Thesis Archive
A multi-crop production planning model for hydrophonic systems with nutrient mix reusability (2011)
Haniel Johanan P. Chua
John Francis H. Ramirez
Kyle Fitzgerald A. Sy.
Abstract:
-The world population is growing. At a least count of 6.8 billion people, it is bound to balloon to approximately 10 billion people by the year 2050. This is not only entails higher rate of food production to feed this vast amount of people, but in conjunction to that, an equally large amount of land is required to be able to accommodate growing all the food using the current methods of farming. However, even though we can produce more food, we cannot produce more land. Eighty per cent of the earths land area is already utilized. There is a need to find a better way to produce food without having to take up horizontal space or damaging the environment, which agriculture poses as the main culprit.
Being one of the fastest growing sectors of urban agriculture, hydroponics promises to provide a solution to agricultures food and land shortage and is beginning to replace traditional agriculture to feed the increasing population.
Research literature review of over 200 articles in urban agriculture, hydroponics, and production planning revealed two main gaps of the research: 1) that commercial hydroponics does not integrate nutrient reusability, incurring unnecessary costs while lacking in engineering support and 2) agriculturists do not delve into the scheduling of its intercrop production plan with regards to the orders that they receive. Therefore, there is a need for an optimization model for the design of multi-crop hydroponic system operations that considers the details of the key processes and factors in a hydroponic system which includes nutrients use optimization given a deterministic demand with the goal of minimizing cost due to different operational costs. The need was obtained from the significance of water and nutrients as a key factor in hydroponics, giving the bulk of the cost of the entire operational cost.
The mathematical model formulated is a mixed integer nonlinear programming problem. In order to obtain an optimal solution for the model, the GAMS language with the DICOPT solver as used to input and run the model.
Validation of the model consisted of three runs. The first run provided a means to validate the system in simple scenarios having demands for a single crop type whereas the second run provided a scenario wherein there were demands for both crop types. Multiple time period demands both for the crop types were also introduced by the third run. These validation runs were done in order to check whether the logic of the system coherent and consistent.
For the sensitivity analysis, 2k Factorial Design is used as a preparation phase for the Response Surface Methodology. Factorial results returned growth days, starting weight, nutrient expiration and table capacity as the significant factors, and were input as the factors for the RSM analysis. RSM was done in order to check for the optimal settings of the model since there are still other parameters that the model can consider.
The main results o the research include an algorithm that can be integrated into the management of commercial hydroponic systems, reducing resource costs of up to thirty per cent and making the technology feasible for developing countries. This algorithm can be easily used by existing farmers in cooperation with engineers.
Adviser:
Mr. Dennis Cruz
[email protected]