IMPACT OF CLIMATE CHANGE ON JHARKHAND AGRICULTURE: MITIGATION AND ADOPTION

摘要

Jharkhand state, geographically located at 22 deg 28 min N -25 deg 30 min N latitude and 83 deg 22 min - 87 deg 40 min E Longitude with an altitude up to 1142 m above msl and having humid to sub-humid tropical monsoon type of climate, has a number of agro-climatic/physiographic constraints. Undulating terrain, shallow soil depth, low water retentive capacity and poor fertility of soils, fragmented holdings, high intensity (causing severe soil erosion) often erratically distributed (prolonged dry spells) rainfall and very meagre irrigation potential (10-12percent) are the most important constraints. Hence, agriculture is more difficult, tedious and challenging here than most other parts of the country. A considerable increase in average monthly maximum temperature and consistent increase in rainfall pattern with high variability, in recent decades, has further enhanced the agricultural problems in Jharkhand. Analysis of more than 40 years data of rainfall and temperature, recorded at Agrometeorological observatory located at Kanke (Ranchi) has revealed an increase in occurrence of extreme weather events with marked change in climate of Jharkhand state. The state is privileged to receive good amount of rainfall almost round the year.The annual average of rainfall has shown an increasing trend over the decades, the period 2001-08 being an exception because of the few drought years in this period.. It increased consistently from 1250.5 mm (1961-70) to 1623.5 mm (1991-2000). The quantitative increase in rainfall may be considered as a positive change in Jharkhand but it was associated with simultaneous increase in variability also (cv: 13percent in 1961-70 to 20percent in 1991-2000) which increased the level of uncertainty and possibility of intermittent prolonged dry spells. The increase in annual rainfall was mostly confined in the monsoon period. High intensity rainfall, often received in monsoon months, intensify the problem of soil erosion. Uncertainty on the dates of monsoon onset and its withdrawal also puts a great problem before the farmers. A considerable rise in temperature, over the decades, has been recorded in Jharkhand which might be one of the climatological reasons why the productivity has remained stand still over the decades though the total production has increased due to many other scientific efforts. From 1961 onwards the maximum temperature has been found in increasing trend. The increase in temperature, particularly the maximum temperature has been found to have considerable adverse effect on crop performances, more on the rabi season crops.