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12. Biotechnology And biofertilization: Key To Sustainable Agriculture (New) 11. Agriculture situation is not satisfactory in Pakistan (Interview) 10. Hydroponics: Key to Sustainable Urban Agriculture 9. Pakistan Agriculture in Global Perspective 8. THAR: Potential natural resource in need of exploitation 7. Agriculture Perspective: An imaginative insight 6. Aquaculture And Integrated Farming System 5. AGRICULTURE: THE ISSUES AND CHALLENGES 4. SUSTAINABLE AGRICULTURE FOR FOOD SECURITY 3. AGRICULTURE EDUCATION: A VISION FOR CHANGE 2. Biological control: a vital component of IPM 1. SAU: A road map to sustainable agriculture
Hydroponics: Key to Sustainable Urban Agriculture
Prof. Dr. Bashir Ahmed Sheikh Vice Chancellor Sindh Agriculture University
Agriculture forms the largest sector of national economy of Pakistan. It is strongly linked with food security, poverty alleviation, rural development as a means to achieve bigger goals, for example, employment led economic growth through its linkages and multiplier effects. The agriculture sector, however, faces some crucial and critical challenges. Pakistan population during the last three decades has increased from 65 million to 162 million at present, and is expected to increase to 234 million by 2025 reaching 357 million by 2050. This buildup of massive population momentum will place immense pressure on agriculture resource base calling for substantial increase in food production.
Worldwide arable land is already less than 0.2 ha per capita at present, and is expected to further shrink to 0.15 in 2050. Situation is extremely alarming in Pakistan, where per capita land availability has progressively declined to 0.15 ha at present, shrinking further to 0.06 ha by 2050. Similarly, the per capita water availability has dropped from 5600 cu meters to 1200 cu meters, which could slip further to the water-deficient level below 1000 cu meters per year by 2010 onwards. Therefore, we must possess the potential and the ability to meet growing demands for food. The greatest challenge lying ahead for all of us is to increase food and fiber production while maintaining the ecosystem stability and rehabilitation of the environment. The issues and challenges in this regard are to be overcome in such a manner, so that, everyone can be adequately and nutritiously fed without over-exploiting the natural resources. Hydroponics is one such valuable means of growing fresh vegetables not only in countries having shrinking arable land resources and have large populations.
Hydroponics is a very young science. It has been used on a commercial basis for only 40 years. However, even in this relatively short period of time, it has been adapted to many situations, from outdoor field culture and indoor greenhouse culture to grow fresh vegetables. It is a space age science, but at the same time can be used in developing countries of the Third World to provide intensive food production in a limited area. It’s only restraints are sources of fresh water and nutrients. In areas where fresh water is not available, hydroponics can use seawater through desalination. Therefore, it has potential application in providing food in areas having vast regions of non-arable land, such as deserts and dry coastal belts.
Hydroponics can simply be defined, as the growing of plants in a water and fertilizer solution containing necessary nutrients for plant growth. It can also be defined as soilless agriculture or growing plants in soilless medium. Hydroponics as a word was coined in 1930 by W.E. Gericke of University of California, meaning water and labour in other words i.e. water working or growing plants in a nutrient solution with out soil.
The science of hydroponics leads to prove that soil is not required for plant growth but the elements, minerals and nutrients that soil contains are definitely needed. Soil is simply the holders of the nutrients, a place where the plant roots traditionally live and a base of support for the plant structure. By eliminating the soil, it also eliminates soil borne diseases and weeds and gains precise control over the plant’s nutritional requirements. In a hydroponic solution, one provides the exact nutrients the plants need in precisely the correct ratios so they can develop stress-free, mature faster and, at harvest, are the best in quality possible for costumer and consumers liking.
In 1945 the U.S. Air Force solved its problem of providing its personnel with fresh vegetables by practicing hydroponics on a large scale on the rocky islands normally incapable of producing such crops. With the development of plastics, hydroponics took another large step forward and is now a widely accepted method of producing certain specialty crops such as tomatoes, lettuce, cucumbers, bell peppers, herbs, foliage plants, and flowers. Most of the tulips and roses exported from Holland are also grown hydroponically. The controlled environment agriculture and hydroponics seems to be the answer to many of the difficulties associated with the production of outdoor specialty crops in the wake of continued soil degradation, loss of fertility, indiscriminate chemical inputs use, and above all continued depletion of water resources.
In traditional agriculture fields or gardens, plant roots are in the soil. They support the plant and search for food and water. In hydroponics, a growing medium in place of soil is used to help support the plant and to absorb the nutrient solution. The roots of a hydroponic plant do not work as hard as those of a plant grown in soil because their needs are readily met by the nutrient solution provided. Ideal mediums are chemically insert, porous, clean and able to drain freely.
Keeping in view, the water stresses being frequently encountered with, the soilless agriculture in Pakistan does not seem to be the wave of the future, it’s going to be here specially for high-value crops such as tomatoes, bell peppers, cucumbers, lettuce, herbs, strawberries and flowers as they consume 10-30 times less water than field grown produce for the same area and are also devoid of the hazards associated with indiscriminate use of synthetic fertilizer, insecticide and pesticide sprays. Besides, green house hydroponic crops can be grown all the year around irrespective of seasons and make crops freshly available in the local markets and fetch better prices because of being of better appearance as well as quality and also being devoid of chemical influences. They are grown on more than 30,000 acres all over the world whereas U.S. accounts for more than 1000 acres alone. The most popular hydroponic crops in the US and Europe are tomatoes, lettuce and other leaf crops, cucumbers, herbs, peppers and flowers. However, U.S. also receives more hydroponic produce from Holland, Canada and Mexico than is actually grown there.
With hydroponic technology and a controlled environment green house, one gets the latitude and ability to grow premium quality produce using a minimum of space, water and fertilizer. Hydroponics is an intensive form of agriculture that may fulfill the consumer’s demand for premium produce and provide the grower with a profitable business. The commercial hydroponics in Europe and States has dramatically risen through productivity as profitable ventures during past decade so much so, the growers are harvesting 35-40 lbs of tomatoes per plant as compared to 20 lbs few years back, and an intensive volume could be grown in small space i.e. 4-5 thousand pounds of tomatoes every week in an area of 12000 ft2.
Materials for Hydroponics
Since the beginning of hydroponics, many materials have been used as hydroponic growing mediums, some of which include vermiculite, saw dust, sand and peat moss. More recently, rockwool, perlite and expanded clay pebbles are available as excellent choices for hydroponics.
a) Perlite
Perlite is derived from volcanic rock which has been heated to extremely high temperatures. It explodes like popcorn, resulting in the porous white medium which can be used in hydroponics. In addition to uses in hydroponics, perlite is also used in many commercial potting soil mixes and in non-horticultural areas including construction and as a packing material.
Perlite can be used loose in pots or bagged in thin plastics sleeves (referred to grow bags) as the plants are grown right in these bags. Plants in perlite grow bags are usually set up on a drip feed system and each standard bag holds 3 or 4 long term plants.
b) Rockwool
Rockwool is derived from basalt rock. It too is heated to high temperatures and is then spun into fibers resembling insulation. These fibers are further spun into cubes and slabs for hydroponic production. The cubes are commonly used for plant propagation and the slabs are used similarly to the perlite grow bags. A plant is set onto the rockwool slab and grown there. The plant roots grow down into the slab. Rockwool slabs usually hold 3 or 4 large plants.
c) Expanded Clay Pebbles
Many hobby hydroponic gardeners use expanded clay pebbles for their growing medium because they have a neutral pH and excellent capillary action. For commercial ventures, expanded clay pebbles are generally considered too costly.
Characteristics and Attributes of Hydroponics
Growing methods in Hydroponics
In commercial hydroponic production, the two primary growing methods are drip (also known as substrate) and NFT (Nutrient Film Technique). There are a number of variations of these methods and also several others including the float system, ebb and flow system, aquaponics, aeroponics and passive hydroponics have also been practical. The biggest difference between the drip and NFT systems is the use of a growing medium. In a drip system, the plant roots are in a growing medium such as perlite or rockwool and the nutrient solution is dripped onto the medium to keep it moist. In an NFT system, the plant roots are in a channel where a thin film of nutrient solution passes, keeping them moist but not water logged.
I) Drip (Substrate) system:
The drip system is often used in commercial hydroponic facilities that grow long term crops like tomatoes, cucumbers and peppers. In this system, the nutrient solution is delivered to the plants through drip emitters on a timed basis. The emitters are usually scheduled to run for approximately 10 minutes of every hour depending on the stage of development of the plant and the amount of available light. The drip cycle flushes the growing medium, providing the plants with fresh nutrients, water and oxygen.
In a commercial drip system, the plant roots are most commonly grown in a medium of perlite or rockwool. The biggest variables in a drip system are in the growing medium and the container that holds that medium. Perlite is often bagged in thin, plastic sleeves. Holes are cut in the bag and plants usually, 3-4, are set in with the roots growing down into the perlite. Recently, a bucket system has been developed to contain perlite for drip systems. Each bucket holds lose perlite and one or two plants. In either of these methods, a slot or hole is cut in the container to allow excess nutrient solution to run out. A drain line below the bag or bucket collects the excess.
Another method of a drip system that is becoming popular for lettuce and herb production is the perlite tray, usually about 24 inches wide and 10-14 feet long. An aluminum tray, coated with a non-toxic material, is filled with perlite and set on a gentle slope of 1-inch to 10 feet. The nutrient solution is continuously dripped in, at the higher end of the tray and allows trickling through the perlite to the other end. Essentially, this system is a combination of drip and NFT techniques.
In most drip systems, injectors are used to add nutrient concentrates to water when the feed cycle starts. In this case, there is no need for a large nutrient reservoir tank or the periodic dumping of used nutrient.
II) NFT (Nutrient Film Technique) system:
With the NFT technique, the plants are grown in channels (also called gullies) through which the nutrient solution is pumped. The plant roots are kept moist by the thin film of nutrient solution as it passes by. Ideally, the bottom of the roots are exposed to the nutrient solution while the top are kept moist but not waterlogged.
Most NFT channels are fed continuously at a rate of approximately 1 liter per minute. Since the plant roots are not in a growing medium, it is crucial that they are kept moist at all times. In most NFT systems, the nutrient solutions mixed in a primary reservoir, are cycled through the channels and back to the reservoir. With the development of on-demand dosing equipment, a nutrient reservoir can automatically be adjusted, and with proper aeration and pH adjustment can effortlessly be kept fresh for weeks at a time.
NFT is ideal for lettuce, leafy crops and herbs, all of which are short terms crops. Larger NFT channels are used for long term crops such as tomatoes and cucumbers in many locations around the world. One great benefit of NFT, especially for leafy crops, is that the crops are clean and no washing is necessary. Growers, grocers and consumers all appreciate this type of crop even if, to be marketed as such.
NFT channels are usually set up on waist-high stands that slope slightly to allow the nutrient solution to drain to one end. Although round pipes have been used in NFT production, most growers have found flat bottomed channels or gullies provide greater surface area for root development and oxygen uptake, resulting in better and faster plant growth.
III. Float system:
Float systems have the advantage of the economy and the surface for the nutrient solution. Most float systems are long, rectangular reservoirs built out of cement or wood and lined with a durable poly liner. Holes are cut in a foam board which floats on the surface of the water and plants in net pots are set in the holes. The plant roots dangle in heavily aerated nutrient solution.
In areas where raw materials are limited and manufactured hydroponic systems are not available, the float system can be an economical means of hydroponic crop production.
Ebb and Flow system:
The Ebb and Flow (also know as flood and drain) method of hydroponics simply floods a growing area for 5 or 10 minutes and then the nutrient solution drains away. The nutrient solution is stored in a reservoir that can be located under the grow table. Ebb and Flow is common in hobby systems but not often found in commercial production. In an Ebb and Flow system, the plant roots are usually grown in a medium of perlite, rockwool or expanded clay pebbles.
IV Aquaponics system (Integrated system approach):
In hydroponics, you mix a specific nutrient formula in solution which is fed to the plants. In aquaponics, you combine aquaculture (fish farming) with hydroponic production. The nutrient-rich waste water from the fish tank is pumped through plant grow beds. Although not as precise as a hydroponic fertilizer mix, the effluent from a fish tank is high in nitrogen and many other elements and most plants do quite well in aquaponics, through this integrated system approach. The key to aquaponics is the establishment of a healthy bacteria population. Beneficial bacteria that naturally occur in the soil, air and water convert ammonia (the primary form of fish waste) to nitrite and then to nitrate, which the plants readily uptake. In consuming the nitrate and other nutrients in an aquaponic system, the plants help to purify the water. Although the combination of hydroponics and aquaculture is quite new, the interest in this technology is booming. Aquaculturists who normally have to buy expensive water purification equipment to purify the water see aquaponics as a great way to clean the water and end up with another, very marketable crop. Hydroponic growers see the value in a natural source of nutrients, already in solution. The water from a fish tank can be pumped through any hydroponic grow bed in place of a hydroponic fertilizer solution. The commercial aquaponic production system is designed to show great promise as it may include the float, NFT and ebb and flow, methods.
V) Aeroponics
Aeroponics is the method of growing where the plant roots are constantly misted with a nutrient solution. Designs include frame with boards on each side, plant plugs set in each side and a mister between the boards spraying the roots. A round, large diameter PVC pipe set vertically with plant plugs all the way around and a mister mounted inside is another way to set up an aeroponic system. Although aeroponics is a unique way of growing, it is not a common means of commercial production.
VI) Passive hydroponics
Passive hydroponic systems are sometimes used by hobbyists. A passive system does not use pumps or timers to flood the root zone. The roots usually dangle into the nutrient solution and draw what they need. A passive system is generally slower growing and not as productive as the other methods discussed, above.
The growing awareness of environment and ecosystem among the people make hydroponics technology most ideal to protect the degradation of natural resources. This technology requires no soil, less water for culture, less area, free of disease and pest and highest food production, it plays vital role in developing areas with water scarcity, small arable land area, environmental concerns in controlling pollution and quality of groundwater and problem of food security. It can effectively be exploited as a tool in backyard farming and house top agriculture practices. In urban atmosphere with limitations of soil accessibility, hydroponics could serve as best means to earn livelihood through continued growth of vegetable and even flowers on a limited scale under given local environment.
Pakistan Agriculture in Global Perspective B.A. Sheikh*, S.A. Sheikh* and G.H. Soomro*
The agriculture sector faces some crucial and critical challenges. Pakistan population during the last three decades has increased from 65 million to 161 million at present, and is expected to increase to 234 million by 2025 reaching 357 million by 2050. The situation of per capita availability of land and water in the country is extremely alarming and has further accentuated the problem of agriculture productivity. The per capita land availability has progressively declined to 0.15 ha at present, shrinking further to 0.06 ha by 2050. Similarly, the per capita water availability has dropped from 5600 cu meters to 1200 cu meters, which could slip further to the water-deficient level below 1000 cu meters per year by 2010 onwards. Therefore, we must possess the potential and the ability to meet growing demands for food, for which the planning in the past, had been half hearted, erratic and uncertain. The demands on the use of natural resource base will almost surely increase in ways we cannot even imagine today. In a finite, interdependent, and rapidly changing world, the maintenance of strong food, fiber, and forest production systems and the protection and wise use of our natural resources is the need of the hour. The interdependency of agricultural production practices with conservation of land and water systems has now linked farmers with environmentalists. Food safety concerns and ground water contamination are changing contemporary thinking about food and fiber production with the balance of nature. Genetic engineering, biotechnology, alternative practices, and sustainable rural development are simultaneously linked with global climate change, acid rain, ground water contamination and extinction of species. The projected annual increases in food production in the coming decades to meet our domestic needs are 3-4%. Expanded crop areas or higher production per unit land area per unit time are the only sources for the achievement of 3-4% increase in production. The only way to obtain these increases could be from intensification of landuse for higher yields and increase in the number of crops produced per year. It is thus mandatory for all the stakeholders including policy planners and decision makers not to loose their sight while ensuring food security in the backdrop of expected population growth, from livelihood security and ecological rehabilitation in years to come particularly in Pakistan.
Agriculture forms the largest sector of national economy of Pakistan. It is strongly linked with food security, poverty alleviation, rural development and as a means to achieve bigger goals, for example, employment led economic growth through its linkages and multiplier effects. The agriculture sector, however, faces some crucial and critical challenges. Pakistan population during the last three decades has increased from 65 million to 161 million at present, and is expected to increase to 234 million by 2025 reaching 357 million by 2050 on the basis of UN medium variant projection (assuming to drop from total fertility rate (TFR) of 5 children per woman to 2.1 during the next 25 years). This buildup of massive population momentum will place immense pressure on agriculture resource base calling for substantial increase in food production. There will be no option except to import food, if increases in demographic and socio-economic demands and related constraints are not matched by an adequate increase in productivity through land. ----------------------------------------------------------------------------------------------------------- *Sindh Agriculture University, Tando Jam Worldwide arable land is already less than 0.2 ha per capita at present, and is expected to further shrink to 0.15 in 2050. Situation is extremely alarming in Pakistan, where per capita land availability has progressively declined to 0.15 ha at present, shrinking further to 0.06 ha by 2050. Similarly, the per capita water availability has dropped from 5600 cu meters to 1200 cu meters, which could slip further to the water-deficient level below 1000 cu meters per year by 2010 onwards.
Therefore, we must possess the potential and the ability to meet growing demands for food, for which the planning in the past, had been half hearted, erratic and uncertain. The greatest challenge lying ahead for all of us is to increase food and fiber production while maintaining the ecosystem stability and rehabilitation of the environment. The issues and challenges in this regard are to be overcome in such a manner, so that, everyone can be adequately and nutritiously fed without over-exploiting the Earth’s resources.
This is more so necessary in the light of Agriculture Scenario in Pakistan in the past half century during which we have only witnessed stagnation instead of expansion and environmental degradation instead of upgradation. This had further been aggravated due to inadequate resource allocation to the sector commensurating to its contribution in G.D.P. (Gross Domestic Products) further jeoperdising R&D efforts in the sector to keep pace with time and the needs which happen to be emergent in nature.
It is projected now, however, that almost all future increases in food production will be through increase in yield (output per unit land area / or animals per unit time) and from growing additional crops during a given year on the same land. There are really, no other viable options. This underscores in a dramatic way, the importance of science and new technologies for meeting future national and global food needs. Environment issues will become more challenging as more land, water, fertilizers and pesticides are diverted to food production to attain higher productivity. New technologies will accentuate for the use of more, not less, inputs and chemicals (fertilizer, pesticides) to increase food production. This is going to happen as population continues to increase and demands continue to inflate.
As a matter of fact, due to shrinkage in arable land and intense cultivation, many societal global problems have emerged relating to agricultural sustainability and food security. These include poverty, malnutrition, inflation, unemployment, loss of soil fertility, soil erosion, deforestation, desertification, firewood shortages, toxic chemicals in our environment, changing climate impacts, and agricultural production stability. These problems strongly suggest for developing world including Pakistan to reassess the human needs and seek technologies that will result in stable production through higher yields. These challenges therefore must be seriously addressed to their accomplishment in a sustainable manner. Sustainable agriculture biodiversity, including that of plants and animals, and natural resources, requires that their ownership and control lie with decentralized agricultural communities to generate livelihoods, provide food and conserve the environment and the ecosystem. These three dimensions i.e., ecological security, livelihood security and food security must be the essential elements of a national agriculture policy and development programs, which must be launched and embarked upon in a focused manner not only to overcome issues mentioned above but also through utilizing the technical expertise to surmount the challenges lying ahead, which are:
a) The Gene Revolution
The past two decades have seen dramatic advances, in understanding of how, biological organisms function at the molecular level, as well as in our ability to analyse, understand, and manipulate DNA molecules, and the biological material, from which the genes in all organisms are made. The entire process has been accelerated by the Human Genome Project, which has contributed substantially into the development of new technologies, for working with human genes. The same technologies are directly applicable to all other organisms, including plants and animals. Thus, a new scientific discipline of genomics has arisen. This discipline has contributed to powerful new approaches in agriculture and medicine, and has helped to promote the biotechnology industry. Genomics is being followed by the science of proteomics, which is likely to provide exciting insights into the working of the cell. The future increased needs in agriculture productivity could only be envisaged through genetic manipulation in crops, fruits and vegetables.
b) The Ecotechnology Revolution
Knowledge is a continuum. There is much to learn from the past, in terms of the ecological and social sustainability of technologies. At the same time, new developments have opened up new opportunities for developing technologies, which can lead to high productivity, without adverse impact on the natural resources base. Blending traditional and frontier technologies, leads to the birth of ecotechnologies, with combined strength in economics, ecology, equity, employment and energy.
c) The Yield Revolution
Productivity improvement will be possible only, if, greater attention is paid, to improving the efficiency of input use, particularly nutrients and water. To cite just one example, cotton yields in Pakistan are less than 20 percent of the yields, achieved in several other countries like Egypt and USA. To bridge the gap between actual and potential yields, prevailing at the currently available levels of technology, a multidisciplinary constraint analysis will have to be undertaken in different regions and farming systems. In the short term, the highest priority should go to utilizing the untapped production reservoir, existing at current levels of technology. In the longer term, the prospects for improving yields further without associated ecological harm, will have to be explored.
d) Sustainable Agriculture and Technological Advancement:
Sustainable development is the management and conservation of the natural resource base, and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. Such sustainable development (in the agricultural livestock, fishery and forestry sectors) which concerns land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable.
Sustainability concerns have occupied a place on the global agenda, with publication of the International Union for the Conservation of Nature’s (IUCN) World Conservation Strategy and the Brundtland Commission’s report “Our Common Future”. Though visions of sustainability vary across regions and circumstances, a broad international consensus has emerged that its goals should be to foster a transition toward development paths to meet human needs while preserving the Earth’s life support systems and alleviating hunger and poverty integrating the three pillars, namely environmental, social and economic sustainability.
Reckless exploitation of natural resources to push up agricultural growth in the past, has put severe pressure on the resource base of several developing countries. Improvement in the household food security may not be possible without ensuring a sustainable agriculture through the blend of conservation of the resource base and induction of new technological breakthroughs by harnessing biotechnological approaches in agriculture.
Science in its diverse forms has much to offer by way of solutions, to finding escape routes from poverty and answer questions of resource sustenance, through sustainable agriculture and technological advancement. Therefore, the need for policy makers to come to grips with these issues, cannot be overstated. Biotechnology has matured to the stage of generating products of commercial significance. The acceptance of these technologies, however, depend upon many factors, which are beyond the realm of science. There is a general agreement that biotechnology offers many advantages both through productivity increase as well as, through improvement in the quality of agricultural products. Serious reservations, however, persist about health and environmental implications of large-scale application of biotechnology. It is important that these concerns are adequately addressed to.
Despite the fact that population pressure will demand increased supply of food, agriculture and biotechnology research offers the best solution. For developing the technologies it is essential to harvest advantages of genetic engineering, stem cell propagation and tissue culture etc. However, it is yet to be certain if the products of its application will find consumer acceptability. Therefore, there is need for discussions and demystifying the technology. A decision relating to the acceptance of technology should be based on the balance sheet of risks versus benefits. However, the risks if associated, including the perceived ones, need to be evaluated in the aftermath of overall national needs and interests.
Another important concern relates to the ecology and environment. Increasing emphasis on environmental protection, as a policy objective, has a bearing on the structure of agricultural production. So, the agriculture development plans, need to be synchronized to the agro-ecological systems, in different regions of country, keeping in view, the peculiarities of situations. But, it is also a fact and be kept in mind that the modern technologies will continue to affect agriculture-environment interface. The future development strategies must therefore, simultaneously address the economic objectives, the social concerns and ecological restraints warranting a partnership approach amongst various stakeholders i.e. farmers, economists, scientists and government in the sphere of technical change. The precision technology has potential to make a major contribution to agricultural production without influencing the environment negatively.
e) Liberalized Trade Regime
Liberalized agriculture trade is the issue of potential concern, that agriculture sector is faced with these days. Along with the technical breakthroughs, agriculture has witnessed significant institutional changes. The most important among these is the liberalized agricultural trade regime characterized by the Agreement on Agriculture (AoA) under the World Trade Organization. The Agreement on Agriculture is seen by many to enhance welfare gains of the partner countries. There are skeptics, however, who not only question the volume of gains but also raise serious concerns on the distribution of gains from the perspective of the developing countries. One may objectively argue that the implications of AoA have not been fully comprehended by the developing countries in their rush to sign the agreement. An important question is whether a rushed agricultural trade liberalization will really help the developing countries? Any developing economy can go down the hill from a fairly reasonable state of growth situation to a situation of ever rising imports of foodgrain. This, in turn, would also have a significant dampening effect on agriculture productivity, employment and social stability.
f) Societal Characteristics, Inequities and Food Security:
It is now widely accepted that poverty is currently the principal root cause of food insecurity at the level of households. Food security at the level of each individual is hence, important. UNDP’s Human Development Report for the year 2000, titled “Human Rights and Human Development” chronicles the different kinds of inequities prevalent in contemporary societies. The report points out that “poverty limits human freedoms and deprives a person of dignity”. The Vienna Declaration, adopted at the 1993 World Conference on Human Rights, also affirms that “extreme poverty and social exclusion constitute a violation of human dignity”. The report stresses that expanding human capabilities and securing human rights can empower poor people to escape poverty. It is clear that the poor in this country are poor only, because, they have no access to the resources. Hence, the basic approach to poverty eradication has to be asset building and human development.
Food Security is another issue that we are confronted within the perspective of the population growth trends in Pakistan. Therefore, adequate food availability is fundamental to human health needs. The demand for plant and animal food is determined by multiple factors. Amongst them are, the population size, rate of change in per capita income, process of urbanization, changes in dietary patterns and changes in income generation.
Since land and water will be shrinking resources for agriculture, there is no option in the future except to produce more food and other agricultural commodities from less per capita arable land and irrigation water. In other words, the need for more food has to be met, through higher yields per units of land, water, energy and time. It would therefore be useful to examine, how science can be mobilized for raising further, the ceiling to biological productivity without associated ecological harm.
Keeping in view the exponential increase in human population and their food needs in the coming years, it is to be decided what kind of planning is needed to be done? It will surely be within the framework of human needs, that agriculture and animal production systems will perform, over the coming decades.
When we talk about our agricultural resource base, we are talking about severe and growing problems. Our annual top soil loss is increasing and water may soon outrank land as a major constraint to Pakistan food production. The finiteness of our land and water resources; the impact of overuse and erosion of our lands, the increasing pressures of our people for more mouths to be fed, but also in their growing demands for the use of land and water resources will affect our agricultural production capacity.
The projected annual increases in food production in the coming decades to meet our domestic needs are 3-4%. Expanded crop areas or higher production per unit land area per unit time are the only sources for the achievement of 3-4% increase in production. The only way to obtain these increases could be from intensification of landuse for higher yields and increase in the number of crops produced per year. To do this, one must consider the resource inputs (land, water, energy, fertilizer, pesticides, human labour, machinery), their costs, availability and renewability.
g) Global Warming and Glaciers Meltdown in Himalayas
Global warming is defined as “the increase in average temperatures on the earth caused by the greenhouse effect, through gas emissions due to extensive use of fossil fuels as a principal contributor to pollution leading to change in climate”.
United Nations Framework Convention on Climate Change (UNFCCC) has predicted that humanity’s emissions of carbon dioxide and other greenhouse gases will raise global average temperature by 1.4-5.8oC (2.5-10.4oF) by the end of the century which will affect weather patterns, water resources, the cycling of seasons, ecosystems and extreme climate events.
Temperatures in the Himalayan region have increased by more than 1oC recently and are set to rise by a further 1.2oC by 2050, and by 3oC by the end of the century. This heating has already caused 24 of Bhutan’s glacial lakes to reach ‘potentially dangerous’ status. The conditions are not different in Nepal. Similar is the situation in northern mountains of our beloved country in Himalayan, Hindu-kush and Karakorum ranges.
Future disasters around the Himalayas will include ‘floods, droughts, land erosion, loss of biodiversity and changes in rainfall and the monsoon’. The roof of the world is changing, as can be seen by Nepal’s Khumbu glacier. Which has retreated three miles since 1953. Almost 95 percent of Himalayan glaciers are also shrinking---and that kind of ice loss has profound implications not just for Nepal and Bhutan, but for surrounding nations, including China, India, and Pakistan. Eventually, the Himalayan glaciers will shrink so much that their melt waters will dry up. At the same time, rivers fed by these melted glaciers---such as the Indus, Yellow and Mekong---will turn to trickles. Drinking and irrigation water will disappear. Hundreds of millions of people will be affected. There is a short-term danger of flooding too much water as coming out of the Himalayas and a greater long-term danger of their not being enough in years to come, leading to loss of agriculture, productivity, starvation and increased poverty etc. It is therefore, mandatory for all in the region to plan for future and embark upon execution of options available to us.
h) Environmental Degradation & Wetland Rehabilitation:
Another problem that is of specific concern to the agriculture and human health pertains to environmental degradation through global warming, unabated waste and industrial effluents particularly in rivers, canals and wetlands, which may be lead to environmental disaster in years to come, particularly in developing countries. Wetlands have been defined as “areas of marsh, fen, wetlands or water, whether natural or artificial, permanent or temporary with water static or flowing, fresh, brackish or salt-laden including areas of marine water, the depth of which at low tide does not exceed six meters”.
Wetlands in Sindh are undergoing a process of decline and degradation primarily due to population pressure, industrial/ domestic pollution, pesticides runoff and lack of awareness about the wetlands. A major threat to wetlands has been ignorance of the ecological services provided by them. Due to wetland’s importance on productive ecosystem, serious steps need to be taken with special emphasis to the potential of their conservation, productivity, and the extent of degradation. There is need to address the factors for conservation vis-à-vis degradation of wetlands with respect to the biodiversity, water quality, and aquatic ecosystem.
The agro-industrial toxic waste and the so called anthropogenic effluent drained through the freshwater canals discharge into wetlands has severely damaged the food chain. The toxic waste is hazardous not only to the wild birds, but, to the whole biodiversity of wetlands, which include fish, turtles, and other aquatic life. The fish from these heavily polluted wetlands is netted in large quantities and sold in the markets without testing and residue analysis of bio-accumulated pollutants present inside cells and tissues of fish exposing the consumers to health hazards. Similar conditions prevail for domestic livestock (grazing and drinking polluted water) and the fishing communities inhabiting the area (consuming unhygienic water, fish, birds and aquatic plant foods).
Degradation of environment will also result due to use of new technologies which will call for increased use of chemicals (fertilizer, pesticides) to increase food production. Toxic chemicals in the environment (many of them pesticides and fertilizers) have been declared environmental threats and hazards to human health and well-being. Debates will continue on issues of food safety, deleterious effects on fish and wildlife, endangered species and caracinogenicity. It has not yet been clarified by anyone, as to what an environmentally sustainable set of agricultural production technologies might be?
In the light of given perspective, it is anticipated that demands on the use of natural resource base will almost surely increase in ways we cannot even imagine today. In a finite, interdependent, and rapidly changing world, the maintenance of strong food, fiber, and forest production systems and the protection and wise use of our natural resources is on the anvil. The interdependency of agricultural production practices with conservation of land and water systems has now linked farmers with environmentalists. Food safety concerns and ground water contamination are changing contemporary thinking about food and fiber production with the balance of nature. Genetic engineering, biotechnology, alternative practices, and sustainable rural development are simultaneously linked with global climate change, acid rain, ground water contamination and extinction of species.
References 1.
Aquaculture And Integrated Farming System Prof. Dr. Bashir Ahmed Sheikh and Dr. Saghir Ahmed Sheikh
Fisheries are destined to play an important role in human nutrition but it is becoming a luxury food in some of the countries. Utilization of grain and animal protein as feed for aquaculture may not be economical as it might reduce the food availability for human consumption. The world’s energy and food crises are redirecting the attention to an intelligent and wiser use of all resources and integrated fish farming offers a solution to the problem.
Integrated Fish Farming may be defined as the association of two or more normally separate farming systems which become part of the whole farming system. The major features of this system include recycling of waste or by-product in which the waste of one system becomes the input of other system, and efficient utilization of farm space for multiple production.
Integrated livestock-fish, poultry-fish, and rice-fish farming and crop rotation in fish ponds have been well developed and practiced in countries like China, Hungary, Germany and Malaysia. The freshwater aquaculture in Pakistan and more so in Sindh, has been largely organic-based. The inputs for it derived are from activities of agriculture and animal husbandry with plants and animal residues forming the major component of feeds and fertilizers in crop polyculture. Small - scale farmers in this part of the world, have sustained themselves by practicing different kinds of crop diversification for centuries. About 70% of Pakistan’s population live in rural areas at subsistence or near subsistence level. The rural folk in the region are greatly under-nourished and need not only a large supplement of animal protein in their diet but also new sources of gainful employment. Pakistan being an agrarian economy, produces large quantities of plant and animal residues. It is known that the country supports the large bovine population of over 59.3 million cattle heads along with 79.4 million sheep and goats 357.8 million poultry and other livestock. Activities like goat production and rabbitry, poultry, etc. apart from providing for diversification of farming systems, also provide huge quantities of organic material, that may become resources in the aquaculture system. The agro-based industries like distilleries and food processing plants also produce the different kind of waste that could be recycled to aquaculture apart from the well known resource-the domestic sewage.
Ecosystem of Integrated Fish Farming is characterized by Trapping of solar energy and production of organic matter by primary producers, Utilization of primary producers by phagotrophs or tertiary consumers, Decomposition of primary producers and phagotrophs by saprotrophs or osmotrophs, Release of nutrients for producers. Apart from above, the food chain within the ecosystem also thrives and subsists on animal waste which gets access through feed, autotrophic production and heterotrophic production i.e. certain bottom feeders like Cyprinus carpio and Cirrhinus mrigala directly utilize the organic particles from feed which are generally coated with bacteria along with other material, where as some of the decomposed protein of waste products provides nutrients for the micro-flora (autotrophs), while non-mineralised protein provides food base for bacteria and protozoa (heterotrophs). Temperature, light, micro and macroflora, inorganic nutrients, carbon, phosphorous and nitrogen are the basic inputs required for photosynthesis process. However, the micro fauna (zooplankton) feed on small manure particles coated with bacteria. In the process, bacteria are digested while rest is excreted. In this heterotrophic production system micro fauna (protozoans and zooplanktons) are produced finally shortening food chain. This system of production is not linked with the process of photosynthesis.
Integrated fish farming system utilize the waste of live stock, poultry and agriculture by-products for fish production. About 40-50 kg of organic manure can produce 1 kg of fish. Fish farms having an integration with mulberry cultivation, sericulture and silk extraction from cocoons allow the pupae to be utilized as fish feed and the worm faeces and wastewater from the processing factory to be used as pond fertilizers. Pond silt can be used as fertilizer for fodder crops which in turn can be used to raise live-stock and poultry or as fish feed. Thus a recycling of waste is done in integrated fish farming system.
The scope of integration in a fish farm in considerably wide. Ducks and geese may be raised on the pond. The pond dykes may be used for fruit plants and mulberry cultivation or for raising goats, cattle, and dyke slopes for fodder production. From integrated fish farming systems not only fish but meat, milk eggs, fruits, vegetables, mushrooms etc. can be obtained. This system fully utilizes the water body, the water surface, the land, and the pond silt to increase food production for human consumption. The integrated fish farming system holds great promise and potential for augmenting production, improvement in rural economy, generation of employment leading to poverty alleviation.
Integrated Aquaculture System is not merely a fish culture but it is essentially a blend of variety of fishes with crops, horticulture, livestock, poultry, birds etc. The system may have an integration such as rice and fish, fish and prawn, horticulture and fish, duck and fish, fish and livestock, rabbit and fish, goat and fish, poultry and fish and so on so forth. The features of such integration may however vary and the output is always associated its management and utilization of inputs and resources.
Rice-Fish System
Rice is the dominant cereal crop in Asia. It is the staple food of over 1.6 billion people in the world, mostly in Asia where 90% of all rice is grown and eaten. For most rural farmers, this single crop is virtually their sole livelihood. The practice of collecting wild, naturally occurring fish for food rice field is probably as old as rice cultivation itself.
The reason for decline in rice-fish culture has been the introduction of various insecticides, which are harmful to fish. Rice-fish culture plays an important role in rural economy of Asian countries. This is because fish culture lends itself well to small labour intensive farming operations. It can be used in conjunction with rice cultivation to increase productivity. Rice fields from the natural habitat for a larger variety of indigenous species of fish which gain entry only from the nearby perennial water bodies. The fishes feed and grow on natural food available and the farmers usually collect the fish during rice growing season and / or when the water level subsides.
Scientific rice-fish systems can ensure higher productivity, farm income and employment in these areas.
Fish and Prawn
Catla, rohu, mrigal and common carp in combination with freshwater giant prawn are stocked in equal proportions @ 10,000 individual / ha. These are fed with rice bran and mustard groundnut oil cake @ 2-3% of the total body weight. Manuring schedule includes application of cow manure at 10 t/ha/yr, while liming is done @ 200 to 500 kg/ha. These are harvested periodically along with receding water levels.
Horticulture on the Dykes
After the harvest of rice certain crops which require lesser amount of water like water melon, groundnut, vegetables, cow pea, etc. can be grown. Top of the bund which is 10% of the pond area is utilized for growing vegetables and fruit bearing plants.
Rice-fish system results in 168% intensity of cropping in field and 400% on bunds as compared to 52% in the case of traditional monocropping of rice. Rice-fish system provides a net annual income of around Rs. 30,000/ha in the first year which accounts for about twelve folds income over farmer’s traditional practices and three folds over the improved monocropped rice.
This system encourages synergism between rice and fish leading to increase in grain yield by 5-15% and straw yield by 5-9%. It facilities crop diversification, there by reducing investment risk. It promotes gainful linkage between rice, fish, prawn, vegetables, fruit crops and other resulting in better resource utilization as well as conservation of the ecosystem. It generates year-round employment in the farm.
Horticulture-fish system
Ponds are well situated for growing horticultural plants. The top, inner and outer dykes of ponds as well as adjoining areas can be best utilized for horticulture crops. These crops are fertilized by the pond silt and fertile pond water is used for watering. The success of the system depends on the selection of plants, which should be Dwarf variety, Less shady, Evergreen, Seasonal, and Highly remunerative.
Dwarf variety of fruit bearing plants like mango, banana, papaya, lime can be grown around the pond. This will not obstruct the sunlight to the water bodies and also the pond will be free of dry leaves. Ginger, turmeric, chilly can be grown as intercrops. Ponds dykes are used for growing vegetables solo as well as intercrops. During summer season, brinjal, tomato, chilli, gourds, cucumber, melons, ladies finger is cultivated while during winter peas, beans, cabbage, cauliflower, carrot, beet, radish, turnip, spinach, etc, is raised. Pond slit and pond water is used for providing nutrient for these crops.
Flower bearing plants like tuberose, rose, jasmine, gladiolus, marigold, cassandea, chrysanthemum are grown on the pond dykes. These flowers have tremendous market potential in the cities which provides additional employment to the farmers.
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