A group of researchers has introduced a technique to assess, compare, and convey the impact of various crops on agricultural soil loss. Their goal is to enhance awareness about this issue and promote strategies for safeguarding this crucial resource.
A research team from the Department of Agronomy has proposed a method to evaluate, contrast, and communicate how different crops contribute to agricultural soil loss, aiming to increase awareness of this challenge and encourage solutions to protect this vital resource.
Agriculture is facing a significant challenge that largely affects the future of our planet: the need to sustainably feed a growing global population while ensuring the careful utilization of essential natural resources for food production and life. In this framework, terms such as ‘carbon footprint’ and ‘water footprint’ have emerged, which indicate the resources consumed in producing goods, food, or services. These terms assess the impact of production on the environment and help to evaluate the sustainability of consumption practices. A new concept relates to another limited resource that is equally critical for life—soil—whose erosion leads to nutrient loss, diminished biodiversity, and reduced water retention capacity.
The ‘soil footprint’ of a food refers to the amount of soil that is lost during its cultivation, calculated by dividing the erosion rate by productivity levels. This term is part of the ‘A Soil Pact for Europe’ initiative and has been formally defined and applied in Spain by researchers Andrés Peñuela, Vanesa GarcÃa Gamero, and Tom Vanwalleghem from the Hydrology and Agricultural Hydraulics team in the MarÃa de Maeztu Unit of Excellence at the Department of Agronomy at the University of Córdoba (DAUCO). Their aim is to simplify the communication of the serious issue of soil erosion to engage consumers, joining them with the current network of scientists, policymakers, and the agricultural sector.
The approach of the research team is straightforward: Similar to how ‘water footprint’ awareness has influenced society by highlighting food origins and costs while promoting changes in consumption behavior, introducing the concept of ‘soil footprint’ can also facilitate the shift towards more sustainable production methods that are mindful of soil resources. All parties involved must contribute: the scientific community needs to investigate erosion causes and suggest solutions; political authorities must implement regulations to protect soil; and the agricultural sector should adopt sustainable practices that optimize resource use. Consumers play a critical role as well since their choices can significantly impact market dynamics. By opting for foods that do not harm soil, consumers can lobby the production sector to embrace sustainable farming methods, akin to the shift seen with eco-labeled and cruelty-free products.
Olive trees rank highest in ‘soil footprint’
Beyond defining the concept and establishing measurement parameters, the research team assessed the ‘soil footprint’ of Spain’s top ten crops, identifying regions across the Peninsula facing the most significant issues. Their findings indicate that olive trees have the highest soil footprint (i.e., they produce less food relative to the level of erosion they cause), with cherry trees and wheat following closely. Conversely, onions, potatoes, and oranges emerge as the crops with the smallest soil footprints among those studied.
The reality that Spain’s most damaging crop to soil is also one of its key economic drivers and a national symbol is concerning. However, the researchers clarify that soil erosion is influenced not only by crop characteristics but also by environmental factors such as climate, landscape, and farming practices. “The answer is not to decrease the number of olive trees but to adopt measures that shield the soil from erosion, like ground cover vegetation,” stated researcher Andrés Peñuela. Multiple studies have demonstrated that effective management techniques can significantly reduce soil erosion in Mediterranean olive groves. This approach would help lower the soil footprint of this crop and protect a vital resource whose future is of collective concern, similar to the already prominent issues surrounding water and energy conservation.
