Experimental Study of an Automatic Irrigation System on Sensing Soil Moisture Content, Temperature and NPK Level

Abstract

This research focused on the experimental study and development of an automatic irrigation system capable of sensing soil moisture content, temperature, and NPK (Nitrogen, Phosphorus, and Potassium) levels for efficient agricultural water and nutrient management. The study was motivated by the need to reduce water wastage, improve crop productivity, and minimize human involvement in irrigation practices, especially in developing countries where traditional irrigation methods are still predominant. The developed system integrates soil moisture sensors, temperature sensors, NPK sensors, a microcontroller-based control unit, relays, solenoid valves, and a water pumping mechanism to automate irrigation and nutrient application processes. The system continuously monitors soil conditions and responds intelligently by supplying the required quantity of water and nutrients whenever the soil parameters fall below preset limits. The control unit was implemented using an ATmega328P microcontroller programmed through the Arduino platform, while the sensing unit provided real-time feedback on soil moisture, ambient temperature, and nutrient status. Tests were carried out on different soil samples to evaluate the performance and responsiveness of the system. The results showed that the system effectively detected variations in soil moisture, temperature, and nutrient deficiencies, and automatically regulated water and nutrient supply accordingly. The system also successfully suspended irrigation during excessive temperature conditions to prevent water loss through evaporation and inefficient irrigation practices. The study concluded that the developed automatic irrigation system is efficient, reliable, affordable, and suitable for sustainable agricultural practices. The system preserved soil structure, reduced unnecessary water application, minimized nutrient leaching, and enhanced proper crop growth under varying environmental conditions. The research therefore demonstrates a cost-effective approach to smart irrigation management that can improve agricultural productivity and support peasant farmers, particularly in developing nations such as Nigeria.