Effects of Soil pH on CO 2 Emission from Long-Term Fertilized Black Soils in Northeastern China

Content Provider	Semantic Scholar
Author	Wang, Lianfeng Han, Zuoqiang Zhang, Xilin
Copyright Year	2011
Abstract	Soil pH in a large extent alters the rates of microbial carbon turnover, and thus can regulate CO2 emissions. Laboratory incubation experiments were conducted to investigate the effects of different soil pH on the CO2 flux from acidified black soils. The experiment was designed as a full factorial with 3 N-fertilization (None, Ammonium and Nitrate) and 4 pH values (3.65, 5.00, 6.90 and 8.55). The results showed that CO2 emission increased significantly due to N fertilizer addition. CO2 emission increased positively with soil pH (R=0.98, P<0.01). The lowest CO2 emission (30.2 mg CO2-C kg) was presented in pH3.65 soils without N-fertilization. For ammonium fertilization, the highest cumulative N2O emissions appeared in the pH8.55 soils was 199 mg CO2-C kg. For nitrate fertilization, the highest cumulative N2O emissions appeared in pH6.90 soils was 184 mg CO2-C kg. However, there was insignificant difference in CO2 emissions between ammonium and nitrate fertilization at soil pH values from acidic to alkaline (P>0.05). Dissolved organic carbon (DOC) dramatically decreased with N-fertilization at all soil tested pH values. The findings suggested that pH-increasing and N-fertilization significantly enhanced CO2 emissions and heterotrophic microbial respiration played a dominant role in CO2 emissions in the tested soil.
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Language	English
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Content Type	Text
Resource Type	Article