The 27^th Resilience Seminar

Date & time:	Wednesday July 8th, 2009 15:00-16:00
Venue:	RIHN Seminar Room 3, 4 ( access)
Title:	"Quantifying the impact of climatic change on yields and yield variability of major crops and optimal land allocation for maximizing food production in different agro-climatic zones of Tamil Nadu, India: An Econometric Approach"
Speaker:	C.R.Ranganathan Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
Language:	English

Abstract:

This paper provides a framework for optimal land use planning in the context of climate change. All agricultural activities are very sensitive to climate change resulting in variability in crop yields. Hence it becomes necessary to study the effect of climate change not only on mean yield but also on variability in yield. The quantitative information so obtained should be used for optimal land allocation in order to utilize natural resources in a judicious way. Previous studies using regression techniques concentrated on the estimation of average productivity only but little attention was given for optimal land allocation to competing crops with climate change induced productivities. The problem becomes more important in the context of gradual decline in available land area for agriculture due to urbanization. The present study focuses on these issues for major crops grown in Tamil Nadu State. It employs econometric modelling for estimating the mean yield and yield variability and also covariance between yields of different crops. The mean yields so obtained which reflect the impact of climate change are then used in multi-objective linear programming models for meeting objectives like maximum food grain production, maximum paddy production and minimization of agricultural land area for maintaining at least the current level of production of crops etc. Finally the study attempts to link the optimal food grain production with the projected population of Tamil Nadu for 2020 to determine the quantum of food grain availability per individual. The study shows that precipitation and temperature have varying effect on productivity and variability of crops. Trend has positive impact on most of the crops. Also, climate change, as dictated by HADCM3A2a scenario, will have modest impact on crop productivities across the five zones of Tamil Nadu. Zones where paddy is grown traditionally may witness modest increase in productivity followed by increase in variability while many other crops may have decrease in productivity and there is no uniformity in changes in their variability. The study indicates that when land is the only constraint, with climate change induced productivities, optimal allocation of crop area will result in increased production of food grain. These results will be useful for policy makers in finding the gap between supply and demand of food grain for projected population.

Key words: Impact; Climate Change; productivity; Just-Pope Production function; mean yield; yield variability; optimization