Skip Furrow Irrigation Increases Water Productivity, Maintains Yield and Decreases Soil Salinity for Sunflower in the Coastal Zone of the Ganges Delta

ABSTRACT Water‐saving irrigation is essential for crops in saline regions where freshwater resources are scarce. We tested furrow irrigation methods and planting techniques in terms of yield, water savings, water productivity (WP), soil salinity (EC e ) and soil water content (SWC) for sunflower in saline soils. Planting on the top of the ridge (T) or side slope on the ridge (S) were tested in factorial combination with (i) skip fixed furrow irrigation (SFFI), (ii) alternate furrow irrigation (AFI) or (iii) every furrow irrigation (EFI). The sunflower yield was significantly greater with the side of the ridge planting than on the top of the ridge. In consecutive years, sunflower yields were not significantly different among the furrow irrigation combinations with planting on side slopes of ridges. However, compared with the EFI, the SFFI and AFI saved 25 28% of the irrigation water and improved the WP. At a soil depth of 30 cm, the SFFI and AFI had significantly lower EC e values than did the EFI. Both skip furrow methods, with side slope planting on the ridge, offer water savings without sacrificing yields while decreasing the soil salinity and increasing the WP of sunflower in the water‐scarce, saline coastal regions of the Ganges Delta.