Determination of Crop Coefficient and Water Use of SUWAN-1-SR with a Mini Lysimeter in Ibadan, Nigeria

Accurate irrigation planning requires basic information about the soil, environment and the water requirements of the crop to be cultivated. With new variety of a crop comes the physiological characteristics that may be somewhat different from known varieties. Crop Water Requirement (CWR) and Crop Coefficient (K c ) are major factors required in irrigation planning and they vary with crop developmental stages. Four non-weighing Lysimeters (Diameter, 60cm and Depth, 50cm) were used to determine CWR, K c as well as crop performances under specific conditions. The CWR and Kc of Maize variety (SUWAN-1-SR) were determined across the four developmental stages (Initial, Development, Mid and Late) using the lysimeter system.  The CWR were 58.8, 176.8, 206.0, 59.6 mm and K c were 1.0, 1.6, 1.4, 0.7 for the respective stages.  In comparison with FAO 56 maize K c and CWRvalues, SUWAN-1-SR requires more water across the developmental stages and a sum of 501.2mm for the crop cycle. The average yield was 14.1t/ha, while average Water Use Efficiency (WUE) in the Lysimeter plots was 2.68±0.44 kg/m 3 at a planting spacing of 40cm x 40cm, The WUE is high confirming the yielding potential of SUWAN-1-SRif given necessary nutrient inputs, and water requirement met. The developed lysimeter can be used to efficiently determine CWR. Keywords - Lysimeter, Crop Coefficient, Crop Water Requirement,  SUWAN-1-SR maize variety