Studies Regarding the Establishment of the Optimum Conditions of Obtaining Process of NP Fertilizers with Micronutrients

Abstract: The fertilizers play a very important role in the plant growing and development. The fertilizers with micro-nutrients supply to the plant the needed nutritive substances, which doesn’t exist or are insufficient in soil. In the present paper were established the optimum conditions for the obtaining process of some NP fertilizers with zinc and copper as micronutrients. The zinc and copper-ammonium phosphates were synthesized using diammonium monohydrogen phosphate, zinc sulphate and copper sulphate solutions mixed at various molar ratios (Zn:Cu:P = 1:0:1; 0.8:0.2:1; 0.6:0.4:1; 0.4:0.6:1; 0.2:0.8:1; 0:1:1) and at various pH values of the reaction mass (4; 5; 6; 7). In order to find the optimum conditions for the fertilizers obtaining process, it was determined the dependence of the zinc and copper residual concentrations on the pH of the reaction mass at the studied molar ratios. We found that the optimum conditions of the obtaining process of NP fertilizers with zinc and copper micro-nutrients are: a value of the pH of the reaction mass between 6 and 7 and a molar ratio Zn:Cu:P = 0.6:0.4:1 or Zn:Cu:P = 0.4:0.6:1