EFFECTS REGARDING THE USE OF INDUSTRIAL WASTE FOR SOIL FERTILITY IMPROVEMENT PUBLISHEDHortensia RADULESCU, Adina BERBECEA, Lidia TAUBERT
The paper presents the effects of soil treatment with industrial mineral waste on some fertility characteristics of acid soils. Two industrial waste were tested by treating luvosoil, a low fertile acid soil, with different doses of waste. These two mineral sources have resulted from the magnesium products industry and contain in their composition significant contents of magnesium and calcium as well as low contents of trace elements such as iron, copper, manganese and zinc. Both waste types have resulted in the industrial processes of manufacturing magnesium compounds from dolomites as waste products and deposits on the industrial equipment. The difference between the two waste types lies in the double magnesium content, established for the crusts deposits. Because of their alkaline reaction and nutritive elements content, the two waste types can be revaluated in agriculture as fertilizer and amendment for acid soils. The experimental alternatives consist of treating luvosoil with four different doses from each waste, without and with adding a nitrogen supplement (ammonium nitrate) to the soil. In order to establish the effects of soil treatment with waste on soil fertility, the available content of soil nutrients and soil reaction were determined. The available nutrient soil content was analysed by using the EDTA extraction method along with atomic absorption spectrophotometry. Soil reaction was determined in watery extracts by means of a pH-meter. The results show that low doses of waste increase by 14-18% the available potassium content. Nitrogen supplement rises the potassium content increase till 26 - 30%. The available calcium content rises proportional with the administered waste doses for both waste types. Nitrogen contribution increases the values by 133% for waste A and 106% for waste B. The dynamics of available magnesium content is similar to that of calcium. The increases represent 65% for waste A and 46% for waste B. Soil acidity was neutralized in all experimental alternatives. The pH values increased proportional with the added waste dose. The originality of this paper consists in the utilization of the waste resulted from the magnesium products industry in agriculture as soil amendment and also as calcium-magnesium fertilizer. The importance of this study lies in the fact that, on the basis of the obtained results, a new technology to improve acid soils fertility can be conceived by specifying the suitable dose, usage manner and application frequency of the tested waste.
amendment, mineral waste, acid soil, available nutrient content, soil reation, soil fertility