Soil Scientist, Agroecologist, Geographer, Environmental scientist, IT professional - Specialist in dynamic modelling of complex systems - R&D and consulting experience in agricultural chemistry and physics - Experienced software developer (.NET)
Work experience: Belgium - Dept. Geography, l'Universite Catholique de Louvain Denmark - Dept. Environment, Resources and Technology, University of Copenhagen - Dept. Agroecology and Environment, Aarhus University - Crop production and Soil quality group, Research centre Foulum (Tjele) Germany - Institute for Landscape System Analysis, ZALF (Muencheberg) Lithuania - Dept. Informatics, Klaipeda University Russia - Modelling Unit, RAAS-Agrophysical Institute (Saint-Petersburg) - Dept. Agrochemistry, University of Saint-Petersburg - Dept. Botany, Herzen University (Saint-Petersburg)
Titles: EU Marie Curie fellow (2011, Brussel) Ph.D. (2009, University of Copenhagen) FIVA research school fellow (2003, Copenhagen) M.Sc. (2001, University of Saint-Petersburg) Baltic University fellow (1998, Stockholm)
Abstract: Tillage of arable soils is historically belived to be the most important agro-technological tool. However, wrong application could cause losses of soil due to erosion and arises environmental problems related to crop production. Combination of experimental and modelling approaches for a complex effects of soil tillage on greenhouse gas emisions and soil carbon stocks are discussed in this thesis.
Abstract: Modern modeling methods allows us to optimize complex approach in (agro)ecological investigations, both in a field and in a lab. It could be also used to study of N «behavior» in an (agro)ecosystem. The dissertation is based on results obtained by using of an original system (E.V.A.) created for development and information support of (agro)ecological models. We collect our knowledge about the world to support development of âaggregatedâ models. Thus an (agro)ecosystem will be presented by development of âpreliminaryâ models, in which hypothesis could be presented in quantified way and analyzed. The N models are all applied, but depending on data available for parameters estimation could be called âcomplexâ and âappliedâ. The last models are in use in research as well as in farm planning. The dissertation is based on participation in development and using of models of different aims and complexity: Micro (Institute of Agricultural Microbiology), Root (Saint-Petersburg University), Agrotool (Agrophysical Institute) and AgroSiTo (ZALF). The system suggested by author included tree components. Firsly, databases for literature, experimental data and model algorithms were created. Secondly, a âmodeling managerâ was developed, which allows automatic access to the experimental data with different aggregation and models algorithms in database to build the most suitable model based on DSS options. Thirdly, a system for multi-variant scenario analysis was developed to allow computer experiments run according DSS options. Dissertation partly showed that wrong approach, caused by absence of knowledge about the system, to collect and process an experimental data and physical formulation of the modeling subjects (mathematical description), which a in need to support N models of an (agro)ecosystem, results in a fact that possibilities of computer modeling (program realization of algorithms) today increases our understanding of all complex organization of an (agro)ecosystem. Thus, a fundamental conclusion could be drawn: the ethics should be when we a talking about description of (N) models of an (agro)ecosystem and results, which is used with using of these models to support or processing of experimental data.
Abstract: Two different modelling approaches were used to simulate the N2O emissions from Belgium long-term field experiments, which included croplands and grasslands.
Abstract: Soil tillage has been shown to affect long-term changes in soil organic carbon (SOC) content in a number of field experiments. This paper presents a simplified approach for including effects of tillage in models of soil C turnover in the tilled-soil layer. We used an existing soil organic matter (SOM) model (CN-SIM) with standard SOC data for a homogeneous tilled layer from four long-term field experiments with conventionally tilled (CT) and no-till (NT) treatments. The SOM model was tested on data from long-term (>10 years) field trials differing in climatic conditions, soil properties, residue management and crop rotations in Australia, Brazil, the USA and Switzerland. The C input for the treatments was estimated using data on crop rotation and residue management. The SOM model was applied for both CT and NT trials without recalibration, but incorporated a âtillage factorâ (TF) to scale all decomposition and maintenance parameters in the model. An initial value of TF = 0.57 (parameter uncertainty, PU = 0.15) for NT (with TF set to 1.0 for CT) was used on the basis of a previous study with observations of soil CO2 respiration. The simulated and observed changes in SOC were then compared using slopes of linear regressions of SOC changes over time. Results showed that the SOM model captured observed changes in SOC content from differences in rotations, N application and crop residue management for conventional tillage. On the basis of SOC change data a mean TF of 0.48 (standard deviation, SD = 0.12) was estimated for NT. The results indicate that (i) the estimated uncertainty of tillage effects on SOC turnover may be smaller than previously thought and (ii) simple scaling of SOM model parameters may be sufficient to capture the effects of soil tillage on SOM turnover in the tilled layer. Scenario analyses showed that the average extra C input needed to compensate for soil tillage was 762 (SD = 351) kgC haâ1 yearâ1. Climatic conditions (temperature and precipitation) also affected how much extra C was needed, with substantially larger inputs being required for wetter and warmer climates.
Abstract: The environmental consequences of changing from conventional to reduced soil tillage in winter crops are yet poorly understood under North European conditions. Soil tillage intensity may affect both crop growth and soil carbon (C) and nitrogen (N) turnover and balances, including emissions of greenhouse gases (GHG) such as CO2 and N2O. In this study we compared the effects of conventional tillage (CT) using ploughing to 20 cm depth, reduced tillage (RT) using rotary harrowing to 8-10 cm depth and direct drilling (DD) with disk coulters on fluxes of CO2 and N2O from loamy sand soil under winter oilseed rape (Brassica napus L.) followed by winter wheat (Triticum aestivum L.). The measurements were conducted by use of chambers over a period from August 2003 to September 2005 in a soil tillage experiment established in Denmark in 2002. To integrate information on the C and GHG budgets for the experiment, the FASSET model was used with no recalibration in a two-step modelling procedure. First, we fitted the soil organic matter (SOM) model of FASSET to give the observed ratio of soil CO2 respiration from the CT and DD treatments by scaling all decomposition and maintenance parameters for the DD treatment with the same value (d), called the âtillage factorâ. Second, the complete FASSET model was run with default parameter values for ploughing depth in CT (d=1.00) and the estimated value for DD (d=0.57), in order to quantify the cumulated CO2 and N2O emissions. Both measurements and model simulations showed that the combined global warming potential from CO2 and N2O emissions was lower from reduced tillage treatments (RT and DD) than from conventional tillage (CT). Thus, compared with CT, modelled reduced soil tillage treatments decreased GHG emissions by 0.56 (RD) and 1.83 (DD) Mg CO2-eq. ha-1 year-1. Similar differences between treatments were obtained for simulations over 30 years of observed weather for the specific site. In both cases, negative GWPs for the studied site were obtained. A sensitivity analysis showed that the simulated GHG emissions were primarily influenced by changes in SOM model parameters, whereas observed changes in soil water retention affected only N2O emissions, and soil temperature had only minor effects.
Notes: Danish Ministry of Food, Agriculture and Fisheries and International Research School of Water Resources (FIVA)
Abstract: Soil tillage intensity can be expected to affect the greenhouse gas balance of arable cropping systems through effects on soil
physics and biology affecting soil carbon storage and nitrous oxide (N2O) emissions. The effects of conventional tillage (CT) with
ploughing to 20 cm, reduced tillage (RT) with harrowing to 8â10 cm and direct drilling (DD) on CO2 and N2O emissions from a
loamy sand soil (8.1% clay, 3.5% organic matter) under spring barley undersown with ryegrass were measured by static chambers
over a period of 113 days in spring and summer 2004 in a tillage experiment established in 2002 at Foulum, Denmark. There was a
high temporal and spatial variation in both CO2 and N2O emissions, which made the comparisons of treatment effects on emissions
on single dates difficult. However, this variation was reduced when the measurements were corrected for diurnal variation in the
emissions and when emissions were cumulated over a longer period. Both CO2 and N2O emissions decreased in the order
CT > RT > DD. Compared with CT (40 kg C day-1) the cumulated CO2 emissions during the 91 days after tillage were 21 and
25% lower for the RTand the DD treatments, respectively. The cumulated N2O emission from CTover the entire observation period
(0.89 kg N ha-1 or 7.9 g N day-1) was about twice that of DD. The N2O emissions were significantly higher for CT compared with
DD and RT, even before tillage and the difference increased after tillage, but decreased after fertilisation. Spring barley dry matter
grain yields were reduced by 14% for RT and 27% for DD compared to CT. Measurements of soil mineral nitrogen (N) at sowing
showed no difference between the treatments, and could thus not explain the differences in N2O emissions and crop N uptake. It is
likely that tillage affected CO2 emissions, N2O emissions and crop growth through different processes, where effects of soil
compactness on root penetration and soil aeration and diffusivity on one side and soil organic matter turnover on the other side
probably played key roles.
Notes: Danish Ministry of Food, Agriculture and Fisheries, International Research School of Water Resources (FIVA)
Abstract: Nitrous oxide (N2O) is a potent greenhouse gas with a high contribution from agricultural soils and emissions that depend on soil type, climate, crops and management practices. The N2O emissions therefore need to be included as an integral part of environmental assessments of agricultural production systems. An algorithm for N2O production and emission from agricultural soils was developed and included in the FASSET whole-farm model. The model simulated carbon and nitrogen (N) turnover on a daily basis. Both nitrification and denitrification was included in the model as sources for N2O production, and the N2O emissions depended on soil microbial and physical conditions. The model was tested on experimental data of N2O emissions from grasslands in UK, Finland and Denmark, differing in climatic conditions, soil properties and management. The model simulated the general time course of N2O emissions and captured the observed effects of fertiliser and manure management on emissions. Scenario analyses for grazed and cut grasslands were conducted to evaluate the effects of soil texture, climatic conditions, grassland management and N fertilisation on N2O emissions. The soils varied from coarse sand to sandy loam and the climatic variation was taken to represent the climatic variation within Denmark. N fertiliser rates were varied from 0 to 500 kg N haâ1. The simulated N2O emissions showed a non-linear response to increasing N rates with increasing emission factors at higher N rates. The simulated emissions increased with increasing soil clay contents. N2O emissions were slightly increased at higher temperatures, whereas increasing annual rainfall generally lead to decreasing emissions. Emissions were slightly higher from grazed grasslands compared with cut grasslands at similar rates of total N input (fertiliser and animal excreta). The results indicate higher emission factors and thus higher potentials for reducing N2O emissions for intensively grazed grasslands on fine textured soils than for extensive cut-based grasslands on sandy soils.
Notes: Danish Ministry of Food, Agriculture and Fisheries within the Danish Research Centre of Organic Farming
Abstract: A system for simulation of crop dynamics is described. It includes a dynamic crop model for several cultures and a model shell. The model permits to simulate crop dynamics on the second level of plant productivity. The model shell serves for organization and implementation of series of computer experiments in dialogue regime. As it is known, soil and climatic conditions in the majority of Russia's regions differ from that in West Europe in a principal way. It especially concerns the continental Russia regions where deep droughts regularly occur, or Northwest regions, which are subjected to excess of water. So a special attention in model development was paid on account of the influence of water stress on plant production process.
Abstract: Klimaændringer forårsaget af menneskeskabte udledninger af drivhusgasser udgør en af de største globale miljøtrusler. Landbruget bidrager også til udledningen af drivhusgasser, især gennem udledning af metan (CH4) og lattergas (N2O).
I Danmark bidrager landbruget til ca. 18 procent af den nationale udledning af drivhusgasser. Heraf udgør udledningen af lattergas den væsentligste post, målt på evnen til at forårsage global opvarmning, da lattergas har en drivhuseffekt der er ca. 310 gange højere end for kuldioxid.
