G Panigrahi’s scientific contributions

Crop planning in a drought prone district is essential to maximize water efficiency, improved crop selection, optimize the use of available resources etc., which reduces the risk of crop failure and ensures better yield. In India, approximately 80% of the annual rainfall comes from the southwest monsoon. The spatial and temporal variations in monsoonal and annual precipitation are well recognized, and this year-to-year fluctuation in monsoon rainfall significantly affects agricultural production. Proper crop planning ensures most effective utilization of the limited resources available in drought prone regions. In this regard a study has been done to analyse the spatial- temporal rainfall distribution and its variability in Bolangir which is a drought prone district of Odisha. Present study reviled that the average annual rainfall in Balangir district was 1245.5 mm, consisting of one block with high rainfall, six blocks under very low rainfall and rest under moderate to low rainfall category. The 90% dependable rainfall is above 1000 mm in Balangir and Gudvella which assures the water requirement of medium duration rain-fed rice for these blocks and probability at 75% is more than 1300 mm in Gudvella block which is considered as suitable for most crops. Blocks namely Bangomunda and Patnagarh showed significant increasing trend where as Belpada and Loisingha showed significant decreasing trend for both rainfall and rainy days. The insights gained from this analysis can help farmers and agricultural planners select suitable crop varieties, determine optimal planting and harvesting schedules, and implement water-efficient irrigation strategies.

The length of the growing period (LGP) refers to a number of days in a year during which the moisture at the root zone of crop plants is adequate to meet the crop water need. Information on LGP provides a basis for the selection of crops, cultivars (short / medium / long duration) and cropping/farming systems of a region. Aim: The study aims to estimate the length of crop growing season of the East and South Eastern Coastal Plain Agroclimatic Zone of Odisha in order to provide a basis for suitable crop planning for the region. Methodology: The LGP for four districts (Jagatsinghpur, Kendrapara, Khordha and Puri) under East and South Eastern Coastal Plain Agroclimatic Zone of Odisha was estimated using rainfall data of 30 years (1991 to 2020). The growing season begins when the sum of daily rainfall (forward accumulation) reaches 75 mm (28 May, 29 May…15 Oct) and ends when backward accumulation (15 Oct, 14 Oct,……, 28 May) of 20 mm reach. The LGP was worked out by adding the duration of the rainy season with the sum of post-monsoon rainfall and the average water-holding capacity of soil divided by the post-monsoon PET of the district. Results: LGPs obtained by the above method varied from 173 to 192 days in this zone with Kendrapara district having the highest LGP (192 days) and Khordha the shortest (173 days). The date of onset and cessation of south west (SW) monsoon was 15-17 June and 13 October, respectively. Conclusion: Double cropping can be followed in Jagatsinghpur, Kendrapara and Puri districts where the length of the growing period >180 days except Khordha district where paira cropping can be followed as the length of the growing period <180 days.

The rainfall data of Jagatsinghpur district of Odisha for 20 years (1995-2014) were collected from Special Relief Commissioner (SRC), Government of Odisha, Bhubaneswar and were analyzed by Weather Cock software to estimate annual, seasonal, monthly and weekly rainfall probability with an objective to find out the risk proof crops based on rainfall probability analysis for the rainfed agriculture.

Extreme rainfall events are a significant cause of loss of life and livelihoods in Odisha. Objectives of the present study are to determine the trend of the extreme rainfall events during 1991-2014 and to compare the events between two periods before and after 1991. Block level daily rainfall data were used in identifying the extreme rainfall events, while district level aggregation was used in analysing the trend in three categories, viz., heavy, very heavy and extremely heavy rainfall as per criteria given by India Meteorological Department (IMD). The state as a whole received one extremely heavy, nine very heavy, and forty heavy rainfall events in a year. When percentage of occurrence of each category out of the total extreme events over different districts was considered, maximum % of extremely heavy rainfall occurred in Kalahandi (5.8%), very heavy rainfall in Bolangir (23.8%) and heavy rainfall in Keonjhargarh (85.4%). Trend analysis showed that number of extreme rainfall events increased in a few districts, namely, Bolangir, Nuapada, Keonjhargarh, Koraput, Malkangiri, and Nawarangapur and did not change in other districts. In Puri district, extremely heavy rainfall frequency decreased. New all-time record high one-day rainfall events were observed in twenty districts during 1992 to 2014, surpassing the earlier records, which could be attributed to climate change induced by global warming. Interior south Odisha was found as the hot spot for extreme rainfalls.