Bangladesh can produce seven crore tonnes of rice a year, more than double the present production, by ensuring proper irrigation and use of fertiliser, and bringing cultivable fallow lands under irrigation.
Excessive irrigation for Boro cultivation and lack of it for Aman now drastically reduce the yield of both.
This is revealed in a study conducted by Bangladesh Agriculture Development Corporation (BADC).
The country now produces around three crore tonnes of rice a year with Boro output 3.66 tonnes per hectare and that of Aman a little above two tonnes. But Boro yield can be raised to six tonnes and Aman output to five tonnes a hectare, the study said.
The major factor behind the wide gap between present yield and potential output of Boro is excessive irrigation, says M Eftekharul Alam, assistant chief engineer of the BADC, who carried out the study for more than two decades.
Explaining this, Eftekhar said, “On an average our farmers use water 50 percent more than is needed for Boro cultivation. Such excessive use of water allows fertiliser to go so deep in the soil that paddy plants cannot collect nutrient from there. This waste of fertiliser reduces yield."
Quoting a report of the International Rice Research Institute, he said irrigation efficiency in Bangladesh is the lowest in the region. Cost of irrigation in Bangladesh is $117.60 per hectare compared to $25.58 in India, $17.94 in Thailand and $17.98 in Vietnam.
In Bangladesh, farmers traditionally do not irrigate Aman field, even during panicle initiation and flowering, which decreases yield.
Farmers now have average knowledge on use of seeds and fertiliser but very poor knowledge on irrigation, the study notes.
“This situation should be changed by training farmers on farm irrigation because the country's success in food production has been possible due to irrigation during Boro season,” says Eftekhar, now doing PhD on improvement of irrigation efficiency and productivity at Bangladesh University of Engineering and Technology (BUET).
The country produced 311 lakh tonnes of rice in 2007 compared to only 85 lakh tonnes in 1960. Boro contributed 70 percent of this increased production, according to Bangladesh Bureau of Statistics and Agriculture Information Services.
Boro cultivation now covers around 44 lakh hectares, Aman 58 lakh hectares and Aus only 11 lakh hectares. Aus production was not considered in the study.
Average output of high yielding variety (HYV) and hybrid Boro now is 3.66 tonnes per hectare. But output of HYV Boro can be raised to 4.0 to 7.5 tonnes a hectare and that of hybrid Boro to more than 7.0 tonnes, the study said.
And 10 lakh to 15 lakh hectares of land, which now remain fallow for various reasons in greater Barisal, Sylhet and some other areas, particularly char lands, can be brought under cultivation by using the water now wasted due to excessive irrigation for Boro cultivation.
Noting that Japan now produces more than six tonnes of rice a hectare, Eftekhar said a little effort could make Bangladesh a rice-exporting country
Bangladesh Agriculture University Professor Dr MA Sattar Mandol, who has made extensive studies on irrigation, said there is much scope to increase irrigation efficiency in Bangladesh.
“There is around 1.5 tonnes to 2.0 tonnes of yield gap (gap between present and potential output) per hectare. It is possible to meet this gap through efficient irrigation, use of better seeds and balanced application of fertiliser.”
He however said, “It is not so easy to bring fallow land under cultivation. It needs special efforts.”