INFLUENCE OF TILLAGE DEPTH, SOIL MULCHING SYSTEMS AND FERTILIZERS ON SOME THERMAL PROPERTIES OF SILTY CLAY SOIL (Published)
A field experiment was conducted to study the effect of three factors; the first factor, tillage depth with three levels (15,25 and 45 cm), the second factor ,soil mulched system with three levels (single sheet plastic, double sheet plastic and no mulch), third factor ,fertilizer type (chemical, organic and without fertilizer) upon thermal flux (w/m2), soil thermal conductivity (w/m.k) and soil volumetric heat capacity (J/m3. k).The effect of tillage depth and mulched system upon soil bulk density (Mg/m3) and volumetric moisture content (cm3/cm3) was conducted. The results showed significant differences between tillage depths on the soil thermal properties, it was observed that increasing tillage depth causes decrease in soil thermal flux while soil thermal conductivity was increased. The highest volumetric heat capacity ( 8.22 X 10 5 J/m3. k ) obtained at tillage depth 25 cm .,The increase of tillage depth causes increase in soil bulk density at 25 cm depth then decrease at 45 cm depth .The results showed no significant differences between fertilizer systems on soil thermal properties. The results showed significant differences between soil mulched system on soil thermal properties , the double mulch system obtained the highest thermal flux( 26.29 w/m2), high soil thermal conductivity (0.822 w/m.k), high soil volumetric heat capacity (9.703 X 105 J/m3. k )and high volumetric moisture content (0.231 cm3/cm3).
Keywords: Soil Mulching System, Soil Thermal Conductivity., Soil Thermal Flux, Soil Volumetric Heat Capacity, Tillage Depth