沈阳市郊玉米连作土壤有机质组成及其对土壤结构的影响

通过对沈阳市郊玉米连作土壤的有机质、结构情况以及二者相互关系研究表明,土壤中有机质大致范围在16.31gkg-1～23.72gkg-1,腐殖质大致范围在15.17gkg-1～21.49gkg-1,非腐殖质大致范围在1.14gkg-1～2.59gkg-1;在腐殖质各组分中,胡敏素的含量最高,约占腐殖质总量的58.93%～66.34%,胡敏酸约占16.26%～22.87%,富里酸约占16.82%～18.20%,胡富比约在0.95～1.32之间;干筛处理后>0.25mm的土壤团聚体占到80%以上,其中以>2mm团聚体为主,湿筛处理后>0.25mm的土壤团聚体仅占20%左右,其中0.25～0.5mm团聚体为主,水稳性系数在17.33%～35.67%。对有机质及其各组分与土壤各级团聚体做的相关分析结果表明,有机质与0.25～5mm粒径组的团聚体呈显著相关,与>5mm团聚体不相关,且胡敏酸主要影响1～5mm大团聚体的形成。

Compositions of Organic Matter in Soil in Continuous Corn Cropping Soil in Shenyang Suburban and Affect on Soil Structure

The tested resulls of soil organic matter, soil structure and their relationship in continuous corn cropping soil in Shenyang suburban, showed that organic matter contents was from 16.31g kg-1 to 23.72g kg-1, hunmic substances contents was from 15.17g kg-1 to 21.49g kg-1, and non-humic substances contents was from 1.14g kg-1 to 2.59g kg-1.Of the humic substances compositions, humin(HM) contents was the most of all, which was 58.93%-66.34%,then humic acid(HA) contents was 16.26-22.87%, fulvic acid(FA) was the least of all which was 16.82%-18.20%, and the ratio both HA and FA was 0.95-1.32. The >0.25mm size group aggregates was over 80% by dry sieving but 20% by Yoder method, and the >2mm size group aggregates was the most of all levels by dry sieving, but the 0.25-0.5mm size group aggregates by Yoder method. The water stability coefficient was from 17.33% to 35.67%.The correlation between the each composition of humic substances and the each size group aggregates at all levels showed that organic matter was correlated significantly with from 0.25 to 5 mm size group aggregates but was not correlated with over 5 mm size group aggregates. Humic acid contributed to form 1-5 mm size group aggregates.