2. EFFECT OF CLIMATIC FACTORS
ON CROP
AGRICULTURE RESEARACH INSTITITUTE
(ARI)TANDOJAM

3. MASHOOQ HUSSAIN ODHANO
ASSISTANT RESEARACH OFFICER
AGRICULTURE CHEMISTRY (SOILS) SECTION
AGRICUTLURE RESEARCH INSTITUTE TANDOJAM

4. As elevation increases, the average temperature decreases.
Above a certain elevation, low temperatures make it
impossible for trees to grow, as seen here on Washington's
Mount Rainier.

5. Pakistan’s Resource Base
 LAND (in million hectare)
 Geographical area = 79.6
 Area under cultivation = 27.6% (21.87)
 Crop area irrigated = 22.6% (17.99)
 Rainfed Agriculture area = 4.97% (21.87)
 Forest = 4.5% (3.61)
 Culturable waste = 11.7% (9.31)
 Range Lands = 59% (46.96)

6. Cropping Seasons
 Rabi
– November-April
 Wheat, Lentil, Chickpea
 Kharif
– May-October
 Rice, Maize, Mungbean, Cotton

7. Climate
Wind,
Temperature Rainfall Sunshine, CO2 level
Solar Radiation
Photosynthetic
Evapo-transpiration (ET) Activity
Crop Water Demand
Canal/ground
water Water Availability
Agriculture (Crop Yield)

8. Agricultural productivity
Crop Yield
Wheat 2262 kg/ha
Rice 1836 kg/ha
Maize 1768 kg/ha
Sugarcane 48.1 t/ha
Cotton 579 kg/ha
Fodder 22.3 t/ha

9. Climate and Food Production
 Weather and Climate are the key factors
in food productivity
 Being open to vagaries of nature, food
production are highly vulnerable
to climate change phenomena

10. What is Crop?
 A crop is a volunteered or cultivated plant (any plant) whose
produce is harvested by man at some point of its growth stage.
 Crops refer to plants of same kind that are grown on a large
scale for food, clothing, and other human uses. They are non-
animal species or varieties grown to be harvested as food,
livestock fodder, fuel or for any other economic purpose (for
example, for use as dyes, medicinal, and cosmetic use).
 Major crops include sugarcane, pumpkin, maize (corn), wheat,
rice, cassava, soybeans, hay, potatoes and cotton. While the
term "crop" most commonly refers to plants, it can also include
species from other biological kingdoms.
 For example, mushrooms like shiitake, which are in the fungi
kingdom, can be referred to as "crops". In addition, certain
species of algae are also cultivated, although it is also
harvested from the wild. In contrast, animal species that are
raised by humans are called livestock, except those that are
kept as pets. Microbial species, such as bacteria or viruses, are
referred to as cultures. Microbes are not typically grown for
food, but are rather used to alter food. For example, bacteria

11. What is Climate?
 Climate is defined as an area's long-term weather
patterns. The simplest way to describe climate is
to look at average temperature and precipitation
over time. Other useful elements for describing
climate include the type and the timing of
precipitation, amount of sunshine, average wind
speeds and directions, number of days above
freezing, weather extremes, and local geography.

12. Climate Related climatic factors of
Agricultural Productivity
 CO2
 Temperature
 Solar Radiation
 Precipitation
 Others (Wind speed and direction, Soil Moisture,
Water vapour, etc.)
Basic understanding of these factors helps
manipulate plants to meet human needs of food,
fiber and shelter
The parameters also help understand impacts of
climate change and devise adaptation/mitigation
strategies

15. Rainfall and Water
Rainfall is the most common form of
precipitation. It is the falling of water in
droplets on the surface of the Earth from
clouds. Other forms of precipitation are
freezing rain, sleet or ice pellets, snowfall,
and hail.
The amount and regularity of rainfall vary
with location and climate types and affect
the dominance of certain types of vegetation
as well as crop growth and yield

16. Light
 Light is a climatic factor that is essential in
the production of chlorophyll and in
photosynthesis, the process by which
plants manufacture food in the form of sugar
(carbohydrate).
 Other plant processes that are enhanced by
this climatic factor include: stomatal
movement, phototropism,
photomorphogenesis, translocation, mineral
absorption, and abscission.

17. Light (Contin;)
 Light is that visible portion of the solar radiation
or electromagnetic spectrum. It is a form of
kinetic energy that comes from the sun in tiny
particles called quanta or photons, travelling in
waves.
 Three properties of this climatic factor that affect
plant growth and development are light quality,
light intensity, and day length or photoperiod.
 Light quality refers to the specific wavelengths of
light; light intensity is the degree of brightness
that a plant receives; and daylength is the
duration of the day with respect to the night period.

18. Temperature :
The degree of hotness or coldness of a substance is called temperature.
 It is commonly expressed in degree Celsius or centigrade (C) and degree
Fahrenheit (F) This climatic factor influences all plant growth processes
such as:
 Photosynthesis, respiration, transpiration, breaking of seed dormancy, seed
germination, protein synthesis, and translocation. At high temperatures the
translocation of photosynthate is faster so that plants tend to mature earlier.
 In general, plants survive within a temperature range of 0 to 50 C .Enzyme
activity and the rate of most chemical reactions generally increase with rise
in temperature. Up to a certain point, there is doubling of enzymatic reaction
with every 10 C temperature increase But at excessively high temperatures,
denaturation of enzymes and other proteins occur.
 Excessively low temperatures can also cause limiting effects on plant growth
and development. For example, water absorption is inhibited when the soil
temperature is low because water is more viscuous at low temperatures and
less mobile, and the protoplasm is less permeable. At temperatures below
the freezing point of water, there is change in the form of water from liquid to
solid. The expansion of water as it solidifies in living cells causes the rupture
of the cell walls.
 The favorable or optimal day and night temperature range for plant growth
and maximum yields varies among crop species.

19. Temperature

20. Air
 The air is a mixture of gases in the atmosphere. According to Miller
(2001), about 75% of this air is found in the troposphere, the
innermost layer of the atmosphere which extends about 17 km above
sea level at the equator and about 8 km over the poles.
 In addition, about 99% of the clean, dry air in the troposphere consists
of 78% nitrogen and 21% oxygen. The remainder consists of argon
(slightly less than 1%), carbon dioxide (0.036%), and traces of other
gases.
 The oxygen and carbon dioxide in the air are of particular importance
to the physiology of plants. Oxygen is essential in respiration for the
production of energy that is utilized in various growth and
development processes. Carbon dioxide is a raw material in
photosynthesis.
 The air also consists of suspended particles of dust and chemical air
pollutants such as carbon monoxide (CO), carbon dioxide (CO2),
sulfur dioxide (SO2), sulfur trioxide (SO3), nitrogen oxides, methane
(CH4), propane, chlorofluorocarbons (CFCs), solid particles of dust,
soot, asbestos and lead, ozone and many more.
 However, the composition of this climatic factor is susceptible of

21. Relative Humidity
 The amount of water vapor that the air can hold depends on its temperature; warm
air has the capacity to hold more water vapor than cold air. There is almost one-half
reduction in the amount of water vapor that the air can hold for every 10 C drop in
temperature.
 Relative humidity (RH) is the amount of water vapor in the air, expressed as the
proportion (in percent) of the maximum amount of water vapor it can hold at certain
temperature. For example, an air having a relative humidity of 60% at 27 C
temperature means that every kilogram of the air contains 60% of the maximum
amount of water that it can hold at that temperature .
 The amount of water vapor in the air ranges from 0.01% by volume at the frigid poles
to 5% in the humid tropics. Compared to dry air, moist air has a higher relative
humidity with relatively large amounts of water vapor per unit volume of air.
 The relative humidity affects the opening and closing of the stomata which regulates
loss of water from the plant through transpiration as well as photosynthesis. A
substantial understanding of this climatic factor is likewise important in plant
propagation. Newly collected plant cuttings and bareroot seedlings are protected
against dessication by enclosing them in a sealed plastic bag. The propagation
chamber and plastic tent are also commonly used in propagating stem and leaf
cuttings to ensure a condition with high relative humidity.

22. Wind
 Air movement or wind is due to the existence of pressure gradient on a global
or local scale caused by differences in heating. On a global scale it consists of
the jet stream flow and movement of large air masses. On the local scale only
a smaller quantity of air moves. Surface winds are lower and less turbulent at
night due to the absence of solar heating.
 When air that is close to the ground cools, it contracts and the pressure rises;
when it warms, it expands and loses pressure. Where both cold and warm air
occur in proximity, as over a lake and its adjacent shore, the cold flows to the
direction of the warm air or from high to low pressure area to correct the
pressure imbalance. This also happens in tropical Asia but in a larger and more
complex way, as the monsoon winds.
 This climatic factor serves as a vector of pollen from one flower to another thus
aiding in the process of pollination. It is therefore essential in the development
of fruit and seed from wind-pollinated flowers as in many grasses.
 Moderate winds favor gas exchanges, but strong winds can cause excessive
water loss through transpiration as well as lodging or toppling of plants. When
transpiration rate exceeds that of water absorption, partial or complete closure
of the stomata may ensue which will restrict the diffusion of carbon dioxide into
the leaves. As a result, there will be a decrease in the rate of photosynthesis,
growth and yield .Each of the above discussed climatic factors has been shown
to produce limiting effects on various growth processes. However, the various
climatic factors always operate together and interact with each other under
natural conditions.

23. Changing Climatic Trends
 Increasing concentration of CO2 in the atmosphere
 Pre-industrial revolution (1789) 280 ppm
 Present (2004) 380 ppm
 Expected level (2050) 550 ppm
 Rising surface temperatures
 Global Av. Temp. rise (20th century) 0.6 °C
 Projections for 2100 1.4 to 5.8 °C
 Changing rainfall patterns

25. So in what ways is agriculture part of
the problem?
CO2: pastoral farms emit CO2 – more meat is being
consumed in MICs, so more pigs, poultry and cattle are
being reared, so more CO2. More machinery powered by
fossil fuels are being used as farm production becomes
mechanised, e.g. huge combine harvesters
Methane: cows in particular give out a lot of methane, but
so do rice paddy fields. Other material left to rot will also
produce methane
Nitrous oxide: results from the breakdown of both organic
(manure) and inorganic (oil based) fertilizer.

26. Projections of IPCC for South Asia
 Increase in surface temperature will contribute
to snowmelt resulting in risk of floods
 Indus river inflows will decrease by 27% by the
year 2050
 Land degradation will cause land to shrink
from present 0.8 ha per capita to 0.3 by 2010
 Areas in mid and high latitudes will experience
increase in crop yield whereas in lower
latitudes will experience a general decrease,
under elevated CO2 conditions

27. Semi-arid areas
 Crop models showed that increase in temperature of
0.9 and 1.8°C resulted in reduction in length of wheat
growing season by 4 and 8 days respectively
 At 0.9°C increase in temperature, wheat grain yield
increased by 2.5% whereas at 1.8°C increase, the grain
yield decreased by 4%
 The increase in temp. would reduce the productivity of
rice crop due to heat stress and reduction in growing
season length

28. Arid areas
 Crop modeling studies showed a non
significant trend in wheat yields under
increased temperature scenarios (0.9 °C
and 1.8°C)
 Wheat straw yields were reduced by 7%
and 12% with temperature increases of
0.9°C by 2020 and 1.8°C by 2050

29. Impacts on Food Production
Due to Increasing Temperatures
 Shift in spatial crop boundaries will have
enormous economic and social impact.
e.g. Rice transplantation, Cotton picking etc.
 Increase/decrease in crop yields
 Rise in evapotranspiration rates, calling for
greater efficiency of water use
 Shift in timing of developmental stages of
pests in Crop-weed-pest relationships

30. Extreme Weather Events
 In addition to changing climate,
increased variability in weather may
occur with consequent frequent extreme
events such as heat waves, droughts,
wind storms and floods having negative
impacts on agriculture

31. Effect of water supplies
 Decreased Surface Water Supplies
 Reduction in yield and quality of crops
due to water stress during critical
growth stages
 Shift in cropping patterns
 Nitrogen volatilization losses from
ammonical fertilizers

32. Due to Change in Precipitation
Pattern
 More dependency on ground water in the
face of low precipitation
– danger of depletion of aquifer due to
injudicious pumping
– increased cost of cultivation
– soil salinization due to poor quality ground
water

33. b) Increased Water Supplies
 Potential development of Water logging and
Salinity/Sodicity
 Denitrification losses from ammonical and
nitrate based fertilizers
 Shift in cropping patterns
 Increased incidence of plant diseases

34. EFFECT OF CLIMATE CHANGE
ON AGRICULTURE
 Climate change may have beneficial as well as detrimental
consequences for agriculture.
 A warming climate and decreasing soil moisture can also result in
increasing need for irrigation.
 Benefits to agriculture might be offset by an increased likelihood
of heat waves, drought, severe thunderstorms and tornadoes.
 With the virtually certain likelihood of warmer and more frequent
hot days and nights, there are projected to be increased insect
outbreaks impacting agriculture, forestry and ecosystems. (IPCC )

36. PAKISTAN AGRICULTURE-
STRENGTHS AND CHALLENGES
 Strong strides made in increasing the production in
the past 50 years, mainly due to adoption of HYVs
and other technological developments
 Subsistence agriculture with small land holdings
 Wide variation in regional productivities
 Majority still depend on rain-fed agriculture
 Frequently affected by extreme weather events such
as droughts and cyclones
 Significant proportion of population still reels under
poverty, mal-nutrition and chronic hunger

37.  The Agricultural Research Institute (ARI) examined
the vulnerability of agricultural production to
climate change, with the objective of determining
differences in climate factors impacts on agriculture
by region and by crop.
 The study found that increases in temperature (by
about 2ºC) reduced potential grain yields in most
places.
 Reductions in yields as a result of climate factors are
predicted to be more pronounced for rain fed crops
(as opposed to irrigated crops) and under limited
water supply situations because there are no coping
mechanisms for rainfall variability.

38. Effect of Climate factor on Soybean
 According to studies,
soybean yields could go up
by as much as 50 per cent if
the concentration of carbon
dioxide in the atmosphere
doubles.
If this increase in carbon
dioxide is accompanied by an
increase in temperature, as
expected, then soybean yields
could actually decrease. If the
maximum and minimum
temperatures go up by 1°C
and 1.5°C respectively, the
gain in yield comes down to
35 per cent.

39. Potential Impact of Climate factor on
Rice Production in Pakistan
 Overall, temperature
increases are predicted
to reduce rice yields. An
increase of 2-4ºC is
predicted to result in a
reduction in yields.
 Although additional CO2
can benefit crops, this
effect was nullified by an
increase of temperature.

40. While temperature rise is what
we hear about….
It is rainfall change that will have more effect.
Those area that become drier will be unable to grow as much
without irrigation – and currently, much irrigation practice
is highly wasteful and can bring long-term damage to the soil.
Extreme events are another cause of concern – unusually
heavy storms or unexpectedly long periods without
precipitation or unexpected heat-waves.
These all give challenges to agriculture that reduced the
production temporarily – challenges the idea of food security.
Then global warming causes icecap and glacier melt that
create rising sea levels and loss of good agricultural land to
salt marsh.

41. What the regional needs are
 Climate information systems in place (Systems to enhance
climate predictability)
 Water management technologies adopted (Improvements in
water collection, drainage, irrigation distribution systems,
maximize use of water in livestock production, etc.)
 Better integrated management of natural resources and
production systems (this includes water management,
conservation agriculture, crop and pasture rotations,
adjustment of planting dates, etc.)
 Technological innovations to reduce climatic risks
(biotechnology innovations to improve drought resistance
and pests and disease resistance, invasive species, and
improvements in irrigation infrastructure).
 Institutional innovations with capacity built for early
warning systems for climate (improved policy and regulatory
frameworks for water management, agricultural and
catastrophic risk insurance, etc.).
 Bottom-up participatory processes for climate change

42. CONCULSI0N
 The climate change will have impact on
agriculture, and agriculture is the livelihood
and most of the Indian population is dependent
on it. The country should set up a National
Food Security Board, to be headed by the
Prime Minister, and establish at least 50 huge
modern storages to build stocks of food grains
to counter any emergency. He finally stressed
the adoption of alternative crops to suit
different weather models, a strategy that may
help immensely in times of poor monsoon.