Linking Drought Intensity with Rice Yield in Nagaland

Background: Rainfall being one of the most important factors of production for rainfed kharif rice, occurrence of drought may have serious implication on rice yield. Hence, this study is an attempt to understand the linkage between drought and yield of rice in Phek and Dimapur district of Nagaland where rice is the primary crop. Methods: Reconnaissance Drought Index was calculated using gridded daily rainfall (0.25o X 0.25o) and temperature (1o X 1o) (o=degree) data for the year of 1975-2013. Result: The annual mean temperature has increased by 0.03oC in Phek and Dimapur district during the study period. The increasing linear trends for annual temperatures are significant whereas, the linear trend for annual rainfall shows decreasing but insignificant trend. About 38.46% and 41.02% of the 39 years under study were ‘Normal condition-dry’ in Phek in Dimapur district, respectively. Moderate and severe drought occurred more frequently in Dimapur than Phek. After 1994, majority of the years were drought years and the frequency of occurrence was higher in Dimapur. The drought occurrences negatively impacted the rice yields and the rice yield may reduce by 13.85% in normal condition dry to 18.45% in extreme drought condition.