the development of ChemFET-based sensors for the soil analysis of nitrogen-based ions is described in this work. Focusing on the fluoropolysiloxane (FPSX) polymer-based matrix, nonactin and tetradodecylammonium nitrate (TDDAN) were shown to have the best properties for the detection of ammonium NH4 + and nitrate NO3ions respectively. Thus, FPSX-based pNH4-ISFET and pNO3-ISFET microsensors exhibited good detection properties (sensitivity around 56 mV/pX in concentration ranges adapted to soil analysis) and acceptable selectivity to soil main interferent ions (K + , Na + , Ca 2+ , Cl-, H2PO4 2-, SO4 2-,…). Following, the two different ISFET sensors were applied to the in-situ soil analysis. Thus, using standard relative moistures, pH analysis in clay-silt matrixes was demonstrated on a six-month period (compatible with agriculture applications during the fertilization period). Then, experimental studies were successfully extended to the monitoring of nitrogen mineralization through pNH4 measurement, as well as to the analysis of soil nitration processes. Finally, long-term analyses were performed, showing contradictory result according to the chosen ionophore: a "zero" temporal drift on a six-month period for nonactin and PFSX-based pNH4-ISFET, and a huge temporal drift for TDDAN and PFSX-based pNO3-ones. This work paves the way for future long-term ionic analyses in soil matrix.