Luxembourg's Ministry of Agriculture, Viticulture and Rural Development has announced the publication of the country's first erosion risk map for arable land.
Soil alteration by erosion, although a natural phenomenon, is a danger to soil fertility which is likely to increase with global warming. Consequently, farmers must constantly adapt their farming and cultivation practices to protect their land. Erosion primarily concerns arable land (45% of the national useful agricultural area) while permanent grasslands (the remaining 55%) are not affected by erosion.
In order to offer an innovative planning tool for the sector, the pedology service of the Agriculture Ministry has published a new map on www.geoportail.lu.
This public map presents the erosion of arable land in the Grand Duchy according to four degrees of risk ranging from very low and low to medium and high. Of the approximately 55,800 ha of arable land, 4% present a very low risk, 19% a low risk, 6% a medium risk and 2% a high risk. The remaining 69% do not present any erosion risks and are therefore not visualised.
The evaluation of the erosion risk was carried out by combining, on the one hand, the theoretical modelling of the risk with the visual analysis of the erosion actually identified on aerial photos, on the other hand. To analyse the actual erosion, thousands of plots were viewed and checked on the eleven aerial photos available on the Geoportal for the period 2001-2020. The modelling approach used geospatial data as diverse as topography, soil cover and tillage, soil type, hydrological modelling and calculation of theoretical erosion based on the universal loss equation.
The new map is deemed an important guidance tool, which helps the farmer to reduce his erosion risks by adapting his agricultural practices and the choice of crops to the context on targeted plots. Erosion control levers include, for example, the use of winter plant cover and catch crops, the choice of crops and their rotation, the installation of grassy strips, weirs or hedges, the reduction of plowing and the intensity of tillage or the regular supply of organic matter to the soil.
To preserve the soil of arable land, the Agriculture Ministry is planning new mandatory measures on plots at risk of erosion as part of its national strategic plan and the new agrarian law aimed at to implement the Common Agricultural Policy (CAP) 2023-2027 in the Grand Duchy.
