Sugarcane Irrigation: Effect of irrigation methods on sugarcane growth and yield

This study was conducted for the first time in the Sugarcane Research Farm, field 42106 on 18th of November 2001 through 2002 crop season in order to compare the influence of the sprinkler and furrow irrigation on sugarcane growth and yield. The plot size was 4 rows X 20 m X 1.55 m apart. The layout of the experiment was a completely randomized design replicated three times. The cane was harvested at the age of 13 months and the following growth and yield parameters were determined. (i) The reference evapotranspiration (ETo) was computed using Penman Monteith approach and the CROPWAT software. (ii) The water required for irrigation sugarcane by the two methods was calculated taking into account the variations in soil moisture, climatic factors and phonological stages of cane growth. (iii) The stalk height, from the soil surface to the top most visible dewlap was determined in a random sampled of 10 plants from the central two ridges (31 m2) of each plot at 7,8,5,9,10,11 and 12 months. (iv) The stalk diameter was measured at harvest time using a vernier calliper at 30 cm above the soil surface. (v) The cane and sugar yields were determined from the central two ridges (31 m2). In the sprinkler irrigation system an operating pressure of 36 psi (2.5 bar) was used and the resulting watering radius under such pressure was 16 meter. The flow rate maintained at that pressure was 0.95 m3/hr. As the prevailing wind in Kenana Estate was less than 10 mph during the growing period, the sprinkler risers holding the rotating heads were spaced (according to the international design) at a distance equal to 60; of the sprinkler watering diameter. In the present sprinkler irrigation system the watering diameter was found to be 16 meter, then the sprinkler were spaced at a distance of 10 meter. This setting provided uniform water coverage by overlapping the area watered by the adjacent sprinkler. In order to ensure that there is enough pressure to run the sprinkler head, two pressure gauges were installed; one gauge fitted at the upstream pipe and the second at the downstream pipe. The sprinkler and furrow irrigation methods gave 44 and 24 irrigations/season, respectively