Variation of Soil Seeds Bank in Natural Rangeland of Wad Omer Agricultural Scheme, West Omdurman, Sudan

Abstract

The study was conducted in Omdurman locality which is located in Khartoum state, at the end of rainy season of two seasons, 2017and 2018. The aim of the study was to estimate soil seed bank in the natural rangeland so as to use them to develop the proper management plans. Stratified sample was done according to the specific variation of soil seed bank, divided the range sites into two sites, namely, rock soil and sandy soil. About 30 samples were taken systematically a long line transect, 15 soil sample for each site, all samples collected from the three soil depth (0-10, 11-20 and 21-30cm),were placed in plastic bags. All samples of the same depth were mixed of sub-samples of 250g, washed in water and CaCl2 solution to extract the live and dead seeds. Computer and micro capture device were used to identify the seed species, according to the reference seeds. The study showed that, the seeds bank density decreases with the increase of soil depth and the lowest seed number in sandy soil. The five dominant seed bank in terms of the live seed density at the upper depth in the sandy soil range site, were, Indigofera spp, Dactyloctenium aegyptium, Schoenfeldia gracilis, Amaranthus graecizans and Corchorus spp respectively. The three dominant seeds bank in terms of highest botanical composition in the rocky soil range site, were Dactyloctenium aegyptium, Corchorus spp and Schoenfeldia gracilis, for all live and dead seeds, respectively in the upper soil depth. The study concluded that, the soil depth had a clear effect on the soil seed bank, and the rocky soil range site was better in seed bank density.