A RATE OF MACROELEMENTS RELEASING FROM GRANULES OF NEW CONCENTRATED PHOSPHORIC FERTILIZERS

Background. The coefficient of use of macronutrients of highly concentrated nitrogen and phosphorus fertilizers does not exceed 50-70 and 20-30%, respectively. In order to reduce the irrational losses of N, P, K, slowly soluble fertilizers are being developed. However, the effectiveness of new prolonged fertilizers with a high content of nutrients in irrigated agriculture is poorly understood. It is assumed that slow-acting fertilizers with a longer period of nutrient release will ensure proper nutrition of plants during the growing season, without an excess of readily available nitrogen and phosphorus, which will prevent losses and environmental pollution. Purpose .The purpose of the work is to establish the prolonged properties of new concentrated phosphorus fertilizers by determining the rate of leaching of ammonium ions, nitrates, and phosphates by irrigation water. Methodology. In a laboratory experiment, the rate of release of ammonium, nitrate, and phosphate ions from traditional and slow-acting fertilizers was compared with soil bulk columns. Originality The scientific novelty is establishment of prolonged properties of new concentrated phosphorus fertilizers intended for irrigated agriculture. A decrease in the rate of release of ammonium ions, nitrates, phosphates from granules of enriched superphosphate, ammonized superphosphate and ammophosphate (by 1.3–5 times or more) is shown. Findings. Under the conditions of a model laboratory experiment with soil bulk columns, it was proved that new concentrated phosphorus fertilizers contribute to an increase in the period of dissolution of grains and the release of nutrients. The level of water-soluble phosphorus in the filtrates with ammophos and prolonged fertilizers reached a maximum on the 7-10th day of the experiment, however, P2O5 in the filtrates with enriched superphosphate was lower at 12.0; ammonium superphosphate - 6.3 and ammonophosphate - 3.1 times. Highlights: - the regularity of release ammonium ions, nitrates, and phosphates during from fertilizers granules were revealed; - the prolonged action of new fertilizers was revealed; - the rate of water-soluble P2O5 forms directly depended on content of P2O5soluble in fertilizers.