Agronomic values of greenwaste biochar as a soil amendment
TL;DR: In this article, a pot trial was carried out to investigate the effect of biochar produced from greenwaste by pyrolysis on the yield of radish and the soil quality of an Alfisol.
Abstract: A pot trial was carried out to investigate the effect of biochar produced from greenwaste by pyrolysis on the yield of radish (Raphanus sativus var. Long Scarlet) and the soil quality of an Alfisol. Three rates of biochar (10, 50 and 100 t/ha) with and without additional nitrogen application (100 kg N/ha) were investigated. The soil used in the pot trial was a hardsetting Alfisol (Chromosol) (0–0.1 m) with a long history of cropping. In the absence of N fertiliser, application of biochar to the soil did not increase radish yield even at the highest rate of 100 t/ha. However, a significant biochar × nitrogen fertiliser interaction was observed, in that higher yield increases were observed with increasing rates of biochar application in the presence of N fertiliser, highlighting the role of biochar in improving N fertiliser use efficiency of the plant. For example, additional increase in DM of radish in the presence of N fertiliser varied from 95% in the nil biochar control to 266% in the 100 t/ha biochar-amended soils. A slight but significant reduction in dry matter production of radish was observed when biochar was applied at 10 t/ha but the cause is unclear and requires further investigation. Significant changes in soil quality including increases in pH, organic carbon, and exchangeable cations as well as reduction in tensile strength were observed at higher rates of biochar application (>50 t/ha). Particularly interesting are the improvements in soil physical properties of this hardsetting soil in terms of reduction in tensile strength and increases in field capacity.
Citations
More filters
TL;DR: A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins as mentioned in this paper.
Abstract: Soil amendment with biochar is evaluated globally as a means to improve soil fertility and to mitigate climate change. However, the effects of biochar on soil biota have received much less attention than its effects on soil chemical properties. A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins. However, no studies exist in the soil biologyliterature that recognize the observed largevariations ofbiochar physico-chemical properties. This shortcoming has hampered insight into mechanisms by which biochar influences soil microorganisms, fauna and plant roots. Additional factors limiting meaningful interpretation of many datasets are the clearly demonstrated sorption properties that interfere with standard extraction procedures for soil microbial biomass or enzyme assays, and the confounding effects of varying amounts of minerals. In most studies, microbial biomass has been found to increase as a result of biochar additions, with significant changes in microbial community composition and enzyme activities that may explain biogeochemical effects of biochar on element cycles, plant pathogens, and crop growth. Yet, very little is known about the mechanisms through which biochar affects microbial abundance and community composition. The effects of biochar on soil fauna are even less understood than its effects on microorganisms, apart from several notable studies on earthworms. It is clear, however, that sorption phenomena, pH and physical properties of biochars such as pore structure, surface area and mineral matter play important roles in determining how different biochars affect soil biota. Observations on microbial dynamics lead to the conclusion of a possible improved resource use due to co-location of various resources in and around biochars. Sorption and therebyinactivation of growth-inhibiting substances likelyplaysa rolefor increased abundance of soil biota. No evidence exists so far for direct negative effects of biochars on plant roots. Occasionally observed decreases in abundance of mycorrhizal fungi are likely caused by concomitant increases in nutrient availability,reducing theneedfor symbionts.Inthe shortterm,therelease ofavarietyoforganic molecules from fresh biochar may in some cases be responsible for increases or decreases in abundance and activity of soil biota. A road map for future biochar research must include a systematic appreciation of different biochar-types and basic manipulative experiments that unambiguously identify the interactions between biochar and soil biota.
3,612 citations
Cites background or methods from "Agronomic values of greenwaste bioc..."
...In a pot trial with a hard-setting Chromisol (an Alfisol in USDA nomenclature), Chan et al. (2007) found a decrease in soil tensile strength from an initial, biochar-free value of 64.4 kPae31 kPa at an amendment rate of 50 t biochar ha 1; the tensile strength was again reduced to 18 kPa at 100 t…...
[...]
...…Chromisol (an Alfisol in USDA nomenclature), Chan et al. (2007) found a decrease in soil tensile strength from an initial, biochar-free value of 64.4 kPae31 kPa at an amendment rate of 50 t biochar ha 1; the tensile strength was again reduced to 18 kPa at 100 t biochar ha 1 (Chan et al., 2007)....
[...]
TL;DR: The maximum sustainable technical potential of biochar to mitigate climate change is estimated, which shows that it has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset.
Abstract: Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO 2 ), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO 2 -C equivalent (CO 2 -C e ) per year (12 % of current anthropogenic CO 2 -C e emissions; 1 Pg = 1 Gt), and total net emissions over the course of a century by 130 Pg CO 2 -C e , without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset.
1,893 citations
TL;DR: In this paper, a review aims to determine the extent to which inferences of experience mostly from tropical regions could be extrapolated to temperate soils and to suggest areas requiring study.
Abstract: Natural organic biomass burning creates black carbon which forms a considerable proportion of the soil’s organic carbon. Due to black carbon’s aromatic structure it is recalcitrant and has the potential for long-term carbon sequestration in soil. Soils within the Amazon-basin contain numerous sites where the ‘dark earth of the Indians’ (Terra preta de Indio, or Amazonian Dark Earths (ADE)) exist and are composed of variable quantities of highly stable organic black carbon waste (‘biochar’). The apparent high agronomic fertility of these sites, relative to tropical soils in general, has attracted interest. Biochars can be produced by ‘baking’ organic matter under low oxygen (‘pyrolysis’). The quantities of key mineral elements within these biochars can be directly related to the levels of these components in the feedstock prior to burning. Their incorporation in soils influences soil structure, texture, porosity, particle size distribution and density. The molecular structure of biochars shows a high degree of chemical and microbial stability. A key physical feature of most biochars is their highly porous structure and large surface area. This structure can provide refugia for beneficial soil micro-organisms such as mycorrhizae and bacteria, and influences the binding of important nutritive cations and anions. This binding can enhance the availability of macro-nutrients such as N and P. Other biochar soil changes include alkalisation of soil pH and increases in electrical conductivity (EC) and cation exchange capacity (CEC). Ammonium leaching has been shown to be reduced, along with N2O soil emissions. There may also be reductions in soil mechanical impedance. Terra preta soils contain a higher number of ‘operational taxonomic units’ and have highly distinctive microbial communities relative to neighbouring soils. The potential importance of biochar soil incorporation on mycorrhizal fungi has also been noted with biochar providing a physical niche devoid of fungal grazers. Improvements in soil field capacity have been recorded upon biochar additions. Evidence shows that bioavailability and plant uptake of key nutrients increases in response to biochar application, particularly when in the presence of added nutrients. Depending on the quantity of biochar added to soil significant improvements in plant productivity have been achieved, but these reports derive predominantly from studies in the tropics. As yet there is limited critical analysis of possible agricultural impacts of biochar application in temperate regions, nor on the likelihood of utilising such soils as long-term sites for carbon sequestration. This review aims to determine the extent to which inferences of experience mostly from tropical regions could be extrapolated to temperate soils and to suggest areas requiring study.
1,787 citations
Cites background from "Agronomic values of greenwaste bioc..."
...Improvements in soil field capacity have been recorded upon biochar addition (Chan et al. 2007)....
[...]
...…soil alkalisation which can increase soil nitrification (Lehmann et al. 2003b; Oguntunde et al. 2004; Topoliantz and Ponge 2005; Yamato et al. 2006; Chan et al. 2007; DeLuca et al. 2009; Hua et al. 2009; Major et al. 2010a, b), but increases in soil nitrification rates do not rely solely on soil…...
[...]
...Certain soils, particularly when dry, limit root penetration at depth and can be improved through biochar application (Chan et al. 2007)....
[...]
...…indicated that when biochar incorporation takes place with the addition of N fertilisers growth stimulation can be synergistic (Steiner et al. 2007; Chan et al. 2007; Chan et al. 2008; Asai et al. 2009), Nutrient bioavailability and plant uptake of P, as well as K, Ca, Zn and Cu have in some cases…...
[...]
TL;DR: In this paper, a statistical meta-analysis was performed with the aim of evaluating the relationship between biochar and crop productivity (either yield or above-ground biomass) with an overall small, but statistically significant, benefit of biochar application to soils on crop productivity, with a grand mean increase of 10%.
1,762 citations
TL;DR: The potential to sequester carbon as thermally stabilized (charred) biomass using existing organic resource is estimated to be at least 1 Gt/yr − 1 and biochar, defined by its useful application to soil, is expected to provide a benefit from enduring physical and chemical properties.
Abstract: Agricultural activities and soils release greenhouse gases, and additional emissions occur in the conversion of land from other uses. Unlike natural lands, active management offers the possibility to increase terrestrial stores of carbon in various forms in soil. The potential to sequester carbon as thermally stabilized (charred) biomass using existing organic resource is estimated to be at least 1 Gt yr − 1 and “biochar,” defined by its useful application to soil, is expected to provide a benefit from enduring physical and chemical properties. Studies of charcoal tend to suggest stability in the order of 1000 years in the natural environment, and various analytical techniques inform quantification and an understanding of turnover processes. Other types of biochar, such as those produced under zero-oxygen conditions have been studied less, but costs associated with logistics and opportunity costs from diversion from energy or an active form in soil demand certainty and predictability of the agronomic return, especially until eligibility for carbon credits has been established. The mechanisms of biochar function in soil, which appear to be sensitive to the conditions prevailing during its formation or manufacture, are also affected by the material from which it is produced. Proposed mechanisms and some experimental evidence point to added environmental function in the mitigation of diffuse pollution and emissions of trace gases from soil; precluding the possibility of contaminants accumulating in soil from the incorporation of biochar is important to ensure safety and regulatory compliance.
1,745 citations
Cites background from "Agronomic values of greenwaste bioc..."
..., 2008) and ‘‘green waste’’ (Chan et al., 2007)—and indicator plants (radish) in pot experiments making comparisons against the function of the charcoal difficult....
[...]
...Results from semi-arid soils in Australia have shown positive response to biochar in combination with fertilizer in pot trials (Chan et al., 2007), and in Indonesia maize and peanut yields were enhanced where bark charcoal was applied in combination with N fertilizer in the field (Yamato et al....
[...]
References
More filters
Book•
01 Jan 1996
TL;DR: The Australian Soil Classification as mentioned in this paper provides a framework for organizing knowledge about Australian soils by allocating soils to classes via a key, and has been widely adopted and formally endorsed as the official national system.
Abstract: The Australian Soil Classification provides a framework for organising knowledge about Australian soils by allocating soils to classes via a key. Since its publication in 1996, this book has been widely adopted and formally endorsed as the official national system. It has provided a means of communication among scientists and land managers and has proven to be of particular value in land resource survey and research programs, environmental studies and education.
Classification is a basic requirement of all science and needs to be periodically revised as knowledge increases. This third edition of The Australian Soil Classification includes updates from a working group of the National Committee on Soil and Terrain (NCST). The main change in this edition accommodates new knowledge and understanding of the significance, nature, distribution and refined testing for soils comprising deep sands, leading to the inclusion of a new Order, the Arenosols. The introduction of the Arenosols Order led to a review and changes to Calcarosols, Tenosols and Rudosols.
The Australian Soil Classification is Volume 4 in the Australian Soil and Land Survey Handbook Series.
2,940 citations
01 Jan 1992
Abstract: This handbook of chemical tests for diagnostic, agricultural, and environmental purposes promotes the use of consistent methods, procedures and terminologies in soil and land surveys undertaken throughout Australia. Soil and water chemical methods include sampling and sample preparation, and measuring electrical conductivity and pH. Soil analysis includes: chloride, carbon, nitrogen, phosphorus, sulfur, gypsum, Other CABI sites
2,597 citations
"Agronomic values of greenwaste bioc..." refers methods in this paper
...The samples <2mm were then analysed for pH, total carbon, total nitrogen, extractable phosphorus (Colwell), and exchangeable cations following Rayment and Higginson (1992); pH was measured in 1 : 5 soil/0....
[...]
...The samples <2 mm were then analysed for pH, total carbon, total nitrogen, extractable phosphorus (Colwell), and exchangeable cations following Rayment and Higginson (1992); pH was measured in 1 : 5 soil/0.01 M CaCl2 extract; total carbon and total nitrogen were measured by combustion method;…...
[...]
TL;DR: A forum to review, analyze and stimulate the development, testing and implementation of mitigation and adaptation strategies at regional, national and global scales as mentioned in this paper, which contributes to real-time policy analysis and development as national and international policies and agreements are discussed.
Abstract: ▶ Addresses a wide range of timely environment, economic and energy topics ▶ A forum to review, analyze and stimulate the development, testing and implementation of mitigation and adaptation strategies at regional, national and global scales ▶ Contributes to real-time policy analysis and development as national and international policies and agreements are discussed and promulgated ▶ 94% of authors who answered a survey reported that they would definitely publish or probably publish in the journal again
2,587 citations
"Agronomic values of greenwaste bioc..." refers background in this paper
...Apart from the carbon offset due to the production of biofuel, the relatively stable nature of biochar material also could have carbon sequestration value (Lehmann et al. 2006)....
[...]
TL;DR: The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is pro- posed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems.
Abstract: The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is pro- posed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver im- mediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C compared to the low amounts retained after burning (3%) and biological decomposition (<10-20% after 5-10 years), therefore yielding more stable soil C than burning or direct land application of biomass. This efficiency of C conversion of biomass to bio-char is highly dependent on the type of feedstock, but is not significantly affected by the pyrolysis temperature (within 350-500 ◦ C common for pyrolysis). Existing slash-and- burn systems cause significant degradation of soil and release of greenhouse gases and opportunies may exist to enhance this system by conversion to slash-and-char systems. Our global analysis revealed that up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set annually in soil, if slash-and-burn is replaced by slash-and-char. Agricultural and forestry wastes such as forest residues, mill residues, field crop residues, or urban wastes add a conservatively estimated 0.16 Pg C yr −1 . Biofuel production using modern biomass can produce a bio-char by-product through pyrolysis which results in 30.6 kg C sequestration for each GJ of energy produced. Using published projections of the use of renewable fuels in the year 2100, bio-char sequestration could amount to 5.5-9.5 Pg C yr −1 if this demand for energy was met through pyrolysis, which would exceed current emissions from fossil fuels (5.4 Pg C yr −1 ). Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.
2,553 citations
TL;DR: In this paper, the authors reviewed the available information about the physical and chemical properties of charcoal as affected by different combustion procedures, and the effects of its application in agricultural fields on nutrient retention and crop production.
Abstract: Rapid turnover of organic matter leads to a low efficiency of organic fertilizers applied to increase and sequester C in soils of the humid tropics. Charcoal was reported to be responsible for high soil organic matter contents and soil fertility of anthropogenic soils (Terra Preta) found in central Amazonia. Therefore, we reviewed the available information about the physical and chemical properties of charcoal as affected by different combustion procedures, and the effects of its application in agricultural fields on nutrient retention and crop production. Higher nutrient retention and nutrient availability were found after charcoal additions to soil, related to higher exchange capacity, surface area and direct nutrient additions. Higher charring temperatures generally improved exchange properties and surface area of the charcoal. Additionally, charcoal is relatively recalcitrant and can therefore be used as a long-term sink for atmospheric CO2. Several aspects of a charcoal management system remain unclear, such as the role of microorganisms in oxidizing charcoal surfaces and releasing nutrients and the possibilities to improve charcoal properties during production under field conditions. Several research needs were identified, such as field testing of charcoal production in tropical agroecosystems, the investigation of surface properties of the carbonized materials in the soil environment, and the evaluation of the agronomic and economic effectiveness of soil management with charcoal.
2,514 citations
"Agronomic values of greenwaste bioc..." refers background in this paper
...Second, biochars can potentially be used as soil amendments for improving the quality of agricultural soils (Glaser et al. 2002a, 2002b; Lehmann et al. 2003)....
[...]
...Beneficial effects of biochar in terms of increased crop yield and improved soil quality have been reported (e.g. Iswaran et al. 1980; Glaser et al. 2002a, 2002b)....
[...]
...(Glaser et al. 2002a)....
[...]