The quality of Andosols under forestry, agroforestry and agricultural management in Zacatlán, Puebla

Abstract

Soil studies on agroforestry systems related to cloud forests have been poorly studied in our country, especially those systems that develop in Andosols, which are very susceptible to land degradation processes with changes in land use. The present study was carried out in the municipality of Zacatlán, Puebla, to characterize the quality of Andosols under different management systems. The methods used were interviews with producers to identify the systems, description of soil profiles, laboratory analysis and similarity analysis of different management systems. In addition, with edaphic information, quality indices of the different management systems were established. The results indicate that the study area is composed of three systems: cloud forest, agroforestry (apple-blueberry-pumpkin-maize-associations) and agricultural management, with addition of organic and inorganic fertilization (OF and IF, respectively). In Andosols under cloud forests, the biological structure is dominant (crumb texture and granular aggregates, up to 55 cm deep). Furthermore, they have high contents of soil organic matter (31%), high moisture retention (194.5%), and low bulk density 0.49 g cm-3. With land use change (to agroforestry or agricultural), the biological structure is reduced in thickness or even disappears from the topsoil, and sub-angular blocks dominate, due to the drastic decrease in organic matter content (16.3 to 6.3%), and water retention (to 97 and 47%). In addition, bulk density increases from 0.49 to 1 g cm-3 in the agricultural system. Conversely, in degraded lands, agroforestry systems with organic fertilization has improved the quality of the surface horizon in less than six years, and with organic or inorganic fertilization some agroforestry systems increase the contents of total N and P. The indexes that best characterize the quality of the Andosols under different systems are soil structure, soil organic matter, Ntot, and moisture retention.