Sri Lanka’s Maha “experiment” to yield uncertain results

Sri Lanka is going into the Maha season not knowing the consequences of suddenly adopting organic farming methods. While authorities believe yields will be as per the current levels, other agricultural experts expect a yield drop of over 20 per cent that could prove detrimental for a country already struggling to import food.

Agriculture Department Director General Dr. Ajantha De Silva told the Business Times that the two organic supplements they have imported will provide 10 and 15 per cent of Nitrogen based on the plant requirement.

“Therefore we feel that if we give the plant nutrient requirement even in organic form we don’t believe that there will be a yield reduction,” he said adding that the current yield of 4.27 MT per hectare can be obtained from the new organic inputs similar to the average yield from chemical fertiliser.

Dr. De Silva explained that they had ascertained the required nutrients by calculating and finding out the requirement of the relevant plant nutrients.

He dismissed other expert opinion and according to him in traditional organic farming only compost was used whereas in this instance the authorities are including certain amounts of nutrients. The organic fertiliser product imported, he said has a high amount of Nitrogen, Phosphorous and Potassium, which is a real requirement.

Traditional compost has 1 per cent of Nitrogen but organic granular fertiliser is between 10-15 per cent, he said.

Senior Professor at the Faculty of Agriculture, Peradeniya University, Prof. Buddhi Marambe however, points out “my analysis is that this mixture will not give the plant the required quantity of nutrients of Nitrogen”.

In this context he believes that whatever is produced there are very low nutrients of Nitrogen and with an average paddy yield of 4.8 MT per hectare and a target of reaching 5 MT per hectare these yield levels cannot be achieved. “There will be a yield drop between 21.5 - 33 percent based on scientific research done at Batalagoda (the rice research centre),” he said.

In that research the Department of Agriculture has tried to compare paddy harvesting carried out by not applying any fertiliser; with applying organic fertiliser at a rate of 10 MT per hectare; and applying synthetic fertiliser; and fourthly applying synthetic and organic fertiliser, he said.

This study which was carried out for a period of 22 consecutive seasons over 11 years recorded that the highest yield was from synthetic fertiliser and organic fertiliser mixed together and that simply applying organic fertiliser would cause a drop of 21.5-33 per cent.

The new method of farming that is using an imported organic source, not used in the earlier research, to enrich the soil is a relatively new concept and in this respect the next Maha season will be a kind of an experiment for the whole country, Prof. Marambe noted.

He also explained that the required nutrients should be given to the plants at the right time to achieve the anticipated yields. Previously, urea which contains 46 per cent of Nitrogen was applied to the plant at two weeks.

In this respect, within a short period of time to obtain a higher yield you need to give it a higher nutrient conversely if you feed the plant less it will produce less, he said.

The grains retained by the farmer as seed paddy will also be of a low quality as they might even contain empty seeds or half-filled seeds. The farmer generally retains about 30 per cent of the production for his family and as seed paddy for the next harvest.

He also pointed out that if the harvest should drop this could prove detrimental to the amount of rice stocks produced as the country is already struggling to import food.