Impact, Adaptation and Vulnerability of Rainfed Agriculture to Climate Change : Research at CRIDA

摘要

Climate -variability and change can immensely affect the agricultural productivity of India. To study the impacts and vulnerability of climate change on Indian agriculture, and developing suitable adaptation strategies, a network project on climate change (NPCC) under the aegis of the Indian Council of Agricultural Research was initiated at 15 research centers during X plan period and the project further expanded in XI plan with additional centre totally to 23 at present. Central Research Institute for Dryland Agriculture (CRIDA) is one among them to work on climate change on rainfed agriculture. The research programme assigned to CRIDA are 1) Agro-climatic trend analysis 2) Impacts of elevated CO_2 on crops, pests and diseases 3) Water resources 4)Soil organic pools 5) Agro forests potentials for combating climatic change. Long term climatic data base have revealed that the temperature regimes in general have shown an upward trend, while the precipitation has reduced considerably in central and eastern parts of the Country. Shifts in rainfall peaks, drought probability and crop water requirements are some studies attempted under this programme. The experiments on impacts of elevated CO_2 on crops showed an increment in total biomass by 46% in C3pulses and 29% in oilseeds at vegetative stage with elevated CO_2 (600ppm), whereas with C4 cereals it was only 15%. Elevated CO_2 levels also significantly reduced the duration of "days to initiation of flowering" and increased the number of female flowers in the spike of castor crop and thereby improving the seed yield. Oil content in groundnut showed an incremental trend from 45.3% at ambient control to 45.7% at 550ppm and 47.7% at 700ppm revealing its influence on improvement in the oil content percentage. Seed protein of groundnut recorded 28.5% at 370ppm showed no change at elevated CO_2. Larvae of A.janata and S.litura consumed slowly on elevated CO_2 foliage as noticed by lower coefficients with an increase of two days larval duration than those of chamber and open ambient. Changes in A. janata and S.litura growth rates can be attributed to variation in food processing efficiencies. Preliminary observations on pathogens suggest that sporulation increased in Trichoderma viride under elevated CO_2, however, the growth was 15-20% slow at 15th generation when compared to the 1st generation. However, the bioefficacy of the strains in terms of competition for substrate remained unaltered up to 15th generation. All the PGPR traits of Pseudomonas were reduced at elevated CO_2 conditions. Using Had CM3 projected scenarios, in Andhra Pradesh, sorghum yields reduced by 8%, 18% and 30% by 2020,2050 and 2080, respectively, for Anantapur where as for Palem the reductions were only 2.2% 5.1% and 9.7% in the years 2020, 2050 and 2080, respectively. Impacts of climate -change and -variability on soil and water resources have also been initiated.