As people get more health conscious about quality
of food and less and less space available for farming,
hydroponics becomes a trend for next generation
farming
Plants that grow only on water requires exceptional
water quality monitoring at a continuous level
Sensors can be used at locations to regularly
monitor water conditions with 4-20mA output.
Soil quality sensor list: 
1. pH
2. Soil Temperature
3. Soil Moisture
4. Irradiation Sun Sensor
5. Rain Gauge Sensor
6. Nutrient (Nitrate, Magnesium,
Potassium, Calcium, Sodium)
Sensor
Applications include:
--
Agriculture farming
-- Greenhouse
--Control output for watering system by soil moisture
level via System automatically