摘要
在温室内用砂培的方法研究了NO-3 N、NH+4 N及其不同配比对水曲柳 (Fraxinusmandshurica)幼苗生长的影响 .结果表明 ,水曲柳幼苗在营养液NO-3 N NH+4 N为 75 2 5时生长最好 ,营养液中NH+4 N比例继续增加则生长下降 .过量的NH+4 N可抑制水曲柳幼苗根系生长 ,降低幼苗的地下 /地上比 .营养液中NH+4 N比例增加 ,水曲柳幼苗的净光合速率下降 ,体内P浓度增高 ,而Zn和Fe浓度下降 .N素形态明显影响基质的 pH值 ,NO-3 N比例增加使基质 pH值升高 ,NH+4 N比例增加则基质 pH值下降 .完全供给NO-3 N时基质 pH值升至 7 2 2 ,而完全供给NH+4 N时基质的 pH值降至 4 2 0 .
The effect of NO\+-\-3 N and NH\++\-4 N and their different supply ratios on the growth of Fraxinus mandshurica seedlings was studied by sand culture in greenhouse.The highest seedling growth was obtained at a NH\+-\-3 N/NH\++\-4 N ratio of 75/25 in nutrient solution.The growth of seedlings declined with the increasing ratio of NH\++\-4 N to NO\+-\-3 N. Excessive NH\++\-4 N inhibited root growth,and the root/shoot ratio of the seedlings significantly decreased as the NH\++\-4 N/NO\+-\-3 N ratio was over 50%.Increasing NH\++\-4 N in nutrient solution led to the decrease of net photosynthetic rate,the increase of phosphorus content in plant tissues,and the decrease of Zn and Fe contents.The pH value of cultural medium was affected markedly by nitrogen form,which was increased with increasing NO\+-\-3 N and decreased with increasing NH\++\-4 N in nutrient solution.The pH value was up to 7\^22 in the medium contained NO\+-\-3 N alone,while decreased to 4\^20 only with NH\++\-4 N.
出处
《应用生态学报》
CAS
CSCD
2000年第5期665-667,共3页
Chinese Journal of Applied Ecology
基金
国家"九五"科技攻关项目!(96 0 1 1 0 2 0 1 )
关键词
水曲柳
pH值
硝态氮
氨态氮
幼苗生长
Fraxinus mandshurica, Nitrate nitrogen, Ammonium nitrogen, pH value.
