Overview

The aim of this study is to analyze the distribution of nitrogen in various types of Tunisian soil, with a dual economic and environmental objective. Characterization and analysis of organic and inorganic forms of nitrogen will enable us to optimize nitrogen fertilization and limit leaching losses, which are sources of groundwater pollution. In an arid to semi-arid pedoclimatic context, limiting organic inputs, the study is based on an approach combining pedogenetic prospecting, laboratory analyses and controlled in situ experiments. The results reveal a high concentration of organic nitrogen in surface horizons, with an enrichment of fine fractions and humus, the main nitrogen reservoir. Mineralization varies according to soil type, with maximum potential in brown limestone soils. The distribution of the different forms of nitrogen is strongly influenced by climatic conditions and soil depth, underlining the importance of differentiated management according to soil type and agro-ecological context.