Effect of adding potassium humate at different levels of moisture tension in some physical properties of soil and in gowth of Zea Maize

Abstract

The need to determine the ideal moisture tension for maize growth is significant, because the plant’s response to water is more related to moisture tension compared to any other single factor and studying the effect of the interaction with the optimal level of potassium humate, considering it a rapid organic intervention that improves the physical and hydrodynamic properties of the soil and increases the nutrients use efficiency Accordingly, A pot experiment was conducted on a clay silty soil to study the effect of different levels of potassium humate (POWHUMUS WSG 85) (0.6- 1.8-3.6 kg/d) at different levels of moisture tension (400-600-800 millibar) on the physical properties of clay silty soil growing maize. The results show that soil bulk density was significantly decreased at 400 millibar in all levels of potassium humate added by 0.05-0.1-0.17 g/cm3 respectively. Increasing moisture tension to 600 and 800 millibar and not receiving humate, bulk density decreased by 0.08 -0.13 g/cm3 compared to the moisture tension 400 millibar treatment. The experimental constants (a) and (b) in ψ=aθb increased as the level of humate addition was increased at all levels of moisture tension. Moreover, leaf area of maize plant at the same moisture tension increases with the increase of humate addition reaching the highest value of 2476 cm2 at 600 millibar and 1.8 kg/d. This study suggests that potassium humate has the potential to increase, nutrient uptake by improving soil physical properties. However, it recommends the application of this material for corn at the rate of 1.8 kg/d on a clay silty soil.