Effects of P, K and Ca deficiency on the root morphology and nutrient absorption of Poncirus trifoliata seedlings Nurtient Omission Experiment of Eucalyptus grandis Seedlings in Six Forest Soil Types Dynamics of several mineral nutrients concentrations during fruit development of Washington navel orange in southern Jiangxi Province Cu and nutrient deficiency on different effects of growth, tolerance and mineral elements accumulation between two Elsholtzia haichouensis populations