Persistence of pesticides in water from farm plots recently converted to organic farming

In Europe, the pervasive use of pesticides in agricultural areas has led to the deterioration of the quality of groundwater and surface water, resources earmarked for human consumption. The aim of the European Water Framework Directive 91/474 is to restore the “good ecological status” of surface water and to protect water that might be used for drinking water production by 2015. Interactions within the soil determine the fate of environmental pesticides. Water resource contamination may persist for a long time after the last use of pesticides (i.e., atrazine). Pesticide persistence is highly variable. The fate and persistence of pesticides in the environment depend on agricultural pesticide practices and on soil interactions, which are interrelated physical, chemical and biological processes that are often sitespecific. This study, which is taking place at INRA’s Mirecourt Experimental Station in the Lorraine region of France, will make it possible to evaluate the persistence and environmental resilience of pesticides in water from plots recently converted to organic farming, within the framework of the WFD. A database includes all pesticide practices from 1969 to 2004, the year of the last treatment. It is hoped that the Mirecourt study, five years after the end of pesticide use, will shed light on the long-term persistence of pesticides in water resources

Use of farm grown cereal/protein mixes by lactating dairy cows in a winter diet

We compared the use of three farm grown cereal/protein mixes (oat/fava bean, barley/lupin, triticale/pea), that were used to complement lactating dairy cow diets based on hay consisting of alfalfa/orchard grass and perennial grassland. The trial took place in 2007 at the INRA experimental station of Mirecourt, where an organic mixed-crop dairy system is being prototyped. The experiment was carried out in a Latin square with three groups of eight cows (50% Holstein, 50% Montbéliarde). The cows were fed 4 kg/cow/day of one of the three cereal/protein mixes, 8 kg DM/cow/day of alfalfa/orchardgrass hay, and permanent grassland hay ad libitum. The three diets were indicative of the animals’ needs. Diets had no significant effect on milk production (20.3 kg/cow/d) and milk fat content (41.3 g/kg). However, dairy cows fed with the oat/fababean mix had a significantly lower protein content in their milk. This is the result of: (i) a nitrogen surplus in relation to energy, and (ii) a lower starch content compared to the two other diets. Therefore, in organic mixed-crop dairy systems with forages that are rich in nitrogen, the choice to cultivate mixtures of cereal/pulses and the composition of these mixtures must be primarily based on their agronomic interest and not on their zootechnical one since they are not essential to a balanced animal diet

Effects of cropping practice dynamics on permanent grassland vegetation during the conversion to organic farming

The aim of this work was to identify the impact of farming practices on permanent grassland vegetation during the conversion from conventional to organic farming. We considered functional and species diversities in order to compare the different grassland categories based on the farming practices used over a period of six years - five years before conversion and one year after. We identified three categories of grasslands: those generally cut twice a year, those intensely grazed, and those that were used under diversified practices. We showed that grasslands characterised by cutting and low fertilization level have the highest species richness compared to the other two categories (23.2, 16.9 and 17 species, respectively), and the lowest pastoral index (45.9, 66.8 and 68.6, respectively). These cut paddocks also presented the highest functional diversity (i.e., richness of functional property attributes) for two of the properties studied: means of dispersal and establishment strategy as defined by Grime. Grasslands with diversified practices (grazing, cutting and nitrogen supply) were not characterised by any single or combined functional property attribute, to the contrary of the two other categories. Finally, farming practices alone do not explain all of the differences in vegetation. We therefore hypothesize that, first, the dynamics of permanent grassland vegetation following conversion to organic farming is only initiated by agricultural practices and, second, other key factors such as landscape characteristics affect these dynamics

Assessing the agro-environmental sustainability of organic mixed-crop dairy systems on the basis of a multivariate approach

Sustainable development calls upon the farming sector to commit itself to the transmission of natural resources to future generations. The INRA research team of Mirecourt studies the design of environmentally-friendly farming systems. The design of these systems is based on a multitude of objectives, and their evaluation is determined by a wide range of criteria. This work aims at determining the practical conditions for implementing agricultural systems considered to be sustainable from an environmental point of view. Two organic dairy systems considered to be environmentally friendly ex ante have been designed in partnership with the staff of the INRA research team of Mirecourt. A grazing dairy system and a mixed-crop dairy system are being experimentally tested at the system scale. The two systems have environmental and agricultural objectives. They are managed using multi-objective decision rules and are assessed on their biotechnical and practical properties, using a structured multiyear experimental design, completed by a model-based assessment. Assessment is oriented towards progressive and permanent re-designing of the systems in order to increase their environmental sustainability and feasibility at the practical level. Knowledge acquired from the two prototypes will then have to be validated on commercial farms

The Dexi-SH* model for a multivariate assessment of agro-ecological sustainability of dairy grazing systems

Dexi-SH* is an ex ante multivariate model for assessing the sustainability of dairy cows grazing systems. This model is composed of three sub-models that evaluate the impact of the systems on: (i) biotic resources; (ii) abiotic resources, and (iii) pollution risks. The structuring of the hierarchical tree was inspired by that of the Masc model. The choice of criteria and their aggregation modalities were discussed within a multi-disciplinary group of scientists. For each cluster, a utility function was established in order to determine weighting and priority functions between criteria. The model can take local and regional conditions and standards into account by adjusting criterion categories to the agroecological context, and the specific views of the decision makers by changing the weighting of criteria

Conversion of a Conventional to an Organic Mixed Dairy Farming System: Consequences in Terms of N Fluxes

International audienceOrganic farming practices are a possible way to reconcile agricultural production and water quality, but the comparative merits of conventional and organic practices regarding the nitrogen (N) issue are complex and still being debated. This study was designed to investigate the choice governing conversion to organic farming of en experimental mixed dairy farm in Lorraine (eastern France) and to highlight the assoicated changes in N fluxes. The study was conducted over a suitably long period of time at a farm scale integrating the diversity of practices in one conventional and then two autonomous organic systems (a grazing livestock system and a mixed dairy system). Two indicators were used to draw up the main features. First, the farm-gate N budgets show the the organic farm has a balance twice as low as the conventional system. Second, the soil surface balance exhibited substantial differences between functional zones. Finally, this study shows that an accurate estimation of soil surface balance requires taking into account the spatial distribution within the farm area based on practices and their rationale

Transition to self-sufficient mixed crop-dairy farming systems

eISSN : 1742-1713International audienceWhile plains favorable to agriculture are still dominated by specialized and intensive agriculture, self-sufficient mixed crop-dairy farming systems increasingly attract policy makers' and scientists' attention. Owing to their limited use of purchased inputs, they can contribute to reducing the environmental impact of agriculture. Furthermore, self-sufficient farming tends to be lindek with a search for autonomy in decision-making, i.e., farmers developing their own technical reference framework. Such farming systems can thus also contribute to alternative development pathways of rural territories. In this paper, we analyze how ten intensive mixed crop-dairy farms have progressively evolved toward more self-sufficient and autonomous systems. Through formalizing farmers' transition in action, we identified 34 tools that the farmers implemented making them reflect on their farming system, shift socio-professional networks, reorganize work routines, and steer the evolution of their production practices. For example, the created temporary pastures in crop rotation, introduced rotational pastures, observed their herds to adjust their feed and keep the animals in good health, and they limited expenditures to manage their cash flow. Which tools were used and when they were used depends on what is meaningful to them at various stages of the transition. Our analysis of transitions in action has three original features : it is centered on the transition as perceived by the the actors who experience and manage it ; it proposes a long-term conceptualization of the dynamics of farming systems, based on the farmer's initiative and creativity ; and it highlights tools implemented by farmers during the transition to self-sufficiency and autonomy