Soil loss due to crop harvesting in the European Union
Over the last two decades or so, there has been many research carried out to understand the mechanics and spatial distribution of soil loss by water erosion and to a lesser extent of wind, piping and tillage erosion. The acquired knowledge helped the development of prediction tools useful to support decision-makers in both ex-ante and ex-post policy evaluation. In Europe, recent studies have modelled water, wind and tillage erosion at continental scale and shed new light on their geography. However, to acquire a comprehensive picture of soil erosion threats more processes need to be addressed and made visible to decision-makers. Soil Loss due to Crop Harvesting (SLCH) is defined as the loss (or export) of top soil from arable land during harvesting of crops such as potato, sugar beet, carrot or chicory roots. During the harvest of root and tuber crops, soil is sticking to the crop and is removed from the field (or it is displaced from the plot) together with stable soil clods and rock fragments (Ruysschaert et al., 2004). In addition, SLCH depends much on the soil disturbance during the harvest operation. Several factors control the magnitude of SLCH and the rates of soil losses. The most important factors are: i) soil (soil moisture, soil texture, soil organic matter and soil structure), ii) the crop type, iii) the agronomic practices (e.g. plant density, crop yield), and iv) the harvest techniques (technology, effectiveness and velocity of harvester).
Since 1986, a small number of studies have pointed to an additional significant soil degradation process occurring when harvesting root and tuber crops. Field observations and measurements have shown that considerable amounts of soil can be removed from the field due to soil sticking to the harvested roots and the export of soil clods during the crop harvest. This study aims to scale up the findings of past studies, carried out at plot, regional, and national level, in order to obtain some preliminary insights into the magnitude of soil loss from cropland due to sugar beets and potatoes harvesting in Europe. We address this issue at European Union (EU) scale taking into account long-term (1975-2016) crop statistics of sugar beet and potato aggregated at regional and country levels.
During the period 2000-2016, sugar beets and potatoes covered in average ca. 4.2 million ha (3.81%) of the EU-28 arable land estimated at 110 million ha. The total Soil Loss by Crop Harvesting (SLCH) is estimated at ca. 14.7 million tons yr-1 in the EU-28. We estimate that ca. 65% of the total SLCH is due to harvesting of sugar beets and the rest as a result of potatoes harvesting. In the period 1986-1999 the total SLCH was ca. 23.4 million tons yr-1. The significant decrease of total SLCH by 37% between 1987-99 and 2000-2016 is due to a sharp decrease in sugar beet production driven by changes in diets and sugar policy after 2006. The insights gained show that the rates of SLCH are particularly significant in Netherlands, Belgium and Ireland plus some North-East French regions where roots crops are dominating their agricultural production.
At continental scale, it is worthy comparing the mean rate SLCH with soil loss rates of other erosion processes (water, wind). Taking into account that the mean soil loss rate from arable lands due to sheet and rill erosion is estimated at 2.67 t ha-1 yr-1 (Panagos et al., 2015), and the corresponding mean soil loss by wind erosion at ca. 0.53 t ha-1 yr-1 (Borrelli et al., 2017a), the estimated mean SLCH value of 0.13 t ha-1 yr-1 soil loss by harvesting these crops seems to play a minor role in total soil loss rates at the scale of the EU-28, compared to water and wind erosion. However, as previously observed in the case of wind erosion also SLCH is an unevenly distributed process that locally may assume a different relevance.
The result of this research are available a zip file for public users. The dataset includes the shape files of the publication (GIS files) plus excel files for non-GIS users
Panagos, P., Borrelli, P., Poesen, J., 2019. Soil loss due to crop harvesting in the European Union: A first estimation of an underrated geomorphic process. Science of The Total Environment. 664: 487-498. DOI: 10.1016/j.scitotenv.2019.02.009.
||Title: Soil loss due to crop harvesting in the European Union|
Resource Type: Datasets, Soil Threats Data
Registration requested: Request Form
Publisher: Joint Research Centre of the European Commission