Impact of climate-change-enhanced salinity stress on rice and maintaining productivity in the future.

Abstract

Abstract The earth is experiencing a faster change in climate in the twenty-first century than it has in the past. The global average temperature has increased over recent years and if the temperature prediction models are anything to go by, the earth's future is going to be hotter. The increasing temperature is accompanied by increased events of flooding, drought and both decreased and increased rainfall and evaporation rate in different parts of the world. A secondary effect of these extreme weather events is changes in water and soil salinity. Salinity patterns under future climate change scenarios (CCSs) have indicated that as the CCSs become more severe, the soil area under higher salinity category will increase. Rice, a primary source of food for more than half the world's population, is a salt-sensitive crop. So far rice productivity has kept pace with the increasing world population, thanks to the 'Green Revolution' and existing farming practices. The world population is still increasing, whereas the gains in agricultural output provided by the 'Green Revolution' have reached a plateau. Recent statistics reveal that rice production and productivity need to be increased by 40% and from the current 4.5 tonnes/ha to 7.5 tonnes/ha, respectively, by 2030 to satisfy the growing demand without affecting the resource base adversely. A considerable portion of the world's cultivated land is affected by salinity, which limits its productivity potential. Cleaning up of salt from these lands is uneconomical and impractical on a large scale, whereas improvement of rice germplasm for salinity tolerance is a feasible and promising alternative for maintaining stable global food production.