I-Corps: Decentralized fertilizer production for improving soil quality and plant growth

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project lies in introducing a new process for producing fertilizer locally in rural areas using locally available resources and labor. By reducing the need to transport bulky fertilizer components from centralized production plants, this process can significantly reduce the cost of fertilizer access in rural areas, while improving the customizability of fertilizer at the level of almost single-farm granularity. By producing customizable fertilizer formulations that can promote improved crop yield and hence higher income for the end users (e.g. farmers) in addition to reduced requirements of water and commercial fertilizer components, this innovation can lead to economic benefits as well as improved food and water security. Since the proposed technology uses biomass such as farm residue as a feedstock, it also contributes to effective waste management and nutrient recycling without affecting the food chain. This I-Corps project is based on oxygen-lean thermochemical treatment and upgrading of biomass, such that the hard-to-digest lignocellulosic fibers can be broken down 100 times faster compared to traditional mulching or composting processes. The process is autothermal, requiring no external energy to sustain itself continuously. Based on this chemical concept, the project has been modeled, developed, built, and tested a laboratory-scale reactor prototype. Positive control over the reaction condition and output by adjusting the air-biomass ratio and the removal rate of the product from the reactor has been demonstrated. Methods to scale-up the design by defining an index of reaction and linking it to the relevant fertilizer characteristics-such as pH, ionic activity-and developing a control system to process diverse types of crop residues has been planned. The range of feedstock tested include rice husk, hay straws, and walnut shells, producing diverse grades of the output fertilizer component with different characteristics. The output fertilizer component is then mixed with locally available nutrient additives resulting in a porosity- and pH-adjustable formulation that can be custom-tailored for individual farms to optimize soil quality (e.g. water and nutrient retention capacity). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.