Mineral Nutrient Limitations of Calcifuge Plants in Phosphate Sufficient Limestone Soil

Abstract

Twelve species of calcifuge plants were grown in an Ordovician-limestone soil with and without phosphate amendment, as well as in an acid silicate soil of their natural habitat. Phosphate treatment of the limestone soil raised the P concentrations of the plant biomasses to levels within sufficiency ranges reported for cultivated plants and productivity usually increased two- to five-fold. Out of twelve species studied, Scleranthus perennis was unable to survive in the limestone soil unless treated with phosphate, whereas growth and general performance of Galium saxatile was impaired by phosphate additions. Biomass dilution effects on micro-nutrients, but usually not on macronutrients, were recorded as a result of the phosphate treatment. Dilution of Mn was most distinct and Fe was least distinct. However, no foliar symptoms clearly assignable to Mn deficiency were observed. Symptoms of foliar chlorosis, reminiscent of Fe deficiency, developed in Galium saxatile, Carex pilulifera and Veronica officinalis . In C. pilulifera , but not in V. officinalis , chlorosis was accompanied by decreasing foliar Fe concentrations.