IMPORTANCE OF CHEMICAL AND MICROBIOLOGICAL WATER QUALITY FOR IRRIGATION IN ORGANIC FOOD PRODUCTION

The quality of water used for irrigation of organic food crops is important for maintaining and protecting the environment on which the product quality often depends. Water quality requires a careful approach because of the adverse effects that can be manifested both in the soil and in the plant products. Intensive technical and technological development in all branches of the economy is a major cause of pollution of the environment, primarily of water. The most frequent polluter of soil (i.e. of the medium from which plants take up nutrients) is irrigation water. Plant products that are used for food production become polluted through this medium. Water with the potential to contaminate plant products with harmful substances can arise from various sources, especially surface waters contaminated with waste industrial and communal waters, or water from agricultural farms. An analysis of some irrigation systems in Serbia reported that 25% of these systems do not meet water quality requirements. This has resulted in an increase in salt concentrations in the soil above allowable levels, precluding the pursuit of organic agriculture. Besides the total amount and the content of certain pollutants in the form of salts, other harmful and dangerous substances found in irrigation water often come from chemicals that are used in agriculture as pesticides and nutrients, and from the waste waters, or wastes deposited in the watercourses. In addition, certain microorganisms can also be responsible for the presence of toxic components. Water quality and its hygienic safety, especially in vegetable irrigation, are extremely important due to the increased demand for healthy and safe food. Irrigation water can transfer microorganisms to plant products, leading to outbreaks of diseases such as salmonella, Escherichia coli 0157:H7, Cryptosporidium parvum and others. Water from surface sources is more prone to contamination than is water from underground sources.