Expert Opinion (∗): Improving process knowledge about ammonia emission from field applied liquid manure

Abstract

Agriculture contributes about 80 % of global ammonia (NH₃) emissions which must therefore be reduced to tackle issues of global human health as well as biodiversity and fertilizer loss. We carried out a review of current knowledge about processes of NH₃ emissions from field applied liquid manure, which is the basis for our opinion about the need for better process understanding. Detailed information on the reviewed literature is given (supplementary material). We recommend process based research about NH₃ emission effects of a. soil surface pH and temperature on concentration of dissolved NH₃(aq); b. Liquid manure dry matter concentration (DM) and soil cation exchange; c. Liquid manure viscosity and hydrophobicity interacting with soil water content and texture; and d. Effects of weather conditions as solar radiation, wind, canopy and rainfall/irrigation.