SELENIUM STATUS IN SOME NORTH SINAI SOILS 1. COASTAL AREA

Authors

1 Inst. Heliopolis Military Sec., Cairo, Min. Edu., Egypt.

2 Dept. Soil and Water, Fac. Environ. Agric. Sci., Arish Univ., Egypt.

3 Inst. Soil Water and Environ., A.R.C., Egypt.

Abstract

The present study was conducted during the two seasons of 2013/2014 and 2014/2015 in North Sinai Governorate to investigate the spatial variations of (se) concentrations in coastal regions using two indicator range plants (atriblex and acacia). Total Selenium, and available seleniums were determined in the soils of the studied area of the Governorate including (Rafh, El-Sheikh Zoid, El-Arish and Bir El-Abd). Soil samples were taken from (0-30, 30-60, 60-90 and 90-120 cm) layers. The soil samples were taken from three sites from which both atriblex and acacia range plants were naturally grown.  Leaves samples from two studied range plants were taken in April during the two studied seasons, while selenium concentrations were determined in such plant samples. The obtained results indicated that total selenium concentration in studied soils ranged from 0.20 ppm to 0.97 ppm in the whole coastal area studied soils compared to global crucial concentrations of 0.083 ppm. The high content of the total selenium concentration under such condition may be due to the effect of marine water via volatilization under relatively high rain fall precipitation. Such effect could be caused an enrichment factor of the upper soil layers with such rare element. Hence geographical aspects, specially the distance from sea could not be complete ignored with respect to the selenium status under coastal area conditions. With respect to extractable Se from the studied soils, obtained data reveal that the Se extractable using DTPA ranged from 0.022 ppm to 0.052 ppm compared to those extracted with water and CaCl2 which ranged from 0.01 to 0.029 ppm and from 0.0 21 ppm to 0.037 ppm, respectively .It is worth to mention that Se extracted with DTPA was higher than that extracted using other two extracting agents. At all cases, using all studied extracting agents few quantities which ranged from 2.16 % to 18.50 % of total Se in the all studied soils. Such obtained results revealed that most total Se in the studied soils found in forms not extracted with the studied extracting agents and hence, not available for plant. The average selenium concentrations in the two studied range plants varied from 3.25 to 3.60 ppm in atriplex compared to 0.23 and 0.29 ppm in acacia plant. Such results clear that the potential differences between range plants used by animals with respect to selenium concentration (animal require mints 0.1 ppm).

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