Soil characterization from the Rio Grande high basin for preparing a technosol that retains phosphorus to prevent eu-Trophication in the dam water of the Presa Propósito Multiple Chone

Abstract

Agriculture and livestock have the most economic significance in the Chone canton. These activities are some of the causes of the phosphorus increases in the Rio Grande basin, making, as a consequence, that there is an excess of nutrients in water so there are many plants growing and leading to eutrophication. So, the objectives of this research were the soil characterization from the Rio Grande high basin for obtaining a Technosol that will retain phosphorus so the eutrophication in the dam water from the PPMCH will be reduced. 17 soil samples were analyzed. The samples were obtained during the rainy season and during the dry season in 2016. The physical characteristics as bulk density, porosity and humidity were used to determine if the soil retains and transmits water to crops while the chemical characteristics as pH, electrical conductivity (EC), Cationic Exchange Capacity (CEC), available phosphorus, exchangeable aluminum and phosphorus retention, were used to determine the capacity of soil to solubilize inorganic phosphorus and the capacity of forming insoluble aluminum compounds that will fix phosphate anions. As a consequence, according to the tests the best soils were the ferric soils, because they have a high potential for preparing a Technosol. The phosphorus fixation percentages for profile 60,96%, for profile 16 was 54.60% and 79.51% for profile 17. In profile 17 the aluminum content is 5 cmol/kg.