Relationship between mineral nutrition and seedling growth as well as nodulation of Ammopiptanthus mongolicus

Taking perlite as the potted medium, seedling growth and its morphological characteristics were studied when N,P,K,Ca,Mg,Fe and other trace elements were lacking in a nutrition liquid.Resultsshowed that seedlings lacking in N,P,K showed notable differences,in comparison with full nutrition,in the indices of seedling growth, including plant height, stem diameter, chlorophy content and dry weight. Typical nutrient deficiency symptoms showed up in morphological characteristics. In addition,the effects of different N levels on seedling growth and nodulation were studied when seedlings were inoculated with rhizobia . At the level of 0 mol/L, the average number of root nodules reached 28 for each plant; at 0.003 75 mol/L level, it was only eight on average; at 0.007 5 mol/L level, there were no nodules.Resultsshowed that seedling growth is positively correlatied with N levels. Furthermore, inoculating rhizobia can promote seedling growth in the soil with low level of N.