Standard ion-selective electrodes (ISEs) rely on plasticized polymer membranes and Ag/AgCl reference gels that biofoul and drift within weeks underground. Solid-state mineral sorbents avoid soft gels but trap ions after a fertigation pulse, creating washout memory hysteresis.
Clamped by a screwless metallic retention frame, an inert mineral barrier blocks soil bacteria and clay particles while allowing dissolved nitrate ions in pore water to equilibrate passively without surface vacuum pumps.
Instead of binding nitrate into a perishable polymer membrane, the hermetically isolated transduction core measures dissolved nitrate (NO3-N) directly and compensates for soil organic matter and temperature on the probe.
Combines reagent-free soil nitrogen sensing with a pore-water electrical conductivity array and a bulk soil moisture waveguide, streaming calibrated data over standard SDI-12, RS-485 Modbus, and robotic UART field buses.
A single heavy rain or fertigation cycle can flush nitrate below the roots in an afternoon. Without a buried sensor that survives full-season soil contact, nutrient management relies on guesswork and delayed lab extracts.
Roughly 55% of synthetic nitrogen applied globally leaches into groundwater or volatilizes before crop uptake.
Subsurface nitrous oxide spikes following over-fertilization are the largest greenhouse gas source in crop production.
Manual soil coring and KCl wet-chemistry extraction are too slow and expensive to control daily irrigation valves.
Potentiometric membrane probes lose accuracy rapidly underground as biofilms and organic acids alter reference potentials.
Replacing fragile polymer membranes and wet reagents with a sealed inorganic probe opens up continuous monitoring across irrigation control, field trials, autonomous machinery, and catchment protection.
Standard electrical conductivity (EC) probes cannot tell nitrate (NO3−) apart from accumulated chloride (Cl−) or sulfate salts. Separating true nitrate from background salinity lets irrigation controllers dose only when the crop actually needs nitrogen.
Fertilizer producers, nitrification-inhibitor developers, and food supply chains need physical root-zone measurements across field trials to prove nitrogen-use efficiency and verify Scope 3 emissions reductions without relying on satellite proxies.
Autonomous scouting rovers, spot-dosing machines, and tractor implements lack a solid-state chemical sensor with a hard mineral face that can survive repeated soil insertion or seasonal deployment without tearing a polymer membrane.
Municipal waterworks (Stadtwerke) and environmental agencies need continuous vadose-zone leaching data across Nitrate Vulnerable Zones (91/676/EEC and EU 2020/2184) without installing €10,000+ surface vacuum-pump lysimeter stations.
Satellites and drones only observe the top millimeter of the leaf canopy. Mechanistic crop simulators (such as DSSAT and APSIM) and agronomic models need continuous underground chemical flux data to close the nitrogen mass balance.
Long-term underground plume monitoring for civil drainage corridors, mine-tailing remediation sites, and regulated stadium or golf root zones without manual water sampling.
Current soil nitrogen monitoring tools force a trade-off between short-lived buried polymer membranes, manual walk-and-push spot checks, or expensive surface-pumped analyzer cabinets.
In aerated agricultural soils, ammonium (NH4+) is rapidly oxidized into nitrate (NO3−) by soil nitrifying bacteria. Dissolved nitrate in pore water therefore accounts for 80% to 95% of mobile plant-available nitrogen and nearly 100% of the nitrogen lost to groundwater leaching and denitrification.
Conventional ion-selective electrodes (ISEs) use soft plasticized PVC membranes and Ag/AgCl reference gels. Underground, root exudates and biofilms foul the membrane while reference potentials drift (1 mV shift causes ~4% concentration error). Solid-state mineral sorbents avoid soft gels but suffer from desorption hysteresis during rain washout.
Standard electrical conductivity (EC) probes measure total dissolved ions and cannot separate nutrient nitrate (NO3−) from background chloride (Cl−), sulfate (SO42−), or sodium salts. Terra M1 measures nitrate selectively alongside pore-water EC and bulk moisture so controllers do not confuse salt buildup with available nitrogen.
Yes. Terra M1 is designed as a low-power 4.2 mm blade with an abrasion-resistant mineral face that streams calibrated nitrate (mg/L NO3-N), pore-water conductivity (dS/m), volumetric moisture, and temperature over standard SDI-12, RS-485 Modbus RTU, and digital UART interfaces.
Terra M1 is currently in pre-commercial hardware development in Munich. To survive months of continuous root-zone burial, the probe is designed around four practical constraints:
We are currently moving Terra M1 from numerical physics modeling into prototype fabrication in Munich. Leave your details below if you would like to be notified when bench validation data and field pilot units become available.