Study the rainfall variability and impact of El Nino episode on rainfall and crop productivity at Parbhani

Abstract

The weekly rainfall data for 36 years (1981-2016) recorded at Vasantrao Naik Marathwada  Krishi Vidyapeeth, Parbhani were analyzed for mean seasonal, weekly rainfall and also weekly rainfall probabilities. The mean seasonal rainfall was 796 mm, received in 38 rainy days. The seasonal rainfall indicated that there is 53% chance of receiving less than 700 mm with variable intensities and 36% chance of getting more than normal rainfall and 11% chance of seasonal rainfall, in between 700 mm to 800 mm. The mean weekly rainfall during crop season was 45.8 mm with a CV of 116%. Highest mean weekly rainfall was recorded 71.8 mm with SD (95.3) and CV (132.7%) in 30^th MW. Sowing of Kharif crops should be undertaken during 24^th MW to 27^th MW. Significant and positive correlation between yield and rainfall was observed for Soybean, Pigeonpea, Black gram, Green gram and rice. The predictability of productivity of crops using seasonal rainfall is 10-20% variation in productivity for all the crops at the Centre. The El Nino episode was negatively influencing Southwest monsoon and annual rainfall as well as rainfall during the months of July and September. El Nino episodes exhibit more negative influence on productivity of all the crops except rice crop. Among the different categories of El Nino, weak events exerted more negative impact on productivity of short duration crops (i.e., sorghum, soybean and Black gram)  as compared to moderate and strong El Nino events.