施用秸秆对土壤有机碳组成和结构稳定性的影响

EFFECT OF STRAW ON SOIL ORGANIC CARBON CONSTITUTION AND STRUCTURAL STABILITY

在室内条件下培养 6个月时随秸秆添加量的增加 ,土壤中总有机碳 (TOC)、焦磷酸钠提取有机碳 (SPPC)、水解碳水化合物 (HDC)、热水提取碳水化合物 (HWC)的含量和水稳性团聚体含量极显著增加 ,粘粒分散率除一个盐土土样外其余 3个土样显著降低。虽然玉米秆和小麦秆分别对TOC、SPPC、水稳性团聚体和粘粒分散性的影响之间没有显著差异 ,但是有小麦秆处理比玉米秆处理HDC和HWC含量高的趋势。TOC、SPPC、HDC和HWC分别与水稳性团聚体显著正相关 ,与粘粒分散率显著负相关 ,但总体而言 ,HWC与团聚体的稳定性更相关 ,HDC和粘粒的分散性更相关。

Effect of applied straw on soil total organic C, extractable organic C and structural stability were examined in an incubation experiment. The results showed that with increase in straw application rate, total organic carbon (TOC), sodium pyrophosphate extractable carbon (SPPC), hydrolyzable carbohydrates (HDC) and hot water extractable carbohydrates (HWC) in soils were significantly increased after 6 month's incubation. Water stable aggregates were significantly increased with increase in straw application rate for all 4 soils studied; clay dispersion rates were significantly decreased in 3 soils except 1 saline soil. Though there were not marked differences between the effects of corn stalk and wheat straw on TOC, SPPC, water stable aggregates and clay dispersion, it seemed that HDC and HWC in soils in wheat straw treatment were higher than those in corn stalk treatment. TOC, SPPC, HDC and HWC were all significantly positively correlated with water stable aggregate and negatively with clay dispersion rates, respectively. In all, however, HWC was more correlated to water stable aggregates and HDC was more correlated to clay dispersion rates than others.\;