use of Soil Moisture sensor in a project

I would like to ask if a soil moisture sensor is still effective when used on paddy types of soil or flooded types? Would the sensor always read that it is somehow wet since it is flooded? Basicall what Im asking is would the sensor work even if almost submerged to water?

Not the cheap ones.

With a capacitive moisture sensor that has its electronics well covered/potted and with a good cable, then you can put that at any depth and also in water.
Perhaps you can make it yourself, or buy them.
At tindie.com they have a ruggedized version, it seems they used a glue-lined heatshrink for that.
https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/
SoilWatch 10 - Soil Moisture Sensor | Indiegogo
SoilWatch 10 - Capacitive soil moisture sensor - PINO-TECH
Ruggedized Arduino Capacitive Analog Soil Moisture Sensor - Waterproof / Corrosion Resistant

It would simply read (near) 100% wetness. Doesn't sound very useful to me.

So does it mean that there is no soil moisture sensor that is effective and wont always read near 100%wetness to be used on paddy/floody types of soil?

What reading other than 100% wet do you expect from soaked soil? Don't forget water is wet!

Perhaps you should be thinking about using a water level sensor instead.

We show how to ruggedize off-the-shelf capacitive moisture sensors via the video on adosia.io (see link above).

You can also generously coat the entire sensor (even the capsense portion of the sensor below the electronics) with the urethane conformal coat seal - this helps keep moisture from seeping into the PCB edges over time, and also reduces sensitivity. For example, a sensor having a regular range of 250-750 (not coated below the electronics) might rage from 550-750 with the entire sensor coated.

And yes, following the urethane seal we use a double coated adhesive lined heat shrink - you'll want to order it in 3/4" diameter.

@adosia, thank for sharing the information.
I put a link to your website at the bottom on purpose, because I could not find an address or country on the website. I had even no clue on what continent your are, so ordering something would be very weird to say the least.

Just now I discovered your twitter account where it says: North Carolina, USA.