A field experiment was conducted in Bihar, India during the winter of 2002-04 to determine the effects of irrigation and tillage on the soil-water-plant relationship and productivity of maize cv. Deoki. The treatments included disc ploughing + 2 harrowing + planking (T1), 2 cultivator + planking (T2), rotavator (T3) and zero-till planter (T4), in combination with 3 irrigations during the pre-knee height of the crop (30 days after sowing (DAS)), knee height and silking stages (I1), I1 + irrigation during the milking stage (I2), irrigation during the pre-knee height, knee-height, tasseling, milking and grain filling stages (I3) and irrigation during the pre-knee height, knee height, tassel initiation, silking, milking and grain filling stages (I4). The physical properties of the soil of rotavator-tilled plots recorded higher bulk density (1.33 and 1.30 mg/m 3), soil strength (2.10 and 2.05 MPa), infiltration rate (0.420 and 0.432 cm/ha) and porosity (49.81 and 50.94%) during 2002-03 and 2003-04, respectively. Plant height (189.33 and 190.07 cm), leaf area index (2.673 and 2.728) dry matter accumulation (369.77 and 392.78 g) and relative leaf water content (94.61 and 93.36%) were highest with rotavator tilling during 2002-03 and 2003-04. Plants receiving 5-6 irrigations exhibited superior crop yield and yield attributes. Rotavator-tilled maize showed higher water expense efficiency compared to plants under different tillage systems. Rotavator tilled maize irrigated 5-6 times recorded the highest grain yield (5831 and 5960kg/ha) and net returns (Rs. 16 173 and Rs. 17 493) during 2002-03 and 2003-04, respectively.
