<i>Fertigation to cut water, fertiliser cost by half</i>

Irrigation water and fertiliser cost of farmers can be halved using their combined application known as fertigation, its successful trial on tomato and aubergine cultivation in the country shows.
Alongside other crops, this method can also be applied in rice cultivation that requires a large amount of both the inputs, said irrigation experts.
This revelation is important as the government sells urea at Tk 12 a kg with nearly 50 percent subsidy. It gave Tk 2,700 crore in subsidy for non-urea fertilisers during the current Boro season.
Annual demand for urea is 28 lakh tonnes and non-urea 10 lakh tonnes. The irrigation cost for rice cultivation is Tk 5,000 an acre with diesel-run water pumps and Tk 2,000 an acre with electric pumps.
Agriculturists say that over 50 percent water and fertiliser gets wasted with the traditional method.
According to Bangladesh Rice Research Institute (BRRI), a kg of paddy requires 2,000 litres of water during production but in Bangladesh farmers apply over 4,000 litres during the Boro season.
Rice cultivation on a hectare of land requires 220 to 250 kgs of urea but over 60 percent fertiliser is wasted due to excessive irrigation.
"This is because when excessive water is used dissolved fertiliser goes beyond the reach of roots of plants," said Engineer Eftekharul Alam, head of Minor Irrigation Information System Unit at Bangladesh Agriculture Development Corporation (BADC).
As a result, paddy plants fail to get nutrients contributing to decreased yield, he said. Average paddy yield in Bangladesh is around three tonnes a hectare when it could be 5.5 tonnes.
"Fertigation has shown to enhance overall plant-root activity, improve the mobility of nutritive substances, their consumption as well as reducing the contamination of surface and ground water," says a report of Food and Agriculture Organisation (FAO).
Bangladesh Agriculture Research Institute (BARI) in a three-year study on tomato and aubergine cultivation during 2001-04 found tomato yield increase of nearly 29 to 31 percent using the fertigation method.
This method saved 60 percent urea, 36 percent muriate of potash and 46 percent irrigation water. Almost similar results were also found in the case of aubergine cultivation.
With the traditional application method of fertiliser, only 40 percent of it is absorbed by plants at best while fertigation allows plants to absorb up to 90 percent of the fertiliser, Eftekharul Alam said.
"That means the yield could be same with 50 percent less fertiliser and water," he said.
"But if we apply BRRI-recommended fertiliser--250 kg a hectare--rice yield would be five to six tonnes," the irrigation expert said. Water use in this case also has to be halved, he noted.
MA Sattar, head of Irrigation and Water Management Division at BRRI, said irrigation channels should be built with cement so that fertigation in rice cultivation could start.
Eftekharul Alam, however, said another fertigation method can be used in which diluted fertiliser is applied in irrigation water as it goes into the paddy fields.
The experts said fertigation could reduce the frequent attack of fungal and bacterial diseases caused by excessive irrigation and help resist depletion of groundwater and arsenic contamination.
Sattar said Japan, China, Pakistan and many other developed countries are using this technology.
Fertigation is also used in New Zealand and Egypt for efficient use of fertiliser and water and to reduce input cost, according to a website.