More reality on fertiliser debate

In common political discourse, it is seldom that differences in measurable facts form the basis of debate. It is a reason for some satisfaction, that the current divergence of opinion on the merits and demerits of “going organic”, for providing harvests that growers expect from them, is a healthy change. The ability to apply basic principles to specific situations is an important purpose of science education. Therefore, discourses of the present type, must be a measure of how virile and healthy our education system is. This trend should be encouraged, away from the drudgery and monotony of personality politics, that currently dominates and trivializes.

Plants (and by extension, live-stock), require a great deal from the environment, fertiliser (nutrients) is one. There are three principal elements (N, P, and K), a few more (Mg, Ca, S, Fe) as median, and six or seven Minor (B, Mn, Cu, Zn, Si, Co and Cd). There may be differences of opinion of what elements are considered “essential” and which of the groups they fall into – but this is of marginal concern, for the present. These “minerals” enter the plant through their roots (always as a solution). Some are of geological origin (by the weathering of rocks) and others from additions as manure (organic) or fertiliser (inorganic). Plant roots are capable of some discrimination – taking what they need and ignoring what they do not, from the soil solution. They are not particularly bothered whether they come from factories or waste dumps!

It is rather intriguing that the elements Aluminium and Silicon, being the most abundant (the “Framework/scaffolding” of soils are alumino silicates), yet have no special position or function in soil dynamics!

Elements that enter the plant go into structural (e.g. Nitrogen in protein and enzymes, Magnesium in chlorophyll Calcium and phosphorus in cell wall structure and so on) – some also intervene in reactions which constitute “life”. The Trace Elements (as Vitamins), are in this category (as catalysts or coenzymes). Potassium is special, as far as is known, it is not a part of any structural entity, nor does it take part in any reaction, even as a co-enzyme or catalyst. Yet, no plant (except a microscopic Alga, Scenedesmus sp) , seems able to do without it!

Soil has fascination when considered as a microcosm, parallel to what goes on upon its surface. It is a World of its own, with a “mineral sector,” deriving from its rocky parent, transformed physically and chemically into aggregates according to particle size (Gravel, sand, silt, clay and most importantly, a ‘colloidal‘ fraction). In the present discourse, the last is the most important. And in this mix, is the fascinating kingdom of the soil biosphere. The throbbing populace of bacteria, fungi, worms, earthworms, insects, ants, termites, snails, slugs and mice abound in a World of their own. Among the bacteria are those that can “fix” nitrogen in the air (nitrification) and those that reverse this (denitrifiers). Some live within the root nodules of legumes – that is one reason why beans should be an important component of crop rotations. This is part of that intricate machine – The Nitrogen Cycle.

The term “organic” has come to mean much more than merely the origin of nutrients. It also requires that no “synthetic” pesticides, weed-killers and “performance enhancers” have been employed. In sophisticated markets, the tag can only be used for products conforming to strict observance of rules, and with prior registration with a licensing authority, who also monitor and certify compliance. Interested readers may wish to access “Biodynamic Farming” on the Internet. In certain senses, it carries a strong message about the wisdom of a “return to nature” approach, incorporating elements of traditional (empirical) wisdom. It is a mix of myth, astrology, astronomy, logic, spirituality, voodoo, Feng Shui and Science. Whichever way one may look at it, it is a fascinating study. In practice, it seems that Australian farmers, (with their massive Farm Size) have taken to it in a big way.

I am unaware of the local situation in respect of “Organic certification”. We may have unknowingly gained a “head start” by the very fact that our “negligence” may have simplified approval of some products – of striking potential (eg. Jak). Whoever manures a jak tree?, leave alone pest control sprays! The so-called “Kandyan Peasant Garden”, usually symbolic of the lazy owner, can become the beacon of an “organic farming “culture! When a person was asked, “Why do you grow a beard?” Responds “I don’t grow it, it simply grows!” Or, when asked, “Are you now retired?” Replies “No, I am just plain tired!”

Apologising for that diversion, to get back to the subject, ignoring the usual irrelevancies of “inferior Western Science” Plots to destroy our farmers, sell their land to rapacious foreigners, Bribed researchers and such rubbishy generalisations, there are some valid points.

(i) Heavy metal and toxic elements entering the food chain. Leached excess phosphates leading to algal blooms in waterways. Contaminants (eg Fluorides, Arsenic, Lead, Aluminium, etc.) by polluting factories.

(ii) Entry of materials hazardous to human health, eg. weed-killers like Roundup (glyphosate). There is much greater risk of say, antibiotics and other medications through deep litter composts.

(iii) Depletion of soil fertility by exclusive reliance on inorganic (chemical/mineral) in the long term. This emphasises the need to evaluate fertility in terms of Physics as much as Chemistry. Texture, aeration, moisture retention, compaction, erosion, adsorption, binding, release, immobilization. In short – as encapsulated in classic Buddhist Philosophy as Apo, Tejo. Vayo and Patavi !

In summary, the problem really revolves not between the use of mineral/chemical/ artificial versus organic/natural/ carbonic, but really the damage possible through abuse of either. This is the crux and if anything, it should lead us to be more mindful of the abuse of fertiliser or any agrochemical input. Greater focus on optimising, and not merely on maximising.

There is no gainsaying the fact that promotion of compost, done sensibly and methodically, will close the circle for a sustainable “nutrient cycle”. Where in theory, that all that leaves the field is only what constitutes the “crop”, all else is recycled – as dropped leaves, twigs and “agro-waste” being composted and returned. This would be on a “home-garden” scale and can get by with a good extension service to provide guidance, and where possible minor inputs, like composting bins and by arranging markets for on-site surpluses. If centralised production is desired, a major effort would be to procure the raw materials on a larger scale. Obvious candidates would be coir fibre dust, paddy husk, water weeds (Salvinia, Japan jabara, Habarala). It was heartening to hear that massive quantities of bagasse from the sugar factories of Pelwatta and Sevanagala are available.

Dr UPATISSA PETHIYAGODA