Chapter 1 - Major Constraints for Global Rice Production

Abstract

Global mean air temperature is projected to rise by 1.4–5.8°C from 1990–2100, due to increasing concentration of greenhouse gases in the atmosphere. Investigations predict that in 21st century the sea level may rise by 1m or more, which would adversely affect one billion people by 2050. Coastal regions, being major irrigated rice-growing zones, are prone to be devastated by climate change, loss of wetlands, heightened storm damage, and increased salinity from saltwater intrusion. Scientists reported 23% improvement in rice-grain yield due to increasing CO2 from 365 to 627mgkg−1; however, this increase is nullified by increasing mean air temperature. Both low and high temperature at high and low altitude respectively, reduce rice yield. Scientists found a 10% decrease in rice yield by per degree centigrade increase in minimum temperature. Similarly, decrease in rice yield was noticed in many parts of the world due to scarcity of good quality water, drought, salinity, land degradation, poor weed control, low input use, uneven patterns of rainfall, high disease occurrence, poor soil fertility, and some socioeconomic issues. Therefore, integrated management systems must be developed through eco-friendly agronomic practices, research, and modeling to overcome these hurdles for obtaining sustainable and profitable productivity of rice.