Managing Tillage, Irrigation Water And Sowing Methods For Production Of Wheat (Triticum Aestivum L.) Under Shambat Conditions

An experiment was conducted for three successive seasons (2000/01 – 2002/03) in the Demonstration Farm of the Faculty of Agriculture, University of Khartoum, Shambat to investigate the effect of tillage (T), irrigation water amount (W), and sowing method (S) on wheat crop yield (Elneelein Variety). Seed lot for each season was brought from Hudeiba Research Station. Tillage treatments constituted five land preparation systems, viz.; offset disc harrow, ridger, chisel plough, disc plough, and no-till (T1 to T5). Irrigation water amounts were determined with aid of the modified Penman (1977) method in terms of crop evapotranspiration (ETc%) and comprised three levels, namely; 100%, 80%, and 60% ETc (W1, W2 and W3). Sowing methods included flat and ridge sowing (S1 and S2). The experiment was laid in a strip-split-plot design with three replications. Tillage treatments were assigned as vertical factor, water amounts as horizontal factor and sowing methods as subplot factor. Irrigation water amount was measured using a 90 V-notch weir. Parameters pertaining to soil physical properties, infiltration characteristics, machine performance, crop agronomic attributes, as well as water utilization efficiency were assessed and processed. Results obtained revealed that tillage method and depth did not induce any significant variations in soil bulk density (g/cm) and porosity (%) in all seasons. However, disc plough and ridger profiles recorded greater initial infiltration rates (22.44 and 20.22 cm/h), while no-till plots recorded the least value (11.30 cm/h) in all seasons. Basic infiltration rate was reached earlier (35 min.) in disc plough and no-till profiles. Disc plough also recorded the greatest total draft (11.00 kN) and unit draft (6.50 N/cm) requirements as well as fuel consumption rates (5.9 l/h and 12.73 l/ha). No-till system and the stressed watering regimes (60% ETc) were significantly (P < 0.05) inferior with respect to agronomic attributes of the crop in comparison to its corresponding treatments, and that, the 100% and 80% ETc regimes were statistically similar for almost all parameters in all seasons. Mean maximum and minimum grain yields (t/ha) were 2.89 and 1.91 as corresponding to plough-till and no-till, respectively. However, both ridger and offset disc harrow systems were almost comparable with respect to crop yield and averaged 2.94 t/h. On the other hand, average grain yields, over all seasons were 2.90, 2.73 and 2.03 t/h for the 100%, 80%, and 60% ETc water regimes, respectively. Flat sowing was significantly (P < 0.05) superior to ridge sowing in terms of number of effective tillers/plant (1.58 vs. 1.09), grain yield (2.85 vs. 2.54 t/ha), and harvest index (42.50 vs. 41.20%) but was similar to it in the remaining attributes, throughout the seasons. Water use efficiency (WUE) was maximized (0.43 kg/m) when 80% ETc watering regime was applied, while the full watering regime (100% ETc) gave the least value (0.36 kg/m). Based on these results, it is evident that, maximum yield of wheat would be obtained with plough-till, based on either ridger or offset disc harrow systems, flat sowing as well as irrigation at 80% ETc.