2022-WIDH-69631:Sustainable Method to Improve Efficiency of Fertilizers


As fertilizer prices increase and the negative environmental impact of overuse gains attention, farmers are looking for ways to use less fertilizer without sacrificing crop health or yield. Depending on environmental conditions (temperature, humidity, etc) 10-40% of nitrogen applied as urea can be lost as ammonia from the soil surface.


Urease inhibitors are used to extend the efficiency of fertilizers by trapping key compounds in the soil that would normally escape into the atmosphere. NBPT, the industry-standard inhibitor accounting for over half of the global market, can be expensive and is not derived from natural sources. Purdue innovators have developed a urease inhibitor that is inexpensive, naturally derived from walnut and pecan trees, and is environmentally friendly.


Joshua Widhalm, Purdue University Associate Professor of Horticulture, College of Agriculture


An Inexpensive and Sustainable Urease Inhibitor to Improve Fertilizer Efficiency: 2022-WIDH-69631


Phone: (765) 588-3475
Fax: (765) 463-3486
Email: otcip@prf.org


Email: sgmartin@prf.org


An Inexpensive and Sustainable Urease Inhibitor to Improve Fertilizer Efficiency

Widhalm, Joshua R (Project leader), Bigelow, Cale A, Meyer, George, Powlen, Jada, Xu, Qin

Researchers at Purdue University have developed a urease inhibitor that improves the efficiency of fertilizers. Urease is an enzyme commonly found in plants, fungi, and bacteria that converts urea-based nitrogen fertilizer into ammonia and carbon dioxide. However, ammonia volatilizes to the atmosphere and most of the nitrogen absorbed by plants is in form of nitrate. Therefore, urease inhibitors can improve fertilizer efficiency. The Purdue researchers’ urease inhibitor traps ammonia at a depth of ~5-10 cm and mineralizes it as plant-usable forms. Unlike the industry-standard urease inhibitor (NBPT), the Purdue researchers’ inhibitor is inexpensive, natural (derived from walnut and pecan trees), and eco-friendly. This technology can benefit farmers and any agricultural operations by increasing fertilizer efficiency, reducing costs, along with reducing environmental problems caused by excess of fertilizers.

Technology Validation: A 100 microliter assay containing 50 microliters of extract from green walnut husks inhibited ~70% of urease activity.