CONSERVING OF THE RESOURCES
A decision support system for field vegetable fertilization
Decision Support System (DSS) is a computer-supported interactive system, i.e., a software product to assist decision-making at any level of management, with an emphasis on making a directly applicable decision. The purpose of this software for the application in the process of fertilization is to organize and classify data, transform information, and choose how to make decisions and embody them. In its sophisticated form, it is an interactive computer program that uses and integrates a simulation model, a database and a decision model for optimal crop fertilization with different fertilizers. Fertilization recommendations in most countries around the world are based on years of fertilization experiments. When using DSS, the user must enter 3 data groups: 1) the type of vegetable and the planned yield; 2) results of agrochemical soil analysis (soil pH, soil organic matter content, available phosphorus and potassium, mineral nitrogen); 3) plans for organic fertilization and available fertilizer data. The flowchart of DSS main part consists of 12 steps: 1) determination of target yield 2) calculating the required amount of nutrient for the target yield; 3) calculating the optimal need of N in fertilization 4) calculating the optimal need of P and K in fertilization 5) determination of optimal organic fertilization; 6) calculation of the liming needed; 7) optimal distribution of N 8) optimal distribution of P and K with respect to fertilization dynamics; 9) the need and plan for application of micronutrients; 10) choosing the optimal form of nutrient and calculating the amount of optimum fertilizers (single and complex) 11) calculation of the nutrient balance 12) calculating the economic effect of vegetable fertilization and growing. DSS groups results into several sets of data: 1) interpretation of the results of agrochemical properties and soil fertility; 2) recommendation of the quantity of N, P, K and types of fertilizers (required quantities of primary nutrients in mineral fertilization of vegetables, types and quantities of mineral fertilizers required for the mentioned fertilization); 3) balance of primary nutrients, tips and warnings (optimal formulation of fertilizers, the balance of planned mineral fertilization, needs of fertilization with microelements). After receiving the results and guidance, the user simply obtains new output values according to the changes made by simply changing the input data (e.g., to plan a lower yield, other formulation fertilizer, cheaper fertilizer). This mode of operation enables rapid multiple comparisons of the required fertilization with different available fertilizers, on different production sites, and for different target yields and economic effects of vegetable cultivation.