Download Factors that Affect Crop Production

Factors That Affect Crop
Production
Plant Introduction
 The process of taking plants from its place of
origin to a place with different climatic
conditions
 Made possible by domestication
 Wild relatives crops, new varieties or new
species can be introduced
 Two types:
 Primary
 Secondary
Plant Introduction
a. Primary Introduction – the introduced plant is
grown in its original state
b. Secondary Introduction – the introduced
species has been genetically manipulated or
crossed with local species
 Successful plant introduction > domestication
+ acclimatization
Acclimatization
 The ability of an introduced plant to adapt to
new climates
 Climate – external conditions that affect plant
growth and development
 Influences:
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the type of vegetation that grows
characteristics of the soil
the crops that can be grown
the type of farming that is practiced
Acclimatization
 Climate includes factors such as:
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Precipitation
Solar Radiation
Sunshine
Light
Temperature
Humidity
Wind
Precipitation (Rainfall)
 Provides water for:
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Plant tissues
Nutrient uptake
Photosynthesis
Osmo-regulation
Seed germination
 Characteristics:
1.
2.
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4.
Average annual rainfall
Rainfall distribution
Rainfall reliability
Rainfall intensity
Average Annual Rainfall
 Calculated from rainfall data gathered over a
number of years
 Used to classify crop production regions:
Average Annual
rainfall (mm/year)
Crop Region
Land use
0-250
Arid
Deserts that need irrigation; mainly used for
animal grazing
250-500
Semi-arid
Irrigation is needed; drought tolerant crops are
better suited
500-750
Sub-humid
Moisture is not adequate; supplemental irrigation
needed
>750
Humid
High agricultural potential; drainage systems
needed; monitor soil fertility, pest & disease
Rainfall Distribution
 Rainfall patterns are associated with global winds and air
masses:
i. South East trade winds
- Originates in Arabia and Africa
- Hot and dry air
ii.
North East trade winds
- Originates in Indian Ocean
- Moist air
iii. Westerlies
- Originates in Atlantic Ocean
- Moist air
Rainfall Reliability
 Inadequate rainfall can lead to drought periods
that affects crop production
 Reliable rainfall is rain providing water when
and where expected
Rainfall Intensity
 Refers to how heavy the rain shower is
 Heavy rains may have negative results
Temperature
 Affects the rate of crop development
 Temperature requirements for adequate crop
growth:
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Minimum: crop growth does not occur below this point
Maximum: plant growth stops above this point
Optimum:
between
minimum
and
maximum
temperatures (best for crop growth; usually between 1532°C)
 Cool weather vs Warm weather crops
 Thermal regime: amount of heat available for plant growth
and development
Light
 Important for photosynthesis
 Some plants are light sensitive
 May affect germination
 Length of day affects flower development, tuber
initiation, fruiting and seed production
Light