Determination of Crop Evapotranspiration (ETc) and Crop Coefficient (Kc) for Maize Using Drainage Lysimeter in Dry Season Period in Enugu State, Nigeria

This study presents the determination of evapotranspiration and crop coefficient for maize using a locally made drainage lysimeter in the dry season period in Agbani, Enugu State, Nigeria. Maize was planted in the lysimeter, three seeds per stand, the planted seedlings were thinned to one seedling per stand, leaving only the most viable seedling to grow till maturity. ETc was determined from the lysimeter experiment using the water balance equation. Similarly, Kc was determined with an equation that expresses the relationship between Kc, ETc, and reference evapotranspiration. Moisture content (MC) was determined by the gravimetric method, effective rainfall, bulk density of the soil was also determined. ETo obtained for Enugu using 30 years of annual data was adopted. The result of the study gave ETc of 1.11 mm and 12.03 mm for the lowest and highest ETc respectively. On the other hand, Kc values obtained were 0.79, 0.96, and 0.91 for the months of January, February, and March respectively. The highest moisture obtained was 26.20 mm while the lowest was 3.21 mm. Soil bulk density was determined to be 1.43 g/cm3. More so, the highest and lowest effective rainfalls during the study period were 9.10 mm and 2.00 mm respectively. Irrigation water supplied during the period of study was within the range of 12.46 mm and 24.92 mm and lastly, the study revealed that the highest water need was during tasseling, cob setting, and filling because ETc obtained was highest at that point.