Tuesday, June 18, 2013

SOIL OF PAKISTAN

Ibrar A. Mumtaz

The Soils of Pakistan


Horticultural Society of Pakistan

Every year our cotton crop is badly affected by many kinds of pests and viruses and we spray pesticides worth billions to control this menace. Despite our best efforts the pests have multiplied and now the government has instituted a fund for the elimination of the major disease which is the leaf curl virus. If the pesticides are not working, we must investigate other causes and as a horticulturist I strongly advocate investigating our soil conditions as well. The remedy may lie in improving our soils to combat the menace rather than fighting it with pesticides alone. We must recognise that a human being who is healthy and strong is better able to fight disease through his immune system which nature has provided to fight diseases. On the other hand a weak person does not have the capacity to fight diseases through his weak immune system and has to be fed various medicines to fight diseases. In addition to medicines, doctors always recommend a good diet to develop a strong immune system. A patient who is fed only antibiotics and vitamins will never be really healthy and will always be susceptible to disease as compared to a person who is fed a healthy natural diet consisting of carbohydrates, proteins and vitamins.

Today our lands are more like a sick patient who is living on vitamins and antibiotics as our lands are only fed chemical fertilisers and once the pests attack, all kinds of pesticides are sprayed on the crops. In the good old days the only form of manuring was natural in the shape of animal dung and organic refuse. The fields were also left fallow for one season to recoup their strength. Today with intensive cultivation, the concept of leaving the fields fallow has died down although this is essential to re introduce humus in the soil. Using organic manures has become old fashioned and the only emphasis is on chemical fertilisers which do give a boost to the crops in the short term but have long term harmful after effects on our agricultural fields if not used in conjunction with organic manures.

The Western world has now learnt the benefits of organic manures after we have discarded it. Today in USA, the farmers have gone back to organic manures in a big way and they have learnt that the long term harm done by chemical fertilisers has been rectified in two to three years by the use of organic manures. The use of organic manures is also environmentally beneficial as instead of dumping waste in land fills or simply letting it rot away as we do in Pakistan, it is recycled and converted into useful manure for the soil. If we do not start recycling all kinds of organic wastes, soon we will have a major cause of pollution in our hands and the world will become just one big trash can littered all over our streets and waterways and we will all choke in this trash can one day. One of the major benefits of organic manuring is that it helps to clean the world that we live in. A whole new industry has now evolved in the developed world in the which the only raw material is all kinds of organic waste. India has embarked upon a billion dollar plant to not only provide organic manure for its agricultural sector as a better alternative to chemical fertilisers but also to clean up their polluted rivers, cities and countryside and they hope that with this beneficial recycling, their rivers Gunga and Jumna will have zero pollution by the year 2005.

It is now time that we started to treat all waste as a precious resource and convert it into useful compost. Our cities generate the largest amount of waste that our municipal authorities cannot dispose off properly. This adds to the pollution in cities. If only we can harness this waste and recycle it as useful compost, not only will our cities be cleaner but we will have a highly value added product to aid and assist our agriculture sector. We need to organise our garbage collection in such a way that organic matter like fruit and vegetable peels, grass clippings, fallen leaves, and other soft refuse is separated from the solid wastes and processed as organic manures and sold at a profit to gardeners and landowners. This can be done on a small scale on a mohalla level and provide employment to our youth or on a larger scale where organic waste is converted in composts in large factories with the aid of bio activators which convert waste into composts in 10 to 12 weeks. Let us try and understand now what composts are and how these are made and how they help in improving the soil conditions.

SOILS AND COMPOSTS

A couple of months ago I met a landlord friend who had come from Khanewal and we were discussing the merits of early and late crops in vegetables as well as the average return per acre in Punjab as compared to Sindh and NWFP. I was amazed to learn that whereas the average return per acre in Sindh is Rs. 50,000 or more per acre, it is less than Rs.10,000 per acre in Punjab. My friend was complaining that whereas the lands in Sindh were relatively fertile having been brought under cultivation only recently, those in Punjab were exhausted soils as they had been cultivated for over 100 years. I have never been able to understand the phrase “ Exhausted Soils “ because if you look after your soils they will always reward you with extra crops or fruit and flowers of exceptional quality. I have also had a number of gardening friends complaining that the quality of their flowers is not the same as his neighbours or friends and they attribute it to everything except the soil. We must remember that soil is something that we are developing all our lives and a good soil like a good garden is a life long affair. A good gardener will always have soil as his number one priority and frankly the bulk of my gardening budget goes to adding all kinds of composts to it to make it more responsive to the plants. This means spending money on composts like leaf manure, farmyard manure, drain silt and recently, filter mud from the sugar mills. All are exce llent composts provided they are fully composted through the aerobic method. Unfortunately the leaf manure that is available is not fully composted even after one year so when I buy my leaf manure, I keep it in an open space for another year before using it. However lately I have come across bio activators and plan on using these to make my own compost on a small scale at home.

ORGANIC MANUREs The common belief is that merely piling up organic matter will eventually produce compost. Unfortunately this concept is a broad and often incorrect generalisation of a very complex micro-biological science. Composting is an exact science with its own rules and limitations. For it to be successful, gardeners must first understand the mechanisms at work. An average garden produces a fair amount of biomass which is either burnt, destroyed or otherwise disposed off. The same biomass can also be composted. Anything that will rot can be composted. Composting is a good practice as the garden residue in the shape of grass clippings, leaves and plants which have finished flowering as well as kitchen waste like fruit and vegetable peels contain a good amount of valuable nutrients. As good money has been paid for these nutrients, it is common sense to re-apply them to the garden soil.

However, the nutrient content is not the only consideration when producing compost. As plants grow, they consume organic matter as humus from the soil. It is the humus content which determines the fertility of the soil. Applying chemical fertilisers as the only form of nutrition does not add any humus forming organic matter to the soil. Instead the soil is gradually robbed of humus and thus of its fertility. Reapplying the garden waste as compost saves money and replenishes valuable used up humus which is needed to maintain optimum quality in your garden or agricultural fields..

HUMUS

Nutrients and water are taken up through the roots in the soil. Soil must have the capacity to allow the storage of nutrients: Humus. This substance is made exclusively by the activity of micro-organisms transforming organic substances, crude nutrients applied to the soil, into stabilised and readily digestible food. The presence or absence of micro organisms in the soil is very important and determines its health status. Decreased microbial activity implies increased susceptibility to diseases and pest attacks. The management of micro organisms should not be considered a hands off responsibility. The common perception is that they grow automatically which is not so. Micro organisms are living creatures and change rapidly with changes in their living conditions. When garden waste is piled into a heap, it is invaded by bacteria that specialises in breaking down organic compounds. The first to invade are the Mesophilic decomposers. They quickly concentrate their efforts to heat up the pile. They increase temperature with the energy they use to break down the waste. Next to enter the chain are thermophilic organisms. At the higher temperatures, mesophilic bacteria are eliminated by their own activity and become food for thermophilic organisms. Their hunger soon causes the temperature in the pile to peak, signalling the end of the breakdown cycle. As thermophilic micro organisms deplete their food supply, overall activity in the pile diminishes. While the temperature drops, several organisms are waiting to initiate the next stage in the process: stabilisation.

When gardeners recognise the sweet smell of good soil, they are usually not aware that it is actually actinomycete

organisms they are smelling. Actinomycetes are crucial to the formation of humus in the soil as well as in composts. These bacteria release nitrogen and carbon equally, and they possess the ability to produce antibiotics.

COMPOSTING SKILLS

Good compost does not just happen. It requires skill. What is often considered to be a compost heap is usually the remains of an anaerobic composting process, where more valuable elements are lost than are stored. Anaerobic composting as practised in Pakistan is an ineffective and long term process. Here mainly the anaerobic bacteria are at work, and despite the fact that compost is produced, it is devoid of much nutrition which is actually used up by the anaerobic bacteria and fungii and such composts may also produce dangerous toxins as well.

AEROBIC VS. ANAEROBIC

Anaerobic composting takes place in pits dug deep in the soil where there is no free oxygen available to the bacteria whereas aerobic composting takes place above ground where free oxygen is constantly available to the bacteria. However not many gardeners are aware of the aerobic composting process which is the most efficient composting process that utilises carefully selected bacteria and fungii strains and is capable of recycling garden waste in six to ten weeks. The final result is a dark crumbly compost with excellent water holding capacity and readily available stabilised nutrients. This composting mix is now available in Pakistan and I have seen the end results of leaf manure which was composted with Khaad Masala in aerobic process. This compost was very much like peat moss, completely decomposed, odourless and almost black in colour. On the other hand the leaf which had gone through the anaerobic process was still not fully composted and was smelly even though it had been lying in the pit for over one year. This is the only kind available commercially in Lahore and it is a pity that large institutions do not use the bio activators to make aerobic composts.

What is more, the aerobic composts have many micro organisms that will continue their work once applied to the soil. The more types of micro organisms in the soil, the better. Beneficial micro organisms need to be introduced to the soil and fed organics to help them multiply. You must bring their population to an appropriate level. This is where compost plays a major role. The result is healthy soil with strong antagonistic abilities to combat diseases and pest attacks. This means less pesticide protection and stabilised nutrients that will not leach but be available to the plant at all times.

EXHAUSTED SOILS OR REFRESHED SOILS.

The moral of the story is that if you do not look after your soil by providing it with quality organic composts, it will not be able to provide the required nutrition to the plants when chemical fertilisers are applied and we will call them exhausted soils. Ofcourse the soil will become exhausted if you just keep on applying chemical fertilisers year after year as the only form of nutrition because the soil is gradually depleted of humus and thus its fertility. Re introduce well prepared organic composts to your fertilising regimen and soon your exhausted soil will become refreshed. Since the organic composts have the ability to make their own antibiotics there will be very little pest attack resulting in healthy plants which have the ability to resist diseases. I strongly suspect that all these new kind of sundis and leaf curl virus attack our cotton crops only because we are adding chemical fertilisers heavily to the soils to increase the yields with the result that over the years humus in the soil has been lost. This has led to very little bacterial action in the soil and plants grown in such soils are prone to all kinds of diseases. This has led to large scale use of pesticides and there has been no effort to educate the farmers on the use of organic manures which can be made available in abundance in Pakistan. We are producing all kinds of wastes which if not burnt off can be converted into the most useful additive for our soils. We are burning cow dung cakes as fuel as well as the filter cake of sugar mills which is also used as a fuel by brick kilns. Here is an analysis of the filter cake of sugar mills after it has been composted:-

Nitrogen 2.5%
Phosphates 1.07%
Potash 1.34%
Sulphur 0.63%
Calcium 4.46%
Magnesium 0.58%
Boron 0.02%
Zinc 0.02%
Manganese 0.09%
Copper 0.009%
Iron 0.13%
Humic Acid 3.6%

As you can see this media contains all the major nutrients as well as micro nutrients that are required by the plants plus a substance that is never available to the plants through chemical fertilisers and that substance is Humic Acid. It is the humus in the soil that will make all nutrients available to the plant besides making it disease resistant.

I would therefore strongly advocate that we start treating our organic wastes as a precious resource and in the cotton growing areas use only the organic manures whether it is the filter cake of sugar mills, municipal wastes, animal dung or simple yard waste that has been composted into useful manures so that our land can become rejuvenated once again and develop the ability to produce its own antibiotics to fight the various diseases that have proliferated in the past ten years or so.

PESTICIDES AND THE ECOLOGY

Excessive use of pesticides should always be avoided as this upsets the ecological balance between pests and beneficial insects which are the predators of many pests. In England, The Royal Horticultural Society has developed a pest management program based on zero use of pesticides. They control harmful pests by releasing insects that are known to devour many kinds of harmful pests thus reducing their population to a manageable level. Nature always provides a balance and for every harmful pest there are always more than one type of insects that use the pest as its food. Indiscriminate use of pesticides has destroyed all kinds of insects, both useful as well as harmful and no insecticide has been developed which will kill only the harmful insects sparing the beneficial ones. Pesticides are basically poisons and they are indiscriminate in their action. These poisons also find their way into the soils as well killing off the beneficial bacteria in the soil making it sterile. When this happens, the soils stop producing antibiotics which are needed to protect the plants and crops. We should therefore be extremely careful in the use of pesticides as plants develop resistance if used in low dosages. Systemic pesticides which have been used indiscriminately in Pakistan find their way into our food chain leading to slow poisoning in humans.

The conclusion that can be drawn is that we must research into the tried and old trusted methods of fertilising our soils and using only organic manures as the basic and chemical fertilisers as a food supplement and avoiding pesticides as far as possible. In Lahore an NGO by the name of Lahore Sanitation Programme has started collecting garbage from homes and they could more than recover their costs by separating the solid and soft wastes and converting the soft waste into useful manures for the garden and make good money out of it. At present gardeners pay approximately Rs. 10/- per kilo for leaf manure. Lahore generates more than 5000 tons of soft waste a day. 5000 tons of waste makes 2500 tons of compost which means that the agency making compost will earn approximately Rs. 25,000,000/- per day. This will more than pay for all the expenses that will be incurred on its collection and be a role model for other agencies to recycle and help protect the environment. The rural areas provide the cities with all their food requirement and at present it is a one way traffic. Let the cities also start giving back to the rural areas organic manures to enrich their soils which produce the food for cities. This will create mutual dependence between the urban and rural areas of Pakistan.

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