engleski

Salt dynamics and soil salinization process in river Neretva Valley

Managing agricultural area is the biggest challenge of sustainable agricultural production. Soil salinization and alkalization as a form of agricultural area degradation, is one of the biggest problems of arid and semiarid areas. Salinization problem also occurs in river Neretva valley. Main causes are intrusive saltwater and using salted surface and groundwater in irrigation. There for, a research was carried out whit aim to determine soil salinization level, and horizontal and vertical salt distribution. The research was carried out during 2006. and 2007. on area of approximately 4 000 ha. In both years, 152 samples per year were gathered on same locations for horizontal distribution, and in 2007. additional 10 samples for vertical distribution. Vertical distribution was studied from probing drillings of depth 1m. All samples were analyzed on pH, EC, Na and Cl. Spatial data analysis, apropos interpolation of sample results was carried out with Universal Kriging geostatistics method. Results are showing that EC minimum and maximum value for 2006. amounts 0, 37 dS/m, with reference to 8, 39 dS/m, while average value amounts 1, 04 dS/m. In 2007. minimum measured value was 0, 42 dS/m, while maximum individual value has reached 11, 86 dS/m which prevents growing of any cultural plant. Average value was amounting 1, 69 what indicates 61% increase. Based on obtained values, interpolation map was made for the purpose of obtaining EC results on non-sampled areas. According to prediction parameters interpolation map is showing small average sample area, but satisfying sample variability, and so with that, satisfying quality of final map of area salinisation. In vertical distribution EC values are considerably higher, apropos on depth of one meter they are averagely higher even for 110, 38% compared to their surface values. Luka and Vidrica areas are most at risk by salinization which is explained with high levels of groundwater on that area. Also groundwater fluctuation has resulted with multiplied increases of salt concentrations with depth. In first 8 months of 2007. precipitation quantities were 44, 4% less then in 2006., which points to reduced salt leaching. Furthermore, the temperatures, in the same period, have showed 13% increase, and evapotranspiration 18% increase regarding on 2006., what indicate thermal regime impact on increase of salt concentration.

Neretva; EC; salinization; GIS; groundwater

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