References of "Degrune, Florine"
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See detailCrop residue management in arable cropping systems under temperate climate. Part 1: Soil biological and chemical (phosphorus and nitrogen) properties. A review
Lemtiri, Aboulkacem ULg; Degrune, Florine ULg; Barbieux, Sophie ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016)

Interacting soil organisms support biological processes that participate in soil functions, organic matter decomposition, and nutrient cycling. Earthworms and microorganisms play a range of beneficial ... [more ▼]

Interacting soil organisms support biological processes that participate in soil functions, organic matter decomposition, and nutrient cycling. Earthworms and microorganisms play a range of beneficial roles in agricultural systems, including increased organic matter mineralization, nutrient cycling, and soil structure stabilization. The following aspects of crop residue management effects are examined in this paper: (i) earthworm composition and structure; (ii) soil microbial communities; and (iii) phosphorus (P) and nitrogen (N) element availability and distribution in the soil profile. Conventional tillage (ploughing) is often reported to generate decreased soil organism abundance and diversity, primarily earthworms and microorganisms, as well as a uniform distribution of the nutrients P and N within the ploughed soil horizon. Soil residue incorporation of mineral particles can maintain P and N levels, however returning soil also increases aeration and the activation of microbial activity. Hence, comparisons of tillage effects on soil biological functioning and nutrient cycling remain unclear. This review highlights the challenges in establishing definitive evidence regarding the effects of crop residue management on soil organisms and nutrient dynamics. The studies examined reported variability in soil and climate, and the complexity of soil processes contributed to the absence of clear findings. Further research is required under temperate climate conditions. [less ▲]

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See detailNo favorable effect of reduced tillage on microbial community diversity in a silty loam soil (Belgium)
Degrune, Florine ULg; Theodorakopoulos, Nicolas ULg; Dufrêne, Marc ULg et al

in Agriculture, Ecosystems & Environment (2016), 224

Among the soil management practices used to promote sustainable agriculture, reduced tillage and retention of residues from the previous crop are reported to enhance significantly both soil fertility and ... [more ▼]

Among the soil management practices used to promote sustainable agriculture, reduced tillage and retention of residues from the previous crop are reported to enhance significantly both soil fertility and crop productivity. Here, high-throughput sequencing (454 technology) was used to see how the tillage regime (conventional vs. reduced tillage) and the fate of crop residues (retention or removal) affect microbial communities at two sampling depths (top soil: 0–5 cm and deeper soil: 15–20 cm) in a fertile silty loam soil in Belgium. All combinations of these three factors were studied. After 6 years of conversion from conventional to reduced tillage, depth emerged as the main factor responsible for variation in microbial diversity, tillage regime ranked second, and finally, crop residue fate had no influence on microbial diversity. For both bacteria and fungi, the diversity appeared higher in the top soil than in the deeper soil, and surprisingly, higher under conventional than under reduced tillage. These differences are explained by changes in community composition due to taxon loss rather than taxon replacement. The specific local set of environmental conditions (a loess-derived soil and an oceanic temperate climate) may explain these results. These observations raise the question: does impoverishment in indicator taxa influence soil processes, and thus crop production? To answer this question, we discuss how the presence of certain indicator taxa liable to play an ecological role might relate to crop productivity. [less ▲]

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See detailNo favorable effect of reduced tillage on microbial communities in a silty loam soil (Belgium)
Degrune, Florine ULg; Theodorakopoulos, Nicolas ULg; Dufrêne, Marc ULg et al

Poster (2015, December 01)

To date, only a few studies have applied metagenomics to investigate the influence of different tillage regimes and types of crop residue management on soil microbial communities. These studies were ... [more ▼]

To date, only a few studies have applied metagenomics to investigate the influence of different tillage regimes and types of crop residue management on soil microbial communities. These studies were conducted under specific climates on soils characterized by particular land-use histories. A very different ecological context is to be found in certain areas of Western Europe, such as central Belgium, whose loess-derived soils are among the most fertile in the world and have long been used for intensive agriculture. Specific objectives were to determine diversity levels and changes in microbial community composition under different combinations of tillage regime (conventional vs. reduced) and crop residue fate (residue removal R- vs. residues left R+ on the field). As reduced tillage results in two contrasting zones (the first centimeters of soil are mixed each year, while the soil below remains unperturbed), we chose to perform the analysis at two depths: 0 to 5 cm and 15 to 20 cm. [less ▲]

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See detailFarms for Future? Contribution of agroecological farms to the delivery of ecosystem services
Boeraeve, Fanny ULg; Dendoncker, Nicolas; Dufrêne, Marc ULg et al

Conference (2015, November 12)

In the western part of the Hainaut province in Belgium, a dynamic network of several farms intentionally incorporates biodiversity within their practices and across multiple scales. While it is suggested ... [more ▼]

In the western part of the Hainaut province in Belgium, a dynamic network of several farms intentionally incorporates biodiversity within their practices and across multiple scales. While it is suggested that such diversification of agricultural practices supports ecological processes in turn favoring biomass production and providing other ecosystem services (ES) to society, few studies have actually attested this fact. A recent review by Kremen and Miles (2012) comparing the provision of 12 ES in organic and conventional systems concludes that ‘integrated whole-system studies of the influence of different farming practices on multiples ES are critically needed’; a conclusion confirmed by the few existing farm-scale ES assessments. This research’s goal is to fulfill this gap by providing comprehensive knowledge about the socio-ecological performance of such systems. To achieve this, we rely on the tool of integrated ES assessment, which includes both a biophysical and a social valuation. Such value-pluralism is of high relevance in agricultural contexts, where multiple values are required to capture the diversity of needs and wants that nature can contribute to fulfill for society and individuals. With the aim to get better insights into societal values, a ‘field thesis committee’ was launched. This latter one includes local farmers and citizens who are consulted throughout the research. For instance, at the start of the project, a participative ES selection was organized to guide the research towards ES important in the eyes of local stakeholders. The presentation first introduces the innovative multi-actor and multi-disciplinary approach developed in this project. Preliminary results are then presented and interpreted. We believe our approach can bring significant contribution to body of knowledge on the reconciliation of social and environmental expectancies. [less ▲]

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See detailTillage as a tool to manage crop residue : impact on sugar beet production
Hiel, Marie-Pierre ULg; Degrune, Florine ULg; Parvin, Nargish ULg et al

Poster (2015, April)

Crop residues and plant cover represent a pool of organic matter that can be used either to restore organic matter in soils, and therefore maintain soil fertility, or that can be valorized outside of the ... [more ▼]

Crop residues and plant cover represent a pool of organic matter that can be used either to restore organic matter in soils, and therefore maintain soil fertility, or that can be valorized outside of the field (e.g. energy production). However, it is crucial that the exportation of residues is not done to the detriment of the system sustainability. Three long term experiments have been settled in the loamy region in Belgium. All of them are designed to study the effect of residues management by several tillage systems (conventional plowing versus reduced tillage) on the whole soil-water-plant system. SOLRESIDUS is a field experiment where we study the impact of crop residue management while in SOLCOUVERT and SOLCOUVERT-BIS, we study the impact of cover crop management. SOLRESIDUS was started in 2008. In this field, four contrasted crop residues managements are tested in order to contrast as much as possible the responses from the soil-water plant system. Two practices characterize the four modalities: soil tillage (ploughing at 25 cm depth or reduce tillage at 10 cm max) and residue management (exportation or restitution). SOLCOUVERT and SOLCOUVERT-BIS were started in 2012 and 2013 respectively. In those fields cover crop management is also diverse: destruction of the cover crop by winter ploughing, spring ploughing, strip tillage (with a chemical destruction if needed) or shallow tillage (with a decompaction before cover crop sowing). Although although the overall project aims at studying the impact of management on the whole soil-water-plant system, here we will only present the results concerning crop production (sugar beet) in SOLCOUVERT experiments. The presented data will include germination rate, crop development (biomass quantification and BBCH stages) weeds population, disease occurrence, pest occurrences, nitrogen uptake by plants, quality and quantity of harvested products.   [less ▲]

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See detailSoil microbial community composition changes according to the tillage practice and plant development stage
Degrune, Florine ULg; Dufrêne, Marc ULg; Taminiau, Bernard ULg et al

Poster (2015, April)

Agricultural practices have a strong impact on soil bacterial and fungal community composition. Furthermore, microbial community composition can change with the stage of plant development. We are ... [more ▼]

Agricultural practices have a strong impact on soil bacterial and fungal community composition. Furthermore, microbial community composition can change with the stage of plant development. We are interested in exploring these effects in relation to changes induced by agriculture (conventional and reduced tillage) and plant stage (germination and flowering) in soil conditions. Here, instead of examining this impact at a high taxonomic level such as phylum and/or class, thus missing potentially relevant information from lower levels, we propose an original method: exploiting the available sequence information at the lowest taxonomic level attainable for each operational taxonomic unit. Results show that some microbial communities were impacted only by the tillage practice , while others were impacted only by the stage of plant. Changes in microbial community composition could be due to the soil conditions induced by the soil practice and the stage of plant. [less ▲]

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See detailA novel sub-phylum method discriminates better the impact of crop management on soil microbial community
Degrune, Florine ULg; Dufrêne, Marc ULg; Colinet, Gilles ULg et al

in Agronomy for Sustainable Development (2015)

Soil microorganisms such as mycorrhizae and plant-growth-promoting rhizobacteria have beneficial effects on crop productivity. Agricultural practices are known to impact soil microbial communities, but ... [more ▼]

Soil microorganisms such as mycorrhizae and plant-growth-promoting rhizobacteria have beneficial effects on crop productivity. Agricultural practices are known to impact soil microbial communities, but past studies examining this impact have focused mostly on one or two taxonomic levels, such as phylum and class, thus missing potentially relevant information from lower levels. Therefore we propose here an original, sub-phylum method for studying how agricultural practices modify microbial communities. This method involves exploiting the available sequence information at the lowest taxonomic level attainable for each operational taxonomic unit. In order to validate this novel method we assessed microbial community composition using 454 pyrosequencing of 16S and 28S rRNA genes, then we compared the results with results of a phylum-level analysis. Agricultural practices included conventional tillage, reduced tillage, residue removal and residue retention. Results show that, at the lowest taxonomic level attainable, tillage is the main factor influencing both bacterial community composition, accounting for 13% of the variation, and fungal community composition, accounting for 18% of the variation. Whereas phylum-level analysis failed to reveal any effect of soil practice on bacterial community composition, and missed the fact that different members of the same phylum responded differently to tillage practice. For instance, the fungal phylum Chytridiomycota showed no impact of soil treatment, while sub-phylum-level analysis revealed an impact of tillage practice on the Chytridiomycota sub-groups Gibberella, which includes a notorious wheat pathogen, and Trichocomaceae. This clearly demonstrates the necessity of exploiting the information obtainable at sub-phylum level when assessing the effects of agricultural practice on microbial communities. [less ▲]

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See detailDetecting microbial patterns in relation to soil agricultural practices and the plant development stage
Degrune, Florine ULg; Dufrêne, Marc ULg; Taminiau, Bernard ULg et al

Poster (2014, December 02)

Agricultural practices have a strong impact on soil bacteria and fungi. Furthermore, microbial community composition can change with the stage of plant development. We are interested in exploring these ... [more ▼]

Agricultural practices have a strong impact on soil bacteria and fungi. Furthermore, microbial community composition can change with the stage of plant development. We are interested in exploring these effects in relation to changes induced by agriculture and plant stage in soil conditions. Some bacteria are influenced only by the plant stage, which induces changes in soil humidity, pH, nitrates, and carbon. We would thus expect these bacteria to be highly sensitive to these parameters. Other bacteria are affected only by the tillage practice applied. Further study is needed to identify the soil parameters responsible for this effect. The plant stage also has a great impact on fungal community composition. [less ▲]

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See detailDiversity of Bacterial Communities in a Profile of a Winter Wheat Field: Known and Unknown Members
Stroobants, Aurore ULg; Degrune, Florine ULg; Olivier, Claire et al

in Microbial Ecology (2014)

In soils, bacteria are very abundant and diverse. They are involved in various agro-ecosystem processes such as the nitrogen cycle, organic matter degradation, and soil formation. Yet, little is known ... [more ▼]

In soils, bacteria are very abundant and diverse. They are involved in various agro-ecosystem processes such as the nitrogen cycle, organic matter degradation, and soil formation. Yet, little is known about the distribution and composition of bacterial communities through the soil profile, particularly in agricultural soils, as most studies have focused only on topsoils or forest and grassland soils. In the present work, we have used bar-coded pyrosequencing analysis of the V3 region of the 16S rRNA gene to analyze bacterial diversity in a profile (depths 10, 25, and 45 cm) of a well-characterized field of winter wheat. Taxonomic assignment was carried out with the Ribosomal Database Project (RDP) Classifier program with three bootstrap scores: a main run at 0.80, a confirmation run at 0.99, and a run at 0 to gain information on the unknown bacteria. Our results show that biomass and bacterial quantity and diversity decreased greatly with depth. Depth also had an impact, in terms of relative sequence abundance, on 81 % of the most represented taxonomic ranks, notably the ranks Proteobacteria, Bacteroidetes, Actinobacteridae, and Acidobacteria. Bacterial community composition differed more strongly between the topsoil (10 and 25 cm) and subsoil (45 cm) than between levels in the topsoil, mainly because of shifts in the carbon, nitrogen, and potassium contents. The subsoil also contained more unknown bacteria, 53.96 % on the average, than did the topsoil, with 42.06 % at 10 cm and 45.59 % at 25 cm. Most of these unknown bacteria seem to belong to Deltaproteobacteria, Actinobacteria, Rhizobiales, and Acidobacteria. [less ▲]

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See detailHow to reveal the amazing soil microbial diversity ?
Degrune, Florine ULg

Scientific conference (2014, May 22)

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See detailImpact of agricultural practices on soil microbial communities in Belgium
Degrune, Florine ULg; Taminiau, Bernard ULg; Dufrêne, Marc ULg et al

Poster (2013, December 11)

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on ... [more ▼]

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on finding ways to reduce the use of chemicals, and investigating microbial life may lead to solutions. We know that bacteria and fungi are deeply involved in nutrient cycles. Recently the emergence of massive parallel sequencing has enabled us to realize that microbial diversity is huger than we expected. With such a tool it should be possible to study how soil management practices affect the microbial diversity of agricultural soils. A few such studies have been conducted, most of them focusing on bacteria. For Belgium in particular, there is a lack of data on this topic. Here the aim was to see how residue management and tillage practices affect communities of both bacteria and fungi in Belgian agricultural soils. For this we used 454 pyrosequencing of 16S bacterial and 28S fungal rRNA genes. Soil samples came from an experiment in which faba beans were grown with four soil management practices (tillage and no tillage, with and without crop residues), each repeated four times in a Latin square. Several chemical and physical characteristics were measured on each sample. The results show that fungi and bacteria are both impacted by Tillage practices. The main soil drivers are Magnesium and Phosphorus for Fungi communities, and Phosphorus and Potassium for bacteria communities. Finally, the fungi variance observed between plots is explained at 38% by Tillage, Magnesium and phosphorus. And the bacteria variance is explained at 28% by Tillage, Phosphorus and Potassium. [less ▲]

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See detailStudy of bacterial diversity in the topsoil and below the hardpan in an agricultural soil by metagenomics following by two analysis pipelines
Stroobants, Aurore ULg; Lambert, Christrophe; Degrune, Florine ULg et al

Poster (2013, June 10)

On earth, Bacteria are ubiquitous and even present in extreme environments (pH, temperature,…). In soils in particular, bacteria are very abundant (up to 109 cells per gram of soil) but still poorly ... [more ▼]

On earth, Bacteria are ubiquitous and even present in extreme environments (pH, temperature,…). In soils in particular, bacteria are very abundant (up to 109 cells per gram of soil) but still poorly characterized. Thus, it is of paramount importance to use relevant study and analysis procedures to ensure that the results obtained closely reflect the real-life conditions. In the present work, we analyze the bacterial diversity in the topsoil and below the hardpan in an agricultural soil using the metagenomics approach, with the Ion Torrent PGM sequencer. The soil samples was collected at three depths : 10 cm (topsoil), 25 cm (topsoil above the hardpan) and 45 cm (below the hardpan), in a tilled and a no tilled plot. The taxonomic analysis of the reads obtained are carried out according to two different procedures with the RDP classifier program and with a confidence score threshold of 0 and 0.99. The 0 threshold is used to assign a species to all reads, each read being therefore assigned to its most closest known species. The threshold of 0.99 enables us to focus on reads being assigned to a species with a high degree of confidence. In this case, each read is assigned to the most specific rank having a confidence score higher than 0.99. The bacterial diversity was then compared between the different conditions. Results obtained demonstrate that the bacterial communities were not the same in the two horizons. For example, some classes of Acidobacteria were up to 11 fold more numerous in topsoil while others was until 12 fold more represented below the hardpan. The biomass and the bacterial diversity (Shannon index) were also greatly different between the two depths. [less ▲]

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See detailImpact of the depth on bacterial diversity in an agricultural soil
Stroobants, Aurore ULg; Degrune, Florine ULg; Lambert, Christophe et al

Poster (2013, February 08)

Bacteria are the most abundant and diverse microorganisms in soils. They play an important role in soil formation, contribute to plant nutrition and are involved in various processes in agroecosystems ... [more ▼]

Bacteria are the most abundant and diverse microorganisms in soils. They play an important role in soil formation, contribute to plant nutrition and are involved in various processes in agroecosystems such as nutrient cycling. The aim of this study was to evaluate the impact of the depth on bacterial diversity and quantity in an agricultural soil. Samples was collected on May 2011 and May 2012 at three different depths : 10, 25 and 45 centimeters. The quantity of total bacteria was measured by real time PCR and the analysis of the diversity was performed by the high throughput sequencing technology. Results obtained by these methods show that the biomass and the bacterial quantity and diversity (Shannon index) decrease with the depth, particularly at 45 centimeters. The biomass is, in average, 6.5 fold less important at 45 cm than at 10 cm and the quantity is 17 fold lower at 45 cm than at 10 cm. Our results also indicate that many taxa, such as Betaprotebacteria, Deltaproterobacteria, Gammaproteobacteria, Acidobacteria and Burkholderiales are influenced by the depth. The results will be presented in more details on the poster. [less ▲]

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