[Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].
To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P < 0.05) higher than that in neutral (pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively.
Zhu
Xue-Zhu
XZ
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China. zhuxuezhu@njau.edu.cn
Huang
Yao
Y
Yang
Xin-Zhong
XZ
D015258:Acid Rain; D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism; D012275:Oryza / Q000254:growth & development*; D018547:Plant Stems / Q000378:metabolism*; D012987:Soil / Q000032:analysis*
D015258:Acid Rain; D009930:Organic Chemicals; D012987:Soil; D002244:Carbon