Our ancestors gave more importance to agriculture and it was basically following all the traditional methods their forefathers followed. As the population increased the need for production was given more importance and the pressure on agriculture increased as the years followed. Green revolution in 1960’s lead to use of various methods which includes good quality seeds, better irrigation techniques, fertilizers and so on. Even then our country’s population never stopped decreasing so this is where the technological advancements started appearing in agriculture and what we see in many parts of the world is called modern agriculture. This incorporates scientific data and technology to increase the yield of the crop. This is considered to be a milestone in agriculture and some of them are monitoring irrigation methods via smartphones, ultrasounds for livestock, crop sensors, robots, drones and most of these technologies fall under ‘precision agriculture’. Some of the advantages of using agricultural technology is more crop yield, saving inputs like fertilizers, water, pesticides. It also reduces impact on natural ecosystems and reduced physical work for farmers.
Now let’s look into a specific technology called soil water sensors, by the name itself we can understand that it is some way related to water, since it is an Agricultural Tech we can say that it is related to detect the amount of water in soil. This Tech have been used by farmers for many years and the usage had been increasing as saving water is the need of the hour. It gauges the volumetric content of water in the soil. Water content can be measured by drying, eliminating and sample weighing but these sensors find the volumetric content by some other factors like dielectric constant, electrical resistance and so on. This sensor is compatible and can be easily embedded with Arduino UNO, Arduino mega 2560, Arduino ADK and many other various kinds of micro-controller.
They have two probes which passes the current through the soil and gets the resistance value. If there is more water in the soil it conducts more electricity and will have less resistance and exactly opposite if there is less moisture in soil. Sensor can be conducted in two modes which are digital and analog mode. It contains a potentiometer which will have a threshold value and this value will be compared by the LM393 comparator. The output LED will light up based on the threshold value. It has three pines and thee one with 5 it means signal – means GND which is ground and + means SV supply. Sensor comes with a small PCB board with LM393 comparator chip, a potentiometer, output signal pins with both analog and digital and input power pins are also present on the PCB.
In analog mode, the analog output of the sensor is used in this method and the output value will mostly range from 0 – 1023. Moisture will be measured by percentage that is from 0 – 100 and these values will be observed in serial monitor. Different ranges can also be set for the moisture values and the water pump can be turned on and off accordingly.
In digital mode, digital output of the sensor will be connected to the digital pin of the micro-controller. Module of the sensor will have a potentiometer which will set the threshold value. Then this value is compared with output value of the sensor using the LM393 comparator which is present on the sensor module. This LM393 comparator plays a main role by comparing the threshold value and the sensor output value. If the sensor value is more than the threshold value, then the digital pin will show 5V and LED on the sensor will light up which means the moisture content is more in soil and if the sensor value is less than the threshold value, then the digital pin will show 0 V and the light will go down.
Some of the advantages of sensor are as follows; Irrigation is the key factor in agriculture and many of the farmers are not so sure about the enough amount of water required and is available in soil which will lead him to wither irrigate more which is over irrigation or irrigate less which will lead to death of the plant. This kind of sensors make automation of farming easier. It consumes less power and works at 5 V and even works on low current less than 20 mA and weighs only 3 grams.
Also have got few disadvantages like they cover only a small sensing area, depth of the deception is only 37 mm and it can’t be used in many parts of India because it works only in range of 10 C- 30 C. In many cases it was found to be less accurate.
Common problems faced by farmers mostly is sensor failure, lack of timely data, excessive labor requirements, wiring issues, lack of timely data and failure of data telemetry.
Innovators Quest VIT 