Soil Quality Problems Associated with Horticulture in the Southern Urban and Peri-Urban Area of Buenos Aires, Argentina

Horticulture is the main productive activity of south Buenos Aires city peri-urban sector. This activity is carried out with intensive land use, based on the high use of inputs, which has generated important pollution and soil degradation problems. Soil degradation processes have their origin in the poor quality irrigation water (sodium bicarbonate) and in the indiscriminate use of fertilizers and organic fertilizers, without considering the requirements of the crop and soil analysis. The results of a large number of surveys in the area, specified in the following chapter, showed salinization, pH increase, structure quality loss, organic matter decrease and phosphorus hyperfertilization. On the other hand, urban gardens are increasingly common, that is, the production of vegetables for own consumption within the urban framework. In this case, the problems are related to the type of soils where it occurs, and they are in general highly modified lands that almost completely lost their natural characteristics and are usually not favorable for plant growth. The results from the cases studied in La Plata city showed that urban soils have low organic carbon content, high bulk density and high pH. In these soils, the horticultural production with agroecological base managed an increase in the organic carbon content and a decrease in the apparent density.