Search results for "Trait"
showing 10 items of 1361 documents
Impacts of climate change on the performance of an insect pest and associated consequences for tritrophic interactions
2019
Global warming poses a major challenge to living organisms, particularly for ectothermic animals like insects, whose physiology and behaviour are closely related with direct thermal surroundings. This thesis aims at experimentally investigating the impacts of climate change on the overall performance of a major grapevine pest, the European grapevine moth (Lobesia botrana), and the associated consequences for interactions involving this phytophagous insect and adjacent trophic levels, more specifically natural enemies (parasitoids). The experiments conducted focus on three facets of climate change: an increase in mean temperature, an alteration of daily thermal range, and the occurrence of h…
Cropping system dynamics, climate variability, and seed losses among East African smallholder farmers: a retrospective survey.
2014
Abstract Climate variability directly affects traditional low input and rain-fed farming systems, but few studies have paid attention retrospectively to the cropping system’s ability to mitigate climate risk. This study analyzes the impacts of rainfall variability on farmers’ seed variety losses over time, considering changes in smallholder farming systems. The cropping system dynamics, in favoring maize at the expense of sorghum and pearl millet, have induced an increasing risk of seed loss during drought. Combining ecological anthropology and climatology, a retrospective survey asking farmers about the period 1961–2006 was carried out at three altitudinal levels (750, 950, and 1100 m) on …
Soil DNA evidence for altered microbial diversity after long-term application of municipal wastewater
2010
International audience; Water resources constitute a social, agricultural and economic problem in most countries of the southern Mediterranean Basin. Alternative strategies have been developed such as the reuse of municipal wastewater for irrigation in agriculture. Despite numerous advantages for soil fertility and crop productivity, recycling wastewater in soils also has several ecotoxicological and sanitary problems. Few investigations have assessed the risk by evaluating the impact of wastewater irrigation on soil microbes. Here, we report for the first time the short- and long-term effects of treated municipal wastewater irrigation on the density and genetic structure of bacterial and f…
Transition to conservation agriculture : changes in cropping practices and responses of weed communities
2020
Conservation agriculture is a farming system based on the continuous and simultaneous application of three principles: minimal soil disturbance, continuous residue cover on the soil surface and diverse crop rotations. Adoption of this form of sustainable agriculture in France since the 2000s has been hampered by a number of constraints, including the development and management of weed populations. From an agronomic point of view, the adoption of conservation agriculture and associated abandonment of tillage results in a significant loss of weed management practices for farmers. From an ecological point of view, its application can modify all the assembly processes that act on weed communiti…
Quantification des flux d’azote induits par les cultures de légumineuses et étude de leurs déterminants : comparaison de 10 espèces de légumineuses à…
2019
In the context of agroecological transition, the reintroduction of legume crops should play a key role in cropping system sustainability by allowing a reduction of nitrogen (N) inputs. But few references are available concerning the agronomical and ecological services provided by a wide range of legume crops, particularly within crops succession scale. Thus, the main objective of our study is to quantify the N fluxes during and after the legume crops taking into account 10 legume crops (peas, lupin, faba bean, soybean...). Our experiment consists in i) quantifying symbiotic N fixation depending on the amount of soil inorganic N, the mineralisation of N present in legume crop residues after …
Herbicides céréales : "Alterner en sortie d'hiver n'est pas suffisant"
2013
Interview article par Marion CoisneDépartement SPEPôle GEAPSI; absent
Highlighting the role of diversity in driving weed dynamics and weed-crop interactions
2017
EAGESTAD INRA; Weeds are responsible for crop losses and their management, mainly through herbicide applications, has led to resistances and environmental impacts. Integrated Weed Management encourages the use of “many little hammers” such as crop rotation, mechanical weeding, stale seedbed technique and delayed sowing … i.e. more complex and diversified cropping systems, in order to increase cropping system sustainability. However, research is still required to test the effectiveness of combinations of these alternative tactics in a wide range of agricultural contexts. Furthermore, the cropping system approach considers all these individual hammers, whose effects on agricultural weeds have…
Capacité des adventices à germer en surface dans diverses conditions
2017
EASPEGESTADINRAAGROSUP; Les espèces annuelles produisent des graines chaque année pour maintenir leur population. Ces graines tombent à la surface du sol. Si aucun travail du sol n’est réalisé (ex. cas du semis direct), les graines doivent germer en surface du sol, exposées aux variations environnementales, et parfois même dans un couvert. Cette étude a permis d’étudier l’effet du non-enfouissement des graines, et des conditions environnementales (humidité, lumière, présence d’un couvert) sur la germination, l’émergence et la croissance de nombreuses espèces annuelles. La germination est réduite (en moyenne, toutes espèces confondues) de 26% lorsque les graines sont laissées en surface, de …
Risque de résistance au glyphosate dans les systèmes de culture à base de maïs et effet sur la production agricole et la biodiversité
2017
EASPEGESTADAGROSUPINRA; L'utilisation répétée du glyphosate, en interculture et/ou en culture (dans le cas de cultures tolérantes au glyphosate), peut conduire à la sélection de populations d’adventices résistantes à cet herbicide. Dans cette étude, nous avons introduit un module de génétique dans le modèle de dynamique adventice FLORSYS prédisant mutation, sélection et coûts de la résistance. Nous avons simulé des systèmes de culture à base de maïs, avec différentes fréquences d'application de glyphosate, rotations, intensités de travail du sol et dates de semis. Nous avons analysé la probabilité et le délai d'apparition de la résistance, ainsi que son impact sur la nuisibilité et les béné…
Soil weed seedbank composition and structure in a long-term nutrient management experiment
2016
EAGESTAD; Weed communities can be influenced by nutrient availability, nutrient form (e.g. ammonium vs. nitrate), amendment timing, amendment type, and by immigration of seeds during amendment applications. New York ranks third in the United States in the number of dairy cows and thus dairy manure applications are prevalent throughout the state. The objective of this work was to compare the effect of dairy manure and inorganic fertilizer on soil weed seedbank composition and structure in a long-term nutrient management experiment. The field experiment was initiated in 2001 at the Cornell Musgrave Research Farm in Aurora, NY and compared ten treatments in a corn-alfalfa rotation using a rand…