GROWTH OF SOME PASTURE PLANTS ON A COMPOSITE NUTRITIVE LAYER WITH RED MUD PUBLISHEDR. LĂCĂTUŞU1, Mihaela Venera STROE1, Mihaela Monica STANCIU-BURILEANU1, Mihaela LUNGU1, T. MARUŞCA2, Nineta RIZEA1, Rodica LAZĂR1, L. FILIPESCU3
Abstract. In order to cover with vegetation the red mud deposition from Tulcea tests with pasture plants have been carried out, in the climate maintenance room. The composite nutritive layer on which the plants were grown consisted of red mud (50%) and phosphogypsum, acid peat, sawdust, compost, and sludge from wastewater treatment, 10% each. In another variant the phosphogypsum and compost percentages were changed, at 5, respectively 15%. Out of the four plant species tested, Lolium perene had the best growth, highlighted both as height and weight. Phleum pratense, Dactys glomerata and Lotus corniculatus followed, in decreasing order. The composite material on which the pasture plants developed had a slightly alkaline reaction and a high organic carbon, total nitrogen, mobile phosphorus and potassium, copper, zinc, cadmium, and chromium contents, and also an advanced salinization, in which natrum sulphate (Na2SO4) predominates. In the dry matter of the plants normal contents of macro elements were determined, except for natrium (Na), which average content was eight times higher than the right limit of the normal content interval. The contents of metallic microelements and heavy metals laid in the normal values area, except for zinc (Zn), which values were twofold the zinc content of plants grown on a normal soil (control variant).
Key words: red mud, nutritive layer, pasture plants