MINIMIZING HARMFUL EFFECT OF SOIL MECHANICAL IMPEDANCE ON SOME SOIL PHYSIO-CHEMICAL PROPERTIES AND GROWTH PARAMETERS FOR MAIZE HYBRID (Zea mays L.)

Abstract

A greenhouse experiment was carried out in soil columns. Surface soil samples (0.0 – 0.2 m depth) were collected from the Faculty of Technology and Development Farm (Clayey soil), and the second one from the Soil, Water and Environment Research Institute, Giza Governorate, Egypt (Clay Loam soil). This study aims to investigate the effect of polyacrylamide (PAM) application on some properties of compacted soil and roots-shoots Maize growth parameters. A nine-soil treatments combined different compaction strengths (CS) (0, 2.5, 4.5kg rammer) and PAM application (0, 0.25, 0.5, and 1 g PAM L-1) in the soils. Soil compaction led to increasing soil bulk density by 25% and 12% for the CS4.5PAM0 treatment (4.5 kg rammer), compared to the uncompacted treatments in the clayey and clay loam soil, respectively. Some growth parameters of maize were deteriorated due to soil compaction. The application of PAM significantly decreased soil bulk density, penetration resistance, and plasticity index in the tested soils. In addition, there are significant increases in mean and geometric weight diameters, and hydraulic conductivity coefficient. Consequently, the PAM application also improved maize growth parameters and biomass yields. The superior treatment generally was CS2.5PAM0.5 at the application rate of 0.5 g PAM L-1 with the second compaction strength (CS; 2.5kg rammer). This treatment achieved the highest effects on soil physical characteristics, increasing maize growth parameters such as stem length, leaf space guide and root length, in addition that the biomass yields increase by 12% in the tested soils, compared to the check treatment without compaction. Conclusively, according to the results, the application of PAM at rate of 0.5 g L-1 was recommended as a sustainable amendment.