Environmental Articles Archive: Sustainability/ Land use
Web version prepared by BCAS
June, 2008

Lives, environment, ecology at risk as illegal hill cutting still rampant 
in Khagrachhari

Unabated hill cutting in eight upazilas under Khagrachhari district is posing serious threat to lives, natural environment and biodiversity of the hill district. 

A scene of hill cutting by a government organisation at Bogirathpara in Dighinala upazila in Khagrachhari district. 

As hill cutting continues in the name of development work, houses and business centres are being made ignoring existing environmental laws and defying ban by Department of Environment (DoE).

At least 50 thousand people in hill district Khagrachhari are facing threat of hill slides at the onset of the rains as they built their houses, business centres and other development structure cutting the natural hill and without any environment friendly plan, sources said.

Divisional Forest Office (DFO) and District Agriculture Extension Office (DAEO) sources said, despite a government ban, illegal hill cutting continues unabated in different parts of hill district Khagrachhari posing serious threat to lives, natural environment and biodiversity of the hill districts. Taking illegal help from government officials groups of influential people including a section of dishonest businessmen are involved in illegal hill cutting, sources said. 

In Khagrachhari, hill cutting is a common sight at Shalban, Comilla Tila, Sabujbag, Panchmile area, Zia Naghor, Boghiroth Para, Rashiknagor, Jamtali, Maischhari, Maidda Karallachhari, Bichitala, Kengalchhari, Tongthakpara, Khagrapur, Kamalchhari, Bhuachhari, Golabari, Laxmichhari, Ramghor, Matiranga, Khagrachhari College Para area, Tetultala and No-1 Kadamtali area.

Several government establishments are now dangerously exposed to collapse during the rainy season due to the hill cutting. 

Local environmental activists and journalists filed several general diaries with police stations in Khagrachhari hill district in regard to hill cutting. But the administration is taking minor initiative to protect the hills from depletion.

Bangladesh Environmental Lawyers Association (Bela) issued legal notice to secretaries of three ministries for taking immediate actions against the plunderers of hills in last year, sources said. The ministries are environment and forest, land and public works. 

In last year, Bela also issued notice to divisional commissioner of Chittagong, deputy commissioner of Khagrachhari, environment departments in Dhaka and Chittagong, SP of Khagrachhari and UNO of Dighinala upazilla in this regard.

In Khagrachhari hill district, this syndicate employs a number of day labourers in hill cutting in different areas in the districts paying Tk 150 to 200 per day as wages. Plunders always cutting hill which created bad impact for the environment, It damaged property, lives, filled up river, canals, create flash flood in the areas, said Abu Daud Muhammad, Member Secretary of local organisation 'Parivesh Surokkha Andolon'.

Chenghi and Mainee rivers in the district have become filthy due to hill erosion, local journalist and environment worker Omar Faruk Shamim said. “We have recently submitted a proposal to district administration to save water bodies and hills,” he said.

The unscrupulous businessmen supply hilly soil to fill up canals and low lands for constructing houses and markets in the districts and as well as Chittagong city and its adjacent areas, said Mohammad Khalilur Rahman, secretary of Parivesh Andolon Forum. 

"Soil supply has become a profitable business among the hill cutters as they need only a little investment for a huge profit. A truck of hilly soil is sold at Tk 700-1000, said Tazul Islam, a truck driver from Bazar area under Sadar upazila in Khagrachhari district. 

Hill cutting causes landslides in rainy season in eight upazilas in Khagrachhari hill district which decreasing soil fertility and damaging life and property in the districts, said Khagrachhari Additional Deputy Commissioner Masud Ahmed. 

Divisional Forest Officer Ali Kabir said, many hilly areas are facing an unexpected danger, at any time any accident would might happened causing harm for people and properties. An integrated approach is necessary for saving environment of natural hilly areas, he said. 

When contacted, Deputy Commissioner Mohammad Shahdat Hossen said he has taken many initiatives to save hills. He has already formed a six-member committee to survey actually how many people are vulnerable in the district. His officials filed at least 21 cases against hill plunders and four people are in jail now, he said.

“I have sent show cause notice to many people including government organisation Roads and Highways Department to explain why they have been cutting hill without permission from Department of Environment.

Source: The Daily Star, June 17, 2008

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Our threatened environment
Delowar Hossain

The main components of the earth's system for living beings are atmosphere, soil and water. If any of these is polluted, the lives of the earth's will be hampered. It is a matter of sorrow that these elements are being changed by different uncontrolled human activities. But we are always busy to develop our life style without thinking about health of the earth. The atmosphere is a thick blanket of gases containing suspended, liquid and solid particles which completely involves the earth and together with they form an integrated environmental system. As part of this system, air performs several functions which have allowed mankind to survived and developed almost any where on the earth's surface. First, it provides and maintains the supply of oxygen required for life itself. Second, it controls the earth's energy budget through such elements as the ozone layer and the green house effect, and by means of internal circulation distributes heat and moisture across the earth's surface. Third, it has the capacity to dispose of waste material or pollutants generated by natural or human activities. Society or human activity has interfered with all of these elements and through ignorance of the mechanisms involved or lack of concern or the consequences of its action has created or intensified the problems which are now causing concern on a global scale. Though air itself is not a specify gaseous element rather it is a mixture of individual gases, each of which retains its particular properties. 99% of the mass of atmosphere lies within 30km of the earth's surface and 50% is concentrated in the lowers of 5km. Most of the world's weather develops in these lower layers. The average gaseous composition of dry air in the atmosphere is nitrogen(78.08%), oxygen20.95%), argon(0.93%), carbon-di-oxide (0.0345%), neon(0.0018%), helium (0.00052%), methane 0.00014%), krypton (0.00010%), hydrogen (0.00005%), xenon (0.000009%), ozone(variable). Two gases Nitrogen and Oxygen account for 99% of total by volume. Oxygen 20.95% by volume particulates readily in chemical reaction and provides one of the necessities of life. It is also capable of absorbing solar radiations. In contrast, Nitrogen is basically inert, seldom becoming directly involved in atmospheric chemical or biological process except under extra ordinary circumstances. During thunderstorm, for example, the enormous energy flow in a lighting stroke may cause Nitrogen to combine with Oxygen to produce oxides of Nitrogen. On a less spectacular but ultimately more important level certain soil bacteria such as Clostridium, Azobacter -along with those fund in the foot nodules of leguminous plants (e.g. bean) are capable of fixing the atmospheric Nitrogen essential for the creation of the complex Nitrogen compounds found in all forms of life on earth. Carbon dioxide, minor gases, has a most important role in the atmosphere in the environmental process. Yet it makes a significant contribution to the heating of the atmosphere and is a major participant in the process of photosynthesis by which sugars, starches and other complex organic compounds are produced in plants.

The atmosphere is quite selective in its response to solar radiation. It is transparent to high energy short-wave radiation, such as that from the sun. But particularly opaque to lower energy long-wave radiation. For example a major proportion of the radiation in the visible ranges of the spectrum between 0.3 and .07 micrometer is transmitted through the surface without losing its high energy content. Once it arrives, it is absorbed the surface heats up and begins to emit terrestrial long wave radiation back into atmosphere.

This radiation from the infrared end of the spectrum with wavelengths between 1-3 micrometer captured and the temperature of the atmosphere rises. The capture of the outgoing terrestrial radiation is affected largely by water vapour and carbon-di-oxide along with methane and traces of about twenty other gases which together are called greenhouse gases. The whole process was lebelled the green house effect since the gases by trapping the heat appeared to work in much the same way the glass in green house. Since the green house effect depends on carnon-di-oxide and the other gases in the atmosphere, it follows that any change in these gases including their relative concentration will have an effect the intensify of greenhouse effect, since the middle of nineteenth century human activities have had a major role in increasing the intensity of the greenhouse effect through the production of higher volumes of carbon-di-oxide, methane and a number of other greenhouse gases. 

There are many other gases which from time to time become constituent to the atmosphere. These include sulphur-di-oxide, oxides of nitrogen, hydrogen-sulphide and carbon-monoxide along with a variety of more exotic hydrocarbons which even in small quantities can be harmful to the environment. These gases releases to the atmosphere, as a result of biological activities created during volcanic eruption of by natural wood or grassfires. Increasingly however, their presence is associated with pollution from industrial or vehicular sources. Anthropogenically produced, acid rain commonly max time more acid than is natural conterpart. The creation of acid rain would not be possible without water, another of the major natural constituent of the atmosphere. Water is unique among the constituents of the atmosphere in that it is capable of existing as solid, liquid or gaseous and of changing readily from one state to another. 

Water is integral part of many global environmental issues such as drought, desertification and acid rain. Water is also involved in the earth's energy budget through its ability to absorb and reflect radiation.

In addition to the gaseous components of the atmosphere and the water in its various forms are also solid or liquid particles dispersed in the air. These are called aerosols and include dusts, soot, salt crystals, spores, bacteria, viruses and a variety of other microscopic particles; collectively they are often regarded as equivalent to air pollution. Although many of the material involved are produced naturally by volcanic activity forest and grass fires, evaporation, local atmospheric turbulence and biological process. The proportion of particulate matters in the atmosphere has increased from time to time in the past. Some times, dramatically, but in most cases the atmosphere building in cleansing mechanisms were able to react to the changes and the overall impact was limited in extent and duration. When the island of atmosphere Krakatoa exploded in 1883, for example, it threw several cubic kilometers of volcanic dust into the atmosphere. Almost all of it is thought to have returned to the earth's surface in less than five years as a result of particles coagulation dry sedimentation and wash put by precipitation (Ponte 1976) 

The earth intercepts only a small proportion of the total energy given put by the sun perhaps as little as one five-billionth and not all of that reaches the earth's surface. Generally accepted that only about 50% of the solar radiation arriving at the outer edge of the atmosphere is absorbed at the surface of other 50% , some 30% returns to space as a result of reflection from the land and sea reflection from clouds or scattering y atmospheric aerosols . this 30%of incoming radiation bounced back unaltered into space is a measure of the earth's reflectivity or albedo. The remaining 20% of the original incoming radiation is absorbed mainly by oxygen ozone and water vapour in the atmosphere. Thus of every 100 units of solar energy arriving at the outer edge of the atmosphere 70are absorbed into the earth/atmosphere system and 30 are returned to space having made no contribution to the system most of the 50 units absorbed by the earth are reradiated as long-wave terrestrial radiation. Some energy is also transferred into the atmosphere by connective and evaporative processes at the earth's surface. The greenhouse gases trap the bulk of the outgoing terrestrial energy but the atmosphere is transparent to wavelengths between 8micrometer and d11 micrometer and this allows 5 units of radiation to escape directly to space through the so-called atmospheric window. The depletion of the ozone layer resulting from human interference disturbs the balance by allowing additional radiation to teach the surface and changes in atmospheric turbidity disrupt both incoming and outgoing radiation. In the immediate future however the greatest change in radiative forcing is expected to come about as a result of the rising levels o greenhouse gases. It is estimated that their effect on the radiative balance of the earth will be greater than that of caused by any other radiative forcing agent, natural or anthropogenic. So atmosphere is the very important component to our living place that plays important roles to balance our environmental effects. If this component lost its balancing capacity the environment will be harmful for us.

Source: The New Nation, June 18, 2008

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545 acres of arable land lost a day
Speakers tell view exchange meeting

Speakers at a view exchange meeting yesterday said that within 2088 there would be no cultivable land in Bangladesh if the present rate of conversion of farmlands into non-cultivable ones remains so. 

They urged the policymakers to adopt a master plan for using the land of the country for cultivation to achieve food security. 

The view exchange meeting on 'Recovering farm land, stopping non-farming use of farmlands and national food security' was organised by Forward Party at the Jatiya Press Club in the city.

Hanif Mahmud, a former researcher of Grameen Bank, in a paper said the available government statistics say that everyday the country loses about 545 acres of cultivable land and if the rate continues then there would be no cultivable land within the next 77 years.

He in his paper recommended imposing strict laws on using lands and creating awareness among the people to this end. Hanif also suggested not building houses, industries, educational or religious institutions in farmlands and creating environment-friendly housing system to accommodate more people in a fewer space.

In the paper Hanif said in 1974, 66 per cent of the total lands of the country were farmlands but in 1996 that was reduced to 59 per cent and now the figure is even lower. Forward Party Member Secretary Abdul Munim said the country needs unity to ensure self-sufficiency in food.

He also urged the political parties to focus on agriculture to achieve food security and invest more on agriculture, recover grabbed farmlands, stop conversion of farmlands into non-farming lands and bring reforms in land management. 

ABM Mostafa Amin, convener of Forward Party, presided over the meeting that was also attended by agriculture experts and party leaders.

Source: The Daily Star, June 23, 2008

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History of dam failures

A few case histories of dam failures in India and in USA are described briefly below. The details regarding other failures are reported by Mahesh Kumar (1992) and Singh. Kaddam Project Dam, Andhra Pradesh, India Built in Adilabad, Andhra in 1957 - 58, the dam was a composite structure, earth fill and/or rock fill and gravity dam. It was 30.78 m high and 3.28 m wide at its crest. The storage at full was 1.366 108 m3. The observed floods were 1.47 104 m3/s. The dam was overtopped by 46 cm of water above the crest, inspite of a free board allowance of 2.4 m that was provided, causing a major breach of 137.2 m wide that occurred on the left bank. Two more breaches developed on the right section of the dam. The dam failed in August 1958. Kaila Dam, Gujarat, India The Kaila Dam in Kachch, Gujarat, India was constructed during 1952 - 55 as an earth fill dam with a height of 23.08 m above the river bed and a crest length of 213.36 m. The storage of full reservoir level was 13.98 million m3. 

The foundation was made of shale. The spillway was of ogee shaped and ungated. The depth of cutoff was 3.21 m below the river bed. Inspite of a freeboard allowance of 1.83 m at the normal reservoir level and 3.96 m at the maximum reservoir level the energy dissipation devices first failed and later the embankment collapsed due to the weak foundation bed in 1959. Kodaganar Dam, Tamil Nadu, India This dam in the India, was constructed in 1977 on a tributary of Cauvery River as an earthen dam with regulators, with five vertical lift shutters each 3.05 m wide. The dam was 15.75 m high above the deepest foundation, having a 11.45 m of height above the river bed. The storage at full reservoir level was 12.3 million m3, while the flood capacity was 1275 m3/s. A 2.5 m free board above the maximum water level was provided. The dam failed due to overtopping by flood waters which flowed over the downstream slopes of the embankment and breached the dam along various reaches. There was an earthquake registered during the period of failure although the foundation was strong. The shutters were promptly operated during flood, but the staff could only partially lift the shutters, because of failure of power. 

Although a stand-by generator set was commissioned soon, this could not help and they resorted to manual operation of shutters. Inspite of all efforts, water eventually overtopped the embankment. Water gushed over the rear slopes, as a cascade of water was eroding the slopes. Breaches of length 20 m to 200 m were observed. It appeared as if the entire dam was overtopped and breached. Machhu II (Irrigation Scheme) Dam, Gujarat, India This dam was built near Rajkot in Gujarat, India, on River Machhu in August, 1972, as a composite structure. It consisted of a masonry spillway in river section and earthen embankments on both sides. The embankment had a 6.1 m top width, with slopes 1 V :3 H and 1 V : 2 H respectively for the upstream and downstream slopes and a clay core extending through alluvium to the rocks below. 

The upstream face had a 61 cm small gravel and a 61 cm hand packed riprap. The dam was meant to serve an irrigation scheme. Its, storage capacity of 1.1 108 m3. The dam had a height of 22.56 m above the river bed, a 164.5 m of crest length of overflow section, and a total of 3742 m of crest length for the earth dam. The dam failed on August 1, 1979, because of abnormal floods and inadequate spillway capacity. Consequent overtopping of the embankment caused a loss of 1800 lives. A maximum depth of 6.1 m of water was over the crest and within two hours, the dam failed. While the dam failed at a peak discharge of 7693 m3/s, the figure was revised to 26,650 m3/s after failure, with a free board of 2.45 m given, providing also an auxiliary spillway with a full capacity of 21,471 m3/s. The observed actual flood depth over spillway crest was 4.6 m with an observed 14,168 to 19,835 m3/s, while the design depth over spillway crest was 2.4 m. Nanaksagar Dam, Punjab, India Situated in Punjab in northwestern India, the dam was constructed in 1962 at Bhakra, with a reservoir capacity of 2.1 106 m3. An estimated maximum discharge of 9,711 m3/s had occurred on August 27, 1967, due to heavy monsoon rains that were heaviest in twenty years. 

This caused dam to fail. The water that gushed through the leakage created a 7.6 m breach, which later widened to 45.7 m. The condition of the reservoir had worsened, causing a 16.8 m boil downstream of toe, which was responsible for the settlement of the embankment. As the dam was overtopped, causing a breach 150 m wide. A downstream filter blanket and relief wells were provided near the toe but were insufficient to control the seepage. The relief wells each 50 mm in diameter were spaced at a distance of 15.2 to 30.4 m. Panshet Dam: (Ambi, Maharashtra, India, 1961 - 1961) The Panshet Dam, near Pune in Maharashtra India, was under construction when the dam had failed. It was zoned at a height of 51 m and having an impervious central core outlet gates located in a trench of the left abutment and hoists were not fully installed when floods occurred at the site of construction. The reservoir had a capacity of 2.70 million m3. Between June 18 and July 12, 1961, the recorded rainfall was 1778 mm. The rain caused such a rapid rise of the reservoir water level that the new embankment could not adjust to the new loading condition. The peak flow was estimated at 4870 m3/s . 

Water rose at the rate of 9 m per day initially, which rose up to 24 m in 12 days. Due to incomplete rough outlet surface the flow through was unsteady which caused pressure surges. Cracks were formed along the edges of the right angles to the axis of the dam causing a subsidence of 9 m wide. An estimated 1.4 m of subsidence had occurred in 2.5 hours, leaving the crest of the dam 0.6 m above the reservoir level. Failure was neither due to insufficient spillway capacity nor due to foundation effect. It was attributed to inadequate provision of the outlet facility during emergency. 

This caused collapse of the structure above the outlets. Khadakwasla Dam (Mutha, Maharashtra, India, 1864 - 1961) The Khadkawasla Dam, near Pune in Maharashtra, India was constructed in 1879 as a masonry gravity dam, founded on hard rock. It had a height of 31.25 m above the river bed, with a 8.37 m depth of foundation. Its crest length was 1.471 m and had a free board of 2.74 m. The dam had a flood capacity of 2,775 m3/s and a reservoir of 2.78 * 103 m3. The failure of the dam occurred because of the breach that developed in Panshet Dam, upstream of the Khadkawasla reservoir. The upstream dam released a tremendous volume of water into the downstream reservoir at a time when the Khadkawasla reservoir was already full, with the gates discharging at near full capacity. This caused overtopping of the dam because inflow was much above the design flood. The entire length of the dam spilling 2.7 m of water. Vibration of the structure was reported, as the incoming flood was battering the dam. Failure occurred within four hours of the visiting flood waters. Tigra Dam: (Sank, Madhya Pradesh, India, 1917 - 1917) This was a hand placed masonry (in time mortar) gravity dam of 24 m height, constructed for the purpose of water supply. A depth of 0.85 m of water overtopped the dam over a length of 400 m. This was equivalent to an overflow of 850 m3s-1 (estimated). 

Two major blocks were bodily pushed away. The failure was due to sliding. The dam was reconstructed in 1929. Teton Dam, Teton river canyon, Idaho, USA, NA - 1976 The construction began in April, 1972, and the dam was completed on November 26, 1975. The dam was designed as a zoned earth and gravel fill embankment, having slopes of 3.5 H : 1 V on the upstream and 2 H : 1 V and 3 H : 1 V on the downstream, a height above the bed rock of 126 m, and a 945 m long crest. The dam had a height of 93 m, a crest width of 10.5 m, and had side slopes of 1 V : 3 H on the upstream side and 1 V : 2.5 H on its downstream side. It had a reservoir capacity of 3.08 * 108 m3. The embankment material consisted of clayey silt, sand, and rock fragments taken from excavations and burrow areas of the river's canyon area. It had a compacted central core. Narrow trenches 21 m deep, excavated in rock and compacted with sandy silt and a deep grout curtain beneath a grout cap the central zone were the measures taken to control the foundation seepage. The dam failed on June 5, 1976, releasing 308 million m3 of reservoir water. A flood at an estimated peak discharge in excess of 28,300 m3/s had occurred. The peak outflow discharge at the time of failure was 4.67 * 104 m3/s. A breach 46 m wide at its bottom and 79 m deep had formed. The time of failure was recorded as four hours.

The cause of failure was attributed to piping progressing at a rapid rate through the body of the embankment. The two panels that investigated into the causes of failures were unanimous in agreement that the violence and extent of failure completely removed all direct evidence of the details and sequence of failure. 

However, the main findings suggested that erosion on the underside of the core zone by excessive leakage through and over the grout curtain was the cause of destruction. "Wet seams" of very low density in the left abutment extended into the actual failure area. These caused local deficiencies in the compaction of the fill, and might have been the locus of the initial piping failure. 

Earlier on the day of failure, leaks were observed about 30 m below the top of the dam. After four hours, efforts to fill the holes failed and the dam breached by the noon time. The fundamental cause of failure was regarded as a combination of geological factors and design decisions, which taken together allowed the failure to occur. Numerous open joints in abutment rock and scarcity of more suitable materials for the impervious zone were pointed out by the panel as the main causes for the failure of the dam. Futhermore, complete dependence on deep dry key trenches that developed arch action, cracking and hydraulic fracturing as a measure adopted against seepage and reliance on compacted material for impervious zone were also attributed as possible causes of failure. 

Malpasset Dam An arch dam of height 66 m, with 22 m long crest at its crown. When the collapse occurred, the dam was subjected to a record head of water, which was just about 0.3 m below the highest water level, resulting from 5 days of unprecedented rainfall. The failure occurred as the arch ruptured, as the left abutment gave away. The left abutment moved 2 m horizontally without any notable vertical movement. 

The water marks left by the wave revealed that the release of water was almost at once. The volume of water relieved was 4.94 Mm3 of water. 421 lives were lost and the damage was estimated at 68 million US dollars. Vaiont Dam This is an arch dam, 267 m high. During the test filling of the dam, a land slide of volume 0.765 Mm3 occurred into the reservoir and was not taken note of. During 1963, the entire mountain slide into the reservoir (the volume of the slide being about 238 Mm3, which was slightly more than the reservoir volume itself). 

This material occupied 2 km of reservoir up to a height of about 175 m above reservoir level. This resulted in a overtopping of 101 m high flood wave, which caused a loss of 3,000 lives. 

Baldwin Dam This earthen dam of height 80 m, was constructed for water supply, with its main earthen embankment at northern end of the reservoir, and the five minor ones to cover low lying areas along the perimeter. The failure occurred at the northern embankment portion, adjacent to the spillway (indicated a gradual deterioration of the foundation during the life of the structure) over one of the fault zones. 

The V-shaped breach was 27.5 m deep and 23 m wide. The damages were estimated at 50 million US dollar. Hell Hole Dam The Hell Hole (lower) dam was a rock fill dam of height 125 m, failed during construction, when the rains filled the reservoir to an elevation of 30 m above the clay core. The capacity of this multipurpose reservoir after completion was 2.6 M m3. 

(Source: Waterwatch. History of Dam Failures Prof. B.S. Thandaveswara Indian Institute of Technology Madras)

Source: The New Nation, June 23, 2008

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Land degradation threatens dryland populations

The survival of more than 250 million people living in the drylands of the developing world is being threatened by a chronic problem - land degradation. 

Drylands cover about 41% of the earth's surface. The poor people in the drylands depend mainly on rainfed agriculture and natural rangelands for their survival. Their livelihoods are at risk due to land degradation, which is exacerbated by increasing population growth that is putting considerable pressure on fragile land resources. 

However, science-based innovations can be mobilized to help arrest land degradation. The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) headquartered in Patancheru in southern India, addresses the problem of land degradation through sustainable land management (SLM) techniques.

According to ICRISAT Director General Dr William D Dar, "Investing in SLM to control and prevent land degradation in the wider landscape is an essential and cost-effective way to deliver other global environmental benefits, such as maintenance of biodiversity, mitigation of climate change and protection of international waters".

ICRISAT is the executing agency and coordinator of the Desert Margins Program (DMP) funded by the Global Environment Facility (GEF). DMP is a collaborative initiative among nine sub-Saharan African countries - Botswana, Burkina Faso, Kenya, Mali, Namibia, Niger, Senegal, South Africa and Zimbabwe, which are assisted by five Centers supported by the Consultative Group on International Agricultural Research (CGIAR) and three advanced research institutes. The DMP focuses on better understanding land and biodiversity degradation and finding ways to counter them. 

ICRISAT, jointly with a sister CGIAR Center the International Center for Agricultural Research in the Dry Areas (ICARDA) based in Syria, is catalyzing a global research program called 'Oasis' to intensify the effort against dryland degradation and desertification. Oasis brings the best global science partnerships to bear across Africa, Asia and Latin America.

To address the issue of poor soil fertility, some consider this a greater food-production constraint than drought in semi-arid Africa, ICRISAT has developed a "microdosing" technique that involves the application of small, affordable quantities of fertilizer with the seed at planting time or as a top dressing 3 or 4 weeks after emergence. This enhances fertilizer use efficiency and improves productivity.

The Institute is also testing two market development strategies to address constraints such as difficult access to fertilizer and credit; insufficient flow of information and training to farmers; and inappropriate policies. In West Africa, the 'Warrantage' or inventory credit system aims to resolve the farmers' capital constraint. 

Farmers place part of their harvest in a local storehouse in return for loans, which they use to pay debts and start various income-earning activities to tide over the long dry season. The stored grain is sold later in the year when prices are high, and the farmer is able to repay the loan. ICRISAT has also succeeded in getting private fertilizer companies to sell fertilizers in small packs that smallholder farmers can afford. 

The Institute has partnered with other organizations and has evolved a new consortium watershed management model to control land degradation and improve rural livelihoods. The approach is built on the principle of harnessing the strengths of the consortium partners for the benefit of all the stakeholders, and is based on a holistic systems approach called the Integrated Genetic and Natural Resource Management (IGNRM) strategy.

The Drylands Eco-farm (DEF) is an innovative trees-crops-livestock system for rainfed crop production. Fast-growing, drought tolerant Australian Acacias and a high value tree crop (Zizyphus mauritania) are intercropped with annual crops. It also incorporates principles of crop rotation, mulch application, windbreaks and nitrogen fixing trees. Profits from the DEF are 3-5 times higher than profits from current cropping systems.

The Institute is also undertaking Bioreclamation of Degraded Lands (BDL) project in barren, unproductive soils that are widespread in the West African Sahel. This combines simple effective techniques such as zaï holes, planting-basin cultivation, trenches and land scarification that concentrate limited water and nutrient resources close to the plant roots. 

In addition the planting of high-value crops that restore organic matter and soil texture earn a handsome profit for the poor from fruit and gum trees, hardy leafy vegetables and legumes. 

Besides developing and promoting these techniques to curb land degradation and improve the quality of agricultural soil, ICRISAT is putting great emphasis on strengthening the national capacities in studying climate, soil, vegetation and livestock trends and dynamics, standardization of methodologies to ensure data quality. It is also looking at building effective partnerships with national (NGOs, rural communities and CBOs), regional and international institutions and the private sector. 

(Source: The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)

Source: The New Nation, June 23, 2008

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