These technologies can improve productivity with increased crop yields. Some of these technologies include drip irrigation and sprinkler systems. In a drip irrigation system, measured quantity of water is applied slowly but directly to the plant roots where it is needed, rather than sprayed everywhere. It can among other things, reduce disease problems associated with high levels of moisture on some plants. Sprinkler system on the other hand, is a method of applying irrigation water in a manner similar to rainfall. Water is distributed through a system of pipes usually by pumping which is then sprayed into the air and it breaks up into small water drops which fall to the ground. As irrigation requirements are crop specific, a soil moisture sensor is required, to know the percentage moisture level at various points across the irrigated land. Moreover the sensor should be able to work in array architecture (network) which allows scanning of the array to obtain voltage values from each sensor. A microcontroller can be used for this purpose. The BJT based sensor gives a voltage. Output corresponding to the conductivity of the soil between the sensor …show more content…
Permanent Wilting Point (PWP) Further, if the soil continues to dry, it will hold some water which cannot be extracted by plant roots. As a result, plants wilt and cannot recover. This is called the Permanent Wilting Point (PWP). If the soil dries to the permanent wilting point, the plant can no longer remove any water from it. Plant production will slow/stop before PWP is reached (a tension of -1500 kPa). Measuring the soil moisture content allows monitoring the water available to the plant for growth. When the water at any depth falls below the refill point or where there is no remaining readily available water (RAW) then an irrigation scheduling event must be undertaken without