Optimizing Sugarcane and Water Productivity Through Surface and Subsurface Drip Fertigation in Subtropical India

Declining water levels in North Indian states are largely attributed to unsustainable consumption of groundwater for irrigation. Drip irrigation, categorized into surface drip (SD) and subsurface drip (SSD) irrigation, offers promising opportunity for reducing crop water requirements while sustaining high water and crop productivity. To compare crop and water productivity of SD and SSD irrigated sugarcane, an experiment was conducted during 2017–18 (plant crop) and 2018–19 (ratoon crop) at Faridkot, Punjab, India. Three irrigation schedules i.e., irrigation at 60, 80, and 100% cumulative pan evaporation (CPE) were applied by SD and SSD methods with 80 and 100% of nitrogen (150 kg ha −1 for plant and 225 kg ha −1 for ratoon) as fertigation. Three standard irrigation practices (surface flood irrigation given to paired row trench at 30–30:120 cm, paired row sugarcane at 130–30:120 cm, and flat bed planted sugarcane at 75 cm spacing) were compared as control treatments. Results revealed that under SD and SSD, the mean cane yield 75.4 to 92.7 t ha −1 during 2017–18 (plant crop) and 72.9 to 79.9 t ha −1 during 2018–19 (ratoon crop) were superior over standard practices. Drip fertigation at 100% CPE with 80% N recorded 31.9 to 46.2% higher water productivity and 49.0 to 44.7% lesser irrigation water than controls. Results of the study highlighted for the use of drip fertigation in sugarcane at 100% CPE with 80% N at 3-day intervals for getting high B:C ratio (1:67–2:78 to 3:04–3:53 under SSD and 1:38–2:60 to 2:49–3:33 under SD), better crop and water productivity, and underground water resource conservation.