FACTORS AFFECTING CROP PRODUCTION

2. FACTORS AFFECTING CROP PRODUCTION
Prof. Shivaji R. Suryavanshi
Asst. Professor of Agronomy,
Dr. D.Y. Patil College of Agriculture,
Talsande.

3. Climate
Rainfall Solar Radiation
Land
SoilBio-diversity
Natural Resources influencing Agriculture

4. FACTORS AFFECTING CROP PRODUCTION

5. • Rainfall
• Temperature
• Solar Radiation
• Atmospheric humidity:
• Wind velocity :
• Biotic factors (plant):
• Edaphic (Soil) factors:
• Physiographic factors:
• Anthrophic factors::

6. 3. Solar radiation:
• It provides two essential needs of plants
a) light is required for photosynthesis
and for many other functions of plants.
Seed germination, leaf expansion,
growth of stem and shoot, flowering,
fruiting and even dormancy and
• b) thermal conductivity - conditions
required for normal physiological
functions of plants.

7. • Light is indispensable for synthesis of
most important pigment of plant i.e.
green chlorophyll carbohydrates
produced by plants during
photosynthesis.
• It regulates rate of transpiration by
opening and closing of stomata.
• Effect of light is four ways: Intensity,
Quality (Wave length), Duration (photo
period) and Direction.

8. • Light Intensity: - The variations in light
intensity are always accompanied with
change in temperature and relative
humidity and hence it is difficult to
evaluate light effects alone.
In the photosynthesis about 1% light
energy is converted into potential
chemical energy.
• Very low light intensity reduces rate of
photosynthesis and may even result in
closing of stomata, which in turn reduce
vegetative growth.

9. • Very high light intensities are detrimental
to plants in many ways. It increases
respiration rate and disturb
photosynthesis respiration balance. It
causes rapid loss of water and results in
closer of stomata. The most harmful effect
of high light intensity is the phenomenon
of solarization in which all cell contents
oxidized by atmospheric oxygen (photo
oxidation).

10. • During cloudy weather the dry
matter production is limited.
Depending upon the nature of crops
such as heliophytes (sun loving) and
sciophytes (shade loving), the dry
matter production is affected. Many
species produce maximum dry
matter under high light intensity if
water is available in plenty.

11. Quality of light: - When white light is passed
through a prism, it is dispersed into
wavelengths of different colours.
short
‘X’ rays
400 435 490 574 595 626 750
Long
Gamma rays violet blue Green Yellow Orange Red Infra
red
The principal wavelengths absorbed in photosynthesis
are violet, blue and orange red regions. Among these short
rays beyond violet such as ‘X’ rays and Gamma rays and longer
rays beyond red such as infrared are detrimental to growth.
Red favorable followed by violet blue for growth. Ultra violet
and shorter wave lengths kill bacteria and many fungi.

12. • Duration of light: - The length of day has
greater influence than intensity. The
response of plants to the relative length of
day and night is known as photoperiodism.
• Plants which develop and produce
normally when the photo period is greater
than a critical minimum (more than 12 hours
of illumination) are called long day plants and
those developed normally when photo
period is less than a critical maximum (less
than 12 hours of illumination) are short day
plants.

13. • Some plants are found to be unaffected
by the photoperiod and are called a day
neutral plants.
• Plant characters like floral development,
floral initiation, bulb formation, and
rhizome etc all are influenced by
photoperiodism.

14. • Long day plants require relatively long day
for floral formation and fruits and they
increase vegetative growth when days are
short. If a long day plant is subjected to
short day periods, the internodes may be
shortened to give a rosette appearance
and flowering will not take place.
• In short day plants, flower initiation takes
place when days are short.

15. • Long day plants: -
Wheat, Barely, Sugar beet,
• Short day plants: -
Rice, maize, millet, soybean
• Day neutral: -
Tomato, sunflower, cotton.

16. • Direction of light: - The shoot, root and
leaves show different orientation to the
direction of light.
• In temperate regions, southern slopes
better growth of crops than northern slope
due to light direction contributing more
sunlight towards southern side.
• Similarly sowing of crops (rows) in North-
South direction also help in getting more
sunlight to the crops.

17. • 4. Atmospheric humidity: - Water is always
present in the atmosphere in the from of
invisible water vapour, which is known as
humidity of air.
• When atmosphere contains maximum
possible amount of water vapour it is said to
be saturated at particular temperature &
pressure.
• In unsaturated condition the water vapour
content of air is usually expressed as relative
humidity (R.H.), which is the ratio between
actual humidity present and saturation
humidity possible at that temperature.

18. • Humidity is also affected by wind, exposure
vegetation and soil moisture content.
• Evapo-transpiration (ET) of crop plants
increases with temperature, but decreases
with high Relative humidity affecting the
quantity of irrigation water.
• The humidity directly affects water relation
of plant and indirectly affects leaf growth,
photosynthesis, pollination, occurrence of
diseases and economic yield.
• In humid areas leaf enlargement (leaf
growth) is high because of higher humidity,
the transpiration is less.

19. • While when the humidity is low,
transpiration increases, causing water deficits
in plants, which cause partial or full closure
of stomata and resist entry of CO2. So rate of
the photosynthesis is affected. The
pollination is also affected by humidity.
Moderately low air humidity is favoured for
seed set in many crops, provided soil
moisture supply is adequate e.g. seed set in
wheat high at 60% humidity as against 80%,
when water availability is not limiting one.

20. • The incidence of insect pests and diseases is
high under humid conditions, e.g. blight
disease of potato, Aphids and Jassids thrive
better under moist conditions.
• Very high or low humidity not conducive for
high grain yield.
• The crops like sugarcane, and rice tolerate
high humidity, but crops like sorghum, pearl
millet, majority of pulses and oilseeds are
sensitive to higher humidity. Similarly, lower
humidity content in atmosphere increases
evaporation losses from soil and water and
there by increase water requirement of crop.

21. Wind velocity: - The wind velocity
of a place depends on various
factors such as geographical
situation, topography, altitude,
distance from sea shore, flat
plains vegetation etc. Its effect
may be direct or indirect.

22. Direct it causes mechanical
lacerations and bruises on the
tissues of crop plants. It tears leaves
and plants are uprooted. Lodging in
wheat, paddy, maize, sugarcane
etc., are caused by violent winds. In
bare desert it causes constant soil
erosion for which shelterbelts of
vegetation are raised.

23. It also responsible for causing rainfall to
very large extent.
Monsoon rainfall is movement of wind.
It helps in pollination of flowers,
dispersal of seeds, fruits micro -
organisms etc.
It is useful in cross-pollinated crops
like sunflower and also for
performing winnowing operation.

24. • Indirectly: affect rate of
transpiration in plants. Much
damage is caused to crops by hot
dry winds at time of flowering.
Another form of damage is blossom
injury caused by evaporation of
secretions from stigmas. Wind also
affects growth mechanically and
physiologically.

25. • Mechanically: - Sand and dust particles
carried by wind damage plant. Roots
covered or may be exposed by strong
winds. Lodging, shedding of grains.
• Physiologically effect: - Increase
transpiration and evaporation.
• Hot dry winds affect- photosynthesis.
Close- stomata- even at adequate
moisture.
• Moderate winds – beneficial effect on
photosynthesis by continuously replacing
CO2 absorbed by leaf.

26. 2) Edaphic (Soil) factors:
• The most important natural resource of any
country.
• In India,
• Total Geographical area – 329 Million hectares
• Cultivable area – 143 M. ha.
• Cultivable waste area – 40 M. ha,
• Forest and pastures area -82 M. ha.

27. • The soil is formed from the parent rock by
the process of weathering over a long
period by action of rainfall (rain water),
temperature, plant and animal residues.
The parent rock is not same at everywhere
and as a result, the soil will be of different
types with variation in fertility and
productivity of the soil.

28. • The surface layer of about 30cm of soil is
known as surface soil. The soil layer below
the surface soil is called sub-soil and at the
bottom undecomposed material, which is
the parent rock.
• The soil, which remains where it is formed,
is called soil in situ.

29. • The soil in the banks of river
which is formed from the soil
particles washed away by rains
from the hill slopes and
deposited at lower levels is
known as alluvial soils. It is much
deeper and more fertile.

30. • It is necessary to study the physical,
chemical and biological properties
of the soil before growing the crop,
so that it will be helpful for proper
irrigation management and applying
required quantities of manures and
fertilizers for proper growth and
crop yield.

31. • The soil is natural medium for plant
growth and gives mechanical support to
plants.
• Thus study of physical properties of soil
is highly essential.
• Similarly, the shallow, medium or deep
layer of soil having varying depth of sub-
soil will act differently to water that is
added to it and plant that grows on it.

32. • Since the soil is formed from different
rocks and under various climatic
conditions, it is essential to know its
chemical properties.
• The soils in heavy rainfall areas, the
salts get loss through leaching while in
low rainfall areas, it may retain many
salts. These salts supply nutrition to
plants.

33. • Every soil has its natural fertility,
which vary from soil to soil and
management of the fertilizers
should be adjusted according to
fertility status of soil. So soil does
not give only mechanical support,
but also provide food material
(plant nutrients) to plants.

34. • Soil is not an inert mass, but a living
mass, which is composed of several
organisms belonging to both plant and
animal kingdom. These organisms act
on plant and animal residues and
release plant nutrients to crops in
available form Similarly, the decayed
organic matter is also useful for
circulation of air and infiltration of
water in the soil.

35. Soil Organisms
Flora (Plant kingdom) Fauna (Animal kingdom)
Macro flora Micro flora Macro fauna Micro fauna
Rootsup
higher
plants
Bacteria
Fungi
Actinomycets
Algae
Earthworm
Moles
Ants
Protozoa
Nematodes

36. • The physical, chemical and biological
properties of soil may differ from place
to place to place depending on types of
soil.
• These properties decide the fertility
and productivity of soil.
• The soil fertility means inherent
capacity of soil to supply nutrients to
plant in adequate amount and suitable
proportions.

37. • . While soil productivity is the capacity of soil
to produce crops with specific system of
management and expressed in terms of the
yields.
• “All productive soils are fertile, but fertile
soils need not be productive.”
• It may be due to some problems like water
logging, saline or all alkaline condition,
adverse climate etc. that restrict crop growth
though the soil has sufficient amount of
nutrients available.

38. 1) Soil moisture, 2) soil air,
3) soil temperature, 4) soil mineral matter,
5) soil organic matter, 6) soil organism
7) soil reaction.

39. • 1. Soil moisture: - Water is considered as life of
crop and must be supplied in adequate
quantity.
• Functions of water:
• Water forms a major part of plant body. On oven
dry basis the herbaceous crop content 85-90%
water. While woody plant contains 50% water.
• It is necessary for photosynthesis i.e. CHO
production.
• It acts as solvent and carrier of plant nutrients,
because of the dipole nature of water.
• It gives turgidity to plants and keeps them erect.

40. • It regulates temperature of plant as well as soil.
• It accelerates the chemical and biological
activities in the soil.
• Soil moisture affect soil structure, friability,
plasticity cohesion, shrinkage, hydrolysis,
microbial activity and gaseous diffusion etc.
• Water increases the nutrient availability and
mobility. While soil strength is reduced due to
presence of water. The soil strength or soil
mechanical resistance is around 0.2 to 0.3 bars in
submerged field, while in upland soils, it range
from 3 to 12 bars. The plant root cannot grow in a
dry soil, because the root proliferation is reduced
due to high mechanical resistance of dry soil.