Soils with Smart Carbon

Prof. Genxing Pan1

1Nanjing Agricultural University, Nanjing, China

Enhancement of carbon storage in global soils has been urged as per the “C 4 per mil Initiative”, launched following “the Paris Agreement” for climate change mitigation. However, what kind of carbon should be increased or how the increased carbon could serve soil fertility and ecosystem functioning while mitigate climate change, has been not yet well understood. Global agricultural soils have been depleted organic carbon and therefore have a big potential to feed carbon. Any forms of organic carbon ultimately derived from biomass could help to build up soil C storage but their effects on carbon cycling and food production are widely variable. While to captured or stabilize C in soil, we need carbon to restore soil fertility and soil health and to promote plant growth and food quality, the “Smart C” in agriculture. Such carbon should have stable structure, high reactivity and bioactivity (for example, plant growth/metabolism promotion). Biochar, as an example, is engineered carbon from crop straw and functions in improving soil aggregation/structure, root growth and plant development, and in stabilizing potentially toxic metals, organic pollutants and even pathogenic microbes. The co-benefits to food production, soil/water conservation and environment protection should be assessed and accounted for in the fight against climate change. The characterization, processing and production, and application of smart carbon in agriculture deserve urgent international collaboration, particularly under the framework of “C 4 per mil” action.


Biography:

Dr Genxing Pan is  a science leader of soil science in Nanjing Agricultural University. He has been devoted his main career to science and technology of soil carbon enhancement in agricultural, particularly of agrochar, in boosting soil C stock and crop productivity for climate change and food

Soil organic carbon stocks as an indicator of land degradation for Sustainable Development Goal 15

Dr Jacqueline England1, Professor Raphael Viscarra Rossel2, Dr Stephen Roxburgh3, Neil McKenzie3, Dr Carly Green4, Dr Glenn Newnham1, Dr Neil Sims1, Dr Alex Held3,5

1CSIRO Land and Water, Clayton South, Australia, 2Curtin University, Perth, Australia, 3CSIRO Land and Water, Canberra, Australia, 4Global Forest Observation Initiative, Rome, Italy, 5CSIRO Astronomy and Space Science, Canberra, Australia

Since 2010 there have been several global and regional targets and initiatives to halt and reverse land degradation and restore degraded land; the most recent being the 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs). SDG indicator 15.3.1, the proportion of land that is degraded over total land area, is assessed in terms of change in three sub-indicators: land cover, land productivity and carbon stocks. Each of these sub-indicators represents a unique perspective on the manifestation and assessment of land degradation. Soil organic carbon (C) is the current metric for assessing the carbon stocks sub-indicator. Good practice guidance (GPG) has recently been developed to assist countries to report on SDG indicator 15.3.1, and support countries to achieve their targets for reducing degradation. Without being prescriptive about the sources of data, the GPG aims to ensure technical soundness and consistency in estimation methods as well as comparability of results across countries and over time. The approach used to quantify change in soil organic C stocks will vary depending on the availability of country-specific data and capability. Key challenges include the establishment of appropriate baselines and methods for determination of significant change in soil organic C stocks. The latter is further complicated by the typically slow rate of change in soil organic C in relation to indicator reporting periods. This paper presents some of the key methodological details of the GPG for assessing soil organic C stocks and describes considerations that may assist in national scale monitoring of soil organic C in order to implement national reporting against SDG indicator 15.3.1.


Biography:

Dr Jacqui England is an ecologist with a particular interest in understanding forests and agro-ecosystems to inform their management and restoration. Her research on ecosystem processes in relation to environmental and management factors in these systems has largely focussed on developing tools for accurate carbon accounting, and assessing the co-benefits they provide, to inform policy and influence land management. This work has directly contributed to improving the national carbon accounting tool and to the development of land-based greenhouse gas mitigation methodologies both nationally and internationally.

Challenges and opportunities for making compound fertilizers with biochar and nutrient rich wastes

Dr Daniel Rasse1, Dr Alice Budai1, Mr Simon Weldon1

1NIBIO, Ås, Norway

There is a need for win-win solutions for increasing soil carbon sequestration and improving the recycling of nutrients from organic wastes, thereby benefiting both climate mitigation and food production. In terms of carbon sequestration, biochar has been presented as a major solution for stabilizing vast amounts of carbon in soils. Analysis reveals that biochar technology outcompetes other methods for storing CO2 from bioenergy systems only if it also leads to increases in crop productivity. However, improved agronomic results have not always been forthcoming, especially in temperate fertile soils, and farmers need to see greater agronomic benefits in order to adopt the technology. This is why recent research recommends improving the fertilizer value of biochar by combining it with organic nutrient sources, especially N & P, fixed to or absorbed on its surface. In theory, the solution is ideal; biochar as a sorbent material has the capacity to capture nutrients in waste streams such as digestate and manure, reduce volatile N losses and GHG emissions, improve nutrient use efficiency and reduce N leaching. However, the mechanisms controlling this nutrient retention capacity are still poorly understood. Here, we report on a meta-analysis of biochar properties that control the retention and release of multiple forms of N and P sources. We further discuss implications for making compound fertilizers with biochar and nutrient-rich wastes.


Biography:
Daniel Rasse holds a PhD in soil science from Michigan State University and is currently heading the Soil Quality department at the Norwegian Institute of Bioeconomy Research. He has coordinated the European Networking Programme MOLTER (2008-2013) on molecular structures in the terrestrial C cycle, and is PI of several large-scale projects. His main research focus is on soil organic matter and the factors influencing its accumulation and its feedback on ecosystem functions. In the last decade, he has been working intensively on biochar technology as a mean to increase C sequestration in soil and improve fertility.

Gaseous emissions from lignite amended manure composting process

Dr Mei Bai1, Robert Impraim1, Dr Trevor Coates1, Dr Thomas Flesch2, Dr Raphaël Trouvé3, Dr Hans van Grinsven4, Dr Yun Cao5, Dr Julian Hill6, Professor Deli Chen1

1Faculty Of Veterinary And Agricultural Sciences, The Univeristy Of Melbourne, Parkville, Australia, 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2R3, Canada, Edmonton, Canada, 3School of Ecosystem and Forest Sciences, Faculty of Science, The University of Melbourne, Richmond, Victoria 3121, Australia, Richamond, Australia, 4PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands, The Hague, The Netherlands, 5Circular Agriculture Research Centre, Jiangsu Academy of Agricultural Sciences, NanJing 210014, China, Nanjing, China, 6Ternes Agricultural consulting Pty Ltd, Upwey, Victoria 3158, Australia, Upwey, Australia

Emissions of ammonia and greenhouse gases from agricultural systems results in the loss of valuable nitrogen (N), and has negative environmental impacts. Composting manure is a typical management practice on livestock farms, used to increase the content and availability of nutrients. We hypothesize that the addition of lignite, readily available in Australia, can retain N during manure composting. To test our hypothesis, a study was conducted at a commercial feedlot during the summer season. Prior to cattle entering a feedlot pen, we applied 6.48 tonnes of dry lignite to the pen surface, while no lignite was applied to a control pen. After 90 days, the cattle were removed, and manure from each pen was collected to form separate manure windrows, with and without lignite amendments. We quantified gaseous emissions of NH3, nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) from both windrows with a micrometeorological technique using open-path Fourier transform infrared spectroscopy (OP-FTIR). Over the 87 days measurement period, the accumulative gas fluxes showed that the addition of lignite reduced NH3 emissions by 54% during composting, but increased greenhouse gas (GHG) emissions (CO2 equivalent, CO2−e). The N lost as N−NH3 was 9.7% and 24.4% of the total initial N in the lignite and non-lignite windrows, respectively, and the N lost as N−N2O was 0.8% and 0.3% of the total N in the lignite and non-lignite windrows, respectively. To estimate the economic and environmental benefits of reducing gas emissions, we applied a cost-benefit analysis and found that lignite addition to cattle pens cost-effectively improved the nutrient value in final compost product, and could justify trade-off increased GHG emissions.

 

Mutual interactions between decaying plant litter, soil microorganisms and mineral particles, controlled by soil texture

Ms Kristina Witzgall1, Ms Alix Vidal1, Mr Steffen Schweizer1, Ms Valerie  Pouteau2, Ms Claire Chenu2, Mr David Schubert3, Ms Juliane Hirte4, Mr Carsten Müller1

1TU München, Lehrstuhl für Bodenkunde, Technische Universität München, Freising-Weihenstephan, Germany, 2UMR Ecosys, AgroTechParis, Batiment EGER, Thiverval Grignon, France, 3TU München, Freising-Weihenstephan, Germany, 4Plant-Soil Interaction Group, Division Agroecology and Environment, Agroscope, Zurich, Switzerland

Soil texture and microorganisms are key drivers controlling the fate of organic matter (OM) from decaying plant litter and thus soil organic matter (SOM) stabilization. A better understanding of mutual interactions between microbial litter decay and soil structure formation controlled by different soil texture remains challenging. We monitored the fate of litter-derived compounds (using 13C isotopic enrichment) from decaying litter (maize leaves) to microorganisms and soil in two differently textured soils (sand and loam). We incubated the two soils with litter mixed in the top layer in microcosms for three months with regular CO2 and 13CO2 measurements. Using a physical soil fractionation scheme, we assessed the fate of the litter-derived OM as free and occluded particulate organic matter (POM) as well as mineral associated OM (MOM) together with the effects of the different textures on the microbial communities using PLFA. The POM and MOM fractions were analyzed with respect to mass distribution, C, N and 13C contents, as well as the chemical composition using 13C-CPMAS NMR spectroscopy. We could clearly demonstrate higher contents of OM in the mineral associated fractions of the sandy textured soil in contrast to the loamy textured soil, where instead higher OM contents were detected in the POM fractions. Thus we show a distinct negative effect of the clay content on MOM, while clay sustains a high level of OM stored as POM. The 13C measurements showed higher enrichment in almost all fractions in the sandy textured soil compared to the loamy soil. The PLFA analysis revealed a coherent pattern between the textures, where microbial activity increased in the top layers and the community structure remained similar in both treatments. This interdisciplinary approach, where biogeochemical and microbiological methods were combined, gave insights in the interactions between decaying plant litter, microorganisms, and soil minerals.


Biography:

Kristina Witzgall, born 1992 in Lund, Sweden.

  • 2016-2019 M.Sc. Sustainable Resource Management, Technical University of Munich, Germany
  • 2018 Internship, Bavarian State Research Centre for Agriculture, Germany
  • 2017-2018 Student Research Assistant, Technical University of Munich, Germany
  • 2016-2017 Student Representative, Technical University of Munich, Germany
  • 2011-2015 B.Sc. Environmental Sciences, Lund University, Sweden

Factors controlling long-term organic carbon dynamics in the soils of Germany

Dr Andreas Möller1

1Federal Institute For Geosciences And Natural Resources, Hannover, Germany

In the past decades the common hypotheses for long-term soil organic matter dynamics was based on controlling factors like biomass source, sorption and desorption processes, climate, land use and soil texture. New research, however, revealed that this hypothesis may have to be adapted and other factors may be more relevant. The major problem is that most factors controlling long-term organic carbon dynamics are connected to each other. Thus, the selection of causal model parameters is essential to eliminate translucent causalities. It is already common understanding that biomass source and carbon pools are not relevant in the long-term. All physically reachable carbon gets microbial degraded over time, even charcoal. Hence, which are the parameters truly triggering the differentiation of organic carbon stocks in soil? A statistical evaluation of Germany wide topsoil data, including data from the state geological surveys of Germany, showed that soil moisture conditions may be the key factor controlling soil organic carbon content apart from soil genesis and land use. Additionally, the age of the soil may also be relevant. Comparing soils of the younger Weichsel with the older Saale glacial era in the lowlands of northeast Germany showed significant differences over different soil moisture regimes. However, less the age of the soil may cause the difference, but more the mineral composition of the soils, similar to the effect known from podsols. Even after hundreds of years of intensive agriculture sandy podsols reveal significantly higher carbon content in the plowed layer than most other soils. On the other hand, factors like temperature and soil texture seem to be less important. The results show that the common hypothesis of long-term organic carbon dynamics in temperate soils may have to be review.


Biography:

Since 03.2001                 Research associate at the Federal Institute for Geosciences and Natural Resources in the unit “Soil Protection, Soil Analysis”; Focus on soil organic matter, carbon stocks, biochar, and technical cooperation

02.2012 – 01.2015         Secondment to the State Office for Mining, Energy and Geology in the department “Agriculture, Soil Protection and Regional Planning”

05.2005 – 08.2017         Lecturer at the University of Hannover; Fundamentals of the WRB

11.1997 – 04.2001          PhD at the Department of Soil Science and Geography, University of Bayreuth; Thesis: Dynamics of organic matter in the mountain forest ecosystem of N-Thailand

10.1994 – 05.1997          Geography at the University of Erlangen

New insights into how organic N is depolymerised

A/Prof. Charles Warren1

1University Of Sydney, University Of Sydney, Australia

Despite nitrogen (N) commonly limiting productivity, most soils contain a large pool of N in high molecular weight organic forms.  High molecular weight forms of organic N are in general not directly available for uptake by microbes or plants, and only become available after they have been depolymerised by extracellular enzymes.

Surprisingly little is known about how high molecular weight organic N is depolymerized. A particular challenge is in determining the products that are produced when high molecular weight organic N is depolymerized. Depolymerisation of organic N is often equated with production of the terminal monomers, primarily amino acids.  For example, many assays of enzyme activity focus solely on reactions that produce amino acids.  Studies to date have not determined the chemical profile of products produced by depolymerisation of organic N, and thus we do not know if amino acids are the main products of depolymerisation.

Determining how high molecular weight organic N is depolymerized has proved challenging for two reasons. First, because the products of depolymerisation are rapidly taken up by microbes; and second, because it has proven difficult to identify and quantify complex mixtures of hydrophilic organic N compounds.

This presentation will describe development of mass spectrometry methods to characterize the products of organic N depolymerisation.  We show that while amino acids are produced by depolymerisation they are not the dominant products.  The main depolymerisation products of native organic matter and added proteins are instead peptides. The same peptides that are produced in large quantities by depolymerisation are at vanishingly low concentrations in intact soil, which is consistent with the idea that peptides are preferred N sources for soil microbes.


Biography:

Charlie Warren is an Assoc Prof in the School of Life & Environmental Sciences at The University of Sydney. Charlie’s research career began as an honours student examining photosynthesis at low temperatures. After a decade examining the ecophysiology of photosynthesis, his research began heading belowground: first to examine uptake of organic N, then to examine root exudates and plant-soil interactions. Nowadays much of Charlie’s research focusses on nutrient cycling, in particular the development of novel analytical methods to solve intractable problems.

The effects of long-term nitrogen addition on the composition and sequestration of SOM in a boreal forest

Dr Shun Hasegawa1, Professor John Marshall1, Professor Torgny Näsholm1

1Swedish University Of Agricultural Sciences, Umeå, Sweden

Boreal forests are responsible for large terrestrial carbon (C) stores. They are typically nitrogen (N)-limited, such that the intense use of fertilisers for forest management in this biome has drawn great attention to the long-term impacts of N additions on biogeochemical processes, especially, decomposition and sequestration of SOMs. We investigated the impacts of N addition on SOMs both qualitatively and quantitatively in a mature Scots pine forest located in Northern Sweden. Two experimental plots were established: reference and fertilised plots. The latter has received the total amount of 950 kg N/ha over the past 13 years (c. 50-100 kg N/ha/yr), resulting in an N gradient in the soil adjacent to this plot. We established soil sampling transects along the gradient and assessed the relationships between the N level and SOMs.

Soils were collected from the litter and humus layers and assessed for 1) the composition of C compounds using solid-state carbon-13 nuclear magnetic resonance (NMR) spectroscopy and pyrolysis-GC/MS and 2) total C mass. NMR demonstrated decreases in O-alkyl relative to N-alkyl/methoxyl C with the N levels. These compounds were derived from carbohydrate and lignin components, respectively. This shift in C compounds was consistent with pyrolysis-GC/MS showing that carbohydrate: lignin ratios were negatively correlated with N. The total C mass was 2.09±0.43 and 1.7±0.30 kg C/m2 (Mea±95% confidence interval) in the fertilised and reference plots, respectively. This treatment difference corresponded to C sequestration of 30 g C/m2/yr. Furthermore, C mass in humus was positively related to the N level. Thus, our study suggests that an N addition in this pine forest alters the composition of C compounds by decreasing carbohydrate-derived compounds relative to lignin and also may increase C sequestration in the organic layer. Our results may help us to disentangle the potential mechanisms of C decomposition/sequestration in N-limited boreal forests.


Biography:
I am a postdoc researcher at Swedish University of Agricultural Sciences with a broad research interest in the impacts of climate and environmental changes on terrestrial biogeochemistry and plant-soil interactions. My current work investigates the effects of nitrogen (N) addition on the molecular composition of soil organic matters (SOMs) in boreal forests with an aim of discerning the mechanisms determining the balance between decomposition and accumulation of SOMs under the elevated N world. In this study, a whole molecular picture of SOMs is meticulously developed using two techniques: Nuclear magnetic resonance (NMR) and Pyrolysis GC-MS.

Bacterial 3-hydroxy fatty acids: Applicability as environmental markers in soils from the French Alps

Mr Pierre Véquaud1, Dr Sylvie Derenne1, Dr Sylvie Collin1, Mrs Christelle Anquetil1, Pr  Jérôme Poulenard2, Dr Pierre Sabatier2, Dr Arnaud Huguet1

1METIS, CNRS/Sorbonne Université/EPHE, Paris, France, 2EDYTEM, Université savoie Mont-Blanc/CNRS, Le Bourget-du-Lac, France

The composition of microbial membrane lipids has been shown to vary with environmental parameters in order to maintain an appropriate fluidity and permeability of the membrane. This is particularly the case for glycerol dialkyl tetraethers (GDGT), used for temperature and pH reconstructions in terrestrial settings, although other environmental parameters might also influence the GDGT distribution. Another family of lipids, 3-hydroxy fatty acids (3-OH FAs) was recently proposed as an alternative to GDGTs. To investigate the applicability of 3-OH FAs as temperature and pH proxies and understand the influence of environmental parameters on these lipids, 49 soils were collected between 200 and 3,000 m altitude in the French Alps. These soils cover a wide range of temperature (0°C to 15°C) and pH (3 to 8) and are representative of the diversity of soil vegetation and pedological covers along the mountain gradients. In agreement with previous studies, a significant correlation is observed between 3-OH FAs and pH. In contrast, no correlation could be shown with mean annual air temperature. Similarly, GDGTs are only poorly correlated with temperature in this sample set. This suggests that other parameters, such as vegetation, soil type or humidity are the main drivers of the variability of 3-OH FA and GDGT distribution. The influence of vegetation type and soil classification was tested on 3-OH FA relative abundances as the sampling allows differentiating 10 types of vegetation and 10 types of soil. Both parameters were shown to have a significant impact on the 3-OH FA distribution. This led us to build a model based on Artificial Neural Network, which allowed the reconstruction of soil types and vegetation with an accuracy of 89 %. This promising approach, developed on soils from the French Alps, will be further applied to a larger number of soil samples and also tested on GDGTs.


Biography:

Distinguished senior scientist (DRCE) CNRS since 2016, Head of the biogeochemistry group of METIS laboratory. My research area is organic geochemistry and I combine various techniques of analytical chemistry to decipher the chemical structure of “geomaterials” to understand their formation pathway and behaviour in the environment. These “geomaterials” belong to a large diversity of natural environments such as sedimentary rocks, soil, natural waters and extraterrestrial materials. I co-authored 218 peer-reviewed papers and supervised 30 PhD students.

Awards: 2009 CNRS Silver Medal, 2019 Geochemical Society Alfred Treibs Medal

Quality of soil organic matter in high-latitude environments: From bulk to water-extractable soil organic matter

Dr Yannick Agnan1, Dr Marie A.  Alexis1, Ms Alice  Kohli2, Dr Edith Parlanti3, Dr Sylvie Derenne1, Ms Mahaut Sourzac3, Ms Christelle Anquetil1, Pr Daniel Obrist4, Dr Maryse Castrec-Rouelle1

1Sorbonne Université, Paris, France, 2Agrocampus Ouest, Angers, France, 3Université de Bordeaux, Talence, France, 4University of Massachusetts, Lowell, Lowell, USA

Soil organic matter in Arctic and Subarctic regions plays a key role for the global carbon cycling. The objective of this study was to evaluate the structure and fate of soil organic matter in the high latitudes by jointly quantifying and characterizing both bulk and water-extractable organic matter in surface soil samples. We compared two study sites with similar tussock tundra ecosystems and distinct mean annual air temperature and permafrost conditions: Abisko, Sweden (−1 °C, discontinuous permafrost) and Toolik, Alaska, USA (<−8 °C, continuous permafrost). Both sites presented different bulk soil organic matter compositions: higher C/N and alkyl C/O-alkyl C ratios were reported at Abisko (27.1 ± 8.6 and 0.57 ± 0.17, respectively) compared to Toolik (17.4 ± 2.3 and 0.44 ± 0.11, respectively). These patterns are attributed to either distinct decomposition stages linked to climate conditions or distinct organic matter inputs with local vegetation influences. Extractable fractions indicated higher water-extractable organic matter concentrations in the colder site (i.e., at Toolik with 4.38 mg gsoil−1 of water-extractable organic carbon and 0.25 mg gsoil−1 of water-extractable total nitrogen) that we attribute to a higher pool of potentially mobilizable matter from a more preserved soil organic matter. Overall, the most significant result is that the intra-site heterogeneity of the soil organic matter quality was higher than the inter-site heterogeneity, in the bulk as well as in the water-extractable fractions. Finally, the qualities of both bulk and extractable fractions were not directly linked together: some specific patterns observed in the bulk fraction (e.g., locally lower alkyl C/O-alkyl C ratios) were not observed in the extractable one, and reciprocally (e.g., singular fluorescence signature).


Biography:

Since 2008, M. A Alexis is assistant professor in Biogeochemistry at the Sorbonne Université (Paris – France). Her studies focus on the characterization of soil organic matter (at elementary, isotopic, or molecular scales) to understand its dynamics and its response to global changes. She especially studied the quality and features of thermally altered organic matter, in soils naturally affected by biomass fires, and in hearths after prehistorical human use. She presently also works on the production of dissolved organic matter through soil leaching and on the consequences for carbon storage and for transfer and dynamics of trace elements in high latitude environments.

12314

SOIL ORGANIC MATTER

7th International Symposium
Soil Organic Matter

6 – 11 October 2019

Hilton Adelaide

Adelaide, South Australia

Australia

Conference Managers

Please contact the team at Conference Design with any questions regarding the conference.

© 2018 - 2019 Conference Design Pty Ltd