| The different methed of estimation labile C of soils under different agriculture ecoysystem were discussed using oxidation in this paper and potassium permanganate oxidation metheds were chioced. Six soil samples from Hunan, Shanxi, Xingjiang, Beijing, Henna, Jillian province were studied in labile carbon and convene physicochemistry analysis at laboratory, the result are as follows: l.the labile carbon (CL) research of six soils The labile C and CMI of soils under different agricultural ecosystem were discussed using potassium permanganate oxidation. Results indicated labile C was significantly affected by fertilization, climate, and soil utilization style and cultivated age et al. From the study of six soils can find that the labile carbons of the sample that not apply fertilizer and only apply chemical fertilizer are declined Apply organic fertilizer can rised the amount of the labile carbon. Incorporating stubble can declined the labile carbon in short time but resound it in long time. 2.the distribution and relative losses of organic carbon fractions in aggregate size fractions The distribution and losses of organic carbon fraction in various aggregate sizes from the red soil and black soil were studied to understand the factors associated with losses of soil organic carbon under cultivation. Five aggregate sizes were separated format of these soils (<5Oum, 50-l5Oum, 150-250um, 250-500um, 500- 1000um). On each of these aggregate fractions, measurements were made for total carbon (CT), labile carbon (CL) by oxidation. CT and CL were found to increase with a decrease in aggregate size. Loss of both CT and CL as a result of cultivation were higher aggregates than in small aggregates. 3 the relationship between CL and soil chemical nature Correlation analysis indicated CL was related or extremely related to total N, total P. hydrolyzable N, mineralisation N, readily available K, and Fe, Cu, Zn, P, pH, but CT was not related to all of above. |
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