analysis of these relevant data sets allowed us to detail the different operative steps and guide the procurement system choice toward those showing the best compromise for both the environment and farmers (cheaper, with no or low impactful).

Wheat straw and its biochar differently affect soil properties and field-based greenhouse gas emission in a Chernozemic soil

A 2-year field study was conducted to compare the effect of wheat straw, its biochar, and wheat straw plus biochar addition on soil fluxes of CO2, CH4, and N2O during the growing season, and soil properties and crop yield in a Black Chernozemic soil planted to barley (Hordeum vulgare L.) in central Alberta, Canada. The objective was to assess the benefit of applying biochar instead of its feedstock, wheat straw, in improving environmental sustainability. Biochar addition did not affect soil CH4 oxidation, but decreased CO2 and N2O emissions as compared with both wheat straw applied alone and wheat straw and biochar applied together in 2010 and 2011 (p < 0.001), and resulted in a lower global warming potential, indicating that the biochar was effective in mitigating greenhouse gas (GHG) emission from the agricultural soil, as a result of biochar suppressing soil microbial activity and reducing soil N availability. Biochar application reduced N2O emission over 2 years, indicating its longer-term impact. Biochar application alone increased barley yield by 9.9 to 20.4% as compared to the other three treatments, thus reducing yield-scaled greenhouse gas emission intensity by 27.2 to 50.9% (p = 0.013 for the control and p < 0.001 for both wheat straw–amended treatments), with an average reduction of 3.43 t CO2-eq t−1 grain. The application of both wheat straw and its biochar reduced the temperature sensitivity of soil CO2 emission (Q10, p < 0.001), but the application of wheat straw or its biochar alone did not affect Q10, indicating that biochar application reduces the sensitivity to temperature changes of the decomposition of the new organic matter added to the soil. We conclude that (1) the application of wheat straw–derived biochar was preferred to raw wheat straw in mitigating GHG emission and (2) biochar can be an effective management strategy for properly handling crop residues in sustainable agriculture.

Vertisols and Cambisols had contrasting short term greenhouse gas responses to crop residue management

In sustainable agriculture crop residues management should consider the interactions between soil and residue properties, which can affect the decomposition and global greenhouse gases (GHGs) emission. Through a laboratory experiment, we investigated the effect of the management (incorporation and surface placement) of wheat and faba bean residues on their decomposition and CO&lt;sub&gt;2&lt;/sub&gt;, CH&lt;sub&gt;4&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O emissions from two soils, a Chromic Vertisol and an Eutric Cambisol. In the Vertisol, wheat residues increased the CO&lt;sub&gt;2&lt;/sub&gt; emission more than faba bean when left on the surface whereas no differences among residues were observed when incorporated. In the Cambisol, faba bean emitted more than wheat when left in the surface and less when incorporated. Total CH&lt;sub&gt;4&lt;/sub&gt; emissions were higher in faba bean in Cambisol for both management and only when applied in the surface in Vertisol. Total N&lt;sub&gt;2&lt;/sub&gt;O emission in the Vertisol was higher when faba bean was incorporated, and wheat was left on the surface. In the Cambisol, wheat addition increased total N&lt;sub&gt;2&lt;/sub&gt;O emissions by 20% compared to faba bean, with no differences between managements. Our study confirmed that contrasting properties among tested soils resulted in significant interactions with residues own degradability and their placement affecting residue decomposition, soil C and N dynamics, and GHGs emission.

Potential of pineapple wastes for Pectin recovery: A path towards waste valorization

Majority of agricultural wastes and crop residues like cereal brans, sugarcane bagasse, peels, pomace and sugar beet pulp act as the vital sources for natural production of biochemicals. The production of natural pectin from various agro-wastes can be focused as the major biotechnological tool taking much demand against the chemical production processes. Investigation was carried out for conversion of pineapple wastes towards isolation of pectin as a part of waste management. About 60% of total pineapple fruit is regards as waste in form of peel, core, pomace and crown. Maximum pectin was detected from pomace part of the pineapple.

Pyrolysis of wheat and barley straw

Pyrolysing agricultural crop residues and other biomass constitutes a newer method of transforming often difficult, waste materials into a novel type of soil amendment/additive. Simultaneously, this process also makes it possible to exploit part of the energy released in the agricultural production. Biochar, viewed as the solid product of biomass pyrolysis, is a remarkable, porous material, rich in carbon. Two agricultural crop residues, such as wheat and barley straw, were selected for the experimental studies. The results indicate that the practical temperature for the production of biochar from the two explored materials occurs in the vicinity of 600 °C. Starting at this temperature, the biochar produced complies safely with the principal European Biochar Certificate standards (EBC 2012). Thus, for the wheat straw and barley straw – originated char, the content of the carbon amounts to 67.2 and 67.0 mass %, the atomic ratio H : C is as large as 0.032 and 0.026, and the specific surface area amounts to 217 and 201 m&lt;sup&gt;2&lt;/sup&gt;·g&lt;sup&gt;–1&lt;/sup&gt;, respectively.

Erratum for “Water Repellency and Hydrophobicity of Some Major Agricultural Crop Residues”, by Miller et al., Agron. J. 111:3008–3019

Erratum for “Water Repellency and Hydrophobicity of Some Major Agricultural Crop Residues”, by Miller et al., Agron. J. 111:3008–3019

Hydrothermal gasification of soybean straw and flax straw for hydrogen-rich syngas production: Experimental and thermodynamic modeling

Biofuels produced from lignocellulosic feedstocks are gaining popularity because of the elevating energy demand, increasing greenhouse gas emissions, escalating fuel prices and dwindling fossil fuel resources. Therefore, it has become important to seek alternative energy resources from renewable waste biomass. In this study, agricultural crop residues such as soybean straw and flax straw were gasified in subcritical water (300 °C) and supercritical water (400 and 500 °C) for H2 production. To maximize the non-catalytic process, the impacts of temperature (300–500 °C), biomass-to-water ratio, BTW (1:5 and 1:10), biomass particle size (0.13 mm and 0.8 mm) and residence time (30–60 min) on H2 production were studied at a pressure range of 22–25 MPa. Maximum H2 yield and total gas yields of 6.62 mmol/g and 14.91 mmol/g, respectively were obtained from soybean straw at the highest temperature (500 °C), lower feed concentration (1:10 BTW), smaller particle size biomass (0.13 mm) and longer residence time (45 min). To evaluate the drift in the experimental H2 yield from the theoretical values, thermodynamic modeling using Gibbs free minimization method was performed. The experimental results showed slight deviations from the thermodynamic models due to the temperature gradient and absence of agitation in the tubular batch reactor. However, the KOH catalyst was found to elevate the H2, CO2 and CH4 yields for soybean straw and flax straw. The findings suggest that supercritical water gasification could be an efficient green technology for H2 production from waste biomass.

Synergistic effect of sugarcane scum as an accelerant co-substrate on anaerobic co-digestion with agricultural crop residues from non-centrifugal cane sugar agribusiness sector

Anaerobic co-digestion (AcoD) of the main residues from the non-centrifugal cane sugar (NCS) making process, agricultural crop residues (ACR) and sugarcane scum (SCS), was evaluated using biochemical methane potential tests. Substrates were pretreated: ACR through particle size reduction, and SCS with dilution. The maximum methane yield of 0.276 Nm3 CH4 kg−1 VSadded occurred at an ACR of 2 mm and at 12.5% dilution of SCS, at a ratio of 75:25 based on volatile solids, which was 30.2% and 5.9% higher compared to SCS and ACR in mono-digestion, respectively. ACR was a substrate of adequate buffer capacity for the AcoD stability, while the SCS, in addition to helping accelerate the process, also helped improve the inoculum's methanogenic and hydrolytic activity. The first-order kinetic and dual-pool two-step models were suitable to describe methane yield. AcoD of ACR with SCS is a good option for the treatment of streams in the NCS agribusiness sector.

Assessment of the modes of occurrence of trace elements in agricultural crop residues and their enrichments and bioavailability in bio-chars

This work investigates the modes of occurrence of trace elements in crop residues, their volatilities during pyrolysis, and bioavailability in bio-chars. Eight major elements (Na, K. Mg, Ca, Al, Si, Fe, and P) and 16 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Cd, Ba, and Pb) were determined. Many trace elements in the five crop residues (peanut straw, cotton straw, corn stalk, sorghum stalk, and reed) had higher concentrations than the average values of world reference plants, with significant correlations to specific major elements. Neutral extractives were a principal host of all of the trace elements detected. While hemicellulose and lignin contained some trace elements (Li, Be, V, Cr, Ni, and Ga), cellulose enclosed lesser trace elements, During the slow biomass pyrolysis at 550 °C, all trace elements except for highly volatile Se and Cd were concentrated in the bio-chars with the enrichment factors ranging in 1.6–2.9. Most trace elements in the bio-chars showed lower solubility in water but much higher dissolution in the ion-exchangeable or chelating solution. Results suggested that the bio-chars originated from crop residues can provide bioavailable nutrients as the essential elements for plants if used as an amendment of soils.

Potential uses and Role of Crop Residues in Agriculture

Potential uses and Role of Crop Residues in Agriculture

Techno-economic assessment of dry fermentation in household biogas units through co-digestion of manure and agricultural crop residues in Egypt

In rural Egypt, communities face multiple challenges such as insufficient infrastructures for waste treatment, limited access to cheap energy and poor soils fertility. A decentralized, low-tech biogas technology for combined waste treatment and energy production, anaerobic digestion can achieve many sustainable development goals and resolve many issues faced by rural communities, treating and stabilizing organic waste into high-quality biofertilizer. Household biogas units for rural communities, however, should be subjected to techno-economic assessment to confirm their feasibility and technical efficiency. Therefore, this paper conducted: (1) survey of household biogas units and agricultural crop residues in rural communities in Egypt, (2) technical study of household biogas units, and (3) financial economic study. The results can be summarized as follows: (1) complete set of technical data on biogas units were documented, (2) crop residues were mapped using GIS software, (3) financial feasibility results were discussed. The total revenues were 1716.01, 2574.02, 3432.02, and 5148.04 EUR for the household biogas unit with the capacity of 2, 3, 4, and 6 m3, respectively. It was concluded that the units available in rural Egypt are considered as profitable projects from the profitability perspectives, and the values of the profitability indicators increased as the unit size increased.

Carbonaceous aerosol emission reduction over Shandong province and the impact of air pollution control as observed from synthetic satellite data

Aerosol loading and trace gas emissions from agriculture crop residue burning has been one of the main factors leading to the deterioration of air quality especially during the harvest time in China. Here, we evaluate the contribution of atmospheric aerosol loading from biomass burning and its relationship to the air pollution control policy. We focused on Shandong province, China because it has the highest level of agriculture burning pollution in October. Satellite-based data related to biomass burning including aerosol optical depth (AOD) and fire pixel counts from Moderate Resolution Imaging Spectroradiometer (MODIS), carbon monoxide (CO) from Measurements Of Pollution In The Troposphere (MOPITT), aerosol index (AI) and tropospheric NO2 from Ozone Monitoring Instrument (OMI), and aerosol layer depths from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). These metrics were synthetically utilized to evaluate spatial and temporal variation of atmospheric aerosols during the agriculture crop residue burning month from 2006 to 2017. Carbonaceous aerosol emission reduction and the impact of the air pollution control policy can be found in the CALIPSO aerosol types and MODIS fire pixel counts data. The AOD, NO2, CO, and AI over three different land covers (cropland, forest and impervious surfaces) were further obtained according to the land cover data set. The results indicated that there was an obvious decrease in all carbonaceous aerosol-related quantities after year 2012 when the local government began to enact and implement strict air pollution control policies, although a period (2–3 years) of transition after the policy implementation time was identified. We also found that CO is stable and low over the cropland versus forest and impervious surfaces; NO2 exhibits a continuously high value in the northern areas of the oil field. The impact of industry activity rather than straw burning should be also considered for NO2 and CO in certain areas.

Water Repellency and Hydrophobicity of Some Major Agricultural Crop Residues

Water repellency of agricultural crop residues may affect the hydrologic balance and increase runoff loss of pesticides by greater wash off from hydrophobic residue. We conducted a laboratory study to measure water repellency and hydrophobicity of 30 major agricultural crops (grass, legume, cereal, oilseed, pulse, and specialty crops). Crop samples were collected in southern Alberta, Canada in 2017 and 2018. Water repellency (WR) of oven‐dried (60°C) and ground (&lt;2 mm) crop residues was measured using the water drop penetration time (WDPT) and molarity of ethanol (MED) tests. Hydrophobicity was evaluated using the ratio of hydrophobic CH– to hydrophilic CO–functional groups using Fourier Transform Infrared (FTIR) spectroscopy. The WDPTs of the 30 agricultural crops ranged from 8.3 to 2438 s, suggesting that crop species influenced WR of the dried and undecomposed residues. Needle‐and‐thread grass (Stipa comata Trin. and Rupr.), blue grama (Bouteloua gracilis [Kunth] Lag. ex Griffiths), and western wheatgrass (Agropyron smithii Rydb.) were the most WR crops based on WDPT. Fababean (Vicia faba), mustard (Sinapis alba L.), and sweet clover (Melilotus officinalis) were the least WR crops. Mean WDPTs were significantly (P ≤ 0.05) greater for grass than the other four crop types by 23 to 44 times. Significant differences in WDPT occurred among crop species within each of the six crop types. A significant positive correlation occurred between WDPT and hydrophobicity (r = 0.54), but not between WDPT and organic carbon. Overall, crop type and species may influence WR of crop residues and could affect the hydrologic balance.Core Ideas Agricultural crop species residue influenced water repellency and hydrophobicity Grass was the most water repellent and hydrophobic crop type A positive correlation occurred between water repellency and hydrophobicity The physical morphology of leaves may contribute to water repellency Water repellency differences also occurred for species within the six crop types

Livestock Occupational Extension of Farmers for Problems Solving Burning in Agricultural Zone: The Case Study of Mae Na Chon Sub-District, Mae Chaem District, Chiang Mai Province

Mae Chaem District, Chiang Mai Province is an agricultural zone and crop residues were burnt the most, especially in livestock and corn field area which later annually affected economics and society of Chiang Mai Province. This study was to support and to replace livestock occupation instead of corn plantation by using Participatory Action Research (PAR) with farmers from Mae NaChon Sub-Districts who voluntarily participated in this research until the end of the process. The study found that farmers needed livestock support including beef cattle, indigenous chicken, and fish. There are four actions: (1) co-brainstorming (2) co-planning (3) co-processing and (4) co-evaluation, which brought about six main activities: cattle breed support, basic knowledge lecture of livestock, corn husk fermentation as animal food, prototype farm project, basic accounting for farming, and building livestock farmer network in the area as motivation for farmer’s decision on area reduction or stopping corn plantation.

Elemental Composition of Biochar Obtained from Agricultural Waste for Soil Amendment and Carbon Sequestration

For an agricultural country such as Thailand, converting agricultural waste into biochar offers a potential solution to manage massive quantities of crop residues following harvest. This research studied the structure and chemical composition of biochar obtained from cassava rhizomes, cassava stems and corncobs, produced using a patented locally-manufactured biochar kiln using low-cost appropriate technology designed to be fabricated locally by farmers. The research found that cassava stems yielded the highest number of Brunauer-Emmett-Teller (BET) surface area in the biochar product, while chemical analysis indicated that corncobs yielded the highest amount of C (81.35%). The amount of H in the corncob biochar was also the highest (2.42%). The study also showed biochar produced by slow pyrolysis was of a high quality, with stable C and low H/C ratio. Biochar’s high BET surface area and total pore volume makes it suitable for soil amendment, contributing to reduced soil density, higher soil moisture and aeration and reduced leaching of plant nutrients from the rhizosphere. Biochar also provides a conducive habitat for beneficial soil microorganisms. The findings indicate that soil incorporation of biochar produced from agricultural crop residues can enhance food security and mitigate the contribution of the agricultural sector to climate change impacts.

Crop Residue Burning: Issue and Management for Climate-Smart Agriculture in NCR Region, India

Today India enjoys the second position worldwide in agricultural output and as well as plays a significant role in the overall socio-economic construction of India too. There is no doubt that intensive agriculture also plays a significant role in climate change over time. Today climate change becomes the major concern all over the globe. The main cause of climate change is the various anthropogenic activities, in these agricultural Crop Residue Burning (CRB) of rice and wheat crops has been identified as a major reason for climate change. This unwise practice as it leads to severe air pollution and emits traces of carbon dioxide, methane, carbon monoxide, nitrous oxide, and particulates which affect causing various respiratory and other health problems along with as a regional polluter as per various studies. In addition, it causes the loss of vital nutrients from the soil resulting in the loss of fertility and unviable for agriculture in the long run. Along with this CRB create visibility problems in vehicle driving which result in many road accidents every year. In a recent study it is estimated that India annually emissions of 824 Gg of Particulate Matter (PM2.5), 58 Gg of Elemental Carbon (EC) and 239 Gg of Organic Carbon (OC). Additionally, 211 Tg of CO2 equivalent greenhouse gases (CO2, CH4, N2O) were also added to the atmosphere. In this regarding Punjab and Haryana are the major contributor to air pollution due to residue burning. These two states contribute to 48 percent of the total emission due to paddy and wheat straw burning across India. Now the time has occurred to tackle this noxious practice with best management practices and capacity building of the farmer community to conserve the climate for the sustainable development of agriculture and the human race in developing country like India. Hence, an attempt has been made in this paper is to describe the current status and available alternative management practices like in situ agronomic management, new machineries viz., zero drill, happy seeder, straw baler as well as capacity building of farmer community for crop residue to minimize the climate change and soil infertility for sustainable on long-run basis.

Effect of using banana by-products and other agricultural residues for beef cattle in southern China.

Banana (Musa acuminata) by-products and other agricultural residues such as rice straw and sugarcane top are abundant in the southern part of China, but most of them are wasted and discarded. Under this experiment, several silages containing banana by-products with other crop residues were investigated for their fermentation characteristics and feeding values to beef cattle. There were three treatments (T) as follows: T1 = fresh banana by-products (FBBP) + 4% cornmeal (CM), T2 = FBBP + rice straw (RS) at 70:30 (fresh weight), T3 = FBBP + sugarcane top (SCT) at 70:30 (fresh weight). Twenty-one beef cattle bulls (220 ± 15kg body weight) were randomly assigned to 3 groups and assigned to one of three silage treatments in a total feeding period of 237days. Results revealed that all of the three silage mixtures had a good fermentative profile with lower pH and higher organic acids. The FBBP + CM group significantly increased DM, CP, EE, and Ca content (P <0.05), while decreased ash, NDF, ADF, ADL, and condensed tannins (CT) content (P < 0.01). Significant effects on weight gain, feed intake, and feed efficiency were observed at the end of the experiment (P < 0.05). The FBBP + CM group also had the greatest total weight gain at 109kg/head, twice of the FBBP + RS group (P = 0.001), as well as the greatest average daily weight gain at 0.48kg/head/day, followed by the FBBP + SCT group at 0.30kg/head/day and the FBBP + RS group at 0.27kg/head/day, respectively. Cattle fed FBBP + CM silage mixture diet had better feed efficiency than the cattle fed with the other mixtures (P < 0.001). Results of body measurements showed that cattle consumed FBBP + CM silage mixture tended to have a greater body diagonal length, height at the hip, hip width, and rump length than those either consumed FBBP + RS or FBBP + SCT (P < 0.05). The findings showed promising results of banana by-products silage with other agricultural crop residues to be used for increasing beef cattle production in southern China.

Crop Residue Management for Sustenance of Natural Resources and Agriculture Productivity

Crop residue management (CRM) through conservation agriculture can improve soil productivity and crop production by preserving soil organic matter (SOM) levels. Two major benefits of surface-residue management are improved organic matter (OM) near the soil surface and boosted nutrient cycling and preservation. Larger microbial biomass and activity near the soil surface act as a pool for nutrients desirable in crop production and enhance structural stability for increased infiltration. In addition to the altered nutrient distribution within the soil profile, changes also occur in the chemical and physical properties of the soil. Improved soil C sequestration through enhanced CRM is a cost-effective option for reducing agriculture's impact on the environment. Ideally, CRM practices should be selected to optimize crop yields with negligible adverse effects on the environment. Crop residues of common agricultural crops are chief resources, not only as sources of nutrients for subsequent crops but also for amended soil, water and air quality. Maintaining and managing crop residues in agriculture can be economically beneficial to many producers and more importantly to society. Improved residue management and reduced tillage practices should be encouraged because of their beneficial role in reducing soil degradation and increasing soil productivity. Thus, farmers have a responsibility in making management decisions that will enable them to optimize crop yields and minimize environmental impacts. Multi-disciplinary and integrated efforts by a wide variety of scientists are required to design the best site-specific systems for CRM practices to enhance agricultural productivity and sustainability while minimizing environmental impacts.