The main objective of this work is to trace and measure the activity of natural radionuclides 226 Ra, 238 U, 232 Th and 40 K in sandy loam soil and leaves of Jew's-mallow plant (Corchorus olitorius). A pot experiment was carried out and Jew's-mallow was cultivated on sandy loam soil with six types of commercial and recommended fertilizers (NPK). The activity concentrations of 226 Ra, 238 U, 232 Th and 40 K in Bq kg -1 were measured using the high purity germanium detector to assess the effective dose of Jew's-mallow that is largely consumed by the Egyptian population. Gamma activities, at the end of growing season on sandy loam soil, contain a slightly higher concentration of natural radionuclides than the soil at the beginning, but still lower than the worldwide values. The transfer factor for 226 Ra, 238 U, 232 Th and 40 K from soil to Jew's-mallow plants was less than unity in all treatments. The estimated annual effective dose due to the ingestion of Jew's-mallow plant varied from 7.89 -21.5µSv y -1 , which indicated that fertilizer addition was not effective on the level of radionuclide in Jew's-mallow and it's safe for human consumption. M.A. Salama et al. 34 and 40 K) in Jew's-mallow plant fertilized with different fertilizers.

Neutron moisture meter (NMM) calibration accuracy and precision must be performed to obtain reliable results. The aim of this study is to investigate the effect of applied organic manure on neutron moisture meter calibration curve of sandy soil. The experiment was carried out at the farm of Soils and Water Department, Atomic Energy Authority. Two rates of organic manure were added (48 and 71.5m 3 /ha) including untreated control to surface sand soil at depth 20 cm. Neutron moisture meter calibration curve for 30 and 50 cm depth were done, the results showed that a 30 cm depth the neutron calibration curves for three treatments have approximately the same slope, and there is differences in the intercept which were 1.131, 1.298 and 1.978 for rate 2, rate 1 and the control, respectively. The values of the volumetric soil water content versus count ration presented in Tables (2 and 3) showed that, at the same count ratio, the values of water content decrease with increasing the rate of the organic matter in the case of 30 cm depth. As for 50 cm depth, the values of soil water content were approximately the same at each count.