For analysis of nutrients, samples were dry-ashed and dissolved in HNO3 and HCl following the A.O.A.C. procedure . Calcium Mg, Fe, Mn, Cu and Zn were determined by FAAS, K by FES and P spectrophotometrically by the molybdate-vanadatemethod. Nitrogen was determined with an NA2100 Nitrogen Analyse . The experiment was run with 3 different batches of plants and 5 samples per treatment were taken for analysis in each experiment.