氮磷添加对麦冬根部养分浓度及其化学计量比的影响

以城市地被植物麦冬(Ophiopogon japonicus(Thunb.)Ker-Gawl.)为研究对象,研究了土壤中添加氮(N)磷(P)后对植物根部N、P养分及其化学计量比的影响。结果表明,实验监测期间(10-12月),麦冬根部N浓度平均值表现为N(5gm-2) P(1gm-2)处理>N(5gm-2)处理=P(1gm-2)处理>对照,根部P浓度和N:P比差异不显著(P>0.1)。而监测期间的N、P月份动态结果表明,同对照相比,N处理、P处理和N P处理的麦冬根部N、P浓度和N:P比的差异性均表现为监测前期(10月)较大,中后期(11-12月)较小的变化趋势。这说明麦冬能保持其根部N、P水平的稳定性,具有较强的应对N沉降的能力,且补充P肥可增强这种能力。因此,麦冬可在大气沉降严重的地区应用和推广。

Effects of Nitrogen and Phosphorus Additions on Nutrients and N:P Stoichiometry in Dwarf Lilyturf Roots

Influences of nutrient (N and P) treatments on N and P concentrations and N:P stoichiometric ratio were studied in roots of urban ground cover plant species dwarf lilyturf (Ophiopogon japonicus (Thunb.) Ker-Gawl). N and P concentrations were determined during October to December after treatment. The average N concentration in roots followed the order: N(5 g m-2) P(1 g m-2) addition> N (5 g m-2) addition = P (1 g m-2) addition > control. Compared with control, significant changes in N and P concentrations of roots as well as N:P stoichiometry ratio were found in October, and none was found during November to December. It was indicated that N and P levels in dwarf lilyturf roots could be maintained stably under high N and P input. Thus, dwarf lilyturf has high ability to adapt N deposition, especially been fertilized with P. Therefore, dwarf lilyturf could be used as a good plant species in N deposition area.