长期不同施肥对黑土团聚体及有机碳组分的影响

本文研究了32年不同施肥对黑土团聚体组成、土壤有机碳(soil organic carbon,SOC)、腐殖酸、微生物量碳(microbialbiomass carbon,MBC)及颗粒有机碳(particulate organic carbon,POC)的影响。结果表明:化肥区与CK团聚体以10~50μm粒级为主,有机肥化肥混施与休闲以50~250μm粒级为主,表明有机肥化肥混施促进大团聚体的生成,有利于良好土壤结构的形成。在不同施肥条件下,"特征微团聚体比例"也存在差异,表明有机肥化肥混施使黑土保供水肥性能提高。化肥,尤其N肥单施使MBC、POC含量降低。有机肥化肥混施区SOC、MBC、POC含量显著高于其他处理区。与化肥单施相比,有机肥化肥混施明显提高了黑土腐殖酸、HA、FA、HS含量,也提高了腐殖质活性。不同类型化肥处理HA/FA差异较大,N肥的施加降低了腐殖酸含量,却能提高腐殖质活性。

Effect of Long-term Fertilization on Aggregate and Fractions of Organic Carbon in Black Soil

This paper studied the effects of long-term different fertilization(32 years) on aggregate composition,SOC,humus,MBC and POC in black soil.The results indicated aggregates were dominated by the size class of 10-50 μm in chemical fertilizer and CK,but chemical fertilizer and organic fertilizer mixed and fallow area increased the size class of 50-250 μm of aggregates,whith indicates that fertilization by using the mixed organic fertilizer and chemical fertilizer could be better to form the macro-aggregate,promoting forming the good soil structure.Fertilization affected characteristics of micro-aggregates.The mixed fertilization of organic fertilizer and chemical fertilizer could promote storing and supplying moisture and nutrients of black soil.Fertilizer,especially N,reduced MBC and POC content in black soil.In the mixed treatment of organic fertilizer and chemical fertilizer,SOC,MBC and POC contents were greater than other treatments.Chemical fertilizer increased the contents of humic acids,HA,FA and HS,also increased humus activity.The different types of chemical fertilizer affected HA/FA.Chemical fertilizer of N reduced humic acids content,but increased humus activity.