Challenges of climate change for agriculture

It is a welcome development that farmers in the vast Barind region in Rajshahi have started cultivation of other cereals in place of paddy as part of preparation for adapting to climate change. This drought-prone region has so long been known as the country's rice bowl. With the sources of irrigation fast drying up, farmers have opted for farming of wheat, maize, chickpea and black gram. Around 3,500 litres of water, according to experts, are needed to produce one kilogram of paddy whereas less than 1,000 litres of water are required for drought-tolerant varieties of crops. Further, irrigation on one bigha of paddy cultivation is sufficient for at least 15 bighas of land for cultivated of wheat. This explains why farmers in Barind region have switched over to producing crops other than rice. Of course this would not have been possible without advice and help from locally-based agro-experts.

Impact of climate change in Bangladesh is now a harsh reality. There is still no worthwhile attempt to make farmers aware of do's and don'ts in the face of rapid climate changes.  There is no denying that changes in the elements of climate can lead to changes in behaviour of plants and other life forms. That can eventually cause a disruption in agricultural calendar long followed by the farmers of the country. This year the country experienced less rainfall. Although lesser than normal precipitation was observed during the peak monsoon in July, heavy downpour took place in many places of the country late in August.

Climate change has already struck Bangladesh silently with its adverse effects felt in various forms. Agriculture has already been constrained by  floods, droughts, soil and water salinity, cyclones and storm surges. These are now common phenomena in coastal regions of this country. The dominant crop grown in its saline areas is transplanted local Aman rice with low yields. The cropping patterns that are followed in the coastal areas are mainly 'fallow-fallow-transplanted Aman' rice. Surely, crop yield is negatively impacted by rise in temperature, erratic rainfall, flooding, salinity etc, but water-logging and drainage congestion are the major problems. Now that there is no doubt about the sea-level rise, salinity and hydrological situation are going to pose a threat to production of normal crop throughout the year. The factors which contribute significantly to the development of saline soil are tidal flooding during wet season (June-October), direct inundation by saline water, and upward or lateral movement of saline ground water during dry season (November-May).

Add to this the increased dependence on fertiliser and irrigation which leads to permanent fertility loss of land, loss of biodiversity, extinction of local varieties, ground water scarcity and loss of sustainability of production. However, adaptation to climate change like agronomic manipulation, sustainable climate-resilient agriculture, shifting the planting dates, using short- duration crop cultivation etc., can reduce vulnerability, delay the process and enhance food security. But such a change in strategy requires early efforts by the relevant government agencies before food security is seriously threatened.