Bangladesh is a very small country of 1,47,570 square kilometer area having a population of 130 millions. The country has only 8.29 million hectare (Bangladesh Krishi Diary 2003) cultivable land against the huge population. The land area is gradually decreasing because of population growth, industrialization and other infrastructure development. This results a declining trend of per capita land availability from 0.13 hectare to 0.06 hectare during last few decades (1960 to 2000) . However, agriculture plays a pivotal role in overall economic development of the country, not only in terms of it contribution to GDP( about 20% of the GDP). More than 70% of the population dependents on agriculture. In order to feed the huge population green revolution has emerged in 1960s and priority was given to produce more food in terms of grain through intensification of land usage. It has created a tremendous pressure on limited land resources. New crop variety (HYV) was introduced as well as chemical fertilizers and pesticides, irrigation in the name of modernization. As a result immediate objectives of more grain production have achieved and grain (rice) production has increased by manifold. For a shorter period Bangladesh has achieved so called self sufficiency in food (rice). A suicidal policy of just extraction of soil was followed. A lot of HYVs, Hybrids has introduced that require increased amount of chemicals. Soil fertility conservation issue is totally ignored. As a result, soil is rapidly loosing its fertility. Acreage production is getting downward despite of using high doses of chemical fertilizer and pesticides.
Consequences of green revolution:
After the green revolution, when the technology and the notion of chemical agriculture were introduced, it seems that the gross production of main grain, rice, has increased. It has, however created a large negative impact on rural farmers and the environment. Chemical agriculture is only oriented to economic profit, ecological and social factors are totally ignored. Chemical agriculture is totally anti-natural and destructive. Consequently this agricultural technology creates many problem. Prominent among these are topsoil depletion and degradation, groundwater contamination, the decline of family farms, continued neglect of the living and working conditions for farm laborers, increasing costs of production, and the disintegration of economic and social conditions in rural communities, health hazards due to food degradation and environment (soil, air and water) pollution because of agricultural poisons.
Degradation of soil:
Use of inorganic fertilizer and pesticides without use of any organic fertilizer results lack of organic matter supply which caused a lot of problems to the soil. Soil become hard, water holding capacity reduced, soil pH become imbalance that caused some micro-nutrient deficiency, reduced soil microbial activities resulted less availability of plant nutrients.
Increasing pest problem::
Degraded soil become unhealthy and unhealthy soil grows unhealthy plants. With out considering the root cause use of chemical poisons to destroy the pest and consequently the pest problem is not solved and become worsen.
Food Quality Degradation:
The products grown with excessive chemical fertilizers and pesticides are low in quality. This low food quality become apparent in taste and preserving capacity of the of the products. Chemically grown product have less nutrient content (protein, vitamins and minarets) and higher water content. The high water content may be one of the main reason for lack of taste and low preserving capacity of chemically grown product.
Pollution of Soil, Water, Air and Products:
Use of chemical pesticides results pollution of the environment as they are chemical poison. They are very much effective in killing living things and have long term residual effect (some cases more than 10 years). The poison pollute the product first and then soil, air and water consequently. This pollution results in poisoned product, soil degradation, and the disappearance of fish, birds and other animals.
People experienced health hazards in two ways. Firstly, people eat the poisoned agricultural products and other contaminated food like, meat, milk, fish etc from chemical agricultural production. The poison accumulates in the living body and through the food chain, the poison is condensed and creates different health hazards. The ultimate destination of any chemical poison, wherever it is used, is the human body. Secondly, the chemical pesticides directly affects the farmers who use it. In Bangladesh, most farmers handle pesticides without protection for their bodies and they are usually the most serious victims. The chemicals also produce a health hazard to other living things, especially livestock’s and poultry birds. Now a days, a common accident in the rural area is death of poultry birds and livestock’s which fed on crop residues and grasses.
Disappearance of Local Genetic Resources:
Local varieties are the genetic base for improving seeds and are very important resource for the future. However, local varieties are disappearing each year. The main reason is the introduction of HYV seeds and hybrid seeds. That also accelerate mono-culture and create ecological imbalance in agriculture.
Increase in Production Cost:
Chemical agriculture is mainly dependent on external inputs and production cost increase is unavoidable. There are mainly two reasons. Firstly increase in the quantity of external inputs (both in terms and number and amount). In the beginning of green revolution farmers used to use only urea and about 50 kg per acre. However, at present farmers are using 6 types of chemical fertilizer (Urea, TSP, MP, Gypsum, Zink and Boron and some where Molybdenum). The amount is also manifold higher than the beginning stage. Secondly, the price of chemical fertilizers were also increased rigorously. Following figure shows the increase of Chemical fertilizer during last eight years:
(Information collected from local dealers)
Price increase rate of pesticides is much more higher than the chemical fertilizers during this period. Cost of irrigation has also increased nearly 6 times.
Decreased in yield:
Though farmers increase the quantity of external inputs, they can not get as much production as before. The reason for the decrease in yield is soil degradation. It is obvious that degraded soil never produce good yields.
The increased use and increased price of agricultural inputs (fertilizer, pesticides, irrigation etc) has made the production cost much higher day by day. Meanwhile the price of rice has only doubled in last 25 years. On the other hand, yield is decreasing. Consequently farmers getting looser day by day. The scenario is that grain production has increased many times but the farmers who produced the crop has marginalized. It is the dilemma of green revolution or so called modern agriculture.
Present Soil Fertility Status of Bangladesh:
Soil fertilityrefers to the capability or ability of soils to supply elements essential for plant growth without a toxic concentration of any element. It is the inherent capacity of soil to supply 14 of the 17 essential nutrient elements to the growing crop. It is the quality of soil that enables it to provide compounds or elements in adequate amounts and in proper balance for the growth of specified plants when other growth factors like light, moisture, temperature and the physical conditions of the soils are favorable. So, fertility is the potential nutrient status of a soil to produce crops. Presence of soil organic mater is the most important indicator or pre-requisite to be fertile or productive soil.
What is the situation now?
It was said that soil of Bangladesh is the most fertile soil in the world. However, after 4 decades of modern agricultural practice, Organic Matter (OM) status of Bangladesh soil has become one of the lowest in the world. At present, the average OM content of Bangladesh soils is less than 1%, ranging between 0.05 and 0.9% in most cases. Soils of peat lands and some low-lying areas usually contain OM higher than 2% on an average. Organic matter supply in soil is one of the major constraints to the agriculture of the country. Yet, the country has been producing good crops and cereal production in 2000 exceeded 27 million ton, with a surplus of 9 million ton. For producing this amount of crop, each year the soil looses 2 million tons nutrition*. According to Dr. Z. Karim ( Agriculture Specialist & ex Secretary), “ Because of intensive cultivation using chemical fertilizers and pesticides for long period, soil has deficit near about 60 million tons organic matter.” Organic matter (OM) is the life of the soil. To keep soil productive for future a certain amount of OM ( 2% to 5%) is must. Other wise the soil will become barren and no result will be found only using the chemical fertilizer. During M S International Rice Congress held in New Delhi in 2007, Professor Swaminathan has mentioned this situation as a red alert. He said that immediate initiative is needed to conserve soil fertility, other wise food shortage will be arisen in near future.
Sustainable Agriculture is a concept that emphasizes on meeting the needs of the present without compromising the ability of future generations to meet their own needs. If natural resources such as soil, nutrients and water are used up at a rate faster than they are replenished, then the farming systems is unsustainable. Sustainability is also dependent on maintaining a high level of biodiversity, especially in the soil and the surrounding environment. Therefore, economic and social issues, as well as the productivity of the land and the broader health of the environment, have to be considered when working towards sustainable agriculture.
Sustainable production practices involve a variety of approaches. Specific strategies must take into account topography, soil characteristics, climate, pests, local availability of inputs and the individual grower's goals. Despite the site-specific and individual nature of sustainable agriculture, several general principles can be applied to help growers select appropriate management practices:
Selection of species and varieties that are well suited to the site and to conditions on the farm;
Diversification of crops (including livestock) and cultural practices to enhance the biological and economic stability of the farm;
Management of the soil to enhance and protect soil quality;
Efficient and humane use of inputs; and
Consideration of farmers' goals and lifestyle choices.
Importance of Sustainable Agriculture Practices:
Bangladesh is under tremendous pressure to produce food grain for a image population utilizing very limited land resource of 8.3 millions hectare. It is it is claimed by the government that if the natural factors remain favorable Bangladesh can grow sufficient food grain (cereals ) for it’s nation. Now the question is how long ? It has already proved that land and other natural resources cannot be exploited endlessly by this time we have damaged our soil, genetic and other natural resources to a great extent. We must find the alternate way out before going the situation at an unprecedented level. We should not utilize the technology for only exploitation of natural resources. We must chose the environment friendly technology that can meet the present need and also conserve the resources for future use. We have huge natural resources, thousands of indigenous knowledge gathered by our ancestors which they learn from nature. We required necessary harmonization between indigenous knowledge and technologies.
Sustainable agriculture concept would be very much helpful to overcome the situation. A sustainable, pro-people agriculture policy should be developed by the government and a strong long term social movement is required for that.