摘要
本试验采用三室盆栽系统研究两种不同形态的氮肥(铵态氮和硝态氮)接种泡囊——丛枝(VA)菌根真菌对三叶草苗期植株生长和磷素营养的影响。测定各处理植株的生长量和根系的总长度,分析植株 N,P,K 等养分的含量和收获后中室边室土壤 Olsen-P 浓度及 pH值。结果表明,施用两种不同形态的氮肥,接种菌根真菌显著增加了植株的干物重,提高了植株中 P 的含量,且在 NH_4-N 的处理中,菌根效应要大于 NO_3-N 的处理。施 NH_4-N,菌根处理的边室土壤 pH 值和 Olsen-P 的含量都显著低于未接种的处理,而施硝态氮的处理菌根对pH 值的影响不显著。说明菌根对寄主植物的营养效应与环境中氮素的形态有密切的关系。
The effect of different forms of nitrogen(ammonium and nitrate)on the growth of red clover(Trifolium prafensel)inoculated by VA mycorrhizal fungi was studied in a greenhouse experiment. The result showed that the shoot dry weight of the infected plants was greater than that of the plants without infection.Both nitrogen forms and mycorrhizal fungi,affected the host plant roots morphology, such as:the total length of the roots,root diameter and root/shoot ratio,mycorrhizal roots were short- er and its diameter was larger than that of non-mycorrhizal roots.Rhizosphere pH was altered by the forms of nitrogen source and the presence of mycorrhizal fungi.In the ammonium treatments,the rhizosphere pH was significantly lower in mycorrhizal soils than in non-mycorrhizal one,but in nitrate treatments the change was very little.The concentration of phosphorus in the soils and the plants was de- termined.It is concluded that the contribution of hyphae in phosphorus supply to host plants in ammonium treatments was larger than in nitrate treatments.
基金
国家自然科学基金
关键词
VA菌根
三叶草
氮素
磷素
营养
VA mycorrhizae
red clover
(Trif olium praf ensel)
phosphorus and nitrogen aquisition
