N{sub}2O and CO{sub}2 Emission from an Arable Soil Amended with Glucose and Alanine Addition

摘要

Laboratory incubation was conducted to investigate the effect of organic carbon species and nitrogen fertilizer type on the nitrous oxide (N{sub}2O) and carbon dioxide (CO{sub}2) at soil water content of 100% WHC. Dissolved nitrogen ((NH{sub}4){sup}+-N, (NO{sub}3){sup}--N) and dissolved organic carbon (DOC) were also determined. The results showed the organic carbon species significantly affected the N transformation. For the ammonium fertilization (75mg Nkg{sup}(-1)), maximal N{sub}2O-N emission was found in the treatment with alanine addition (5.47mg kg{sup}(-1)), minimal emission in glucose addition (0.23mg kg{sup}(-1)), and medial emission in treatment with half alanine plus half glucose (1.87mg kg{sup}(-1)). The similar change trend of N{sub}2O-N emission was also found in the equal rate of nitrate fertilization treatments. These results suggested amino acid-C had the higher bioavailability compared with the glucose. CO{sub}2 emission was highest in the treatment with half alanine plus half glucose in both ammonium and nitrate fertilization. Minimal CO{sub}2 emission was lowest in glucose addition treatment. Absence of (NO{sub}3){sup}--N in all treatments after incubation indicated that denitrification was very strong in the experimental condition. Lowest DOC content was determined in the treatment with amino acid addition. N{sub}2O emission was higher in nitrate fertilizer addition than in ammonium addition, and CO{sub}2 emission was contrary.