Do tropical climatic conditions reduce the effectiveness of nitrification inhibitors? A meta-analysis of studies carried out in Brazil
Pablo Lacerda Ribeiro, Filipe Selau Carlos, Gabriel Barth, Karl H. Mühling
Abstract
Abstract Extensive research has been performed into the effectiveness of nitrification inhibitors (NIs) in preventing N losses; however, tropical agriculture has been underrepresented in recent meta-analyses. Here, we apply a meta-analytic approach using data from 50 articles to identify the impact of NIs (DMPP, DCD, and DCD + NBPT) on crop yield, N 2 O emissions, soil NH 4 + and NO 3 − concentrations, and NH 3 volatilization in subtropical and tropical regions of Brazil. In addition, the survey includes information about location; climate zone; cultivated crops; soil pH; soil organic carbon; soil texture; experimental method; soil management; irrigation; fertilizer source, rate, and type; and NI type and rate. Overall, the data set showed that NIs increased crop yield and soil NH 4 + concentrations by 3 and 60%, respectively, whereas N 2 O emissions and soil NO 3 − concentrations were reduced by 62 and 31%, respectively. Ammonia volatilization was not changed by NI application. However, the combination of a NI with a urease inhibitor decreased such losses by 39%. The effectiveness of the NIs was highest in irrigated fields, fine-textured soils, and mineral N sources. Moreover, NI performance in Brazil was found to be similar in tropical and subtropical climates, and was also comparable to values previously reported in meta-analyses, including those conducted in temperate climates. Therefore, NI application is indicated to be an efficient strategy to delay nitrification and mitigate N 2 O emissions in tropical agroecosystems.