Long term trends in rainfall and its probability for crop planning in two districts of Bundelkhand region

Abstract

Annual and weekly rainfall data for the period of 69 years (1942-2008) of Datia and (1939-2007) of Jalaun districts of Bundelkhand region were analyzed. The overall mean annual rainfall was 778.8 mm with 27.3% variability for Jalaun and 831.8 mm with 30.3 % variability for Datia region. Mann-Kendall rank statistics and Gaussian low pass filter revealed the long-term a decreasing trend in total amount of annual rainfall at Jalaun. However, in past 13 years (1996 to 2008), both regions exhibited significant decreasing trend in total amount of annual rainfall. At Datia, the probability more than 10 mm during 26th (25 June-1 July) and 27th (2-7, July) standard meteorological week (SMW) suggested to initiate field preparation operation for Kharif crop and sowing in subsequent week due to assured probability (70%) of more than 20 mm rainfall. The 27th and 28th (8-15, July) SMW is also an ideal time for the crop fertilization. Overall expected rainfall for getting more than 20 mm rainfall at 60% probability level is for 10 weeks at Datia suggesting that short duration varieties of various crops can be ideal in the region. At Jalaun, the trend analysis showed that field operation may be a week delay than Datia due to late onset on monsoon. Therefore, the ideal combination of crops of the regions may be sorghum for the grain purpose intercropped with cowpea for the fodder purpose as livestock is an integral part of rainfed rural economy.

Keywords

• Rainfall trend analysis
• crop planning
• rainfall probability
• rainfed regions