氮肥对两种沙性栽培基质中有机碳类物质含量的影响

摘要

The effects of continuous nitrogen fertilizer application on the contents of TOC (total organic carbon) , POC (particulate organic carbon) , SMBC (soil microbial biomass carbon) and WSOC (water-soluble organic carbon) under two types of marginal lands (gross sandy soil and pure sand) were studied using switch-grass planted in PVC pipes. Nitrogen fertilizer exerted significant effects on root dry weight, contents of TOC, POC, SMBC and WSOC at different soil depths of both gross sandy soil and pure sand (P<0. 05). In both soil depths of the two types of substrates, the contents of TOC, POC and SMBC all reached a maximum under the N4 gradient, while the WSOC content decreased. For all nitrogen concentrations there was no significant difference in the vertical distribution of root dry weight, contents of TOC, POC, SMBC and WSOC under both types of substrate. The maximum of all indexes appeared at the 0 - 60 cm depth.%为研究粗砂土与河沙2种栽培基质中连续施用氮肥对总有机碳(TOC)、颗粒态有机碳(POC)、微生物量碳(SMBC)和水溶性有机碳(WSOC)含量的影响,本研究采用PVC管栽培柳枝稷开展相关的试验研究.结果表明,连续施用不同浓度的氮肥(CK:0.0 mg/kg、N1:30.0 mg/kg、N2:90.0mg/kg、N3:150.0mg/kg,N4:180.0 mg/kg)对不同土层中的柳枝稷根系生物量、TOC、POC、SMBC和WSOC均有显著性影响(P＜0.05).对于2种沙性栽培基质,不同土层中,TOC、POC、SMBC的最大值均出现在N4梯度下,WSOC含量则随着氮肥浓度的升高而降低,各施氮水平下,2种基质中根系生物量和有机碳的垂直分布趋势一致,各指标最大值均出现在0～60 cm土层.