Development and Evaluation of a Drip Irrigation System in Southeastern Nigeria

Extreme climatic factors (temperature, precipitation etc) which at times lead to drought and flooding affect crop yield negatively. In this study, a PVC drip irrigation was developed and the irrigation parameters were evaluated in a farmland with three tillage methods (conventional tillage, conservative tillage and no tillage). The irrigation treatments comprised of three levels of irrigation (50% Management allowable depletion, 30% management allowable depletion and 10% management allowable depletion). Different irrigation parameters were evaluated for different crop growth stages, different soil treatments and different soil depths (0-25 cm, 25-50, 50-75 and 75-100 cm depths).

The field capacity was determined at -0.01MPa, from the result, the field capacity was minimum at no tillage (0.07 cm3/cm3, 0.11 cm3/cm3, 0.12 cm3/cm3, and 0.14 cm3/cm3) for soil depths 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm respectively, for conservative tillage (0.11 cm3/cm3, 0.11 cm3/cm3, 0.11 cm3/cm3, 0.14 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively and conventional tillage (0.09 cm3/cm3, 0.13 cm3/cm3, 0.15 cm3/cm3, 0.17 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively.

The permanent wilting point was determined at -1.5MPa, from the result, permanent wilting point increased with increase in soil depth in conventional tillage and no tillage with PWP of 0.01 cm3/cm3, 0.05 cm3/cm3, 0.09 cm3/cm3 and 0.11 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for conventional tillage and PWP of 0.02 cm3/cm3, 0.05 cm3cm3, 0.05 cm3/cm3 and 0.08 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for no tillage.

The average net irrigation was found to be 1.2 cm, 1.56 cm and 1.95 cm for conventional tillage, conservative tillage and no tillage respectively, while the average gross irrigation was found to be 1.7 cm, 1.7 cm and 2.1 cm for conventional tillage, conservative tillage and no tillage respectively.

Statistical analysis of net and gross irrigation gave a coefficient of determination of 0.99 and p-value at 0.05 was significant with a value of 0.00007.