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Environmental Engineering and Management Journal November/December <strong>2007</strong>, Vol.6, No.6, 537-540 http://omicron.ch.tuiasi.ro/<strong>EEMJ</strong>/ “Gh. Asachi” Technical University of Iasi, Romania ______________________________________________________________________________________________ SUSTAINABLE IRRIGATION BASED ON INTELLIGENT OPTIMIZATION OF NUTRIENTS APPLICATIONS Codrin Donciu ∗ , Marinel Temneanu, Marius Brînzilă “Gh. Asachi” Technical University of Iasi, Faculty of Electrical Engineering, 53 Mangeron Blvd., 700050, Iasi, Romania Abstract The present paper proposes the design of a modules system of measurement and control of data distributed transmission, implemental on automatic irrigation systems of central pivot or linear movement type. By this it is intended to obtain a complex irrigation system that allows optimization of nutrient application. Key words: Power line communication, soil conductivity, precision irrigation 1. Introduction Nutrients such as phosphorus, nitrogen, and potassium in the form of fertilizers, manure, sludge, irrigation water, legumes, and crop residues are applied to enhance production (Shifeng et al., 2004). When nutrients are applied in excess of plant needs, they can wash into aquatic ecosystems where they can cause excessive plant growth, which reduces swimming and boating opportunities, creates a foul taste and odor in drinking water, and kills fish. In drinking water, high concentrations of nitrate can cause methemoglobinemia, a potentially fatal disease in infants also known as blue baby syndrome. They are a lot of directive adopted by the Council of the EU concerning the nutrients policy. In December 1991, was adopted Nitrates Directive. The objectives of the directive are to ensure that the nitrate concentration in freshwater and groundwater supplies does not exceed the limit of 50 mg NO3- per liter, as imposed by the EU Drinking Water Directive, and to control the incidence of eutrophication. Having set the overall targets, the directive requires individual Member States, within prescribed limits, to draw up their own plans for meeting them. Cadmium and its compounds are toxic to human beings and therefore appear on the EU’s action list. With the exception of phosphate slag, which is a by-product of steel production and in decreasing supply, almost all phosphate fertilizers contain traces of cadmium. After collaboration between EFMA (European Fertilizer Manufacturers Association) and IFA (International Fertilizer Industry Association) the Code of Best Agricultural Practices was developed. The recommendations provided by the codes encourage appropriate application rate, correct timing of the application and the use of a suitable type of fertilizer and a correctly calibrated fertilizer spreader (Sun et al., 2000). During the last few years, in the economically advanced countries a new notion appeared referring to the agricultural practicability called “precision agriculture” one of its constituents being “the precision irrigation”. This new approach supposes the entrapment of new multidisciplinary technologies on the classical structures, such as the satellite geographical localization, distributed measurements and transmissions, micro informatics, broadening the view that in the maintenance and exploitation works of the agricultural crops the heterogeneity of the working plot of land could be taken into account. In the traditional agricultural system the cultivated plot of land was evenly treated even though it is known for a fact that a plot of land is extremely variable from the viewpoint of: soil fertility, topography, parasites and weeds attack. Precision agriculture has ∗ Author to whom all correspondence should be addressed: cdonciu@ee.tuiuasi.ro