%0 Journal Article
%T Artificial chinampas soils of Mexico City: their properties and salinization hazards Suelos artificiales de chinampas de la Ciudad de M¨¦xico: propiedades y riesgos de salinizaci¨®n Solos artificiais da cidade do M¨¦xico- Chinampas: propriedades e riscos de saliniza ao
%A Pavel Krasilnikov
%A Rosal¨ªa Ramos Bello
%A Norma Eugenia Garc¨ªa Calder¨®n
%A H¨¦ctor Manuel Ortega Escobar
%J Spanish Journal of Soil Science
%D 2011
%I Universia
%R 10.3232/sjss.2011.v1.n1.05
%X The chinampas agriculture is a traditional land use practice in the Valley of Mexico since Pre-Hispanic time. The chinampas soils were constructed by excavation of lake sediments that resulted in the creation of a system of islands separated by channels. The agricultural productivity of these artificial soils was high; also the land use practices included forestry, fish breeding and hunting. Nowadays, the chinampas soils are affected by excessive salinity. We studied 10 representative soil profiles in the chinampas zone of Mexico City in order to characterize their properties and origin, to provide their classification, and to evaluate soil salinization, vertical distribution of the salts and their chemical composition. The soils are characterized by a layered structure, uniform dark grey colour, irregular vertical distribution of organic carbon and clay, and high percentage of carbon. Some soils show an increase in organic matter with depth, and other profiles have maximum organic matter content in the surficial layers and in the subsoil. The dynamics of sedimentation resulted in the decrease in organic matter in the upper layers of lacustrine sediments, because of recent increase in erosion rate and consequent increase in the proportion of mineral particles in the sediments. Most probably high organic matter content in surficial layers of some soils is due to excavation and accumulation of organic-rich subsoil material in the course of digging the channels. The concentration of soluble salts in superficial horizons, expressed as electric conductivity, varies in a wide range from 5 to almost 50 dS¡¤m-1. The salts concentrate mainly in the superficial layers of soils. The abundance of the cations of soluble salts is Na+>Mg2+>Ca2+>K+ and that of the anions is SO42->Cl->HCO3->CO32-. The alkaline reaction of soils is caused by exchangeable Na rather than by free sodium carbonates. The restoration of chinampas requires a complex approach, combining soil, water and ecosystems remediation. La agricultura de chinampas es una pr¨¢ctica tradicional de uso del suelo en el Valle de M¨¦xico desde la ¨¦poca prehisp¨¢nica. Los suelos de chinampas fueron construidas por la excavaci¨®n de sedimentos del lago que result¨® en la creaci¨®n de un sistema de islas separadas por canales. La productividad agr¨ªcola de estos suelos artificiales fue alta; tambi¨¦n las pr¨¢cticas de uso del suelo incluyeron la silvicultura, la pesca y la caza. Actualmente, los suelos de chinampas est¨¢n afectados por una salinidad excesiva. Se estudiaron 10 perfiles de suelos representativos de la zona de ch
%K Artificial soils
%K Anthrosols
%K soluble salts
%K lacustrine sediments
%K pyroclastic sediments
%K Suelos artificiales
%K Anthrosoles
%K sales solubles
%K sedimentos lacustres
%K sedimentos pirocl¨¢sticos
%K Solos artificiais
%K Antrossolos
%K sais sol¨²veis
%K sedimentos lacustres
%K sedimentos pirocl¨¢sticos
%U http://sjss.universia.net/pdfs_revistas/articulo_239_1319128222265.pdf