Passive Irrigation Controller

The Food and Agriculture Organization of the United Nations calculates that agricultural irrigation consumes 70 percent of our global fresh water supply, they further express that 60 percent of that water is then wasted before it is used by crops. An important cause of water waste is the inappropriate scheduling of the irrigation periods leading to over-watering. In developed countries, irrigation scheduling is handled using electronic controllers with either timers or environmental sensors to detect when the crops need to be watered. However, in low-income communities such as Pedro Arauz in Nicaragua, there is not a consistent electricity source to power the controllers, nor the technical expertise or materials to maintain the controllers.

This research aims to design a passive irrigation controller that uses the soil water tension (SWT) to actuate a valve to control the irrigation. This technology will be important for irrigation water management on small scale farms in low-income areas.

Sylvia’s Farm, Pedro Arauz, Nicaragua
Installing Passive Irrigation Controller, Nicaragua
Pedro Arauz community members and Anna Jiang after controller demonstration