Study on soil organic C mineralization amount and rate in sugarcane field.

Based on the principle of nitrogen(N) flux mass balance,sugarcane cultivar ROC16 was tested for two years to study soil organic N mineralization amount(SONMA),soil organic C mineralization amount(SOCMA) and soil organic C mineralization rate(SOCMR) in sugarcane field.For the first year (plant cane),SONMA,SOCMA and SOCMR were 115.22±15.77,1644.32±224.97 kg/ hm2 and 3.59±0.49 %,respectively.For the second year(ratoon cane) SONMA,SOCMA and SOCMR were 107.46±11.02,1478.59±151.65 kg/hm2 and 3.63±0.37 %,respectively.On the base of two years' average,SONMA,SOCMA and SOCMR were 111.34 kg/ hm2,1561.46 kg/hm2 and 3.61 %,respectively.There was no significant difference between the first year and the second year for the SONMA and SOCMR.However,for the SOCMA,the first year is larger than the second year.