Journal of plant nutrition vol:22 issue:2 pages:259-268
In experimenting with nutrient solutions in hydroponic plant nutritional research, the chemical feasibility region of the nutrient solution is a conditio sine qua non. If in preparing a nutrient solution some ions precipitate, the desired concentration of the dissolved ions can not be reached. This means that the desired nutritional composition is chemically not feasible. For the six essential macronutrients: potassium(K+), calcium (Ca2+), magnesium (Mg2+), nitrate (NO3-), dihydrogen phosphate (H2PO4-), and sulphate (SO42-), the chemical feasibility region is investigated using the computer speciation program Geochem PC version 2.0. In this way the impact of pH, dissociation reactions, and complexation reactions on precipitation reactions is taken into account. As the total milliequivalent concentration of the nutrient solution increases, the chemical feasibility region reduces.