Distribution of organic carbon with pig manure amendments in a paddy soil

To improve paddy soil fertility，the effects of fertilization on the distribution of total organic carbon along with fractionation and hot water-solubility in paddy field soil profiles were studied. This work included accumulation of soil organic carbon and its soil profile evolution from a 10-year fertilization experiment with pig manure amendments in Pinghu County，Zhejiang Province. Results showed that in the 0－45 cm horizon soil organic carbon content differed greatly between pig manure treatments and no pig manure amendments. With organic fertilizer amendments，soil organic carbon increased with the increase of soil profile. Total organic carbon differed greatly from sandy carbon and amylaceous carbon （P＜0.05）. Soil organic carbon in the 0－45 cm horizon consisted mainly of sandy carbon；whereas in the 45－85 cm horizon it was comprised mainly of amylaceous carbon and sticky carbon. Also，with the pig manure amendments，hot water-soluble organic carbon content of the soil increased.［Ch，2 fig. 4 tab. 28 ref.］