Effect of Rainwater Harvesting Techniques on Field Tree Establishment at Nyala Locality- South Darfur State

Abstract

This study was carried out at South Darfur State (Latitudes 12° , 58′ N and Longitudes 24° , 88′E )where there is a problem of water shortage. The study aimed to measure the effect of rainwater harvesting micro-catchments technique on field tree establishment. Four rainwater harvesting micro-catchments (L- , Saucer , Furrow and control(Pit ) were tested on four tree species viz Acacia senegal , Acacia tortillis, Ziziphus spina-cristi and Grewia tenax in three replicate sites(Mussea , Tono and Rumalya ) at South Darfur State. The results showed significant differences (p≤ 0.01) in soil moisture reserves under the different water harvesting techniques for all tree growth stages and measurement periods . All treatments were significantly more effective than pit water harvesting technique (control treatment ). L-micro-catchment consistently retained more runoff water and produced the highest moisture content than other techniques in both seasons followed by saucer micro-catchment then furrows at the initial and development stages. Saucer -micro-catchment ranked second to L - micro-catchment in moisture conservation. Saucer-micro-catchment gave more moisture at soil upper layers (0-30 cm ) immediately above the bunds which was reflected in good plant performance .On the other hand L -micro-catchment stored more water in the medium and lower layers of the soil (30-60 cm ) . Moreover the trees of L-water harvesting treatment were significantly taller ( 73 cm, 63 cm, 58 cm and 56 cm) - Acacia tortilis , Acacia senegal , Ziziphus spina-cristi and Grewia tenax , respectively. L-water harvesting method gave the highest shoot length than other water harvesting treatments. Survival percentages in the L-water harvesting treatment plots were higher (91%) than under the other treatments. Species wise Acacia tortillis gave best survival percentage (80.6%) followed by Acacia senegal (78.8%) , Ziziphus spina-cristi (63.8) and Grewia tenax (61.1%) .