Is Organic Agriculture ‘Toxin-Free’ and the way forward for us?

Dr Parakrama Waidyanatha

It is regrettable that the President as also some uninformed high-ups are obsessed with the belief that conventional agriculture is fraught with toxins (wasa wisa) and the answer to it is ‘going organic’ which is free from toxic chemicals. The hasty decision to convert the country’s agriculture fully to organic from conventional, virtually overnight and non-provision of appropriate agrochemicals has thrown the country into an unprecedented chaos, with farmers up in arms daily. The poor agriculture minister is the scapegoat, and his effigy is now daily displayed and burnt. Regrettably, the effigies of the several advisors who pushed the President to this decision have not been displayed.

A farmer demonstration against the agrochemical ban

Such a far reaching decision needed a prior in- depth consultation with experts in the field, exhaustive raw material resource assessment and a production and distribution management plan. That these have not happened is also evident from the consistent reaction of the large bulk of the agriculture academics and other experts in the field in recent times.

The crux of the matter is that the country has been driven ‘organic’ in a hurry largely because of empty national coffers and inability to meet the fertilizer and subsidy costs. However, even at this late stage, as the writer has stated in a previous article, in The Island of Oct. 16, rather than ‘biting the bullet’ and continuing, it is better for the government to compromise, for discretion is the better part of valour. It is now happening, but gradually.

Organic agriculture which was rejuvenated in the 1960s has only reached 1.5% of the global cropland to date and is growing at a meagre 2% annually. Of many countries that worked hard to expand their organic farm cover, only 16 were able to reach 10%; and bulk of it is pasture comprising 66% of the total organic farmlands. Bhutan with a mere 54,500 ha of arable land and plenty of animal farming for farmyard manure, targeted in 2008 going totally organic by 2020 but was able to achieve only about 10% and has now extended the target date to 2035. On the other hand its chemical pesticide use is reported to be growing at 11.5% annually.

Constraints relating to organic material availability and other standard technologies such as microbial ones applicable across a wide range agro -ecologies not yet being available, are serious limitations to expansion of organic agriculture locally and globally.

Of numerous calculations of comparable potential for organic and conventional farming to produce food per unit area, the bulk stand out as conventional being superior. Two scientists at the proceedings of the International Crop Science Congress in 2004 pointed out that 25-82% more land would be required to produce the global food needs. The father of the Green Revolution, Norman Borlaug, in his address to the Nobel Forum in 2010 remarked that if all agriculture were organic, the cropland area should have to be dramatically increased, spreading into marginal lands and forests, cutting down millions of acres of forests with huge environmental destruction. A British study supports Borlaug’s contention showing that 65-200% more land would be required to meet the global food demand. Bulk of the calculations reveal that conventional farming is superior in producing food, not that there are no calculations from the organic side claiming organic farming to be more productive.

The real challenge today is generation of technologies to produce 60% more food by 2050 from the same land. Can organic agriculture do it? The oft quoted saying is that organic agriculture may save the earth but conventional will feed the world. And the differences are like night and day. Let us now examine evidence as to which camp is more toxin free.

Fertilizers

It must be stressed that chemical fertilizers of the approved specification used in the recommended quantities are harmless to health. The problem is overuse. The downside, however is that chemical nitrogen fertilizer manufacture (urea, ammonium sulphate ( etc) utilizes five percent of all natural gases and fossil fuels and excessive application of synthetic fertilizer contributes to global warming through production of nitrous oxide. Chemical nitrogen fertilizer through leaching leads to the formation of riverine and oceanic dead zones. Leaching, erosion losses of chemical fertilizers is high, and in tea plantations, for example, because of the terrain on which it is grown, the losses can be as high as 40-60%.

On the other hand, the usual belief is that nutrients from organic soils usually leach into the surrounding water and air far less than from chemically fertilized soils. However, extensive field studies in Sweden in the 1990s revealed that nutrient losses can sometimes be higher from soils under organic farming than conventional. This study showed that whereas, under controlled conditions, 65% of the nitrogen was taken up by crops 35% leached from organic plots; the corresponding values for conventional plots were 81 and 19%. This may appear unbelievable but is reported in the famous book ‘Just Food’ by James E McWilliams (2010). Contrary to expectations, leaching losses from green manures are reported to be higher, especially phosphorus, than from synthetic fertilizers.

Sodium nitrate, a mineral (calche) mined in South America is widely used by organic farmers in America and Europe as it is a mineral like rock phosphate and potash. It contains sodium hyperchloride which, when leaching into the water bodies, enters the food chain and interferes with iodine uptake in humans and animals, and is considered as a contaminant in the U.S.

Pesticides

Organic farming is allowed to use several chemicals such as sulphur , copper and copper sulphate as natural fungicides. Sulphur, for example, is reported to cause worker injuries in Californian grape farms than any other pesticide. Sulphur dust sprayed on organic grapes is reported to cause chronic respiratory problems. Copper sulphate is classified as a Class 1 toxin, especially to fish and soil earthworms. Copper heavily accumulates in the soil after spraying as it does not biodegrade. One study on the accumulation of copper from copper sulphate concluded that a female vineyard employee contaminated with it had 6.2 times more of it in her breast milk than that in an uncontaminated employee. A further study reported that its continued application in organic apple orchards could jeopardize sustainable apple production.

Pesticides whether conventional or organic kill more than the targeted pests, and Bruce Ames, a highly reputed molecular biologist and member of the National Academy of Science points out that 99.9% of the chemicals we are exposed to are completely natural (Strong Views on Origins of Cancer, New York Times ,July 5, 1998) and our obsession with conventional pesticides overlooks this reality. He also argues that when we consume plants, organic or otherwise, we consume, on average, 50 toxic chemicals, most of them natural pesticides.

The evidence is that there is no difference in respect of health effects between natural and synthetic chemicals. A study of the Environmental Protection Agency of the USA (Science, 258, Oct.1992) reported that pesticide residues as dietary pollutants are unimportant. Scientists have also concluded that there is no proven evidence that consuming organic food is healthier.

James McWilliams in his book referred to above also argues that ‘as much as the risks of synthetic pesticides have been overstated, organics own reliance on pesticides has been vastly understated.’ The unsaid purpose obviously is to project a marketable image that what happens in organic farms is ‘all natural.’

Several toxic plant extracts are used in organic farming for insect control such as rotenone and pyrethrins. They cause environmental and health risks. Rotenone is moderately toxic to birds and highly toxic to fish, and kills bees when used in combination with pyrethrum. According to the Occupational Safety and Health Administration of the U.S , it can also cause damage to the human liver and kidney. Certain research has established a connection between rotenone and Parkinson’s disease. Pyrethrum has also been shown to be toxic to many animals. Apart from being a human carcinogen it has been shown to be toxic to some fish and even kill lizards. Most botanicals, because they break down rapidly, have to be applied in high doses to be effective.

Antibiotics and Heavy Metals

Antibiotics in compost heaps is a health risk. Composting helps break down of many organic compounds but antibiotics coming from animals are quite resistant to decomposition. Antibiotics are often shown to appear in fruits and vegetables fertilized with organic matter and their consumption can create resistant bacterial strains in the body.

Heavy metals such as cadmium, zinc , arsenic and lead can accumulate far more in organic fertilizer applied soils than from chemical fertilizers because huge quantities of it are applied (usually 10 tons/ha) than chemical fertilizer; and although similar concentrations (quantities as parts per million) are present, the amounts entering the soil and crops are far greater with organic fertilization. This is evident from substantially higher concentrations reported in organic vegetables and fruits.

Agrochemical vs Air Pollution

Minister after minister are obsessed with the “wasa visa” myth as evident from their utterances both in the parliament and outside. It is the general belief, without evidence, that agrochemicals are the cause of many non-communicable diseases. No politician speaks about ambient air pollution, the leading environmental health risk factor locally and globally. Records reveal that nearly 3.5 million premature, non-communicable disease deaths, for example, in 2017, were from stroke, ischemic heart disease, chronic obstructive pulmonary disease, lung cancer, respiratory infections, and diabetes.

The President should, as a matter of priority, call for a report from the health authorities on this matter of agrochemicals and health. This false belief was aggravated as a result of the initial suspicion that the chronic kidney disease (CKD) of the Rajarata was caused by agrochemicals but none of the research supported this contention. Research evidence gathered over several years, especially during the period 2010 and 2018, by no less than five groups of researchers established that the most likely aetiolating agent is hard water and fluoride in the dug wells especially on high ground, as those who drank such water were essentially the ones that caught the disease. Those who consumed water from the streams, reservoirs or dug wells in the plains did not contact it. The need is then to provide potable water to residents in the affected areas.

Misuse of Fertilizer and Pesticides

One of the serious concerns, especially of conventional farming is excessive use of agrochemicals; not that organic farming is free of the problem as evident from the foregoing evidence. Some programmes in Sweden, Canada and Indonesia have demonstrated that pesticide use can be reduced without loss of crop by as much as 50 to 60% ( Pimental et at al , Bio Science , 55 (7), 573-581 :2005). As regards toxicity of conventional pesticides over the last half century, there has been a gradual evolution from highly toxic pesticides to far less toxic ones.

On the other hand, there have been numerous reports of chemical pesticides detected in crop protectants ( so called herbal formulations) recommended for organic farming . Dr Naoki Motoyama (Tokyo University of Agriculture – 2012) has reported the detection of at least eight toxic pesticides including Abamectin (LD50 = 10mg/kg), a conventional insecticide, in organic pesticide formulations. So authenticity of organic pesticides is sometimes doubted.

Excessive use of chemical fertilizers is rampant, especially among vegetable growers in the upcountry where on top of huge applications of organic matter two to five times chemical fertilizer application has been reported. More is better is the thinking of some farmers, for which cheap, highly subsidized chemical fertilizer is responsible.

From the Sri Lankan context, what is critically important is farmer awareness building in regard to judicious agrochemical use rather than shifting to organic farming to prevent the supposed disadvantages of agrochemicals. Successive governments have failed to address this issue effectively.

In conclusion, organic farming is not toxin-free but its impact on the populace and environment is small as it occupies only a mere niche in the global agriculture setting. However, judicious use of agrochemicals and generation of safer technologies in the future should substantially reduce their health and environmental risks.