Localized Delivery of Liquid Fertilizer in Coarse-Textured Soils Using Foam as Carrier

Abstract

AbstractAgrochemicals and fertilizers are central to modern agriculture and are credited with the large increase of crop yield as a part of the Green Revolution of the 1960’s. Timely and targeted fertilizer application to crop root zones enhances effectiveness and reduces unintended release to the environment. This is particularly important for highly mobile liquid fertilizers (e.g., nitrate) that can be mobilized with infiltrating water to bypass root-bearing soil volumes. We report a novel liquid fertilizer delivery method using foam as carrier. The high degree of control and mechanical stability of liquid fertilizer foam (defined dispersed gas bubbles in a continuous liquid phase) injection into coarse soils (most susceptible to preferential flows) is proposed a novel delivery method to targeted root zone volumes at concentrations and geometry that promote uptake and reduces losses. This note and preliminary communication meant to serve a proof of concept report comparing foam and conventional liquid fertilizer applications. The results indicate that foam-delivery reduced fertilizer leaching thus improving its retention in soil for similar flow conditions of liquid delivery. Theoretical estimates suggest that the effects of fertilizer retention could be enhanced in more localized (3-D) injection of foam fertilizers and other agrochemicals thus enhancing agronomic efficiency and reducing environmental risk of contamination.