The Strategy of Sustainable Agricultural Development, Identifying and Zoning Certain Indices of Environmental Pollutants in the Underground Water (A Case Study: Sarvestan Plain)

Abstract

Abstract. The efficient and appropriate use of basic resources in agriculture and considerations of environmental requirements not only it helps in producing healthy crops but also lead to sustainable agriculture. Planning for optimal use of water and soil resources on one hand and on the other hand, moderate consumption of inputs in other agricultural areas is a fundamental and important principle. This study is done based on the data of physic-chemical parameters including pH, electrical conductivity, bicarbonate and sodium absorption ratio in 29 water wells of the area located in Sarvestan Plain from 2005 to 2011 analyzed by Excel and GIS (Surfer10 version) applications. As the last step, the results of data analysis, diagrams, and zoning and geological maps as well as land use and GIS were compared with FAO standards in regard to irrigation water quality so as to enable further review and inferences. According to the results of data analysis and their comparison with FAO standard, it is estimated that electrical conductivity in 75% of wells have very high degrees of restrictions, the sodium absorption ratio of 65% of wells were of high and very high restrictions, bicarbonate content and acidity of 28 water wells were respectively had low to moderate restrictions and normal range of irrigation water quality as codified in FAO standards. The maximum value of parameters of sodium absorption ratio and electrical conductivity in wells 7 and 9 were respectively (45/6 – 49/7) decisiemens/m and (46/5 – 70/5) milliequivalents/liter. Due to recent droughts, reduction of precipitations, increase in temperature and evaporation intensity along with usage of chemical agricultural fertilizers and the kind of formations surrounding the plain bed as well as locations of wells 7 and 9 in the evaporative area of salty Maharloo Lake, the diffusion phenomenon and migration of salty water of the Lake towards the plain and its influence on underground water of plain are seemingly the most important factors of increasing electrical conductivity and sodium absorption ratio. Therefore, planning for continuous monitoring of water resources seems essential.