Effect of Irrigation Regimes on Water Productivities of some Rainy Season Sown Forages in the Gezira, Sudan

Abstract

An experiment was conducted in the Gezira Research Farm
(GRF) during the Rainy seasons of 2007 and 2008 to determine the water
requirements, optimum irrigation regime, forage yield and forage water
productivities of Sorghum cv Wad Ahmed (Sorghum bicolor L.Monech),
phillipesara (Vigna trilobata), clitoria (Clitoria ternatea L.) and lubia
(Lablab purpureus L.) as affected by irrigation regimes. The study
involved 12 treatments arranged in split plot design replicated three times
and with three irrigation regimes viz every 7, 14 and 21 days(W1,W2 and
W3) in the main plots and the four crops as sub plots. The results
indicated that in both seasons the irrigation regimes did not significantly
affect the dry matter yield of any crop and hence W3 was considered as
optimum for all crop. In W3 however Wad Ahmed, (means of two
seasons) was associated with the lowest water requirements, (3818
m 3 /ha), highest dry matter yield/ha, (7.2t/ha) and highest water
productivity, (1.89 kg/m 3 ). The three legumes seemed to have comparable
water requirements, but phillipesara (among the legumes) was associated
with the highest DM yield, (5.4t/ha) and highest water productivity, (1.18
kg/m 3 ). Irrigation every 21 days (W3) seemed to be optimum for each
crop during the rainy season.