Assessment of Irrigation Water Requirement of Maize Crop for Different Tillage Practices in Bangladesh

A study was conducted to assess the irrigation water requirement of maize crop for different tillage practices. Irrigation water was applied at three-growth stages viz. treatment one (I1), 20-25 days after sowing (DAS), treatment two (I2), 45-50 DAS and treatment three (I3), 80-85 DAS. Under I1 irrigation treatment with zero (T1), minimum (T2) and traditional (T3) tillage practices, the seasonal water requirement was 26.3, 29.3 and 31.0 cm respectively. In I2 treatment with T1, T2 and T3 tillage practices, water requirement was 34.5, 37.5 and 42.5 cm respectively and in I3 treatment with T1, T2 and T3 tillage practices, water requirement were 46.3, 51.3 and 60.0 cm respectively. The highest yield was in I3 treatment (8.3 t ha-1) which was similar to I2 treatment (8.2 t ha-1) and the lowest was in I1 treatment (7.3 t ha-1). In this study, no significance different was found in I2 and I3 treatment but in I3 treatment required more 42 cm water than I2. From the economical analysis, the highest net return (USD/ha 1501.45) and the highest benefit cost ratio (3.1) were found in T2I2 treatment combination. Therefore, T2I2 (minimum tillage with two-time irrigation) treatment combination is the best suit for maximum water resources saving in maize cultivation without compromising with yield in Bangladesh at dry season (Rabi).