The rate of decomposition of various plant materials in soils
1936
Millar, H.C. | Smith, F.B. | Brown, P.E.
The rate of decomposition of 12 plant materials containing about the same amount of carbon but varying widely in percentage of nitrogen was determined by measuring the production of carbon dioxide in Dickinson fine sandy loam treated with the different materials. Preliminary studies were made on a comparison of two methods for determining carbon dioxide production in soils. The results obtained may be summarized as follows: 1. The aspiration method for measuring carbon dioxide production was found to give higher results than the respiration chamber method during the first part of the experiment, but after 624 hours the amounts of carbon dioxide evolved from the soils treated with the same kind of organic matter were about the same by both methods of determination. 2. The results obtained indicated that all of the carbon dioxide was being absorbed by the respiration chamber method. 3. The respiration chamber method was found to require less time and equipment than the aspiration method. 4. The plant materials high in nitrogen decomposed more rapidly during the first few days of decomposition than the plant materials low in nitrogen. After this initial period of decomposition the materials low in nitrogen decomposed more rapidly than the materials having a high nitrogen content. 5. The decomposition of plant materials high in nitrogen resulted in a greater fixation of carbon in the soil than the decomposition of materials with a low nitrogen content. This was evidenced by a decreased total carbon dioxide evolution from the soils treated with the plant materials containing a relatively high nitrogen content.
显示更多 [+] 显示较少 [-]