Productivity and water-use efficiency of spring-planted sugarcane (Saccharum sp. Hybrid complex) under various planting methods and irrigation regimes.

Abstract

A field experiment was conducted during the spring seasons of 2010–12 at Sugarcane Research Institute, Bihar, Pusa (Samastipur), to investigate the effect of planting methods (conventional, paired row and furrow-irrigated raised bed system) and irrigation regimes [Irrigation water: cumulative pan evaporation (IW: CPE) ratios of 0.50, 0.75 and 1.00] on productivity and water-use efficiency of sugarcane (Saccharum sp. hybrid complex). Number of millable canes increased by 12.4% in conventional method, followed by 7.2% in paired row over furrow-irrigated raised bed system (FIRBS) respectively. Cane yield obtained under conventional method of planting was higher over paired row and FIRBS by 5.7 and 12.9% respectively. The water requirement, water-use efficiency and water productivity were higher under conventional method followed by paired row and FIRBS planting. Conventional method of planting fetched significantly higher net returns ( 142.4 × 103/ha) followed by paired row ( 136.4 × 103/ha) and FIRBS ( 112.5 × 103/ha). Significantly higher benefit: cost ratio was recorded in paired row planting (3.21) than FIRBS planting (2.68) whereas it remained at par with conventional method (3.13) of planting. Among the irrigation regimes, irrigation at an IW: CPE ratio 1.00 significantly enhanced all the growth and yield-attributing characters. Though the differences between IW: CPE ratios of 1.00 and 0.75 and 0.75 and 0.50 were not significant. However, crop irrigated at an IW: CPE ratio of 1.00 gave significantly higher number of millable canes (110 × 103/ha) and cane yield (98.0 t/ha) being at par with an IW: CPE ratio of 0.75 and both the treatments showed superiority over that of an IW: CPE ratio of 0.50. Sucrose content in juice was not influenced significantly due to different irrigation regimes. Crop irrigated with an IW: CPE ratio 1.00 showed the maximum values of water requirement, water-use efficiency and water productivity. Net return increased markedly with increase in irrigation regimes from an IW: CPE ratio of 0.50 to 1.00. Irrigation at 0.75 and 1.00 IW: CPE ratio increased the net returns by 29.0 and 39.5% over that with the 0.50 respectively. However, an IW: CPE ratio of 1.00 (3.24) being at par with that of 0.75 (3.11) gave significantly higher benefit: cost ratio than that of 0.50.