Nathaniel T. Smith

By Daniel P. Smith and Nathaniel T. Smith

This chapter presents an approach to recover nitrogen from human waste-water at local-scale for cultivation of Solanum tuberosum (potato) as food crop. Nitrogen capture is by ion exchange of ammonium (NH4+) onto zeolite, a natural low cost mineral which is available worldwide. A coupled process is described in which wastewater ammonium is sorbed to granular zeolite, biologically extracted (desorbed), and used to support Solanum tuberosum growth in fill-and-drain or irrigation cultivation. The system employs separate components to optimize conditions for ammonium sorption (anaerobic ion exchange), desorption (aerobic bioextraction), and cultivation (flexible timing of water and nitrogen supply and nutrient recycle). System architecture provides a low cost and readily implemented system for highly efficient nitrogen capture and incorporation into potato tuber. The nitrogen recycle system enables sustainable local-scale intensification of Solanum tuberosum production and enhanced food security through use of a reliable local nutrient supply. Metrics are presented for per capita tuber production, land area, and productivity. A system design is presented with a path forward for demonstration and development.

Part of the book: Solanum tuberosum