Impact of Climate Change on Bangladesh Agriculture
The changes in climatic condition is reflected in the increment in temperature initiated by increment of
Green House gases like carbon dioxide, methane, nitrous oxide, chloroflurocarbon, etc. Due to the increased amount of green house gases, it is anticipated that there will be lot of changes in agricultural productivity. This is because crop yield is directly dependent on weather prevailing in the growing season. There remains open debate with regard to the different levels of flood: normal annual flood, below normal annual flood and the severe flood as happened in1954, 1955, 1974, 1987, 1988, 1998, 2004 and 2007. In Bangladesh floods are a reality. The adaptation to flood has to be guided by conscious planning for maximizing benefits and minimizing the loss. Early warning system for information dissemination to the remote areas needs to be developed. Any attempt for environmental manipulation should take agronomic, social, economic and environmental points into account, especially for crops, livestock, fishery and forestry.
Bangladesh is situated between 88˚10’ and 92˚11’East and between20˚34’and26˚38’North latitude. The country is flat throughout and stretches from near the foot hills of the Himalayan Mountains in the north to the Bay of Bengal in the south.
It is known that climate variability has a significant impact on rice production. Floods, drought, and cyclone cause serious loss of crops. Weather and climate affect plant growth, development and occurence of climate extremes, particularly at critical crop growth stage may reduce yield.
It is known that Bangladesh has emerged in the flood plain of the Ganges, Brahmaputra and the Meghna rivers. The rivers and ground water of the flood plain have been used to provide agriculture and fishery. The flood plain may be divided according to the probability and type of risk where the fish resources are concentrated. Integrated agriculture and fish culture need to be developed matching the livelihood of the people.
Bangladesh is a disaster prone country. The major elements include: (1)floods, (2)cyclones, (3)drought, (4)abnormal rainfall, hailstorm and lightning, (5)nor- westers and tornadoes, (6)landslides and erosion, (7) earthquake, (8)saline intrusion, (9)Industrial and other Pollution, (10)deforestation, (11)ecological imbalance, (12)effect of green house gases leading to global warming, sea level rise, depletion of ozone layer, (13)effect of El-Nino-southern oscillation and other climatic changes(Pramanik,1994).
Flood damage in 2014
The flood in 2014 affected the major areas in the Brahmaputra, Jamuna, Ganges, Padma and Meghna basins during August-September. The flood affected 20 districts including Gaibandha, Nilphamari, Kurigram, Bogra, Lalmonirhat, Rangpur, Dhaka, Jamalpur, Tangail, Sirajganj, Faridpur, Netrokona, Sunamganj, Rajbari, Munshiganj,Sylhet, Manikganj, Madaripur, Shariatpur and Bhola.
A total of 2, 98, 3, 330 people were affected. 66,522 families were fully affected and 5 ,59 , 487 families were partially affected. Flood extensively damaged crops of 200,000 hectares .Aus paddy in mature stage and aman paddy in vegetative stage of growth suffered badly. Jute, vegetables, sugarcane, lemon, maize and other crops were inundated. The flood not only damaged crops but also left people homeless, destroyed roads, washed away fish ponds, inundated shelters and feeding grounds of livestock and poultry birds. The crop loss caused by the recent flood has been estimated at Tk. 1592 crore by the Department of Agriculture Extension (the Independent, 15 September 2014).
The flood in Bangladesh, generally comes during July-September, covering the harvest time of aus paddy and early stage of growth of aman paddy. Land races of rice and other crops were selected by the farmers matching specific niche.
Broadcast aman rice varieties are sown in the areas prone to flooding and transplanted aman varieties are selected for relatively higher elevations. 168 varieties were identified for broadcast sowing. These included Chamara , Digha, Vaoila, etc. A total of 128 varieties were identified for transplanting. One of the transplanted aman rice varieties is GAINJA (UBINIG,2010).
A sense of immediacy and realization must come into post flood rehabilitation. The flood has ruined standing aman paddy which is related to food sovereignty next year. It is pleasing to see that farmers were busy in transplanting one of the locally developed late sowing varieties of aman rice, GAINJA. GAINJA is a popular variety in the districts of Kurigram , Gaibandha, Bogra, Rangpur, Lalmonirhat and Nilphamari. This variety is suitable for transplanting and broadcasting up to end September depending on recession of flood water. It has tolerance to low temperature as well.
GAINJA raised through broadcast sowing matures in 120 days and that of transplanting in 100 days .It yields 10-12 maunds (1 maund= 37.32kg) per bigha(33decimals). It does not need irrigation and chemical fertilizer (the Jugantar, 21 September 2014).This variety may be extended in other late sowing flood prone areas of Bangladesh for late sowing after recession of flood water. The other local and improved varieties of paddy may be studied for their suitability in late sowing.
The other indigenous and improved varieties of crops need to be studied for their response to changing environmental variations including soil nutrient status, moisture, humidity, temperature, salinity, pests and pathogens. The domestic animals, livestock, and poultry birds may be studied exposed to changing environmental regimes.