PERI-URBAN HORTICULTURE, ANALYSIS OF SOIL FERTILITY IN GREENHOUSES

Abstract

The peri-urban horticulture of Gran La Plata produces fresh vegetables for 13 million inhabitants. Although production is located close to the city, it presents problems associated with technological processes, and represents a fragile production system with a high environmental impact risk. Soils used for the production of horticultural crops under cover are classified as Vertic Argiudol and Typic Hapludert. A large number of species, mainly tomatoes (Solanum lycopersicum), peppers (Capsicum annuum. L.) and lettuce (Lactuca sativa L.), are grown without conducting soil tests and applying high amounts of fertilizers and/or amendments, which results in environmental (pollution, degradation) and productive (induced deficits, high costs) consequences. This study aimed at making a diagnosis of the chemical soil fertility, using routine soils tests, and determining its relationship with crop development. In most cases, salinization (average 4 dS m-1), alkalization and sodification (PSI 18%), as well as loss of organic matter (average 3.4%) and hyperfertilization (P concentrations up
to 535 mg kg-1) affected crops. Therefore, if soil management continues without proper adjustment to soil types and crop requirements, not only vegetable production will be seriously affected, but contamination and degradation will also increase.