SARMENTI develops a multisensor, low power IoT secure node to provide decision support to farmers by monitoring in real-time and in situ soil nutrients and gaseous emission. From this data measured on a daily basis over crop lifecycles, the farmer will timely perform appropriate actions regarding fertilisation, with direct impact on crop growth, soil & water quality and farmer income. The SARMENTI system will embed electrochemical sensors to measure e.g. NOx, POx, NH4, K, urea, pH, moisture, temperature. They will stay ideally during the crop lifecycle in the soil with packaging issues to protect them from their environment. A hygroscopic membrane will attract water from the soil, avoiding integration of a power hungry active pump usually used to exact water from a soil sample. SARMENTI will also monitor N2O (may appear in the nitrate cycle) and CH4 (generated by decomposition of manure under anaerobic conditions) just above the ground. These gases are greenhouse ones with higher warming potential than CO2. SARMENTI is part of the IoT (e.g. LoRa, BLE connexion). Data integrity is guaranteed by developing a secure node via combination of attack detection and automatic countermeasures application. Partners bring SoA prototypes of electrochemical and gas sensors and communication submodules, know-how in security for IoT nodes, and expertise in Agriculture. SARMENTI will further improve the prototypes (power, usage duration, hygroscopic membrane, packaging, sensitivity, selectivity) and integrate them with advanced processing in a connected secured device. Cloud Decisions support will allow evaluate the overall solution, SARMENTI demonstrator being tested in real fields. SARMENTI directly addresses ICT-7 challenge: “develop and validate new generation of cost-effective ESS ...”, RIA aim: “demonstrate ESS bringing intelligence ... integration of sensor systems, processors, computing and networking elements..." and “verification", "exploitation... clearly identified".