Investigation of soil erosion rates using radioactive tracer in Manisa and surrounding agricultural areas

Soil erosion affects both agricultural and natural landscapes, and is one of the most important of today's environmental problems. The loss of soil from farmland can induce reduction of crop production potential, decrease surface water quality and damaged drainage networks. There are many methods to measure the rate of erosion. 137Cs technique has been widely used as tracers to study the erosion and deposition of soils. In this study, the physical and chemical properties of the soil were determined in samples taken from five regions selected from agriculture areas in Manisa and surrounding areas. In addition, the concentration of 137Cs of these areas was determined by the HPGe detector and than the erosion rate was calculated. It has been found that the organic matter content of the soil samples in the examined area changes between 0,32 and 5,88 %. Erosion and deposition rates at five different sites were calculated by both Proportional Model and Simplified Mass Balance Model. With Proportional Model, erosion and deposition rates varied between -0,38 and -45,05 t ha-1y-1, +0,93 and +23,93 t ha-1y-1, respectively. With Simplified Mass Balance Model, erosion and deposition rates varied between -0,38 and -70,01 t ha-1y-1, +0,92 and +19,81 t ha-1y-1, respectively. It is observed that there is a good agreement between two models up to 30,00 t ha-1y-1 soil loss and gain. It is concluded that the erosion problem exists in these agriculturel areas. Keywords: Soil erosion, Manisa, 137Cs, Proportional Model, Simplified Mass Balance Model