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Organic farming — myth or miracle?

TOTAL ORGANIC farming would not be feasible, viable and profitable under high-productive intensive agriculture. Farmyard manure has become a scarce commodity due to dwindling animal population.

Green manuring has also become uncommon as the farmers are interested in growing as many crops of economic importance as possible and it has become difficult to have green manure crops in the crop sequences.

Green leaf manuring also has become limited due to over-exploitation of shrubs and trees.

Recycling of farm wastes as manures is not practised widely due to disinterest and cost factor towards labour engagement. And and so most of the farm wastes are disposed off by being burnt in the fields themselves, thereby polluting the environment besides wasting the organic materials most precious for our arable lands, most of which are low or very low in organic matter status without which the earthworms and beneficial hetrotrophic micro organisms cannot survive in the soil.

Organic farming could be possible on small scale under special situations where plenty of organic manures like farm yard manure (FYM) would be available as in dairy-based farms and where horticultural crops like flowers, vegetables and certain fruit crops, requiring low amounts of nutrients, are cultivated. Crop yields cannot be sustained at high levels through exclusive organic farming particularly in case of high nutrient-responsive field crops.

Exclusive organic farming without using fertilizers and agricultural chemicals would be possible under natural ecosystems like forestry but not under high-productive intensive agriculture growing field crops. The productivity per unit area per unit time would decline over the years under exclusive organic farming.

Although organic manures can supply all the essential plant nutrients, the full requirements of certain nutrients like nitrogen, phosphorus, potassium, calcium, magnesium and sulphur which are required relatively in larger amounts for the normal growth and high yields of crops, cannot be supplied through organic manures alone.

Insufficient supply of these nutrients will lead to malnutrition of the crops resulting in low yields and poor quality of the produces.

Nutrients supplied both through manures and fertilizers are absorbed by plants in the same way. They don't function differently within the plant. The plants do not and cannot differentiate between the nutrients from the organic and the inorganic sources. For example, plants can absorb nitrogen either as NH{-4}{++} ion or as NO{-3}{+-} ion. The plants will absorb these ions released either from the fertilizers or from the manures and they will function similarly within the plant irrespective of their sources.

Crop produces produced through organic manuring or inorganic fertilisation will have almost same composition and the individual proximate constituents will have the same elements in the same proportions.

Fertilizers do not contain any toxic substance, other than the plant nutrients, which would affect the quality of the agricultural produces or would affect the health of the human beings consuming these produces.

The decline in the quality of the produces is not due to the use of fertilizers but due to distorted and disproportionate use of certain fertilizers only.

There would be contamination of the produces with toxic chemicals due to excessive use of pesticides but not due to use of fertilizers.

It is, of course, true that the crop produces are of better quality when the crops are grown with manures also.

This is due to supply of all the plant nutrients including the secondary and micronutirents and also the growth promoters and growth regulators which are not usually supplied through the fertilizers.

When all the plant nutrients with the growth promoters and regulators are supplied, the metabolic functions of the plants would progress in the right direction and rate and the proximate constituents which govern the quality of the crop produces would be synthesised sufficiently and in the required proportions.

Judicious use of insecticides, fungicides and weedicides also would be necessary under intensive agriculture as the endemic outbreaks of pests, diseases and weeds cannot be controlled using nonchemical botanicals and biopesticides alone.

We should not neglect the fertilizers and agricultural chemicals overemphasising the demerits that would arise if misused or overused, as the consequences of such dispensation of fertilizers and agricultural chemicals would lead to disastrous consequences in production and sustainability as a commercial proposition would become impossible.

Dr. K. Kumaraswamy

Dept. of Agricultural Chemistry

TNAU, Coimbatore 641 003

Dr. K. Kumaraswamy

Dept. of Agricultural Chemistry

TNAU, Coimbatore 641 003

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