Abstract

An experiment was achieved in laboratories of college of Agriculture / Anbar University. A sample of clay loam soil with 50% lime content was brought from sefen mountain, Shaqlawa district / Erbil province, to study the effect of lime percentage on soil spectral reflectivity. Different lime percentage were removed from origin soil using 0.1 N HCl to obtain same soil texture with 40%, 29.5%, 24.5%, 20%, 15.8% and 9.4% lime contents. Spectroradiometer was used to measure the reflectance of the soil with different lime levels at 22% soil moisture content. The result showed an increasing of the soil reflectance with increasing of lime content. Also the result showed an absorption band at 2350 nanometer was appeard, which may be attributed to the presence of lime in soil. It was noted that the depth of the band was increasing with increasing lime percentage in the soil. Results also showed that a significiant correlation between lime content and reflectance in the all studied bands, especially with the two near infrared bands (B6 and B9) was found, whereas the correlation coefficient (r) for the two bands were 0.968 and 0.958, respectively. The quantitative relationship between the two variables was also found. The linear, quadratic and cubic models were efficient to forecasting lime content from reflectance data at near infrared band (B6). The determination coefficient (R2) for the three models were 0.93, 0.98 and 0.99, respectively. While the standard error values were 3.8, 4.8 and 2.7, respectively.