Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production

1. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production ZhivkoZhivkovBulgaria,University of Forestry, Agricultural Faculty, Sofia,Nicholas Kathijotes Cyprus University of Technology, Civil Engineering Department, LimassolStanislav TormaSlovakia, Soil Science and Conservation JozefVilcek Research Institute, BratislavaPeter DimitrovBulgaria, Institute of Land Reclamation and Agricultural Mechanization, Sofia

2. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 1 The objectives of the study: • Water resources protection - assessment of the water quality indicators for efficient use of the water resources in accordance with the requirements of the water consumers; • Soil resource protection - knowing the irrigation water and the soil characteristics the farmer should predict the water impact on the modification of the soil parameters; • Crops protection - usage of water for irrigation according to the needs of the crops towards water quality and taking into consideration the economic efficiency of the irrigation permits obtaining stable crop yields; • Consumers protection - the sustainable agricultural development is a precondition for the crop production, which eliminates the health risks for the consumers.

3. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 2 Main tasks of the study: • Determination of the impact of low quality water as irrigation water during greenhouse and field experiments; • Development of recommendations for agro-ecological use of the low quality water, on the base of its agro-chemical, chemical, physic-mechanical and sanitary indicators with the view to its usage for irrigation; • Assessment of low quality water impact on yield and soil characteristics and its effect as a product of fertilizing process in a greenhouses and field experiments; • Development of recommendations how to use low quality water in agriculture in environment friendly way, depending on crops’ and soil’s requirements;

4. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 3 • Implementation in agricultural irrigation practice of recommendations for application of low quality water without increasing risk of environment pollution; • Dissemination of developed recommendations among farmers. The research work is clearly oriented towards the everyday practice and is very significant for agriculture and food and environment protection - the low quality water will be used for irrigation at water scarcity conditions. The users of the results will be farmers, wastewater treatment stations management, extension services in agriculture, agencies and offices of the ministries of agriculture and environment.

5. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 4 The database for the quality of the irrigating water contains: • Information about: water users, water sources, type of water, soil characteristics, methods of irrigation, cultivated crops, date of water sample, taken for laboratory analysis; • Full information about the results of the chemical laboratory analysis of the irrigation water. The information of the results from the laboratory water analysis contains: pH factor, electrical conductivity of the water, biochemical oxygen demands, chemical oxygen demands, suspended solids, bacterial populations, anions and cations. The main trace elements are included.

6. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 5 The degree of restriction on the usage of irrigation water has been presented as a remark for all analyzed parameters in conformity withFAO methodology on water quality for agriculture. The parameters are, as follows: • Salinity (affects crop water availability); • Infiltration (affects infiltration rate of water into the soil). Assessment of the infiltration is on the common base of electrical conductivity of the water and of the sodium adsorption ratio in the case of fresh water for irrigation, and of the adjusted sodium adsorption ratio in the case of waste water;

7. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 6 • Specific ion toxicity (affects sensitive crops), as follows: Sodium - cases of surface irrigation and sprinkler irrigation; Chloride - cases of surface irrigation and sprinkler irrigation; Boron; Trace elements – arsenic, cadmium, chromium, copper, iron, manganese, lead, zinc; • Miscellaneous effects (affects susceptible crops), as follows: Nitrogen (NO3-N); Bicarbonate (overhead sprinkling only); pH factor; Clogging problems (in the case of localized, drip irrigation): Langelier saturation index, suspended solids, bacteria population, etc.; • Suggestions about application availability of the irrigation water, taking in consideration the previous estimations, biochemical oxygen demands, chemical oxygen demands and other factors.

8. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 7 Elaboration of recommendations for irrigation water use The forms for potential irrigation problems assessment, for specific toxicity assessment and for side effects assessment contains tables which could be activated by the user, i.e. it can be shown in the form, in this way, possible negative consequences for the crop in the table using irrigation water could be assessed. The recommendation and suggestion form contains not only the recommendation formulated in the result of the complex assessment but basic data and preliminary results. In this way, user education is helped for better interpretation of information and if the user is knowledgeable it means qualified usage of the recommendations.

9. Assessing Impact of Low Quality Water Used in Irrigated Agriculture on Food Production 8 Socio-economic benefit Economical benefits of the solution consist of saving of good quality water, used at present for irrigation with an increase of the crops yield and significant decrease the pollution of intakes for recycled water, mainly river flows. The results will be obtained by: • owners and users of agricultural soils, • extension services in agriculture, designing organisations at projects processing of agricultural production development, • environment protection bodies on central and regional levels, • management of wastewater treatment stations, • counseling organisations providing information services.

10. Thank You!