tip of the tube is closed over with any device suitable for keeping soil from entering the tube non limiting examples of such a device are tape or a small conical insert tip i e made of metal or hard plastic fig2 shows a conical tip 201 inserted into the sensor hole 202 in some embodiments the tube plus any optional tip is placed directly into the soil without a previous step of drilling a hole i e the tube plus tip makes the hole optionally an advancer rod 301 at least two inches longer than the tube 302 is pushed into the tube to puncture or move the tape 303 or other device at the lower tip of the tube and create additional space in the soil for the sensor i e an additional two inches is cleared beneath the tube see fig3 as shown in fig6 the pressure sensor assembly includes a sensor bulb 601 connected to a thermocouple wire 602 and flexible tubing lines 603 as shown in fig4 the pressure assembly 402 is inserted down the tube 406 or hole to position the sensor bulb beneath the bottom of the tube in other embodiments the pressure sensor is lowered simultaneously with the tube and optional tip 405 fig4 also shows the control system 401 that monitors the expansive force of the polymer being injected through holes 404 and 403 in other embodiments the pressure sensor is lowered simultaneously with the advancer rod the upper ends of the thermocouple wire 501 and both tubing lines 502 are connected to the u201c pump reservoir control box u201d using u201c quick connect u201d insertion connections the control box comprises a fill shut off valve 503 an overfill vent 504 a vent shut off.