Pearl Millet Yield and Drought Assessment using Standardized Precipitation Index

Abstract

Using Standardized Precipitation Index (SPI), an analysis on incidence and severity of droughts occurred in arid Rajasthan during the period 1960-2009 showed that the drought frequency varied from 32 years at Barmer to 24 years at Hanumangarh. The decades 1960-1969, 1980-89 and 2000-2009 experienced highest number of moderate and severe droughts. Year-wise and monthly SPI was also calculated for Barmer, Churu and Jodhpur, to know drought severity during the cropping period of July, August and September. To validate the SPI as a drought indicator, a multiple-linear regression analysis between SPI of July, August and September as independent variables and pearl millet grain yield as dependent variable was made. The regression model using SPI predicted pearl millet yield up to 83% of Barmer district, 47% of Churu district and 62% of Jodhpur district, thus the SPI is found useful as an indicator for monitoring drought conditions in arid Rajasthan Key words: Standardized Precipitation Index, drought, pearl millet, arid Rajasthan.