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 (Kc) 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, Kc 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 Kc were 1.0, 1.6, 1.4, 0.7 for the respective stages.  In comparison with FAO 56 maize Kc 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/m3 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