Tensio tube with clock for on spot reading of humidity of the soil in the rootzone.
The tensio tube is dug in at level of the rootzone, the ceramic tip will interact with the soil and either release water or take up water, this will create under pressure in the tube, which is measured by the tensiometer.
The tensiometer is not an ad-hoc meter, the tube is left in the ground for days / weeks / months, the longer the better, it will need at least one week to get established.
To measure the moisture level at different points, multiple tubes are needed. If more than than 5-6 tubes are needed the digital tensiometer TM-93 is the most economical and easiest option.