2022 Volume 32 Issue S Pages 83-87
Irrigation is essential for agricultural production in drylands, but improper water management such as over-irrigation and poor drainage has caused salinization. In India, in places where border irrigation (BI) is widely adapted, the high salinity of irrigation water and tendency of over-irrigation have promoted salinization, with areas of salt-affected soils extending to approximately 6.7 million ha. Water saving and improved drainage are effective in mitigating salinization; however, drip and/or sub-surface drainage are difficult for farmers to implement because of the high initial and maintenance costs. Therefore, it is necessary to introduce low-cost measures that farmers can easily implement.
Permanent skip furrow irrigation (PSFI) is an easy and low-cost water saving method that can save water by irrigating every alternate furrow instead of all furrows, with the irrigated furrow being fixed. Cut-soiler is a low-cost shallow sub-surface drainage technology that can make drain holes at 40 to 60 cm depth for burying the crop residue by pulling a tractor attachment. In this study, we evaluated water saving with PSFI under Cut-soiler construction.
A field experiment was conducted using mustard (October to April) during three dry seasons from 2018 to 2021. Test plots (30 m square) were set up without drainage (Control) and 2.5, 5.0, 7.5, 10.0 m construction intervals of shallow sub-surface drainage with the Cut-soiler. In each plot, BI, every furrow irrigation (EFI) and PSFI was applied with 10 m width respectively, and yield of mustard was measured. The total applied depths of EFI and PSFI were approximately 90% and 45% of BI, respectively. The results showed that the yield was highest in the plot using the Cut-soiler at 2.5 m interval under PSFI, 42% and 56% increases compared with Control in 2020 and 2021, respectively. This implied that there were no adverse effects on PSFI application due to Cut-soiler construction. In terms of irrigation method, the yield in PSFI decreased by 7% in both 2019 and 2020, but increased by 22% in 2021 compared with that in BI. Although PSFI saved around 50%, there was a possible risk of yield reduction. Therefore, by applying PSFI, supplementary irrigation should be conducted according to growth conditions.
