Effect of Subsurface Drip and Furrow Irrigation System on Growth and Yield Indices in Sugarcane Cultivation

This study aimed to investigate the effect of subsurface drip irrigation on leaf area index, root distribution, quality and yield of sugarcane for the first ratoon. Two fields including one field with subsurface drip irrigation and other field with closed-end furrow irrigation were studied as control. Three measurement stations were selected in each field. The results were statistically analyzed. Number of plants, number of green leaves, leaf length and width over one meter were counted and measured six times at 91, 99, 105, 112, 119 and 128 days after harvesting of plant, respectively. Leaf number and leaf length and leaf width were not significantly different in both irrigations. Number, length and width of leaves in furrow irrigation averaged 7.6, 100 and 3.2 cm and in subsurface drip irrigation averaged 7.2, 101 and 2.9 cm. The number of plants and LAI were significantly different at 99 and 95% level. The number of plants and LAI were in subsurface drip irrigation 2.06 and 1.77 times higher than furrow irrigation, respectively. The LAI value was affected by the number of plants. The value of all qualitative parameters in subsurface drip irrigation was higher than furrow irrigation, but none of them had significant differences in two types of irrigation. Weight of 20 stalks, brix, POL, purity (PTY), yield (Y) and sugar yield (SY) in subsurface drip irrigation 9.7%, 1.3%, 2%, 0.08%, 2.8% and 45.4% were more than furrow irrigation respectively. Weight, length, area and volume in subsurface drip irrigation were 32.9%, 42.4%, 42.4% and 42.5% more than furrow irrigation, respectively. Diameter of root in subsurface drip irrigation was 1.9 times less than furrow irrigation. Therefore, roots in subsurface drip irrigation were finer and deeper than the furrow irrigation. Also, in subsurface drip irrigation the roots were 20% deeper than furrow irrigation. The efficiency of subsurface drip irrigation and furrow irrigation was 88.2% and 62.3%, respectively. Water use efficiency in subsurface drip and furrow irrigation was 9.43 and 8.01 kg/mm.ha, respectively.