Agriculture has always been the major profession for the many people of the world since times immemorial. Before few centuries, the growing food to feed per capita was not an issue, but today on the eve of new millennium it is a challenge before the farmers and scientists to produce the food to feed the fast increasing population with the rate of160 people per minute. Majority of the population is living in developing countries where agriculture is a main profession but still there are many hurdles to achieve the desired food production. It is estimated that we need to produce food during next 40 years as we had produced since the evolution of agriculture and of course we are now in the race between growing population and food production, and now it has become a dream of every agriculturist and agricultural scientist of the world to produce a qualitative and quantitative food production in a less area than what it was supposed to be. Since the evolution of agriculture the conventional farming system has always remain beneficial to producers in terms of production and economic. “The revolution after the post war has changed the entire face of agriculture. The introduction of farm based tractor closely by that of synthetic fertilizers, pesticides and factory farming of livestock. There was a desperate need for food in the recovering economics of the 1940s 50s and 60s. And farmers everywhere were encouraged to rely increasingly on synthetic inputs and intensive production methods in order to maximize the yield and quality.” (Letterick et al. 1999) Therefore it shows us that the conventional and intensive farming system has played an important role in crop production and labour efficiency. With the use of such intensive farming system, many environmental issues were raised which includes soil fertility, and environmental sustainability. Thus the organic farming system was the alternative option before the producers. However organic production can’t meet the total requirement of food since it requires full awareness, sufficient knowledge and also lot of natural organic components to be used for increasing the soil fertility, plant protection...etc. It is not possible to have a production of required quantum in a stipulate period of time. On the other hand, in conventional farming system the intensive use of chemical fertilizers, chemicals, synthetic pesticides, monoculture has helped to obtain the desirable crop production everywhere. Besides this there is one circular argument in the aspects of “seed sowing”. Despite of all of these benefits of conventional farming system we cannot neglect its adverse effects over a soil fertility and environment sustainability.
According to The United States Department of Agriculture, organic farming is a production system which excludes the use of synthetically compounded fertilizers, pesticides, growth regulators and livestock feed additives, and therefore it has never ever had any adverse effects on soil, and on any other environmental aspects. “Organic farming took on a new lease of life during the 1980s not just in Britain but around the world”(Lamkin, Organic Farming, 1990) The farmers could perceive the importance of organic system since they realized the problems occurred due to over industrialization and excessive use of synthetic fertilizers. Objectives of organic farming are concisely expressed in the International Federation of Agriculture Movements (IFOAM) and some of them are as follow:
1) High nutritional quality food production in sufficient quantity
2) Working with natural systems
3) To encourage and enhance biological cycles in the farming system
4) Maintenance of soil fertility for long term
5) Maximize use of renewable energy sources
6) To avoid all agricultural techniques those causes pollution
7) To maintain genetic and bio diversity
8) Consideration of the wider social and ecological impact of the farming system
Many factors in the recent years like pollution, soil erosion has brought kind and immediate attention towards the implementation of organic techniques. “Heavy agricultural reliance on synthetic chemical fertilizers and pesticides is having serious impact on health and environment” (Pimentel et al.2005). In The United States of America 90% of farmers rely on herbicide to control the weed. The most commonly used pesticide ‘Attrazine’is found in streams and ground water, and which is obviously would have had been be a serious issue( Pimentel,1993).
In 1862, Friedrich Albert Fallou wrote : “ There is nothing in the whole of nature which is more important than or deserves as much attention as the soil. Truly it is the soil which makes the world a friendly environment for mankind. It is the soil which nourishes and provides for the whole of nature; the whole of creation depends upon the soil which is the ultimate foundation of our existence” Besides this Soil has been given a place of mother in many cultures of the world. As a mother plays an important role in taking care of her child, a similar role is played by soil. Soil provides greater support to big buildings, houses, industries. It also acts as a layer for road construction, which is one of the mean for transportation. It is therefore very hard to imagine about food production without quality soil. Agricultural yields are increased in last 50 years but this remarkable production could not become possible without paying cost. This cost has been paid by gradual reduction in organic matter levels in the soil and especially in the area where highly production obtained with the use of intensive conventional farming system. As per to the Strutt report Modern Farming and the soil, published by Ministry of Agriculture, Fisheries and Food (MAFF) in 1970, some soils were suffered from low organic matter level and they were not expected to sustain the farming system imposed on them. Available nutrient and energy supplied by organic matter runs all biological activities of soil therefore biological activity of soils were declined by low organic matter level. The soil contains different organisms of different size and function and all of them play an important role in the metabolism of nutrients in the soil.
(Picture source- textbook organic farming by Nicolas Lampkin pp- 16)
Rapid loss of soil which we call as a soil erosion is the another factor responsible for loss of organic matter level from soil. The soil erosion is mostly accelerated by modern agricultural practices, and the estimated annual cost of public and environmental health loss related to soil erosion exceed $45 billion( Pimentel et al. 1995). In organic farming system, crop rotation is followed with grass leys, green manuring and under sowing of crops such as maize; which significantly helps to reduce the soil loss. The best example can be taken of Reganold et al. (1987) who compared the soils from conventional farm and another organic farm, the soil loss was found 16 cm greater on conventionally managed farm( please see the figure above). Even though the soil loss on organic farm was 5 cm but of course it was less than that of conventional farm. Many research studies have been conducted till date to carry out the comparison of the effect of organic and conventional farming system on different soil properties. In Washington State, USA, the detailed study of two commercial wheat farms was made (Weilgart Patten 1982, Bolton, Jr et al. 1985,Reganold et al. 1987, Reganold 1988) .The organic farm was managed ideally without use of chemicals, chemical fertilizers with just limited application of pesticides for nearly 80 years, on the other hand the another farm received recommended rates of fertilizers and pesticides. In organic farm complex crop rotation was followed with the use of green manuring, cover crops as legumes. In contrast to this, the conventional farming system was followed with simple rotation system without green manuring. The following results were obtained.
1) High organic matter was found on organic farm soil.
2) High amount of active micro flora with better structures soil found on organic farm.
3) Top 16 cm layer was found fertile in organic farm.
4) This difference in top soil had attributed considerable soil erosion on conventional farm in between 1948 to 1985.
From these results it is clear that the organic system is more effective than conventional farming system in maintaining soil fertility, productivity, tilth of soil. “The ability of the organic farm to produce yields similar to those of neighboring conventional farms, even after almost 80 years of farming without chemical fertilizer, may be attributed in part to the reduction in soil erosion and maintenance of soil organic matter”(Reganold et al. 1987).
In New Zealand, Robertson (1984) too carried research a comparative study of soil properties, on two different market gardens out of them one was an organic market garden and another was a conventional market garden. On organic farm, the soil treatments included use of compost, poultry litter, biodynamic preparation 500, green manuring and on conventional farm the applications of nitrogen, phosphorous, potassium, and lime were made. Weed and pest control methods were of course non chemical on organic farm whereas chemical sprays were used to control pest and weed on conventional farm. The soil from organic farm had a higher organic matter with more earthworms, higher transpiration rate, more extractable phosphorous, potassium, magnesium, higher pH and water content. Soil properties were more favourable on organic garden as compared to conventional farm garden.
To fulfill the dream of quality production, producer has to undergo with many hurdles including soil quality, fertility, genetically pure plant material, seed availability, climate, market, pest disease...etc. Out of all these hurdles the impact of pest and disease attack on crops is quite considerable and has greater effect on quality and quantity of food produce. Insects has always been a certain interrelation with the world, their population is more than that of humans!!!! Accordingly to the John Kent (1991) “Pesticides (or farm chemicals, agro chemicals or agvet chemicals) are those substances which are used to control, destroy, repel or attract pests in order to minimize their detrimental effects”. Different viruses, bacteria, fungi, weeds, insects, animal are referred as a pests and all these may reduce the production and affect the quality of the food produce. In organic farming system, major importance has been given on non chemical pest control methods. These methods often control use of biocontrol agents, nematodes, natural enemies, and natural insecticides for eg. Neem oil, neem seed kernel extract, neem powder. In contrast to this, in conventional farming system the recommended doses of chemical pesticides are sprayed. Chemical pesticides are having several disadvantages. After application of them over a crop they affect the nervous system of insect, affect the metabolism, pigment system, and affect the translocation of organic food by affecting the phloem. There are some benefits behind using the chemical insecticides, as they kill or repel the insect pest those causes the quality and yield of the food produce. Many of the chemical insecticides are economic. But while considering these benefits we cannot neglect the hazardous effect of chemical pesticides over a pests and crops since they cannot distinguish between pest and non pests and may become harmful to useful organisms. After spraying chemical insecticide they just kill any insects those come in their way. “Many of these early chemicals had disadvantages. They were often highly toxic, were very persistent, posing a threat to the environment, or they damaged the crops they were meant to protect.”(Kent 1991). They often leaves residual effect behind and these left residues in the food may contaminate poison to human, during spraying they may damage to the crop, environment and other livestock. Weather condition and the way of application of pesticide can affect the drift. While applying chemicals over the crops if they are applied in excess and their leaching may contaminate the irrigation water as well as ground water. It is very necessary to take prevention method while spraying the chemical pesticides otherwise it may affect adversely to the sprayer and may pollute the environment.
Table 1
2005 Global pesticide market by region ( figures in $ US Billion)
| North America | 8.60 |
| Europe | 8.74 |
| Asia | 8.16 |
| Latin America | 5.65 |
| Rest of World | 2.45 |
| Total 33.6 | |
Source: Allan Woodburn Associates/Cropnosis.
“The past ten years have been marked revival of interest in the biological method of insect control. It arose from a growing realization that supplements and alternatives to chemical insecticides are needed to overcome some of the faults and weaknesses now recognized as Inherent in the chemical method of pest control”.( Bryan. P. 1962, p-387). Many people, farmers, agriculture industries are now realizing the hazardous effect of chemical pesticides and therefore they are moving towards the adoption of biopesticides. Because of the public awareness, demand for biopesticides is gradually increasing in all over parts of the world.
Estimated sales of microbial and nematode biopesticides
| | Sales Estimates ($) | |||||
| | North America | Europe | Asia and Australasia | Latin America | Africa and Middle east | Total |
| Total Bt. | 72.75 | 26.77 | 43.12 | 14.45 | 2.48 | 159.57 |
| Other bacteria | 15.20 | 2.60 | 11.58 | 0.65 | 0.10 | 30.13 |
| Viruses | 1.03 | 5.45 | 5.33 | 2.89 | 0.55 | 15.25 |
| Fungi | 11.76 | 2.17 | 11.52 | 22.16 | 0.49 | 48.10 |
| Protozoa | 0.05 | 0.00 | 0.02 | 0.00 | 0.00 | 0.07 |
| Nematode | 8.25 | 6.00 | 0.37 | 0.03 | 0.00 | 14.65 |
| Total | 109.04 | 42.99 | 71.94 | 40.18 | 3.62 | 267.77 |
· Produce based on B. thuringiensis serotypes. Source- ( CAB reviews: Perspectives in Agriculture , Veterinary Science, Nutrient and Natural Resources 2007 no.51)
Now a days it has become a challenge before the growers to produce a qualitative and quantitative food for fast increasing population in many part of the world in due course of time. The food scarcity would be the big issue and people will starve because of food. It is not only because of the availability of the food but also because of safety food. From all above discussed points, it is clear that, total crop production to feed ever increasing world population is not practically possible with organic method alone, since it will take some time to change the cropping pattern from conventional to organic and again to change the mind set of farmers. So to meet the challenges of food production we have to set the Integrated Farming System. With the combined use of conventional and organic farming system, we can surely complete the target of food production.
References
Pimentel D, et al. 1995. Environmental and economic costs of soil erosion and conservation benefits. Science 267: 1117–1123.
Pimentel D. 2005. Environmental and economic costs of the recommended application of pesticides. Environment, Development, and Sustainability. Forthcoming.
Regnold. J .P. , Elliott, L. F. and Unger Y.L. (1987) – Long term effect of organic and conventional farming system on soil erosion Nature 330 pp- 370-372.
Robertson, M.K. 1984. A Comparative Study of Soil Factors Affecting Plant Growth within a Set of Organic and Conventional Market Gardens. Diploma Thesis, Massey University, Palmerston North, New Zealand.
Lamkin, N.H., (1990) Organic Farming, Farming press.
Blake, F. (1994) Organic Farming and Growing. The Crowood press.
Trends in applied biological control of insects,
By Brayan P. Beirne , 1962 p 387-400.
PESTICIDES IN AGRICULTURE
Kent, J. (1991). Education and training in farm chemical management. Proc. conf. Agriculture, Education and Information Transfer. Murrumbidgee College of Agriculture, 1991.
Web Supports.
No comments:
Post a Comment