Use of Controlled Spate Irrigation for the Improvement of Sorghum Growth and Productivity in North Darfur State

Abstract

A split-plot field experiment was conducted in two consecutive seasons (2006-2007) in Al-Fashir University Farm in North Darfur State to investigate the impact of controlled spate irrigation on the growth and yield of two sorghum varieties, namely Wad Ahmed and Tabat. The soil was classified as fine loamy, mixed, isohyperthemic Typic Haplocambid. The irrigation treatment consisted of adding Supplementary irrigation at three available depletion (AWDL) namely 25, 50 and 75 %. The irrigation treatments accommodated main plots and sorghum varieties sub-plots. The main plots were arranged in randomize block design. The soil was initially filled to field capacity and a daily water balance method was used to monitor AWDL. When an AWDL reached a predetermined value, water was applied to raise the soil moisture to field capacity. In both seasons, Wad Ahmed variety gave significantly greater germination percentage, plant height, leaf area index and number of heads than Tabat variety.In general, the germination percentage was low due to termites and low seed quality. Thus, transplanting was made to compensate for this low germination. For both seasons, the mean plant height and leaf area index ranged from 147.5 to 168.4 cm and from 3.9 to 6.7, respectively. The range of the mean number of heads was 77 to 143. The impact of the growth components was reflected on fodder fresh and dry matter yield. The mean fresh fodder yield of Wad Ahmed was significantly 33% and 37% greater than that of Tabat in the two successive seasons. The mean dry matter yield of Wad Ahmed was 11.2 ton/ha in the first season and 12.8 ton/ha in the second season. The mean thousand grain weight (TGW) ranged from 26.0 to 29.5 g. The effects of treatments were not significant in the first season. In the second 5 season, Tabat gave significantly greater TGW than Wad Ahmed. In general the grain yield was high ranging between 6.2 and 9.4 ton/ha. Wad Ahmed gave significantly greater yield than Tabat in the first season. However, in the second season the impact of variety was not significant. In general, supplementary irrigation improved sorghum growth and yield. Furthermore, in most cases, application of water at 25% AWDL gave better growth and yield than at 50 or 75% AWDL. However, the impact of the different AWDL was not significant because of the random variation of occurrence and quantity of rainfall. The experiment showed that controlled spate irrigation using harvested water offers a great potential for improving crop production in North Darfur.