不同NH_4^+/NO_3^-配比对红松幼苗生长的影响

Effects of Different Ratios of NH_4^+/NO_3^- on Growth of Pinus koraiensis Seedings

对NH4+-N,NO3--N不同配比盆栽试验条件下红松幼苗生物量,NPK养分的吸收,培养基质中的NH4+-N、NO3--N浓度及pH作了比较研究。结果表明,红松幼苗在以NH4+-N为主的营养液中生长好。营养液中NO3--N比例增加则幼苗生长下降,过量的NO3--N可抑制幼苗根系生长。NH4+-N为主的营养液对红松幼苗NO3--N的供应无明显效果。营养液中NH4+-N比例增加,植株体内P浓度增加,K浓度下降。NH4+-N/NO3--N配比显著影响基质的pH值,NH4+-N比例增加,基质pH下降;NO3--N比例增加,基质pH升高。

The concentrations of NH4^＋-N, NO3^--N and pH in vermiculite, the dry weight, total N, P and K contents of Pinus koraiensis seedlings grown with, Ammonium-N （ammonium sulfate） or Nitrate-N （calcium nitrate） and their different supply ratios were studied under pot culture in greenhouse. The results showed the higher growth were obtained at NH4^＋-N, NO3^--N ratio of 4 ： 0 and 3 ： 1. The growth of seedlings declined with the increasing ratio of NO3^--N. Excessive NO3^--N inhibited root growth. There were no significant effects in the capability of supply NO3^--N with NH4^＋-N. Increasing NH4^＋-N in nutrient solution led to the increase of phosphorus content in plant tissues, and the decreased of potassium contents. The pH of cultural medium （vermiculite） was affected markedly by the ratio NH4^＋-N and NO3^--N, which was decreased with increasing NH4^＋-N and increased with increasing NO3^--N.