Monitoring of soil nutrients is very important in precision agriculture. In this paper, we have demonstrated a micro electro mechanical system based lab-on-a- chip system for detection of various soil macronutrients which are available in ionic form K+, NO3-, and H2PO4-. These sensors are highly sensitive piezoresistive silicon microcantilevers coated with a polymer matrix containing methyltridodecylammonium nitrate ionophore/nitrate ionophore VI for nitrate sensing, 18-crown-6 ether for potassium sensing and Tributyltin chloride for phosphate detection. A complete lab-on-a- chip system integrating a highly sensitive current excited Wheatstone's bridge based portable electronic setup along with arrays of micro-cantilever devices mounted on a printed circuit board with a liquid flow cell for on the site experimentation for soil test has been demonstrated. (C) 2017 Elsevier Ltd. All rights reserved.