Impacts of temperature and rainfall variation on rice productivity in major ecosystems of Bangladesh

Md Abiar Rahman,Robert Macnee,Suchul Kang,Nidhi Nagabhatla

doi:10.1186/s40066-017-0089-5

Abstract

BackgroundInconsistency in climate regimes of rainfall and temperature is a source of biotic and abiotic stresses in agricultural systems worldwide. Several studies from Bangladesh report that this variability is a cause of poor yield potential and crop failure. This study investigates the impact of temperature and rainfall variation on rice productivity for different ecosystems in Bangladesh. Three ecosystems under investigation include: dry (Rajshahi), terrace (Mymensingh) and coastal (Barisal).ResultsThe terrace ecosystem recorded the highest rainfall, followed by coastal and dry ecosystems. The temperature variation, both maximum and minimum, showed an increasing trend; however, the incremental rate was higher in case of minimum temperature. Monsoon rainfall showed an increasing trend, while dry season (November to March) decreased slightly. The climatic variations and impacts were captured using a standardized precipitation index (SPI), diurnal temperature range (DTR) and rice productivity index (RPI). The rainfed rice crop (aman) observed a significant trend between RPI and seasonal SPI, and between RPI and seasonal DTR. Overall, the SPI indicated the prevalence of frequent dry and wet periods and DTR recorded a decreasing trend. The multiple regression analysis identified a significant correlation between RPI, SPI and DTR accounting for 41, 45 and 49% of yield variability in dry, terrace and coastal ecosystems, respectively.ConclusionRainfall has shifted with an increasing trend during monsoon and almost static during other seasons. Rice production, especially rainfed rice, is at risk due to frequent drought and decreasing DTR. Stress-tolerant rice varieties requiring less irrigation water and survive at high temperature should be introduced. Research on rescheduling crop calendar and cropping pattern is necessary to mitigate the adverse climatic conditions.

Highlights

Inconsistency in climate regimes of rainfall and temperature is a source of biotic and abiotic stresses in agricultural systems worldwide
Climatic variability: rainfall and temperature trends Trends The trend of annual rainfall anomalies shows an increasing pattern across the ecosystems reporting an increasing trend with a significant (P < 0.05) value recorded during July to October (JASO) (Fig. 2)
A significant increment in mean annual rainfall per decade was recorded for the terrace ecosystem (59.6 mm) that was followed by the coastal (52.2 mm) and dry (38.6 mm) regions

Summary

Introduction

Inconsistency in climate regimes of rainfall and temperature is a source of biotic and abiotic stresses in agricultural systems worldwide. This study investigates the impact of temperature and rainfall variation on rice productivity for different ecosystems in Bangladesh. Three ecosystems under investigation include: dry (Rajshahi), terrace (Mymensingh) and coastal (Barisal). Most of the parts of Bangladesh are vulnerable to adverse impacts of climate change. The coastal, dry and terrace ecosystems are sensitive due to their geo-climatic profiles and anthropogenic influences. The coastal region, encompassing about one-fifth of the country’s landmass and supporting nearly one-third of the total population of the country, is a sensitive landscape [19]. The northwestern region of the country is vulnerable as it is drought prone and often impacted by the late arrival or early withdrawal of the monsoon. The terrace ecosystem accounts about 8% of the countrys landmass, which is relatively highland and cannot hold water during monsoon

Methods

Results

Discussion

Conclusion