Local soil knowledge and management of Anthrosols: A case study in Teoloyucan, Mexico

The irrigation district “Los Insurgentes” was established within the region of Lake Zumpango as a means to control frequent flooding events in Mexico City during the 70s, and as reception area for recharging the subsoil moisture and the development of agricultural land. Nonetheless, the irrigation district mostly stored sewage, and all of the dredged saline lacustrine material was placed on parcels adjacent to the lake burying the original soils. Since then, the farmers have significantly influenced the formation of soil on their lands through wastewater managements. The objectives were to establish the influence of management practices on soil properties, and to determine how the addition of lacustrine sediment, wastewater and amendments are reflected in both local and scientific soil classification. A soil survey was carried out taking into account the local soil knowledge, and soil management and irrigation practices information were obtained through interviews. Also physical and chemical analyses were conducted. The main contributions of farmers to the reclamation of saline soil with low agricultural productivity include the use of wastewater, the use of differing irrigation frequencies with various crops and materials added to existing soil, and the appropriate combination of amendments (manure and soils). These soil managementʹs strategies have strongly modified the soil properties which are now expressed as different anthropogenic horizons (hydragric, terric, and hortic). They are now classified as Anthrosols. This case study shows how human beings are able to adapt to degraded environments and to produce knowledge and strategies for transforming their surrounding landscape.