Abstract
The demand for physically mixed compound fertilisers has increased in recent years as a result of individually mixable formulations and lower production costs. For three fertiliser blends, three different components were used in each case. Each blend included different amounts of a 27 % calcium ammonium nitrate (round granule or corn), an angular corn NPK complex fertiliser (15 % N/15 % P2O5/15 % K2O/3 % S) and a 60 % potassium chloride (angular corn). The extent of segregation of the individual fertiliser components was tested in the conical pile formed after the mixing operation, in big bags and in unloaded piles from silo tanker truck and tipper truck respectively. Systematic sampling of the conical pile showed particularly with fertiliser blends 2 and 3 substantial deviations from the target nutrient mix. In the conical pile the target blend proportions were distorted through an increased proportion of K2O. The angular K2O corns predominated at the top of the conical pile while CAN round corns settled more at the base of the heap. This separation was reduced in the heap unloaded from the tipper truck while the pneumatic unloading from the tanker truck promoted separation. In the big bag, the nutrient distribution could vary significantly. © 2017 by the authors.