黄土区六种植物凋落物与不同形态氮素对土壤微生物量碳氮含量影响.pdfVIP

2010, 30( 24): 7092 7100 Acta Ecologica Sinica * 王春阳, 周建斌 , 董燕婕, 陈兴丽, 李! 婧 (, ! 712100) : , , 6( + - 15. 1 50. 7)( NH N NO N), 4 3 , + - () NH NO , 4 3 , , C /N , C/N , , : ; ; ; Effects of plant resi ues an nitrogen forms on m icrobial biomass an m ineral nitrogen of soil in the Loess Plateau * WANG C unyang, ZHOU Jianb in , DONG Y anjie, CHEN X ingli, LI Jing College of Resources and Environmen,t NorthwestA F University, Yangling, Shaanxi 712100, China Abstract: Bot t e quality and quantity of plant residues returned into t e soil ecosystems in t e gu lly and valley region of t e Loess Plateau ave been substantially c anged w it t e returning of croplands to forests and grasslands since 1990 in Nort western C ina. H owever, no study as reported if soil carbon ( C) or nitrogen (N ) as been increased after one decade of suc a land use c ange. An mi portantm ec anism to understand t ese c anges is to know if and ow soilm icrobial b iom ass C and N ( SMBC, SMBN) andm ineralN ave been altered in t is region. W e conducted a tmi e course incubation expermi ent to study t e effects of external addition of t e sole plant residue and t e dual residue plus inorgan ic nitrogen fertilizer on t ese t ree param eters to a Loess soil ( smi ilar to U stoc nept in t e US or Calcic cam bisol in FAO system) under laboratory conditions. S ix local plant residues (Astragalus adsurgens al.l, Caragana K orshinskiiK o