Small-scale potato farmers using furrow irrigation can make use of little water to bring more acreage under cultivation by applying the partial irrigation method.
The partial Root-Zone Drying method, which can save between 30 per cent and 50 per cent of the total water used in an acre, relies on the alternate supply of the commodity to the root system of the crop.
One side of the root system is supplied with water while the other is left dry. On the second round of irrigation, the other roots that were left without water are fed.
David Ramírez of Potato International Centre says the method allows for better development of abscisic acid in the sections of the soil that were ‘skipped’ during the process.
Ramírez, who heads the Crop Ecophysiology department, says the acid is a hormone that induces tuber formation and promotes the closing of leaves’ stomata. Closing of the stomata reduces water loss via transpiration.
One acre of sweet potatoes requires between 1,400 cubic meters and 2,600 cubic meters for a farmer to receive maximum yield for best returns.
Furrow irrigation is one of the methods that has been used for several years, majorly relying on gravity to push water from one point to the other.
Farmers near rivers and streams find it easy to fetch and pour or channel some water through parallel pathways into crop-growing fields.
However, the expert said more research is ongoing to determine the exact amount of water to be supplied to avoid reducing carbon intake by the plants.
Alternate irrigation has been tried and worked well in Peru, China and Ethiopia.
Once adopted by farmers it would increase harvests, at a time when climate change is reducing the amount of water available for irrigation and domestic use.