Determination of the Temporal Changes on the Soil Samples Using ASD-Field Spectroradiometer in Sofia Area-Ramady City/Iraq

Abstract

The aim of this study is to measure the effect of organic matter on soil reflectivity in the Sofia area-Ramadi city, especially when there are no standard reflective curves for the region .Soil reflectivity characteristics change with some factors, and lose their main properties, which can lead to errors in soil reflectivity interpretations for many applications. This study is the first step in designing these curves for area and others. To produce rabidly decomposing organic matter within the soil, leaves of orange and pear (different in characteristics) were selected and placed inside mesh bags and buried at depths of 40 cm and 100 cm to ensure that the samples were not affected by surface or underground moisture. The total range of reflectivity (visible to infrared) of both types of plant leaves and of surrounding soil before the burial by using the device " spectroradiometer-fieldspec®3". Also, the temperature and humidity of the samples and surrounding soil were measured before and after burials. In the laboratories of the chemistry department, total organic matter in the soil was measured using the method (hydrogen peroxide H2O2). And the measurement process was repeated approximately every two months until the total period of measurements was 247 days. Final readings showed decrease in soil reflectivity by rate 15% with relation of the increase organic matter by rate 5.3%. Also both types of leaves gave different reading with rate of 20% depend on type and shape of leaves . The reflectivity did not have fixed stander curves along the measurement period. Also, there was no clear effect of climate changes on the readings, especially humidity, because the measurement period was a dry, low-precipitation period in the region where the total amount of precipitation was (7.336 cm) during the measurement period. Therefore, moisture has no effect on reflectivity in the same location as buried samples. The samples gave different readings because at a depth of 40 cm, the environment for the fungi responsible for bio decomposition is more active than at a depth of less analytic activity. In general, the current study indicated that there are no standard reflectivity curves that can be used for all regions and times or for all plant species. But with similar soil conditions our recent readings can be the reference for new soil reflectivity studies to avoid any error in interpretations.