Anyone visiting the countryside will notice a certain change in the scenery: the croplands look like yellow and green canvases.

Md Rezaul Karim, a farmer of Pabna's Vangura upazila, says a mustard field is not just for producing mustard seeds as it brings him honey too.

Karim engages in beekeeping on his mustard plantation in order to produce the golden nectar.

The 50-year-old farmer has sown mustard on 10 bighas of land without cultivating the rain-based Aman rice this year after he bagged bumper mustard crops last season by keeping bees in the field.

In the past, he usually got 4-4.5 maunds of mustard seeds from each bigha. The yield grew to 6.5 maunds when he leased out one bigha of land to beekeepers.

"So, I have cultivated mustard and set bee boxes in one bigha of land this year to make good profit," Rezaul said.

He is one of the many farmers who keep bees in mustard fields with the aim to boost yields and collect honey at the same time.

Bees help increase yields by pollinating the plants while collecting nectar to produce honey. Bangladesh has some 25,000 beekeepers that collect honey from mustard, coriander and black cumin fields apart from litchi garden and the Sundarbans.

The country produces nearly 10,000 tonnes of honey annually and the main collection season spans from November to April.

Some 80 per cent of the honey is collected during the mustard cultivation season, said Khandoker Aminuzzaman, who headed a beekeeping project of the Bangladesh Small & Cottage Industries Corporation for seven years until 2019.

Aminuzzaman said beekeeping in mustard fields increases yields by 15 per cent per bigha but many farmers were previously reluctant to allow beekeepers in their fields apprehending that it would affect production.

However, that perception has changed a lot.

Mustard cultivation areas have been increasing as a result of production growth from beekeeping, said Md Idris Ali, deputy assistant agriculture officer of the Department of Agricultural Extension (DAE) office in Pabna.

Farmers have sown mustard on 5.83 lakh hectares of land this season, up from 5.68 lakh hectares a year ago. Some 7.5 lakh tonnes of mustard were produced in fiscal 2019-20, the DAE data shows.

Md Jahangir Alam, president of North Bengal Beekeepers Association, said mustard flowers bloom in 40 to 60 days.

As the flowering period is long, beekeepers can collect a better amount of honey from mustard fields than other croplands.

"So, most beekeepers prefer setting their bee boxes in mustard fields," he said.

In Pabna, bees boxes have been set up on 9,040 hectares of mustard fields.

Bee farmers said honey collection would double this year because of good flowering in the country's mustard fields and favourable weather.

"In the previous year, we collected honey from the mustard field twice. We expect to collect honey four to five times this time though because of good flowering this year," said Alam, who expects to collect 100 tonnes of honey from the mustard fields in Pabna.

He has set 50 bee boxes in one bigha of land by paying Tk 10,000 as lease for the land. He also invested Tk 25,000 for honey collection.

The beekeeper expects to earn a minimum Tk 1 lakh by collecting honey from mustard fields this year.

Aminuzzaman, who recently retired from the Bangladesh Small and Cottage Industries Corporation, said beekeepers collect honey shifting from one crop season to another, from mustard, coriander and black cumin to litchi.

This year, production might be affected as mustard cultivation was delayed by repeated rainfall.

He also said the BSCIC has established a processing centre for honey.

Md Ebadullah Afzal, president of Bangladesh Beekeepers Foundation, said Bangladesh has 2,500 beekeeping farms whose produce were enough to meet local demand.

"We are exporting honey," he said, citing that his firm exported 200 tonnes last year. This year though, he aims to export 500 tonnes of honey.