Feathered guests: Birdhouses and the ecosystem of organic paddy farming

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Scroll.in, West Bengal, India

Common Indian Mynahs are frequent visitors to these paddy fields / Credit: Moushumi Basu

It’s sowing season in West Bengal and Bablu Burman – a farmer from Bhattadighi village of Uttar Dinajpur district – is busy with other work. Using bits and pieces of wood he is building birds’ nesting boxes.

“They will provide shelter to feathered guests as Mynahs, barn owls and sparrows this cropping season to feed on the paddy pests,” he says. Each box is about 4 feet tall and 2 feet wide, with a sloping roof to keep away rain water and perches within for birds to rest or even roost.

Burman owns about 1.33 hectares of land where he cultivates about 50 varieties of organically grown indigenous rice. Previously he was a conventional farmer, growing high-yield rice using chemical fertilizers and pesticides. His transition from chemical to organic cultivation during the last five years has transformed the ecosystem in his paddy field.

“Nature has its own ways of rejuvenating the soil when synthetic or chemical inputs are gradually kept away,” says Abhijit Kundu, Officer with Government of India’s Agricultural Technology Management Agency (ATMA), at Gangarampur block of Dakshin Dinajpur.

Nesting boxes put in old trees next to paddy fields to attract birds / Credit: Bablu Burman

Explaining the transition from chemical to organic he says that the process is gradual over a few seasons. Rainwater washes away chemical residues from the upper soil crust which are gradually replenished with the addition of organic and decayed materials. While stray traces of persistent pesticides such as DDT and HCH may remain for some time, tests reveal that most of the soil gets purged of chemicals within three to four years, says Kundu.

“In due course, the paddy field gets so lively, teeming with countless insects, frogs, earthworms, snails and birds during the crop season,” says Burman. Next to his field are tall trees of neem, mango, black plum, and wood apple.  Thanks to the ecological transformation of his field, Burman feels that these trees are ideal for suspending his nesting boxes. They will remain there for the next three-four months to attract avian visitors, which according to him are the best and free deterrents against pests and rats.

“Burman’s efforts will not go in vain,” says Rupak Paul, Assistant Professor of Geography, Dewan Abdul Gani College, in Dakshin Dinajpur district of West Bengal. Birds that nest in hollows or cavities of old trees will use these boxes, as with the spread of farm land resulted in deforestation in the region, taking away their old homes.

Paul is a member of the Forum for Indigenous Agricultural Movement (FIAM) which is working with farmers to construct nest boxes to draw these feathered friends to the fields.

 “When cultivated by using natural manures and fertilizers, they represent the best examples of temporary wetland systems that develop (a) self-sustainable stable food chain,” says Paul. Seeing a return of owls, mynahs, and herons is a good indicator of a healthy and vibrant rice field ecosystem that ensures a good yield.

Cattle egrets on the paddy fields / Credit: Moushumi Basu

 

Paddy Wetland Food Chain

Paul says that this paddy wetland system has a minimum of four basic trophic (hierarchical) levels of organisms linked to the food chain. The rice plants and accompanying flora – nutgrass, Indian pennywort (a perennial creeping herb), water primrose – form the base. They offer a habitat and food for herbivores such as centipedes, millipedes, earthworms, grasshoppers, and snails which form the second stage.

Actively foraging in the rice fields are those in the omnivorous third layer – beetles, ants, predatory wasps, dragon flies, damsel flies, fireflies, frogs, tadpoles – that climb up the rice plants to feed on the above. The fourth level is capped by various predator birds as owl, paddyfield pipits, bee-eaters, pond herons, feeding on the second and third layer organisms.

Tracing a practical example of these interconnections, Paul pointed out that the branched and erect water primrose grows in abandon in the paddy wetlands. Its conspicuous yellow flowers easily attract insects as Grass Jewel or Grass blue. And perching on the branches of the plant, these insects in turn are preyed upon by birds as Indian mynah or the fork-tailed black drongo.

“They also eat various rice pests as (the) stem borer, leaf-folder moths, thus proving to be natural, free of cost pesticides. Unless eradicated by the use of chemicals, the rich predator diversity of paddy fields, usually overrides that of the pests in fields like Burman’s,” says Paul.

An Indian pond heron in a paddy field / Credit: Moushumi Basu

To further enhance the diversity of birds, the farmers also grow certain plants such as the Sesbania Pea at intervals across the paddy fields as they act as bird perches. “The woody branches prove to be comfortable seats for them and they merrily consume various rice insects. Nocturnal birds (such) as nightjars and owls also use the same perches to prey on rats in the fields,” says Salim Sarkar, a young organic farmer from South Dinajpur district. For similar reasons, farmers sometimes create T-shaped bamboo structures tied to paddy plants, for birds to sit on them and devour insects. They are however removed once the grains start ripening, he adds.

Sparrows and parrots however sometimes feed on ripened grains prior to the harvest. However, the proportion of this crop loss is rather meager, points out Salim. Nonetheless, to keep away birds, farmers use scarecrows or bird tapes made from flashy shimmering material to shoo them away from the fields.

Birds feeding on pests far outnumber the pesty birds that feed on crops, says Arvind Mishra, a noted ornithologist. “The paddy fields also bear characteristics of aquatic grassland ecosystems that can nurture a wide range of bird diversity,” he says. Rice plants are basically types of grasses, which can tolerate standing water. Hence, organic paddy fields ideally provide ecological benefits of both grasslands and wetlands.

Open billed storks and Ibis for instance are perfect “eco-managers” of paddy fields. Near the organic rice fields at Bhattadighi village is the Kulik Bird Sanctuary. These fields are ideal foraging grounds for open billed stork which feed on mollusks, rats and other crustaceans that abound there. Such birds not only control harmful pests, but their movement through paddy water oxygenates the soil and their droppings act as natural manure.

A pair of black drongo perched on Sesbania plant / Credit: Moushumi Basu

 

Fish in the Fields

The inundated organic rice fields are also invaluable habitats and nurseries for various kinds of fish, mollusks, and tortoise that often enter naturally from surrounding waterways when flooding occurs. Besides being easily available sources of protein, species as catfish in particular, fetch good price in the market and are raised with paddy for additional income, says Salim.

“Safely hidden from birds, the fish and paddy plants easily enter into a symbiotic relationship with each other,” explains Dr. Anupam Paul, Assistant Director of Agriculture, Agricultural Training Center at the Nadia-based Agricultural Research Center.

Fish survive near the roots of paddy in water levels ranging from six inches in July, peaking at three feet in September. They control unwanted filamentous algae and aquatic weeds which may reduce rice yield. Fish also eat the insect pests of rice – like stem borers – and malaria causing mosquito larvae, thereby controlling water-borne diseases in human beings.

Angling for fish in paddy pond / Credit: Moushumi Basu

 

Raising the Water Table

As biodiversity improved the paddy fields it has also helped Kulik, a stream in Raiganj area of Uttar Dinajpur. It had turned dry in summer months with the river bed getting shallower each season. In the past few years water has returned.

Paul explained that this could be a possible indication of rise in water table in the region. During the last few years, certain patches of folk rice cultivation by local farmers may have helped recharge the ground water.

Chemically grown high yield varieties of rice require more water, resulting in over-extraction of groundwater and lowering water tables. Folk paddy are more water efficient. Surplus water from irrigated fields seeps below, restocking the ground water. This phenomenon has likely to have resulted in the appearance of water on the Kulik river bed during the recent years. Other natural water bodies or lost rivers may also get rejuvenated with the practice of native organic farming, he says.  

Paul’s theory is supported by a study which says that there is 15-20% greater movement of water through soils in organic fields underground, leading to higher water table recharge.

Bablu Burman continues to put up the nesting boxes around his paddy field. Soon, he will have winged guests knocking.

 

This story is produced under the EJN Asia-Pacific Story Grants 2018 with the support of Sweden/SIDA. A version of it was first published in Scroll.in on Aug. 20, 2018.