Effect of Gum Arabic on Some Soil Physical Properties And Growth Of Sorghum Grown On Three Soil Types

Abstract

Three pot experiments were carried out to study the effects of gum arabic on some soil physical properties and growth and yield of forage sorghum (Sudan grass hybrid) grown on three soil types.These experiments were conducted at the Faculty of Agriculture, shambat, University of Khartoum, for two successive seasons. The soils under study were of different clay contents as follows: 21% clay (El-Rawakeeb soil), 45% clay (Shambat soil),and 62% clay (El-Damazin soil). Two rates (1 and 3 tones/fed) of gum alone or in combination with other organic amendments namely: farmyard manure (FYM), chicken manure (CHM) and Bagasse (BAGS) were applied. All organic amendments were applied at a rate of 5 tones/fed. Treatments were arranged in a completely randomized design (CRD) with three replications and means were separated by Duncan s multiple range test (DMRT) . Soil samples were analysed at the end of each season for Water retention (WR), aggregate stability (AS), Hydraulic conductivity (HC),pH (paste),electrical conductivity of the saturation extract,Calcium,Magnesium,Potasium,and Sodium.Growth parameters measured were plant height and fresh weight. The results of El-Rawakeeb soil experiment showed that the two rates of gum alone did not affect soil water retention, aggregate stability or hydraulic conductivity significantly. Water retained in pots in case of FYM and CHM is lower compared to gum alone and BAGS. This was attributed to the better growth and higher yield of FYM and CHM treatments, where more water consumed by the plant. Gum in combination with BAGS insignificantly increased AS and decreased WR and HC.The results of Shambat and El-Damazin soils study showed that the two rates of gum alone or in combination with FYM, CHM and BAGS increased WR and AS insignificantly. Chemical analysis of El-Rawakeeb, Shambat and El-Damazin soils showed that all chemical properties were insignificantly affected. With respect to plant growth all treatments increased growth and yield compared to the control. The values obtained for fresh weight and plant height were statistically significant (p،ـ0.05) for gum + FYM and gum + CHM in EL-Rawakeeb soil and gum +CHM in El-Damazin soil. Gum +BAGS decreased plant height and fresh weight slightly.