Ecophyto R&D. Vers des systèmes de culture économes en pesticides. Volet 1. Tome II : analyse comparative de différents systèmes en grandes cultures

Abstract

This report compared the performances of different farming methods for major field crops at the scales of the culture alone and of the cropping system. It allows to consider several possible strategies to reduce the use of pesticides in crops (i) strategies based on the reasoning of chemical interventions (level 1), (ii) strategies involving agronomic levers during the annual cropping cycle (level 2a) and at the scale of the crop rotation cycle (level 2c), (iii) and strategies using the specifications of the Organic Farming (Level 3). The results produced in this report (description of agronomic, environmental and economic performances) were based on methods taking into account regional performances and on available experimental field datas. It appears that all crops do not contribute with the same weight to the use of pesticides. In terms of reduction of TFI, the margins of progress are clear for all three strategies, without decrease of gross margin, except for the potatoes. Cropping systems in 2a and 2c levels allow theorically to maintain or even increase gross margins (4% on average for level 2) compared to intensive culture and allow a drastic decrease in pesticides use (by almost 40% from the level 2a). For comparable economic performances, the level 1 (reasoned) allows an average decrease of 21% of TFI. The analysis of others indicators temper or consolidate the results. For exemple, some systems of 2a and 2c levels involve an increase of working time, all systems of 2a and 2c levels reduce energy consumption. Level 1 is very similar to the intensive culture for these 2 criteria. But the only level 2a will not allow to achieve 50% of reduction in the use of pesticides at the scale of the french cropping area. To achieve this goal requires the implementation of cropping systems deeply modified (like the level 2c), leading changes in rotation that are important to assess. These results do not analyse either constraints for farmers or learning necessary for their implementation. Therefore, they must be considered as a first approach of the opportunities to improve practices in field crops in France. These results will be developed by the groups Scenarios and Strategies players on social and economic aspects.