The objective of this experiment was to determine the rate of decomposition and nitrogen mineralization of plant residues in soil under laboratory conditions. The experiment consisted of six treatments: control, industrial tobacco residues, rice straw, rice straw + mineral nitrogen, rice husks and rice husks+mineral nitrogen. The plant materials were added at a rate of 2000 mg/kgC and the amount of NH 4 + -N completed the C:N ratio of the added materials to 12.5. After adding the plant material the following measurements were carried out: soil respiration measurements 14 times, dehydrogenase activity 14 times, mineral nitrogen (ammonium and nitrate). The results show that the C:N ratio was found to affect the net mineralization and nitrogen mineralization under the present conditions for decomposition of plant residues. Mineral nitrogen addition is conducive for short-term decomposition when the C:N ratio is large.

The objective of this experiment was to determine the rate of decomposition and nitrogen mineralization of plant residues in soil under laboratory conditions. The experiment consisted of six treatments: control, industrial tobacco residues, rice straw, rice straw + mineral nitrogen, rice husks and rice husks+mineral nitrogen. The plant materials were added at a rate of 2000 mg/kgC and the amount of NH 4 + -N completed the C:N ratio of the added materials to 12.5. After adding the plant material the following measurements were carried out: soil respiration measurements 14 times, dehydrogenase activity 14 times, mineral nitrogen (ammonium and nitrate). The results show that the C:N ratio was found to affect the net mineralization and nitrogen mineralization under the present conditions for decomposition of plant residues. Mineral nitrogen addition is conducive for short-term decomposition when the C:N ratio is large.