外源氮和硅添加对毛竹植硅体碳的影响OA北大核心CSTPCD

[Objective]This study aims to investigate the response of phytolith and phytolith-occluded organic carbon(PhytOC)formation to exogenous nitrogen(N)and silicon(Si),and study the effect of exogenous N and Si addition on PhytOC sequestration capacity of Ph.edulis.[Method]N-Si two factor three level orthogonal cultivation experiment was designed[CO(NH2)2:0(N0),250(N1),500(N2)mg·kg-1,Na2SiO3:0(Si0),75(Si1),150(Si2)mg·kg-1],and samples of leaves,branches,culm,culm stump and litter were collected to analyze PhytOC content in different organs under different treatments.[Result]With the increase of Si addition,PhytOC content of different organs and litter showed an upward trend.PhytOC contents in different treatments of leaves,branches,culm,culm stump,and litter were 3.15-4.68,2.10-3.47,0.30-1.18,1.09-2.15 and 3.21-4.63 g·kg-1,respectively,and all showed the highest content of PhytOC in N2Si2 treatment[CO(NH2)2:500 mg·kg-1,Na2SiO3:150 mg·kg-1],while the lowest content of PhytOC in N0Si0 treatment[CO(NH2)2:0 mg·kg-1,Na2SiO3:0 mg·kg-1].The results of the difference significance analysis showed that PhytOC content showed significant differences(P＜0.05)between N0Si1,N0Si0 and N2Si2 treatments in culms.The correlation analysis results showed that there was a highly significant positive correlation between PhytOC and Si(R2=0.481 8,P＜0.01),as well as between PhytOC and phytolith(R2=0.463 2,P＜0.01).There was a highly significant negative correlation between PhytOC and C(R2=0.318 3,P＜0.01).[Conclusion]Exogenous N addition contributes to the absorption of Si and the accumulation of organic matter in Ph.edulis,while Si addition helps to increase the content of phytolith and PhytOC,as well as the proportion of PhytOC to C.[Ch,1 fig.9 tab.36 ref.]