The carbon and nitrogen contents and distribution characteristics of surface layer soil (0 ~ 30 cm) at three altitudes [ High altitude (1 615 ~ 1 682 m) , Medium altitude (1 532 ~ 1 555 m) and Low altitude (1 445 ~ 1 468 m) ] in Yuanyang terraced paddy soils were studied. The results showed that; the surface layer soil organic carbon (TOC) content was up to the "second" level in average, but the soil total nitrogen (TN) content, pH value and microbial biomass carbon and nitrogen (MBC, MBN) contents were low, the soil dissolved organic carbon and nitrogen (DOC, DON) contents , DOC/TOC ratio and DON/TN ratio were high, and the soil readily oxidizable organic carbon (ROC) content, light fraction carbon and nitrogen (LFC, LFN) contents were medium level. In general, all of the indexes mentioned above decreased along with the fall of altitude, and the altitude showed significant positive relation (P<0. 05) to the soil DOC, DON, ROC, LFC and LFN. There were no significant difference in soil TOC, TN, MBC, MBN and NH4+ -N contents among the three altitudes , and the soil pH value, DON, ROC, LFC and LFN contents at high altitude were significantly higher than that at low altitude (P <0. 05).
dissolved organic carbon and nitrogenmicrobial biomass carbon and nitrogenreadily oxidizable organic carbonlight fraction carbon and nitrogenaltitudinal gradient
国家科技期刊平台
NSTL
万方数据
维普
