How to produce more with less water?
1 – Avoid the risk of drought
An avoidance strategy consists of avoiding products whose cycle is mainly at risk periods, in a leveraged, non-irrigable situation. For example, a meslin to fodder corn. It remains possible to choose spring-summer crops, but with economic and agrotechnical interests, with the least water capacity (sunflower, sorghum, etc.). In the case of maize, the abundant variety offer allows the selection of those whose earlier characteristics prevent exposure to the most drought-sensitive stages.
2 – Reduce the risk of drought
The escape strategy does not offer all guarantees, as it is difficult to know in advance when dry periods will occur. Diversify your cultures For this reason, it is useful to spread the risks over different periods.
3 – Limit tillage…
In August, many farmers had trouble sowing canola seed or cover crops. soil dryness. It is better to work them as little as possible to keep as much moisture as possible in the first centimeters. This strategy also affects deep infiltration and soil water storage. In conservation agriculture (SCA), maintaining soil structure and biological porosity built up over time creates an effective water reservoir to hold water. In addition, the coatings used in ACS promote infiltration by avoiding slapping and runoff. According to Thierry Gain, technical coordinator of Apad (Association for the Promotion of Sustainable Agriculture), “infiltration can be increased by 100 mm per hour in grassland or non-ploughed land with vegetation.”
4 – … and use vegetation
In addition to protecting the soil from heavy rains, knife contributing to their effective structuring through root development. They gradually reduce any areas of compaction, allowing crop roots to descend further to collect water. Cutlery also brings organic matter. It acts as a sponge against water and feeds soil fauna (earthworms, microorganisms) which also affects biological porosity. Finally, covers buffer soil temperature and limit water evaporation, especially in hot weather. The presence of trees (hedges, agroforestry) is also a means to improve soil water retention.
5 – Increase irrigation efficiency
The use of management and decision support tools (water balance, probes) allows to adjust the intake as best as possible. Thanks to them, according to Arvalis, it is possible to do one or two turns in the corn campaign without water. In a resource-limited situation, the goal is to target the most productive water resources, such as maize flowering, a period of great vulnerability to water stress. The institute is also testing a new tool that aims to control irrigation when there is insufficient water volume. On the sensor side, future innovation relates to measuring the actual needs of plants rather than soil water status. Irrigation efficiency is also linked to the equipment used: Arvalis is particularly testing the interests of in-field modulation of water supply with a variable flow loop.
6 – Limit evaporation using photovoltaic shades
In Haute-Saône, a shade house equipped with rotating photovoltaic panels has been commissioned this year on an area of more than 3 hectares. Carried by poles 5 m high and 27 m apart, it is designed for large crops. Using trackers that automatically tilt the panels along the sun’s axis, this canopy reduces evaporation and reduces thermal and water stress. Tests will be carried out by the TSE company – at the start of the project – with the cooperatives of INRAE and the BFC Alliance to measure the compatibility of such equipment.
