El Nino Effect on Climatic Variability and Crop Production : A Case Study for Andhra Pradesh

47 Pages·2011·2.62 MB·English

37
Res. Bull. No. 2/2011
El Niño Effect on Climatic
Variability and Crop Production :
A Case Study for Andhra Pradesh
V.U.M. Rao
A.V.M. Subba Rao
B. Bapuji Rao
B.V. Ramana Rao
C. Sravani
B. Venkateswarlu
National Initiative on Climate Resilient Agriculture (NICRA)
All India Coordinated Research Project on Agrometeorology
Central Research Institute for Dryland Agriculture
Santoshnagar, Saidabad, Hyderabad – 500 059, A.P., India
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Citation :
Rao, V.U.M., Subba Rao, A.V.M., Bapuji Rao, B., Ramana Rao, B.V., Sravani, C. and
Venkateswarlu, B. (2011). El Niño Effect on Climatic Variability and Crop Production : A Case
Study for Andhra Pradesh, Research Bulletin No. 2/2011. Central Research Institute for Dryland
Agriculture, Santoshnagar, Hyderabad, Andhra Pradesh, India. 36 p.
2011
500 copies
Published by
The Director
Central Research Institute for Dryland Agriculture
Santoshnagar, Hyderabad - 500 059
Ph : 040-24530177 Fax : [phone]
website : http://www.crida.ernet.in E-mail : [email protected]
Printed at : Sree Ramana Process Pvt. Ltd.
1-7-267, S.D.Road, Secunderabad - 500 003. Ph : 040-27811750
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CONTENTS
Title Page
Summary 01
Chapter 1:
Introduction 04
Chapter 2:
Methodology 10
Chapter 3:
El Niño effect on rainfall and thermal regime 12
Chapter 4:
Total food grain production and crop yields 18
Chapter 5:
Possible options for enhancing agricultural production 33
References 35
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LIST OF FIGURES
S.No Title Page
1. A cross-section of the Pacific Ocean, along the equator, 06
depicting the pattern of atmospheric circulation typically
found at the equatorial Pacific in normal years
2. The cross-section of the Pacific Ocean, along the equator, 07
illustrates the pattern of atmospheric circulation that
causes the formation of the El Niño
3. Global climatological effects of the El Niño 08
4. Location of the stations in Andhra Pradesh for 10
which temperature data were analyzed
5. Year-wise rainfall during southwest monsoon season 15
(June-September) in Andhra Pradesh (1981-2009)
6. Year-wise annual rainfall in Andhra Pradesh (1981-2009) 15
7. Year-wise production of total food grains in 19
Andhra Pradesh (1981-2007)
8. Yearwise average yield of total food grains in 19
Andhra Pradesh (1981-2007)
9. Per cent change in average food grain production 20
in strong and moderate El Niño years compared to average
production during remaining years in Andhra Pradesh
10. Per cent change in average food grain yield in 21
strong and moderate El Niño years compared to average
yield in remaining years in Andhra Pradesh (1981-2007)
11. Year-wise yield of Castor in Andhra Pradesh 31
12. Year-wise yield of Pigeonpea in Andhra Pradesh 32
13. Year-wise yield of Chickpea in Andhra Pradesh 32
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LIST OF TABLES
S.No Title Page
1 Per cent change in average seasonal rainfall (mm) 13
during El Niño years compared to normal rainfall
from 1971 to 2009 in Andhra Pradesh
2 Per cent change in average annual rainfall (mm) during 14
El Niño years compared to normal rainfall
from 1971 to 2009 in Andhra Pradesh
3 Mean annual temperatures (°C) during El Niño years 17
compared to normal temperatures at some selected locations
in Andhra Pradesh
4 The mean diurnal range of temperature during southwest 17
monsoon season compared to normal at some selected stations
in Telangana region
5 Per cent change in average area sown, production and 23
productivity of groundnut during El Niño years compared to
normal years during 1981-2008 in Andhra Pradesh
6 Per cent change in average area sown, production and 24
yield of groundnut during El Niño years compared to
normal years during kharif season in Andhra Pradesh
7 Per cent change in average area sown, production and 26
yield of groundnut during El Niño years compared to
normal years during rabi season in Andhra Pradesh
8 Per cent change in average area sown, production and 27
yield of pearl millet during El Niño years compared to
normal years during 1981-2007 in Andhra Pradesh
9 Per cent change in district-wise average yield of rice 28
during El Niño years compared to normal yield
from 1981 to 2009 in Andhra Pradesh
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S.No Title Page
10 Per cent change in average area sown, production and 29
yield of rice during kharif season in El Niño years compared
to normal years in Andhra Pradesh (1981-2007)
11 Per cent change in average area sown, production and 30
yield of food grains other than rice during El Niño years
compared to normal years
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PREFACE
Though agriculture is the backbone of India’s economy, the
contribution from farm sector is declining constantly from 57 per cent
in 1950-51 to 17.2 per cent in 2008-09. This decline will have a direct
impact on the employment opportunities and livelihoods in rural areas.
National food security in the backdrop of climate change is a concern
for everyone in the society. Extreme weather conditions such as floods,
droughts, heat and cold waves, cyclones and hail storms cause huge
losses to crop production, but even more subtle fluctuations in weather
during critical phases of crop can also have a substantial impact on the
ultimate yields. Some of these fluctuations may go unnoticed on a
regional scale but the science of Agricultural Meteorology has
established that the performance of southwest monsoon in the country
has a tele link with El Niño phenomenon. Thus information on the
anticipated fluctuations in both monsoon rainfall and the resultant
agricultural production prior to the start of the growing season has
wider implications for decision making at the farm and policy levels.
Regional scenarios anticipated in the event of El Niño help the state
administration to mobilize resources and inputs like seeds, fertilizers
etc. Therefore an attempt has been made to examine the possibility of
using El Niño factor as a signal for climatic variability which can help
in moderating any likely adverse effects on crop production with better
planning and management. I sincerely hope that there is an urgent need
to carry out analogous studies for all those regions where the impact of
climatic variability on crop production is significant.
(B. Venkateswarlu)
Hyderabad
11.11.2011
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Summary
During the recent years, the inter-seasonal and intra-seasonal variability in weather
is believed to outsmart the abilities of climatologists and statisticians in defining the
limits within which these variabilities can be observed. This has lead the weather experts
to realize and convince themselves that the global climate is changing due to enhanced
human activities detrimental to natural environment. Therefore, the meteorologists are
now required not only to predict weather on short term basis but also climate on long
term basis as many critical decisions in agriculture are required to be made well ahead of
the season before those weather conditions are realized. Such predictions offer the potential
for farmers and other decision makers to predict crop responses to expected climate, and
modify decisions to decrease unwanted impacts or take advantages of expected favourable
conditions.
El Niño is fundamentally a warming of the surface waters of the tropical eastern
Pacific Ocean from South American coast to the International Date Line that persists for
three or more seasons. El Niño is a pervasive climatic phenomenon which was found to
be associated with regional climatic variations throughout the world.
Analysis of long term data suggests an inverse relationship between El Niño and
southwest monsoon rainfall in India. However, there is no one to one relationship as El
Niño years have not always produced severe droughts. Studies on the effect of El Niño
either on crop production or productivity at regional level were not so far carried out in
India.
Therefore, an attempt has been made to examine the effect of El Niño for
m identifying changes in seasonal rainfall as well as annual rainfall in different
districts of Andhra Pradesh,
m quantifying the changes in annual temperature at some selected locations in
the state for which records are available,
m assessing the changes in total food grain production as well as production of
some of the crops rice, groundnut, castor, pigeonpea, chickpea and pearl millet
and
m suggesting the possible strategies to enhance agricultural production in the event
of adverse climate situations.
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