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BMe Research Grant |
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George A. Olah Doctoral School of Chemistry and Chemical Technology
BME Faculty of Chemical Technology and Biotechnology – Department of Applied Biotechnology and Food Science
Supervisor: Dr. Molnár Mónika
Innovative Soil Improvement with Biochar ‒ from the Laboratory to Field Demonstration
Introducing the research area
The objective of my PhD research is connected with the topic of the Terra Preta project (HU09-0029-A1-2013) aiming at innovative soil improvement and waste recovery. My work’s objective is the application of biochars produced by pyrolysis from various industrial and agricultural waste biomass feedstock to degraded soils’ improvement, and also characterizing their effects and mechanisms of action as soil additive and as microbial soil inoculant carrier.
In the frame of a tiered technology development, at first in laboratory microcosm experiments then in a field trial I study the influence of biochar alone and in combinations with various additives on the nutrient and water management properties [1, 2], biological activity of soils, the living conditions of soil microflora [3, 4], and soil fertility [5, 6].
The focus of my studies is set to the mechanisms by which biochar influences the soil’s biological status, the characterization and evaluation of microbial activity and diversity in soil, and the development and application of a methodology for their monitoring.
Brief introduction of the research place
The research takes place at the BME ABÉT Environmental Microbiology and Biotechnology Research Group. Over the past 20 years, the group pioneered in the development of engineering tools for environmental risk management, including innovative soil improvement and remediation technologies, environmental risk assessment and environmental toxicology.
History and context of the research
The large-scale growth of the world population brings about the increasing demand for food. However, with the expansion of densely populated areas soils may become overexploited, depleted, thus the condition of agricultural lands is constantly declining because of pollution, climate change and soil degradation processes. There are large sandy-soil areas in Hungary and around the world. These soils are colloid deficient, have low water holding capacity but high water permeability [7]; furthermore they’re nutrient deficient, unsuitable for agricultural cultivation, therefore their improvement is of great importance.
Another remarkable consequence of overpopulation is the increased growth of waste production and the humanity’s ecological footprint.
It is a key issue to reduce and reuse waste as well as improve the degraded soils’ quality in order to keep our planet alive. The ideal solution would be turning waste into useful material or energy, so a risk-oriented use of waste as a soil improver additive can be a good alternative (Figure 1).
Applying biochar in soil could be an environment-efficient solution with proper sustainability parameters to improve unfavourable and contaminated soils. However, the establishment and development of an efficient and risk-oriented technology application from environmental point of view require case-by-case assessment [8].
Figure 1: Risk-based waste management
Research goals, open questions
My doctoral research’s main question focuses on the effects of the joint application of biochar and soil inoculant on the properties of degraded (acidic) sandy soils (Figure 2).
Figure 2: Terra Preta Project
My primary objective was to develop a soil improvement technology to degraded sandy soils using large amounts of organic waste. As part of this objective, I applied an up-scaled technology development to analyse the biochar’s effects individually and in combination with other soil additives on the physico-chemical, biological, ecotoxicological properties and fertility of a degraded acidic sandy soil in the frame of a so-called integrated test methodology (Figure 3).
Figure 3: Complex integrated test method
The beneficial effects of biochars on soil include organic matter input, which results in improved soil water and nutrient retention [9], and also the biochar’s alkaline pH decreases acidity [10, 11, 12]. Highly important to note that we cannot define a general biochar applicability rate to soil since biochar characteristics and its effects on soil (Figure 4) is clearly dependent on biochar feedstock, production conditions (pyrolysis) and soil properties. So before applying biochar in soil improvement, a case-by-case survey is required, where possible toxic effects can also be explored using analytical and environmental toxicology methods [8].
Figure 4: Advantages and disadvantages of biochar
Methods
The scale-up development of biochar-mediated soil improvement covers the entire innovation chain, from the idea through biochar characterization and scale-up experiments to the field demonstration and the complex evaluation of technology (Figure 5).
Figure 5: Scale-up technology development steps
First, 13 biochar products prepared from different feedstock and by different pyrolysis techniques were analysed and characterized by an integrated methodology. Based on a multicriteria pre-screening method developed by us, we ranked the tested biochars for further experiments.
I performed laboratory microcosm experiments with the three best-performing biochar products. In doing so, I tested the effects of biochar, compost and fertilizer mixtures in different combinations and concentrations in 3 kg test vessels. As a result of the 8-week experiment, one product was selected (paper fibre sludge and grain husks) for application in the small field plot experiment.
During the field application it was possible to monitor soil-biochar interactions in real environment and the additives’ long-term effects (biochar and soil microbial inoculant). Biochars tested during the technology development were purchased from two producers, Sonnenerde GmbH. (Austria) and Pyreg GmbH. (Germany). The soil used in the experiments originates from Nyírlugos, located in eastern Hungary. It has low pH (pH=4.9), it’s poor in humus and nutrients, and is extremely sensitive to environmental adverse effects such as acidification, soil contamination and drought.
Since the environmental and risk-centred approach is of utmost importance in my research, I used an integrated methodology for monitoring and evaluating the technology efficiency (Figure 6). The methodology includes the following physico-chemical tests: dry matter content, water holding capacity, pH, electrical conductivity, loss of ignition, humus content, determination of toxic elements, and nutrient content measurement. In the frame of biological monitoring I determined the number of aerobic heterotrophic bacteria number, the fungi number, measured the substrate-induced soil respiration, and determined the microbial substrate utilization capacity as well as various biological enzymatic activities.
Figure 6: The integrated methodology used in the technology development
To assess and evaluate the potential toxic effects I performed Aliivibrio fischeri bioluminescence inhibition test, root and shoot inhibition test with white mustard (Sinapis alba) and common wheat (Triticum aestivum) as well as a Folsomia candida (Collembola) mortality test.
During the field experiment, the methodology was complemented with measurements and characterization of plant parameters (maize (Zea Mays)) to monitor the treatments’ effect on soil fertility. I used a one-variable statistical analysis of variance to determine the significant treatments.
Results
We developed an evaluation system to assess the biochars produced from 13 different feedstock under different pyrolysis conditions. Within this system a score was assigned to each biochar to express how they performed in various studied soil characteristics. Based on the total score and considering also the price and availability of the product additionally to its effects on soil, we set up a priority list to select the biochars potentially applicable as soil improvers.
Table 1: The biochars’ final rankings
Based on the scores (Table 1), the following biochars were selected (Figure 7): grain husks and paper fibre sludge (A1), wood screenings (B1) and post-treated grain husks and paper fibre sludge (A2). In the next step, the effects of these products on acidic sandy soil were studied with different combinations of compost and NPK sources in microcosm experiments.
Figure 7: Biochars used in the microcosms, A1, A2 and B1 respectively
With the integrated methodology, I monitored the processes in the soil, and similarly to the previous phase, I evaluated the results with a complex system, and then applying multicriteria scoring I set up a priority list showing the applicability and effectiveness of each treatment. The microcosm experiments have shown that in the short term, biochar produced from grain husks and paper fibre sludge has the most favourable effect on acidic sandy soil. It can be seen, that this biochar product resulted the most positive effects on its own and combined with other additives, so these treatments were given the highest score (Figures 8‒9).
Figure 8: Microcosm experiment results
Biochar addition resulted in a significant increase in soil microorganism concentration and most importantly, absolutely no toxic effects were measured on the bacterial-, plant- and animal species used as test organisms, and in some cases, it created a favourable environment for the test organisms. The habitat function of the soil has clearly improved: the Collembola tests and the plant tests showed 20‒40% stimulating effect.
Figure 9: Overall scores from microcosm experiment results
Microcosm experiments completed prior to the field application provided a good basis for field demonstration. Based on the results, biochar A1 was selected for the third phase of technological development, where the final testing of biochar was initiated in a small-field plot test in an experiment with multi-year span. This experiment aimed at the complex monitoring of long-term effects and soil-biochar interactions. Similar complex studies can scarcely be found in scientific literature.
Expected impact and further research
Our research was echoed both on professional platforms and in the media; two Student Scientific Seminar papers won 1st and 2nd special prizes on "K&H Bank ‒ For Sustainable Agriculture Fellowship". The Hungarian television channel M1 presented a recording with our group in the "Blue Planet" programme on this topic. In addition, we presented 3 oral lectures from our results at the Conference on Environmental Engineering and Management (Bologna, September 2017). I plan to publish the results covering the full experiment in impact factor journals, and to give further, oral presentations and also launching a scientific research blog on the topic.
Publications, references, links
Publications, conference presentations, conference issues:
Journal Article:
Molnár M, Vaszita E, Farkas É, Ujaczki É, Fekete-Kertész I, Tolner M, Klebercz O, Kirchkeszner Cs, Gruiz K, Uzinger N, Feigl V. (2016) Acidic sandy soil improvement with biochar—A microcosm study Science of the Total Environment 563‒564: 855‒865
Conference Presentations:
1. Soil improvement with biochar ‒ biochar’s effect on soil’s nitrification activity Innovation in Natural Sciences 2015 ‒ Conference of PhD Students, Szeged, Hungary, 26th September, 2015
2. Acidic soil improvement with biochar made from waste with pyrolisys, Conference of PhD Students on Environmental Sciences, Budapest, Hungary, 16th April, 2016
3. Éva Farkas, Enikő Takács, Viktória Feigl, Emese Vaszita, Csaba Kirchkeszner, Mónika Molnár, Innovative soil improvement and plant growth increase with eco-friendly additives at an eco-farm ‒ complex methodology to assess and evaluate the efficiency, VI. Ecotoxicology Conference, Budapest, Hungary, 18th November, 2016
Conference issues:
1. Éva Farkas, Enikő Takács, Viktória Feigl, Emese Vaszita, Csaba Kirchkeszner, Mónika Molnár, Innovative soil improvement and plant growth increase with eco-friendly additives at an eco-farm ‒ complex methodology to assess and evaluate the efficiency, VI. Ecotoxicology Conference, Budapest, Hungary, 18th November, 2016, VI. Ecotoxicology Conference, issue of presentations and posters. 44 p. Budapest, Hungarian Society of Ecotoxicology, 2016, pp. 12‒13 (ISBN:978-963-89452-6-6).
2. Kirchkeszner, Cs., Farkas, É., Uzinger, N., Rékási, M., Molnár, M. (2017) Investigation of the effects of biochar and compost produced from agricultural wastes and industrial by-products in the case of degraded sandy soils. 13th Carpathian Basin Conference for Environmental Sciences, Cluj-Napoca, Romania, 5‒8 April 2017.
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Links
ABÉT Department of Applied Biotechnology and Food Science) in Hungarian
Environmental Microbiology and Biotechnology Research Group website
Innovative soil improvement (SOILUTIL)
Remediation ‒ Hungarian description
Sandy-soil areas in Hungary ‒ map in Hungarian
Ecotoxicology ‒ Hungarian description
Microcosm ‒ Hungarian description
Aliivibrio fischeri bioluminescence inhibition test ‒ in Hungarian
Folsomia candida mortality test
1st prize (K&H): Szilvia Bacsárdi - Rózsa Máté ‒ Hungarian article
2nd prize (K&H): Csaba Kirchkeszner ‒ Hungarian article
References
[1] Glaser, B., Lehmann, J., Zech, W. (2002) Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal ‒ a review. Biol. Fert. Soils 35, pp. 219–230
[2] Lehmann, J., Rillig, M.C., Thies, J., Masiello, C.A., Hockaday, W.C., Crowley, D. (2011b) Biochar effects on soil biota—A review. Soil Biol. Biochem. 43, pp. 1812–1836
[3] Mitchell, P.J., Simpson, A.J., Soong, R., Simpson, M.J. (2015) Shifts in microbial community and water-extractable organic matter composition with biochar amendment in a temperate forest soil. Soil Biol. Biochem. 81, pp. 244‒254
[4] McCormack, S.A., Ostle, N., Bardgett, R.D., Hopkins, D.W., Vanbergen, A.J. (2013) Biochar in bioenergy cropping systems: impacts on soil faunal communities and linked ecosystem processes. GCB Bioenergy 5, pp. 81‒95
[5] Atkinson, C., Fitzgerald, J., Hipps, N. (2010) Potential mechanisms for achieving agricultural benefits from biochar application to temperate soils: a review. Plant Soil 337 (1–2), pp. 1‒18
[6] Jeffery, S., Verheijen, F.G.A., van der Velde, M., Bastos, A.C. (2011) A quantitative review of the effects of biochar application to soils on crop productivity using meta-analysis. Agric. Ecosyst. Environ. 144, pp. 175‒187
[7] Stefanovits, P., Filep, Gy., Füleky, Gy. (1999) Talajtan, Mezőgazda Kiadó
[8] Jeffrey, S., Meinders, M.B.J., Stoof, C.R., T., Bezemer, T.M., van de Voorde, T.F.J., Mommer, L., van Groenigen, J.W. (2015) Biochar application does not improve the soil hydrological function of a sandy soil. Geoderma pp. 251‒252, pp. 47‒54
[9] Basso, A.S., Miguez, F.E., Laird, D.A., Horton, R., Westgate, M. (2012) Assessing potential of biochar for increasing water-holding capacity of sandy soils. GCB Bioenergy 5, pp. 132‒143
[10] Xu, R.-K., Zhao, A.-Z., Yuan, J.-H., Jiang, J.R. (2012) PH buffering capacity of acid soils from tropical and subtropical regions of China as influenced by incorporation of crop straw biochars. J. Soils Sediment. 12, pp. 494‒502
[11] IBI (International Biochar Initiative) (2013) Standardized Product Definition and Product Testing Guidelines for Biochar That is Used in Soil v. 1.1. http://www.biochar-international.org/characterizationstandard (accessed on 28th June, 2017)
[12] EBC, 2012. European Biochar Certificate—Guidelines for a Sustainable Production of Biochar. European Biochar Foundation, Arbaz, Switzerland, http://www.europeanbiochar.org/biochar/media/doc/ebc-guidelines.pdf, (accessed on 27th June, 2017)