Bangladesh government has desperately been trying to reduce the coverage of boro paddy cultivation in the country for the last few years, despite its role as a major source of food grain for the nation.
Legitimating its point, the government has argued that the reduction of boro paddy cultivation is required to avoid the rapid ground water table depletion, as this particular type of paddy demands consistent irrigation during its production cycle.
According to Bangladesh Rice Research Institute (BRRI), that invented most of the popular varieties of boro paddy, such cultivation requires plenty of water -- about 3500 liters -- to produce one kilogram of rice, which is considered to be an obvious headache for the country.
But in recent times, Bangladesh Agricultural University (BAU) scientists have invented alternative boro paddy cultivation (dry) method that requires only half of the water if compared to traditional clay method.
Dr Md Moshiur Rahman, an agronomy professor of BAU who led the invention said, “It reduces the amount of water used by around 50% than the traditional clay method of cultivation.”
The scientist has named the method as dry direct-seeded boro rice production technology.
How it works
Usually, the farmers prepares their land in the middle of December to grow seedlings in seedbed, and it takes around 45 days to prepare the seedlings for sowing in the clay field.
But in the dry method, the seed is directly planted in the field without having seedlings and clay.
It is as simple as that of wheat cultivation technology, except the seed has to be wet for 24 hours before sowing it in the field, with the distance of 25cm between lines and 15cm between one seed to another.
By avoiding the seedling stage and clay process, the cultivation will reduce by around 35% water demand. Another 5% can also be saved as well because the new method will no more require 15 days standing water after sowing in the clay.
But in both cases, the paddy requires regular water in the field for 30 days period between Panicle Initiation and grain filling stages.
In the dry process, the seed needs to be planted directly at the end of January, and it will take around 105 to 115 days to be harvested, while the clay method takes 95 days after sowing the seedlings.
But the most important part of the dry process is that it takes the number of irrigation between 4 to 17 times in the whole cycle, while the traditional clay method requires 15 to 50 times of irrigation.
In an account, a hectare of land produces around 6 tonnes of paddy, which can be converted into 4 tonnes of rice. From seedling to husking, the total cycle of rice production requires 35 million liters of water, while it takes only 5.5 million liters of water for equal amount of cultivation in same land if the dry method is applied.
The lead researcher, Dr Md Moshiur Rahman, first took up the initiative in 2006 at the laboratory space of his university, but success did not come that easily.
However, he did not lose his track. Later in 2007 and 2008, the researcher successfully finished the trial at his own university.
To convert the idea into reality, the scientist is demonstrating his dry direct boro paddy cultivation technology at farmers level in different districts of Bangladesh, including Rajshahi, Rangpur, Dinajpur, Tangail, and Netrokona since 2009-10.
Boro paddy cultivation in traditional clay method takes around 95 days after transplanting of seedling in the field, while the dry method takes around 105 to 115 days.
When the farmers practicing clay method cultivation start to harvest their paddy from the vast patch of lands, the farmers with dry method will have to wait for another 15/20 days to harvest.
“By that time, the pests are supposed to attack the rest of the waiting ground,” said Moshiur Rahman, calling the situation enough for the reducing the amount of production.
To overcome the situation, he could not suggest the farmers to shift the seed sowing period at 15 days earlier as end of December to end of January is the coldest period in Bangladesh.
The time cannot be shifted to earlier as the seed would not be able to tolerate such cold bite by that time, he explained.
If the farmers in mass level adopt the technology spontaneously, the situation will be changed, he suggested.
Meanwhile, expressing its interest, the government of Bangladesh has already invited the scientist to experiment his invention soon.
Praising the invention as ground-breaking, Jibon Krisna Biswas, former director general of BRRI said that, “I have personally gone through the invention and I believe that it will work in reducing the water use in the country’s boro paddy cultivation remarkably.”
But, now we need to make the farmers informed about the new technology to get the best output of the invention, he added.
Boro, the dry season paddy, is not the traditional one in Bangladesh since the early 1980s. Later, the BRRI invented those varieties with higher production rate to cultivate them in dry season, with the support of extensive irrigation.
The life cycle of boro paddy is from December to April, the dry period of the year.
Boro is the largest paddy in terms of production, as Bangladesh usually produces around 19.5 million tonnes of boro, while the second largest paddy, aman production is around 13 million tonnes annually.
Bangladesh produces around 34.7 million tonnes of rice against the demand of annual 32.4 million tonnes.