Effects of N Application Rate and Dicyandiamide on the Fate of 15N Fertilizer and the Abundance of Microbial Genes in a Sandy Soil Amended with Sugarcane Litter

Autor: Eduardo Mariano, Beatriz N. Boschiero, Luis F. Merloti, Alexandre Pedrinho, Miriam G. Chaves, Siu M. Tsai, Paulo C. O. Trivelin
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Journal of Soil Science and Plant Nutrition, 22(1), 359-373
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Journal of Soil Science and Plant Nutrition 22 (2022) 1
ISSN: 0718-9516
Popis: Renewable energy produced from sugarcane (Saccharum spp.) has clear advantages over fossil fuels in mitigating climate change. However, N2O emissions and NO3− leaching from fertilizer nitrogen (N) addition can jeopardize the sustainability of sugarcane production worldwide. One of the possible approaches to mitigating these N-loss pathways is the use of nitrification inhibitors such as dicyandiamide (DCD). However, the effects of DCD on the fate of fertilizer-derived N in soil pools and functional N genes (e.g., nitrifiers and denitrifiers) remain unclear. We performed a laboratory incubation study for 54 days to evaluate the influence of DCD and fertilizer N rate ((15NH4)2SO4 applied at 40, 80, 120, and 160 µg N g−1) on 15N transformation and abundance of total prokaryotes (16S rRNA), nitrifiers (ammonia-oxidizing archaea (AOA) and bacteria (AOB)), and denitrifiers (nirK and nosZ) in a tropical sandy soil amended with sugarcane residues. Especially for high N rates (120 and 160 µg N g−1), DCD not only increased the NH4+-15N recovery by inhibiting nitrification but also stimulated microbial immobilization. However, the nitrification inhibitor decreased N losses (i.e., unrecovered 15N). The abundance of total archaea and bacteria was unaffected by both the fertilizer N rate and DCD. While the abundance of AOB and nirK was suppressed by DCD, AOA and nosZ abundance increased, with the latter gene being the highest at 160 µg g−1. We conclude that DCD mitigates N losses from ammonium-based fertilizer by inhibiting NO3− production and changing nitrifying and denitrifying microorganisms in sandy acidic soil.
Databáze: OpenAIRE
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