Metrics of soil degradation by recent filling of permanent gullies: A study case on annual rainfed crops at the Campiña landscape (Spain)

Authors: CASTILLO, CARLOS - University Of Cordoba; TAGUAS, ENCARNACION - University Of Cordoba; VALLEJO, MIGUEL - Namibia University Of Science And Technology (NUST); PEREZ, RAFAEL - University Of Cordoba; Wells, Robert; Bingner, Ronald; GOMEZ-MACPHERSON, HELENA - Institute For Sustainable Agriculture

Submitted to: Precision Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2025
Publication Date: 1/3/2026
Citation: Castillo, C., Taguas, E.V., Vallejo, M., Pérez, R., Wells, R., Bingner, R., Gómez-MacPherson, H. 2026. Metrics of soil degradation by recent filling in permanent gullies: A study case on annual rainfed crops at the Campiña landscape (Spain). Precision Agriculture. Precision Agric 27, 12. https://doi.org/10.1007/s11119-025-10312-7
DOI: https://doi.org/10.1007/s11119-025-10312-7

Interpretive Summary: The manuscript explores gully filling from the standpoint of soil quality and crop yield. The study takes place in Southern Spain, near Cordoba. Soil sampling and yield monitoring were conducted between 2014 and 2020 on disturbed and non-disturbed positions along four gullies that were filled at different times. A unique soil quality index (SQI) was developed using organic matter, soil color, and clay and silt fractions. The SQI and topographic setting provided an estimate of reduced soil quality between 40 and 60% within the bounds of the filled gullies. Also, an analysis of digital elevation maps of the gullies and adjacent areas showed 90-cm cuts and 2-m fills between 2014 and 2020. Within the same disturbed areas, there was a reduction in productivity of 90% and the sunflower yields were lower than wheat yields.

Technical Abstract: When you fill a gully is there an expectation of a fresh start or blank canvas where productivity returns to days of yore? A soil quality and crop yield study was devised and carried out in the Campiña of Southern Spain, near Córdoba. Both disturbed and non-disturbed sites near and within the bounds of four different gullies that were filled at different times were sampled, a single soil quality indicator (SQI) was developed, and the spatial and temporal dynamics were evaluated to quantify the impact of gully filling. Soil properties and landscape position were important attributes that attributed to soil degradation in the study. The SQI and topographic setting provided an estimate of reduced soil quality between 40 to 60% in disturbed areas due to filling operations. Analysis of elevation maps confirmed 90-cm cuts and 2-m fill depths between 2014 and 2020. These same disturbed areas also had 90% reduction in production, more for sunflower than for wheat.