中文摘要：

在（30±2）℃条件下对3种不同有机肥施用量（中量、高量和不施肥）耕层土壤和土壤母质（40～60cm）及其加入玉米秸秆的相应土壤培养100d,研究了玉米秸秆对不同有机肥施用量棕壤水溶性无机氮和有机氮的影响。结果表明：所有处理可溶性有机碳（DOC）含量表现相同的趋势,先增加后降低而后达平稳状态,玉米秸秆对土壤DOC含量影响主要在培养初期。所有处理可溶性有机氮（DON）含量表现为随时间先增加而后下降趋势,在培养后期玉米秸秆和有机肥施用量对DON含量的影响较大。有机肥施用量和玉米秸秆相互作用对浸提液中NO-3含量在整个培养期间都有显著影响（P〈0.05）。高量有机肥施用量条件下无玉米秸秆的浸提液中NO-3含量最高。加入玉米秸秆的母质土壤浸提液中NO-3含量最低。随培养试验进行有机肥高施用量的土壤DOC/DON值变宽,有玉米秸秆加入的土壤相对于原土DOC/DON值变窄。加入玉米秸秆后,水浸提液中NO-3-N占总可溶氮的比例显著降低,水浸提的DON占总可溶氮的比例增加。DON比例表现为随土壤肥力增加而降低。有机肥中高施用量土壤DON与DIN呈极显著负相关,有玉米秸秆加入的土壤相对于原土相关系数降低。在中高量有机肥土壤上DON比DOC优先分解,DON易矿化部分可能主要为氨基酸N,NO-3含量增加。玉米秸秆的加入后土壤水溶有机质C/N变窄和相关系数降低表明有机物料影响水溶性有机质的分解速率。

英文摘要：

The effect of maize residues on water extracted dissolved inorganic and organic nitrogen in Brown earth with different amount of manure application was studied over the period of 100 d at（30±2）℃.The experiment was composed of different types of treatments：four fertilization level soil and addition of corn straw.Water extractable dissolved organic carbon（DOC） displayed the same trend with time in all treatments that soil DOC content increased immediately and returned rapidly to background level.DOC showed a little response to maize straw amendment at initial stages of incubation.Water extractable dissolved organic nitrogen（DON） displayed the same trend with time in all treatments that soil DON content increased significantly and decreased.DON showed great response to maize straw amendment and manure amounts at the end of incubation.Manure application amounts and the presence of maize straw interacted to have a significant effect on the concentration of NO-3 in extracts.Highest concentration was observed in extract of high fertilization soil without corn straw,whereas lowest concentration was observed in extract of subsoil with corn straw.The C∶N ratios of the extracts widened in manuring treatments as the incubation progressed,indicating that the soluble organic matter was rich in labile organic N.Maize straw amendments made DOC/DON ratios relatively narrow.After application of organic material,the ratios of NO-3 to total dissolved nitrogen（TDN） decreased distinctively,and DON made a greater contribution to TDN.The ratios of DON to TDN decreased with application amount increase of manure.DON had remarkably negative correlation with DIN in medium and high fertilization soil.Maize straw amendments made coefficient relatively decrease.These results suggested that DON was decomposed preferentially in medium and high fertilization soil.Readily mineralizable N of DON was dominantly amino acid-N maize straw amendment affect the rate at which it was decomposed.