Emission of nitrous oxide and carbon dioxide from semi-arid tropical soils in Chiapas México

Abstract

SUMMARYThe semi-arid region of Chiapas is dominated by N 2 -fixing shrubs, e.g., Acacia angustissima. Urea-fertilized soil samples under maize were collected from areas covered and uncovered by A. angustissima in different seasons and N 2 O and CO 2 emissions were monitored. The objective of this study was to determine the effects of urea and of the rainy and dry season on gas emissions from semi-arid soil under laboratory conditions. Urea and soil use had no effect on CO 2 production. Nitrons oxide emission from soil was three times higher in the dry than in the rainy season, while urea fertilization doubled emissions. Emissions were twice as high from soil sampled under A. angustissima canopy than from arable land, but 1.2 lower than from soil sampled outside the canopy, and five times higher from soil incubated at 40 % of the water-holding capacity (WHC) than at soil moisture content, but 15 times lower than from soil incubated at 100 WHC. It was found that the soil sampling time and water content had a significant effect on N 2 O emissions, while N fertilizer and sampling location were less influent. Index-terms: Acacia angustissima, denitrification, nitrification, soil water content, urea. RESUMO: EMISSÕES DE ÓXIDO NITROSO E DIÓXIDO DE CARBONO EM SOLOS TROPICAIS SEMIÁRIDOS DE CHIAPAS -MÉXICO

Land cover changes and greenhouse gas emissions in two different soil covers in the Brazilian Caatinga

“…Our results show that gas fluxes were mostly positive, indicating emission of GHG from soil to atmosphere and that emissions vary with season according to the gas species. Soil N 2 O emissions can be highly variable over time, and they are regulated by different factors such as soil water content, temperature, aeration, ammonium, and nitrate concentrations, pH, mineralizable C, among others (Bouwman, 1990;Davidson et al, 2000;Ponce-Mendoza et al, 2010;Tiedje, 1988). Soil moisture is a major driver of N 2 O as it regulates the oxygen available to soil microbes (Butterbach-Bahl et al, 2013;Davidson et al, 2000), even though, in this study, soil moisture did not show any evident effects on N 2 O emissions.…”

“…Conversion of native forest to pasture and agricultural land affects turnover of soil carbon and nitrogen and increases emissions of GHG in the short-term (Matson and Vitousek, 1990) However, little is known about soil C and N dynamics in semiarid regions, particularly in NE Brazil (Menezes et al, 2012;Ponce-Mendoza et al, 2010;Sousa et al, 2012;Zhao et al, 2009). Nevertheless, in the Caatinga biome, where a semiarid climate is predominant, the available studies are consistent in showing N and P as the most limiting nutrients in the soil (Menezes et al, 2012).…”

Nutrient Management Drives the Direction and Magnitude of Nitrous Oxide Flux in Crop Residue-Returned Soil Under Different Soil Moisture

“…The individual effect of crop residue, nutrient management, and soil moisture on N 2 O emissions was well documented by previous studies (Feng et al, 2003;Toma and Hatano 2007;Mutegi et al, 2010;Ponce-Mendoza et al, 2010;Chen et al, 2013;Shan and Yan 2013;Gao et al, 2016;Lan et al, 2017;Kumar et al, 2018;Takakai et al, 2018;Tao et al, 2018;Hongjin Zhang et al, 2020;Liyanage et al, 2020;Wu et al, 2020;Yujin Zhang et al, 2020;Li et al, 2021). However, the interactive effect of crop residues, nutrients, and soil moisture driving the magnitude and direction of soil N 2 O emission and underlying mechanisms is lacking.…”