ISHS Acta Horticulturae 481: International Symposium on Growing Media and Hydroponics
APPLICATION OF MIXTURE THEORY FOR THE OPTIMISATION OF THE COMPOSITION OF NUTRIENT SOLUTIONS FOR HYDROPONIC CROPPING: PRACTICAL USE |
| Authors: | G. De Rijck, E. Schrevens |
| Keywords: | mixture systems, multifactorial, nutrient solutions, optimisation |
| Abstract:
In hydroponic plant nutrition, nutrient solutions usually consist of 6 essential macronutrients (K+, Ca2+, Mg2+, NO3, H2PO4 and SO42) and 7 essential micro-elements (Fe, Mn, Mo, Cu, Zn, B and Cl). The ionic balance constraint postulates that the total amount of cations equals the total amount of anions, expressed in equivalents per litre. This constraint defines nutrient solutions as “double mixture systems”. Optimising nutrient solutions means to describe the zone of the mineral composition of the nutrient solution that gives an optimal development, production and quality of the crop. Considering nutrient solutions as “double mixture systems” makes it possible to experiment simultaneously with their cation and anion composition in a systematic multifactorial way. This research elaborates a general methodology for the design, the analysis and the optimisation of nutrient solutions in hydroponic plant nutritional research. The relationship between the nutritional composition and the response is represented with a mathematical model. This model quantifies both the main and the interaction effects of the mixture components and can be used to graphically represent the response over the experimental region, to calculate zones with optimal response, to investigate gradients, etc. A justified methodology to experiment with the mineral composition of nutrient solutions is the first prerequisite in hydroponic plant nutritional research. An example is elaborated. | |
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