Agricultural land in France
In France, in 2019, the utilised agricultural area (UAA) represents 45% of the country's surface area, and 52% when focusing only on metropolitan France.
The proportion of UAA in the total surface area varies greatly from region to region: over 68% in Normandy, Pays de la Loire and Hauts-de-France and less than 1% in French Guiana, where 90% of the territory is covered by forests [2].
Because of their properties, soils largely explain the agricultural or forestry vocations of our regions as well as the development of certain agricultural production systems. Intensive arable farming dominates the deep silty soils of the sedimentary basins (Aquitaine Basin, Paris Basin, Limagne). With the development of fertilisation or irrigation, field crops have also developed in certain regions characterised by calcareous soils (Champagne, Poitou-Charentes). Pasture-based livestock farming is mainly found in the moderately acidic environments of ancient massifs (Brittany, Manche, Massif Central) and in regions with strong climatic constraints (Jura, Causses).
The poorest and most acidic soils (Landes de Gascogne, Sologne, Vosges) are generally exploited by forestry production. The constraints or particular characteristics of certain soils have generated specific occupations: rice on the soils of the Camargue, meadows or poplar groves in the wet soils of lowlands, vines on the gravelly soils of the ancient terraces of the Bordeaux region or on the rocky soils of the ancient terraces of the Rhone valley, maritime pine on the Atlantic dunes, etc. [3]
In total, 26.8 million hectares are composed of arable land, permanent grasslands, and permanent crops [2]. In 2020, field crops covered 44% of the UUA, one third of which is sown in the spring [1].
Challenges for this land type
The major issues relating to French agricultural soils, whether in metropolitan France or in the overseas territories, cover two complementary dimensions [2]:
The protection of the agricultural use of soils, as France, like many countries in Europe, is faced with a difficult equation to solve: an increase in needs in terms of housing, infrastructure, economic, commercial and leisure activities, natural areas for resourcing and preservation of the ecosystems, and, of course, food. It is therefore necessary to balance between these different land uses, considering the various local and territorial specificities to do so, to preserve agricultural land in the face of land artificialisation and urban expansion.
In addition to excessive artificialisation, abandonment of agricultural land is also a factor leading to the reduction of cultivated areas. It can happen in regions facing desertification, for example, in the absence of a buyer following the departure of a farmer.
Although still limited, land grabbing by private companies is a threat that is starting to grow in France. It usually involves investors looking for maximal profitability which creates a form of unbalanced competition for access to land and is often associated with unsustainable practices.The maintenance or even improvement, where necessary, of agricultural soil quality, which conditions soil physical, chemical and biological fertility. It depends to a large extent on organic matter content, the presence of a rich and varied biodiversity, and the preservation of a good soil structure. Therefore, it will be impacted by natural or anthropic drivers that can increase soil compaction and soil erosion (1.5 tons of land per hectare are lost on average each year due to run-off in France [1]), soil sealing, or lead to a loss of organic matter (and organic carbon) or in soil biodiversity.
In addition to their impacts on agriculture, factors that affect soil functioning can have repercussions on the environment beyond the farm. For example, soil contamination, soil erosion or nutrient leaching (various factors can increase leaching), can deteriorate water quality. Soil compaction, which can have a strong impact on the soil, can also lead to increased greenhouse gas emissions from the soil, which will contribute to climate change.
Some possible solutions
Regarding the preservation and improvement of agricultural soil quality, there are already practices identified as favourable to good soil quality.
For example, the supply of urban sludge, livestock manure and no-tilling can improve soil organic matter content and carbon storage, while a continuous soil cover thanks to an adapted crop rotation, integrating legumes such as alfalfa, clover and protein crops or intermediate crops, can reduce soil erosion and nitrate leaching [2].
The use of adapted equipment can reduce the risk of soil compaction, as well as the planification of field operations at times when the soil is least susceptible to compaction (weather conditions, soil moisture, etc.).
Good soil management is about balance and compromise. Some practices can have a good impact on some soil functions and affect negatively other functions. For example, tilling aerates the soil and improves fertilisation, but it also strongly affects soil structure and soil biodiversity, accelerating carbon removal and nitrogen leaching. Soil conservation techniques, including no tilling, reduce these impacts but also risk increased weeds and insects, which can lead to possible recourse for pesticides.
To help farmers adopt sustainable practices, research and political actions are needed [2].
Development of research and experimentation on agronomic practices favourable to soil quality is needed to strengthen the available knowledge and develop operational tools for farmers whether it is technical tools to operate in the field or decision-support tools. Involving farmers in the innovation and research process and facilitating interactions between farmers and researchers can help the adoption of innovative, operational tools and practices on the field.
Agricultural policies are also part of the solutions as they need to support production and practices that are favourable to good soil quality and help farmers who convert or are committed to sustainable soil management.
Supportive policies and regulations, at European, national and local levels, are also an important tool to prevent land abandonment and protect agricultural land from artificialisation [2]. France has already put in place several policies and regulations in this regard, including the recent introduction of new measures in the law to reduce land artificialisation (Climate and Resilience Law). However, there is still a need to go further and develop a more effective policy and regulatory framework, also based on new knowledge and capacities regarding soil quality and monitoring.
What citizens can do
Citizens can get informed and get closer to the farmers in his or her region to become an informed consumer.
With a better knowledge regarding the origin of the food a citizen buys, he or her can supports farms that implement good soil management practices.
Citizens can also oppose, at their own level, against artificialisation of agricultural land (e.g., by expressing their views during public consultations that precede some development projects).
Sources:
- France's Environmental Performance Review – 2021 Edition, p48-51.
- A. Courtoux, C. Claveirole, 2015. La bonne gestion des sols agricoles : un enjeu de société. Avis du conseil économique, social et environnemental.
- Gis Sol. 2011. L’état des sols de France. Groupement d’intérêt scientifique sur les sols, 188 p.