Climate variability impacts on agricultural production and farmers’ adaptation: A micro level study into agro-climatic zones of Tamil Nadu, India

Recent decades climate variability pose a challenge to the world’s agricultural and natural resource systems, which are already finding it difficult to cope with the growing food demand driven by population growth and higher purchasing power in developing countries. The challenge compounded by the uncertainty and pace of climate variability and its regional effects. It has been increasingly evident that climate variability affects agricultural productivity. Changes in temperature and precipitation will require farmers to adapt, but precisely where and how much is uncertain. In this context, the study examined the effect of climate variability on agriculture for the period of 980-1981 to 2009-2010 and predicted climate variables effect on agriculture production for the year of 2030 and also documented farmers adaptation practices by pre-tested interview scheduled in most vulnerable agro-climatic zones of Tamil Nadu. A Just-Pope production function (1978) was specified to analyze the impact of climate change on average yield and variance of major crops. The results showed that temperature had a positive significant influence on yield of paddy, maize, sugarcane and cotton, while it had negative influence on groundnut. The variance in temperature had positive influence on the yield of banana. Rainfall had a positive influence on sorghum, bajra, cotton and pulses and negative on maize. Precipitation intensity had negative influence on all crops. If temperature increases, the variance in productivity of paddy and groundnut increases. Similarly, if precipitation increases, the variability in productivity for sorghum and bajra decreases. Likewise, if the precipitation intensity increases, the variability in yield increases in case of paddy, bajra and sugarcane. The calculated coefficient from Just-Pope yield function and the projected climatic data from the Regional Climate Models (RCMs) were used to project the yield of crops in the year 2030. The results showed that in North East Zone, Western Zone, Cauvery Delta Zone and Southern Zone, out of nine crops, five crops would experience decrease in productivity. Similarly, in North West Zone there would be decrease in productivity for three crops (maize, cotton and pulses). In South Zone, only two crops (bajra and pulses) will have decrease in productivity. In addition to that, an attempt made to analyze the factors that influence farmers to adapt crop choice with respect to changed climate condition, by estimating a Multinomial Logit Model. The primary data collected from the sample respondents during the months of January and February 2012. The results showed that older farmers were more likely to select groundnut, sorghum and less likely to select maize, fruits and vegetables. Education had positive and significant impact on growing groundnut, sorghum and chilies. Owning of livestock positively influence the probability of selection of sorghum and maize. The own prices of sorghum and groundnut are significant and positive as expected. Farmers are more likely to choose these crops when the market prices are higher. When non-farm income increases, farmers are most likely to prefer sorghum, cotton, maize and groundnut. When temperature increases by 1°C, farmers tend to choose maize, cotton, fruits and vegetables less often while the farmer chooses pulses, sorghum, chilli and groundnut more often. If precipitation increases by 1 cm, farmers move away from sorghum, chilli, Groundnut to pulses, maize, cotton, fruits and vegetable. Hence, local government policies and programs in agriculture should have a built in component to address the climate change issues.