Computer system for fertilizer recommendations and economic analyses of field vegetable ecological production in Croatia.

摘要

The increase in organic farming all over the world has influenced its development within Croatian agriculture. Existing laws and regulations for organic farming require ongoing analyses of soil and fertilizer quality and contamination. In 2003, 62 farmers were registered as organic farmers in Croatia, and 68 more farmers registered in 2004. This computer system for fertilizer recommendation and economic analyses of field vegetable organic production has been created to help them in educational, advisory, prediction and analytical ways. The computer program is based on existing laws and regulations, and uses results of several field vegetable fertilization experiments and results of economic analysis of field vegetable production in eastern Croatia. The vegetables used in the experiments were white cabbage [Brassica chinensis], Savoy cabbage [B. oleracea var. capitata], cauliflower [B. oleracea var. capitata] and bell pepper [Capsicum annuum]. The computer program is composed of three major parts: testing of soil suitability for organic farming, calculating fertilizer recommendations and economic analysis. The soil suitability testing is based on the concentration of harmful or toxic components in aqua regia extracts of soil, with a separate recommendation that humus content is higher than 2%. Fertilizer recommendations are based on nutrient removal, soil analyses and the fertilizer types allowed in organic farming according to law. Expected and achieved yields in organic farming are lower than in conventional farming and the amount of nitrogen applied by organic fertilizer is limited to 170 kg ha-1; therefore nitrogen availability is used for estimating target yield limitations. The third part of the program includes simplified economic analyses of field vegetable organic farming. All amount, price or cost structure changes are allowed. Thus, it is very simple to compare different production conditions, and to analyse the economic importance of soil fertility, production investments, prices or any other factor. The organic farmers in Croatia have shown a great interest in receiving help in education and advice, but at the moment are not ready to cooperate more completely..