Search results for "GRI"
showing 10 items of 10209 documents
Influence of resource quality on the composition of soil decomposer community in fragmented and continuous habitat
2004
Abstract The aim of this field experiment was to explore the combined effects of two factors potentially affecting the local composition of soil decomposer community: resource quality and habitat fragmentation. We created humus (habitat) patches with three different resource quality: (1) pure homogenised humus; (2) humus enriched with needle litter; and (3) humus enriched with needle and leaf litter. These patches were embedded either in a mineral soil matrix, thus representing fragmented habitat, or in natural forest soil, representing continuous (non-fragmented) habitat. The development of faunal (colonisations/extinctions of soil animal populations) and microbial communities in the patch…
Investigations in intensification of grain drying by active ventilation applying ozone
2020
The financial support of the Rural Support Service project No l8-00-A01620-000003 “Technology development of grain drying with active ventilation using ozone” is greatly acknowledged. The authors thank for the support and active cooperation the representatives of the farm “Mazkalniņi” Dr.sc.ing. Aivars Cēsnieks and ing. Sandris Cēsnieks.
Soil processes are not influenced by the functional complexity of soil decomposer food webs under disturbance
2002
Abstract A 3 yr experiment, using field lysimeters with seedlings of Scots pine (Pinus sylvestris) growing in raw humus, was established to study how functional complexity of the soil decomposer food web affects ecosystem functioning. The functional complexity of decomposer system was manipulated by (1) allowing either microfauna (fine mesh) or microfauna+mesofauna (coarse mesh) to enter the initially defaunated systems, and (2) treating half of the lysimeters with wood ash. To test whether altering functional complexity of the decomposer community is related to the system's ability to resist disturbance, the lysimeters were later on disturbed with drought. Ecosystem function, measured as l…
Seasonal evolution of the quality of fresh glasshouse tomatoes under Mediterranean conditions, as affected by air vapour pressure deficit and plant f…
2000
Abstract Changes in yield and quality of fresh tomatoes in response to air vapour pressure deficit (VPD) and plant fruit load were studied under Mediterranean summer conditions. Plants thinned to three or six fruits per truss were grown in two compartments, one at a VPD below 1.5 kPa, the other without VPD control. The seasonal trend in fruit yield and quality was assessed from April to September by weekly measurement of number, fresh weight and dry matter content of harvested fruits, together with the occurrence of blossom-end-rot (BER) and cracking. On two occasions, in July and September, sugar and acid content was measured at three ripening stages. The seasonal decrease in fresh yield w…
Transition vers des systèmes agricole et agroalimentaire durables : quelle place et qualification pour les légumineuses à graines ?
2017
Cet article propose une analyse historique du processus de verrouillage du système agroalimentaire en défaveur des légumineuses à graines, à l’aune des théories évolutionnistes. Plusieurs mécanismes d’autorenforcement permettent de comprendre pourquoi ces espèces sont de moins en moins cultivées en France face à un système agro-industriel qui s’est spécialisé en faveur des céréales, favorisant à l’amont l’usage d’engrais azotés de synthèse et limitant à l’aval les investissements pour les légumineuses en alimentation humaine. Cet article s’interroge alors sur les perspectives de déverrouillage.
La fermentation en milieu solide
1998
Art ancestral en Asie, la fermentation a l'etat solide est riche de possibilites industrielles: production d'aliments proteiques, d'enzymes, d'hormones vegetales, de biopesticides, ou culture de champignons depollueurs. Connaissant un regain d'interet dans les pays industrialises, ce procede pourrait fournir egalement de nouvelles ressources aux pays du Sud.
Defoliation effects on Plantago lanceolata resource allocation and soil decomposers in relation to AM symbiosis and fertilization
2009
Plants can mediate interactions between aboveground herbivores and belowground decomposers as both groups depend on plant-provided organic carbon. Most vascular plants also form symbiosis with arbuscular mycorrhizal fungi (AMF), which compete for plant carbon too. Our aim was to reveal how defoliation (trimming of plant leaves twice to 6 cm above the soil surface) and mycorrhizal infection (inoculation of the fungus Glomus claroideum BEG31), in nutrient poor and fertilized conditions, affect plant growth and resource allocation. We also tested how these effects can influence the abundance of microbial-feeding animals and nitrogen availability in the soil. We established a 12-wk microcosm st…
Managing arbuscular mycorrhizal fungi in cropping systems
2005
Market globalization, demographic pressure, and environmental degradation have led us to reconsider many of our current agricultural systems. The heavy use of chemical inputs, including fertilizers and pesticides, has resulted in pollution, decreased biodiversity in intensively-farmed regions, degradation of fragile agro-ecosystems, and prohibitive costs for many farmers. Low input sustainable cropping systems should replace conventional agriculture, but this requires a more comprehensive understanding of the biological interactions within agro-ecosystems. Mycorrhizal fungi appear to be the most important telluric organisms to consider. Mycorrhizae, which result from a symbiosis between th…
Characterization of bread breakdown during mastication by image texture analysis
2012
National audience; Reducing sodium intake in Western diet is advised for reducing hypertension and risk of developing cardiovascular disease. Sodium is mainly consumed via processed foods and among them breads are one of the most important sources of salt [1]. The present study investigated the changes in mastication and salivation for bread samples with different composition and texture, their respective contribution to food bolus formation, and the impact on salt release. The study set-up included five subjects presenting different chewing efficiency and four different breads from different composition and structure (two French baguettes (bakery (BB) and supermarket (BS)), a toast bread (…
Response of total and nitrate-dissimilating bacteria to reduced N deposition in a spruce forest soil profile
2009
A field-scale manipulation experiment conducted for 16 years in a Norway spruce forest at Solling, Central Germany, was used to follow the long-term response of total soil bacteria, nitrate reducers and denitrifiers under conditions of reduced N deposition. N was experimentally removed from throughfall by a roof construction (‘clean rain plot’). We used substrate-induced respiration (SIR) to characterize the active fraction of soil microbial biomass and potential nitrate reduction to quantify the activity of nitrate reducers. The abundance of total bacteria, nitrate reducers and denitrifiers in different soil layers was analysed by quantitative PCR of 16S rRNA gene, nitrate reduction and de…