Evaluating Flexible Gated Pipes Flow Rate, Effect Ofof Slope Andand Furrow Length Onon Irrigation Performance

Furrow irrigation is the most common method of applying water to sugarcane in Zimbabwe. Sugar cane plantations face challenges with respect to irrigation water management. A study was conducted from 2015 to 2016 to evaluate lay flat pipe irrigation and the effect of slope, furrow length and flow rate on irrigation performance. A split-split plot design with three treatments of slope, furrow length and flow rate, each with three levels; 0.06, 0.08 and 0.1% slope, 100, 200 and 300m furrow length and 0.8, 1.2 and 3 l/s flow rate. Performance indicators of application, requirement efficiency and distribution uniformity were evaluated. Discharge and pressure showed strong relationship for all three openings. Discharge varied along the length of the pipe for each slope with the mean coefficient of variation (CV) value of 26.97%. The minimum and maximum values for Ea, Er and distribution of uniformity (DU) were 52.32 and 65.65%; 95.73 and 97.7%; 81.74 and 88.4%, respectively. Performance indices indicated that the effect of slope was not statistically significant (pgreater than0.05) on all indices except DU. Furrow length and flow rate were highly significant (pless than0.01) on all performance indicators. The variation of means due to the interaction effects of furrow length and flow rate were found to be significant (pless than0.05) on all performance indices. As furrow length increases all performance indices except Er showed a decreasing trend. All indices except Er showed increased as flow rate increased. Further research incorporating cutoff and irrigation intervals is recommended.