Abstract: At present many analytical laboratories that provide a chemical soil testing service, some are woefully inadequate testing only for phosphorus, potassium, pH and salinity and ignoring all other nutrients. Others can be very comprehensive but the results badly presented. This makes it difficult for the farmer in particular to make any sense out of his own soil test and puts his decisions regarding fertilizer firmly in the minds of the "experts" who are also often the manufacturers/sellers of particular types of fertilizer. Our main objective is to develop a testing system which can be used for soil analysis, which in term helps the farmers to grow and produce the proper crop that can be a feedback to the farmers to implement “precision agriculture”. The System measures Nitrogen, Potassium, Phosphorous and PH of soil. In the system, nitrate and phosphorous ISE are used to measure concentration of N and K nutrient of soil.

Keywords: Electrical conductivity, Nitrate ISE, Phosphorus ISE, Precision Agriculture.