黑龙江地区不同类型水稻土活性有机碳的特征

The Characteristics of Labile Organic Carbon in Paddy Soils in Hei Longjiang Province

通过野外实地调查取样和室内分析相结合的方法,研究黑龙江地区4 种类型（起源土壤分别为黑土、草甸土、白浆土和沼泽土）水稻土活性有机碳含量及其分配比例、碳库活度.结果表明,4 种类型水稻土易氧化有机碳（ROC）含量及其分配比例均明显高于可溶性有机碳（DOC）和微生物量碳（MBC）,ROC、DOC 和MBC 质量分数分别为1 390.3-15 685.1、533.4-1 329.7 和138.5-1 052.1 mg·kg^-1,其分配比例分别为10.1%-34.9%、1.8%-7.7%和0.5%-3.3%;不同类型对土壤DOC、MBC、ROC 含量及其分配比例和碳库活度（aR）均具有显著性影响,4 种类型水稻土间DOC、MBC、ROC 含量及其比例和aR 均达显著性差异（P〈0.01）,不同类型水稻土的ROC/TOC 比例和aR 的大小顺序相同,依次为黑土型〉草甸土型〉沼泽土型〉白浆土型;4 种类型水稻土的ROC 含量与TOC 含量之间均呈极显著的正相关关系（P〈0.01）.

The content, distribution proportion of labile organic carbon and carbon pool activity in four types of paddy soil which developed from black soil, meadow soil, albic soil and boggy soil in Hei Longjiang Provice were studied by the combination of field survey and lab analysis. The results showed that the content and distribution proportion of readily oxidized carbon (ROC) was significantly higher than dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in four types of paddy soil. The content for ROC, DOC and MBC were 1 390.3~15 685.1, 533.4~1 329.7 and 138.5~1 052.1 mg·kg-1, respectively, and the distribution proportion was 10.1%~34.9%, 1.8%~7.7% and 0.5%~3.3%, respectively. Soil types had a significant effect on the content, distribution proportion of DOC, MBC, ROC and the carbon pool activity (aR). The content, distribution proportion of DOC, MBC, ROC and aR were significant different (P<0.01) in the four types of paddy soil. The ratio of ROC to TOC and the value of aR of different type of paddy soils showed black soil>meadow soil>boggy soil>albic soil . There was a significant positive correlation between ROC and TOC in four types of paddy soil (P<0.01).