In-Depth Observation on the Microbial and Fungal Community Structure of Four Contrasting Tomato Cultivation Systems in Soil Based and Soilless Culture Systems.

As soil and soilless culture systems are highly dynamic environments, the structure of rhizosphere microbial communities is consistently adapting. There is a knowledge gap between the microbial community structure of soil based and soilless culture systems and thus we aimed at surveying their impact on diversity and composition of bacterial communities across a 10-month period in a tomato cultivation system. We compared community metrics between an soil based culture system fertilized with malt sprouts and blood meal, known for its slow and high mineralization rate, respectively and a soilless culture system fertilized with fish effluent or supplemented with an liquid organic fertilizer.

Effects of synthetic fertilizer and farm compost on soil nematode community in long-term crop rotation plots: A morphological and metabarcoding approach.

Soil biodiversity plays a key regulation role in the ecosystem services that underpin regenerative sustainable agriculture. It can be impacted by agricultural management techniques, both positively (through measures such as compost application) and negatively (through, for example, application of synthetic nitrogen). As one of the most numerous members of the soil biota, nematodes are well established as indicators for the soil food web.

Tomato plants rather than fertilizers drive microbial community structure in horticultural growing media.

Synthetic fertilizer production is associated with a high environmental footprint, as compounds typically dissolve rapidly leaching emissions to the atmosphere or surface waters. We tested two recovered nutrients with slower release patterns, as promising alternatives for synthetic fertilizers: struvite and a commercially available organic fertilizer. Using these fertilizers as nitrogen source, we conducted a rhizotron experiment to test their effect on plant performance and nutrient recovery in juvenile tomato plants.

Physiological basis of chilling tolerance and early-season growth in miscanthus.

Background And Aims: The high productivity of Miscanthus × giganteus has been at least partly ascribed to its high chilling tolerance compared with related C4 crops, allowing for a longer productive growing season in temperate climates. However, the chilling tolerance of M. × giganteus has been predominantly studied under controlled environmental conditions.

Morpho-physiological responses to dehydration stress of perennial ryegrass and tall fescue genotypes.

Worldwide drought stress is the most important restriction factor on food and fodder productivity. In this study, morpho-physiological adaptations to dehydration stress were investigated in two tall fescue (Festuca arundinacea Schreb.) genotypes (Fa13 and Fa19 with a high and low sheep grazing preference respectively) and Lolium perenne L.

Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint.

Mineral and organic growing media have distinct community structure, stability and functionality in soilless culture systems.

The choice of soilless growing medium for plant nutrition, growth and support is crucial for improving the eco-sustainability of the production in horticultural systems. As our current understanding of the functional microbial communities inhabiting this ecosystem is still limited, we examined the microbial community development of the two most important growing media (organic and mineral) used in open soilless horticultural systems. We aimed to identify factors that influence community composition over time, and to compare the distribution of individual taxa across growing media, and their potential functionality.

Absorption, translocation and metabolism of metamitron in Chenopodium album.

Background: In recent years, common lambsquarters (Chenopodium album L.) populations from sugar beet fields in different European countries have responded as resistant to the as-triazinone metamitron. The populations have been found to have the same D1 point mutation as known for atrazine-resistant biotypes (Ser264 to Gly).

Genetic modification through oligonucleotide-mediated mutagenesis. A GMO regulatory challenge?

In the European Union, the definition of a GMO is technology-based. This means that a novel organism will be regulated under the GMO regulatory framework only if it has been developed with the use of defined techniques. This approach is now challenged with the emergence of new techniques.

A method to search for optimal field allocations of transgenic maize in the context of co-existence.

Spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm measure to keep the adventitious presence of GM material in the harvest of neighboring fields due to cross-fertilizations below the European labeling threshold of 0.9%. However, the implementation of mandatory and rigid isolation perimeters can affect the farmers' freedom of choice to grow GM maize on their fields if neighboring farmers do not concur with their respective cropping intentions and crop plans.

Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize.

Quantifying the introgressive hybridisation propensity between transgenic oilseed rape and its wild/weedy relatives.

In order to estimate the introgressive hybridisation propensity (IHP) between genetically modified (GM) oilseed rape (Brassica napus) and certain of its cross-compatible wild/weedy relatives at the landscape level, a conceptual approach was developed. A gene flow index was established enclosing the successive steps to successfully achieve introgressive hybridisation: wild/weedy relatives and oilseed rape should co-occur, have overlapping flowering periods, be compatible, produce viable and fertile progeny, and the transgenes should persist in natural/weedy populations. Each step was described and scored, resulting in an IHP value for each cross-compatible oilseed rape wild/weedy relative.

The interplay between societal concerns and the regulatory frame on GM crops in the European Union.

Recapitulating how genetic modification technology and its agro-food products aroused strong societal opposition in the European Union, this paper demonstrates how this opposition contributed to shape the European regulatory frame on GM crops. More specifically, it describes how this opposition contributed to a de facto moratorium on the commercialization of new GM crop events in the end of the nineties. From this period onwards, the regulatory frame has been continuously revised in order to slow down further erosion of public and market confidence.

The co-existence between transgenic and non-transgenic maize in the European Union: a focus on pollen flow and cross-fertilization.

The ongoing discussion on the co-existence between genetically modified (GM) and non-GM crops becomes more important in the European Union (EU). With the recent inscription of 17 GM maize varieties in the common EU catalogue of varieties of agricultural plant species, the acreage of transgenic maize for market purposes is expected to increase in some European countries. In the EU, specific tolerance thresholds have been established for the adventitious and technically unavoidable presence of GM material in non-GM produce, and member states are elaborating legal frames to cope with co-existence.

Management of herbicide-tolerant oilseed rape in Europe: a case study on minimizing vertical gene flow.

The potential commercialization of genetically modified herbicide-tolerant (GMHT) oilseed rape in Europe raises various concerns about their potential environmental and agronomic impacts, especially those associated with the escape of transgenes. Pollen of oilseed rape can be dispersed in space, resulting in the fertilization of sympatric compatible wild relatives (e.g.

Vegetation development and floristical diversity of newly created sown and unsown field margin strips on ex arable land during the first 3 successional years.

Early succesion of newly created sown/unsown margin strips on ex arableland, managed by two cuttings per year with/without removal of cuttings was characterised by the replacement of annuals in favour of perennials, a steadily increase in the importance of monocots and a decrease in non N-fixing dicots. Mowing with removal of cuttings delayed this succession pattern. Sorenson's qualitative similarity index (based solely on species occurrence) revealed that species composition of the sown communities (in terms of species occurrence) became increasingly similar to the unsown plots.

The quantitative and qualitative difference between a F1 hybrid of maize and its F2 generation.

The majority of modern maize varieties are single F1 hybrids. The yield performance of the F2 generation is known to be inferior to the F1 yield performance. We crossed several F1 hybrids and compared these crossings, together with true F2 generations, with the original F1s.

Agricultural effects on yield and nutritive value of grassland under a limited fertilisation rate on sandy soils in Flanders.

From 1999 to 2002, we studied the yield production and quality parameters of grassland installed on sandy soils (1) under normal management (NM), (2) under management with respect to meadow birds (MBM) -first mowing date 15 June or later- and (3) under botanical management (BM) -first mowing date 1 July or later. The experiments were conducted at two locations, Aalter and Geel. The biomass production under MBM and BM decreased by resp.

Effect of long-term herbicide applications on the bacterial community structure and function in an agricultural soil.

Little is known about the chronic effect of herbicides on the soil microbial community, with most studies focusing on acute impacts. In this study, we investigated the effect of 20 years of atrazine and metolachlor application on the community structure, abundance and function of bacterial groups in the bulk soil of a maize monoculture. Group-specific PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) of 16S rRNA genes was used to characterize the composition of the microbial community.

Long-term effects of mineral versus organic fertilizers on activity and structure of the methanotrophic community in agricultural soils.

Agricultural practices, such as mineral nitrogen fertilization, have an impact on the soil's ability to oxidize methane, but little is known about the shifts in the methanotrophic community composition associated with these practices. Therefore, the long-term effect of both mineral (NH4NO3) and organic (manure and GFT-compost) fertilizer applications on the soil methanotrophic community activity and structure were investigated. Both high and low affinity methane oxidation rates were lower in the soil treated with mineral fertilizer compared to the other soils.

Disentangling invasiveness and invasibility during invasion in synthesized grassland communities.

•   An experiment with synthesized grassland communities was performed to identify plant traits that contribute to invasiveness and community traits that promote invasibility, and to study the relationship between, and the relative importance of, invasiveness and invasibility. •   Eight perennial grass species were used both as invasible monocultures and as potential invaders in gaps in these monocultures. Invasion success in the establishment phase, and invader and monoculture traits were assessed.