Carbon Dioxide and Nitrous Oxide Emissions from Naturally Occurring Sulfate-Based Saline Soils at Different Moisture Contents

作     者：Resham THAPA Amitava CHATTERJEE Abbey WICK Kirsten BUTCHER 

作者机构：Department of Soil Sciences School of Natural Resources Management North Dakota State University 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2017年第27卷第5期

页      面：868-876页

核心收录：

学科分类：082802[工学-农业水土工程] 08[工学] 0828[工学-农业工程] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 0901[农学-作物学] 

主　　题：二氧化碳排放量 N2O排放 硫酸盐渍土 氧化亚氮 天然 CO2排放量 土壤盐碱化 含水率 

摘      要：Soil salinization may negatively affect microbial processes related to carbon dioxide(CO_2) and nitrous oxide(N_2O) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity(EC) and moisture content on CO_2 and N_2O emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0–15 and 15–30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space(WFPS) at 25?C. The measured depth-weighted EC of the saturated paste extract(EC_e) across the sampling positions ranged from 0.43 to 4.65 dS m^(-1). Potential nitrogen(N) mineralization rate and CO_2 emissions decreased with increasing soil EC_e, but the relative decline in soil CO_2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N_2O emissions decreased from 133 μg N_2O-N kg^(-1) soil at EC_e 0.50 dS m^(-1) to 72 μg N_2O-N kg^(-1) soil at EC_e = 4.65 dS m^(-1). In contrast, at 90% WFPS,soil N_2O emissions increased from 262 μg N_2O-N kg^(-1) soil at EC_e = 0.81 dS m^(-1) to 849 μg N_2O-N kg^(-1) soil at EC_e = 4.65 dS m^(-1), suggesting that N_2O emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil EC_e and pattern of rainfall over the season need to be considered when up-scaling N_2O and CO_2 emissions from field to landscape scales.