Problems raised by the detection of harmful bacteria in imported organic fertilizers



By PKBalachandran / Ceylan today

Colombo, October 4: On February 28, the media quoted the Director General of the Ministry of Agriculture, Dr Ajantha De Silva, as saying that harmful bacteria (Erwinia) were detected even in the freshly submitted sample from the organic fertilizer imported from a special company in China. Erwinia is a genus of Enterobacteral bacteria mainly containing phytopathogenic species. It contains Gram-negative bacteria related to Escherichia coli, Shigella, Salmonella and Yersinia.

However, the next day Agriculture Minister Mahindananda Aluthgamage said Erwinia’s presence had not been confirmed, but the sample contained harmful bacteria. Even more alarming, he revealed that the polluted stocks imported from this Chinese company had already been distributed to farmers by modifying the laboratory records!

He then made the welcome announcement that the government has banned imports of the Chinese company in question (identified as Qingdao Seawin Biotech Group Co., Ltd.).

Issues raised

The controversy raises three questions that should be considered in the context of a total switch to organic fertilizers: (1) is it safe to import organic fertilizers when they could carry pests (2) is- It is legal to import fertilizers organic fertilizer (3) if it is good to rely entirely on organic fertilizers, whereas, unlike inorganic or chemical fertilizers, it can be easily and quite naturally polluted.

Dr WAJM De Costa, professor of crop science at the University of Peradeniya, points out the dangers of importing organic fertilizers. He says: “Almost all organic fertilizers, whether plant, animal or human, retain a diverse population of microorganisms. Unlike inorganic fertilizers, which are inert materials, organic fertilizers are living materials. Microorganisms, whether in soils, plants or any other place or entity, are often very specific to the environment. The introduction of these exotic microorganisms into Sri Lankan soils could cause all kinds of unforeseen interactions with local microorganisms. Some of these interactions could have environmental repercussions, which are irreversible, because once released into the soil, these exotic microorganisms cannot be recalled. ”(See:

Imported organic fertilizers could be cleaned up, but only to a certain extent, De Costa says. Sterilization is done by fumigation. But the large amounts of organic fertilizers that must be imported and the toxicity levels of the chemicals used in fumigation could lead to environmental problems that organic fertilizers aim to avoid, warns De Costa.

And given Sri Lanka’s poor record in regulating, enforcing and enforcing quality standards on items, both imported and locally produced, De Costa questions whether sterilization would be done properly. Indeed, the falsification of laboratory data in the case of a stock of organic fertilizer recently imported from a Chinese company does not inspire much confidence in the local regulatory system.

Since Sri Lanka does not produce enough compost and the current policy is not to use chemical fertilizers at all, most of the compost has to be imported. But the Plant Protection Law No.35 of 1999 prohibits the mixing of any soil particles or living organisms with the soil of the country, underlines agricultural economist Lal de Silva (See: “This is a very nice piece of legislation that protects the country from the invasion of harmful microbes such as bacteria, fungi and weed seeds,” he says. These microbes could enter through imported organic fertilizers.

Certain weeds such as Striga can pose a huge threat to rice plants. “This particular plant is a parasitic plant that attaches itself to the roots of plants and it grows inside the soil and is not visible because only the flowers of this weed come out of the soil. Since it is a parasite and also since it is not visible, it grows underground (in the roots of the host plant) and remains extremely difficult to control. Several strains of the Striga weed are already present in India and the Philippines. If we import compost from abroad, there is an extremely likely threat to our agriculture, ”warns de Silva.

He points out that Australia and New Zealand have very strict plant quarantine procedures and recalls that Sachin Tendulkar, the captain of the Indian cricket team, was fined while touring Australia because his cricket boot contained soil particles (mud)!

Of the worldwide antibiotic produced, 50 to 80% is used on animals and poultry. It is said that 30% of antibiotics are excreted unchanged and mixed with the soil. These organic materials could also contain heavy metals such as arsenic, cadmium and lead as inorganic fertilizers, says de Silva.

Imported compost will need to be sterilized. But it is extremely difficult to sterilize the compost because chemicals such as methyl bromide or phosphine cannot be used for fumigation as they are prohibited pesticides.

Moreover, unlike inorganic fertilizers, any organic fertilizer or compost produced in Sri Lanka or abroad will not have a standard quality. This is a matter of major concern. The Lankan government says it will help farmers make their own compost. But can farmers do it in the quantities they need? And can they guarantee the quality?

Inherently pollutant

Organic fertilizers, whether imported or home-made, could be toxic, warn University of Peradeniya soil specialist Dr. Warshi S. Dandeniya and collaborator Serene Caucci in their article titled: Composting in Sri Lanka: Policies, Practices, Challenges and Emerging Concerns.

They say that organic fertilizers commonly known as “compost” can carry potentially toxic trace elements. “The long-term use of large amounts of compost and / or the application of poor quality compost to the soil can deteriorate the quality of the environment and pose a threat to food security. The gradual build-up of toxic trace elements such as lead and cadmium in soils has been reported in several studies where there has been long-term application of compost produced from municipal solid waste (MSW).

“Contamination of food with potentially toxic trace elements and human pathogens due to the application of compost to crops has been reported in the literature on the subject”, point out Dandeniya and Caucci.

Poultry litter / manure is a source of antibiotic resistance determinants and, therefore, imposes a “silent threat” to environmental quality and health, they say. And the night earth (human excrement) could also mix with the organic fertilizer. Organic pollutants such as detergents and determinants of resistance to antibiotics and pathogens that survive in nocturnal soils and septic waste, as well as the fate of these constituents during composting, have not been thoroughly investigated. in Sri Lanka.

The two soil scientists warn that microbial pathogens and parasites could spread to the environment through flies and dogs found at composting sites. In addition, bioaerosols and volatile compounds could allow transmission from composting sites to other environments with the wind. According to Dandeniya and Caucci, leachate coming out of compost piles during the production process and runoff from composting sites could contaminate both surface water and groundwater.

Mixed policy

Sri Lankan agronomists and economists are proposing a mixed fertilizer policy to meet the health needs of populations as well as food availability. While organic fertilizers are better for your health (overall), they reduce production because they are deficient in nitrogen. The government could therefore facilitate adequate and high-quality production of organic fertilizers, and at the same time, for the sake of increasing production and ensuring food security, it could allow controlled and scientific use of chemical fertilizers.




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