By P.K.Balachandran/Ceylon Today
Colombo, October 4: On February 28, the media quoted the Director-General of the Department of Agriculture, Dr. Ajantha De Silva, as saying that harmful bacteria (Erwinia) was detected even in the freshly submitted sample of the organic fertilizer imported from a particular company in China. Erwinia is a genus of Enterobacterales bacteria containing mostly plant pathogenic species. It contains Gram-negative bacteria related to Escherichia coli, Shigella, Salmonella, and Yersinia.
However, the next day, the Minister of Agriculture, Mahindananda Aluthgamage, said the presence of Erwinia had not been confirmed, but the sample did have harmful bacteria. Even more alarmingly, he revealed that the polluted stocks imported from that Chinese company had already been distributed among farmers by changing the laboratory records!
He then made the welcome announcement that government has banned imports from the Chinese company in question (identified as Qingdao Seawin Biotech Group Co., Ltd.,).
Issues Thrown Up
The controversy throws up three issues that ought to be considered in the context of a total switch over to organic fertilizer: (1) whether it is prudent to import organic fertilizer when it could be carrying harmful organisms (2) whether it is legal to import organic fertilizer (3) whether it is good to rely entirely on organic fertilizer, when, in contrast to inorganic or chemical fertilizer, it can easily and quite naturally be polluted.
Dr. W. A. J. M. De Costa, Professor of Crop Science at the University of Peradeniya, points out to dangers in importing organic fertilizer. He says: “Almost all organic fertilizers, being material of plant, animal or human origin, retain a diverse population of micro-organisms. Unlike inorganic fertilizers, which are inert material, organic fertilizers are live material. Micro-organisms, whether in soils, plants or any other location or entity, are often highly environment-specific. Introduction of such alien micro-organisms to Sri Lankan soils could cause all types of unforeseen interactions with local micro-organisms. Some of these interactions could have environmental repercussions, which are irreversible, as once released to the soil, these alien microorganisms cannot be recalled.” (See: https://island.lk/fertilizer-saga-in-sri-lanka-a-considered-opinion/).
Imported organic fertilizer could be cleaned, but only to an extent, De Costa says. Sterilization is done by fumigation. But the large quantities of organic fertilizers that are required to be imported and the toxicity levels of the chemicals that are used in fumigation, could lead to environmental issues that the organic fertilizers are aiming to prevent, De Costa warns.
And given Sri Lanka’s poor record of regulation, implementation and enforcement of quality standards on items, both imported and locally-produced, De Costa wonders if sterilization would be done properly. Indeed, the fudging of the laboratory data in the case of the organic fertilizer stock 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 policy now is not to use chemical fertilizer at all, most of the compost has to be imported. But the Plant Protection Act No. 35 of 1999 prohibits the mixing of any soil particles or living organisms with the soil of the country points out agricultural economist Lal de Silva (See: https://manthrana.com/en/2021/06/28/can-organic-manure-or-compost-be-imported/). “This is a very fine piece of legislation which protects the country from the invasion of harmful microbes such as bacteria, fungi and weed seeds,” he contends. These microbes could enter through the medium of imported organic fertilizer.
There are certain weeds such as Striga which can cause an enormous threat to rice plants. “This particular plant is a parasitic plant which gets attached to the roots of plants and it grows inside the soil and is not visible as only the flowers of this weed comes outside the soil. As it is a parasite and also as it is not visible, it grows under the soil (in the roots of the host plant) and remains extremely difficult to control. Several strains of the weed Striga are already present in India and Philippines. If we import compost from abroad, there is an extremely likely threat to our agriculture,” de Silva warns.
He points out that Australia and New Zealand have very stringent plant quarantine procedures and recalls that Sachin Tendulkar, the Indian cricket team’s Captain, was fined while touring Australia as his cricket boot had some soil particles (mud)!
Of the global antibiotic produced, 50 to 80% are used on animals and poultry. It is said that 30% of the antibiotics are excreted unchanged and mixed with the soil. These organic materials could also have heavy metals such as Arsenic, Cadmium and Lead than the inorganic fertilizers, de Silva says.
Imported compost will have to be sterilized. But it is extremely difficult to sterilize compost, as chemicals such as Methyl Bromide or Phosphine cannot be used to fumigate as these are banned pesticides.
Also, unlike inorganic fertilizer, any organic manure or compost produced either in Sri Lanka or abroad, will not have a standard quality. This is a major area of concern. The Lankan government says that it will help farmers make their own compost. But can the farmers do it in the quantities they need? And can they ensure quality?
Organic fertilizers, whether imported or home-made, could be poisonous, warns Peradeniya University soil scientist Dr.Warshi S. Dandeniya and her collaborator, Serene Caucci in their paper entitled: Composting in Sri Lanka: Policies, Practices, Challenges, and Emerging Concerns.
They say that organic fertilizers commonly called ‘compost’ can be a carrier of potentially toxic trace elements. “The long-term use of compost in large quantities and/or application of poor-quality compost to the soil can deteriorate environmental quality and pose a threat to the safety of food. The progressive accumulation of toxic trace elements such as lead and cadmium in soils has been reported in several studies where there has been a long-term application of compost produced from Municipal Solid Waste (MSW).”
“Contamination of food items 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,” Dandeniya and Caucci point out.
Poultry litter/manure is a source of antibiotic resistance determinants and, therefore, imposes a “silent threat” to environmental quality and health, they say. And night soil (human faeces) could also get mixed up with the organic fertilizer. Organic pollutants such as detergents and antibiotic resistance determinants and pathogens surviving in night soil and septic waste, and the fate of these constituents during composting, have not been studied extensively in Sri Lanka.
The two soil scientists warn that microbial pathogens and parasites could spread in the environment through flies and dogs found at the composting sites. Further, bio-aerosols and volatile compounds could enable transmission from composting sites to other environments with the wind. Leachates coming out from compost piles during the production process, and runoff water from the composting sites, could contaminate both surface and groundwater, Dandeniya and Caucci submit.
Sri Lankan agricultural scientists and economists propose a mixed fertilizer policy to fulfil the need for peoples’ health as well as food availability. While organic fertilizer is better for health (on balance) it brings down production because it is deficient in Nitrogen. Government could therefore facilitate adequate and quality production of organic fertilizer, and at the same time, for the sake of higher production and ensuring food security, it could allow controlled and scientific use of chemical fertilizer.