RAINW ATER HARVESTING TECHNIQUES FOR SOIL MOISTURE CONSERV ATION ON THE UPPER TERRACES OF THE WHTE NILE STATE (Sudan)

Abstract

ABSTRACT Field experiments were conducted at Humra, Aba, and Kileikis, White Nile state, Sudan, on a sandy clay soil, following a randomized block design, to study the effect of water harvesting techniques namely: crescents, intersections, ditches and control treatments on some soil physical properties and soil moisture content. The soil moisture content was measured monthly immediately after the rainy season till the beginning of the next season during 2003/04 growing season. Also plant parameters of Acacia nilotica and Acacia tortilis transplants were measured monthly immediately after the rainy season till the next season. Direct rainfall was measured using rain gauges which were installed on the field. The results indicated that the water harvesting techniques affected the soil structure and soil physical properties specially on the upper layer (0-30 cm) which subjected to excavation tools and consequently the soil moisture content as a result of improving infiltration rate, porosity, field capacity and reducing rain water runoff. The results revealed that the crescents treatment was the best technique for improving porosity, infiltration rate, soil storage capacity and reducing runoff which led to a good performance of Acacia nilotica and Acacia tortilis transplants. The intersections techniques came next to the crescents in storage capacity and performance of the plants. Also the results showed no significant differences between ditches and control treatments. The results indicated that the Acacia nilotica transplants gave good results when the moisture content increased while Acacia tortilis transplants gave good results when the moisture content decreased.