How Internal (Plant) and External (Environmental) Factors Influence Nutrient Supply to the Plant Root by Mass flow The plant loses water through transpiration. That's why there creates a vacuum in the plant. Then the plant absorbs water from the soil. This phenomenon is known as mass flow. It also takes the nutritional substances dissolved in the water at that time. As there happens a plant-environment interaction, there are a wide range of plant and environmental factors which can influence the nutrient supply to the roots of the plant Internal Factors or Plant Factors Species and Variety Water absorption by mass flow depends on the species and variety of the plants. Such as Eucalyptus absorbs much water than others. High yielding varieties uptake much water. In this way, it influences the nutrient uptake. Leaf Surface and Age of leafs Leaf Surface and leafage affect transpiration. Broader and younger leaves mean more transpiration. And transpiration is directly related to mass flow. More transpiration means more mass flow and more nutrient uptake. Influx to the Apoplasm For effective use of the nutrients, they need to reach the stele for transportation to the entire plant body. Endodermis creates a barrier to reach the nutrient through apoplasm. Plant Development Stage Transpiration and water uptakes depend on the age of the plant. So Nutrient uptake is affected. Metabolic Activity Ion accumulation depends on the expenditure of energy through metabolic activity like respiration. Thus ion uptake can be affected by metabolic activity. Such as, with lowering the oxygen tension, the uptake of potassium and phosphate is decreased. External or Environmental Factors Air Humidity As the humidity of air decreased, the plan losses more water through transpiration. On the other hand, mass flow increased. After all the nutrient uptake is affected. Concentration of the Solution If the available water is highly concentrated with the nutrient then the plant will get more nutrients. So, applying fertilizer can increase nutrient uptake. Effects of pH Nutrient uptake is largely affected by the pH of certain soil. pH influences the cations and anions of the solution. P, Zn, Fe are less available in alkali soil. Again Al3+ and Mn2+ inhibits the plant growth in the acid soil. Temperature Due to high temperature the rate of transpiration increases. Thus water starts absorbing more water through mass flow. Consequently, it increases the nutrient uptake. Soil properties Soil texture, structure, porosity can affect the nutrient uptake.

1. Mass flow
★Mass flow is the ions transported to the root in the
convective flow of soil water(transpiration of water that was
originally absorbed by the roots through the leaves via
stomata).
★An increase in transpiration pull increase the
Uptake of ions by the roots.
★Thus mass flow of ions through the root tissues
occurs due to the transpiration pull in the absence of
metabolic energy.

2. Amount of nutrients Supplied by the mass flow are
influenced by various external and internal factors.
•External factors :
01.Soil properties: In case of porus soil such as sandy soil, here
the movements of water increased. Thus rate of mass flow
increased and finally supplied nutrients increased. But clay soil
has low amount of pore space. So water can not move as so
much. Thus mass flow can not facultiated. So in clay soil
nutrient uptake by plant root in less than sandy loamy soil.

3. 02. Climate condition:
Climate condition such as temperature, humidity light intensity
and transpiration rate of plant. So mass flow must best affected
by climate condition. As nutrient uptake depends one mass
flow that’s why supplied of nutrients markedly controlled by
climate condition.
★ Temperature : At high temperatures transpiration rate is
high. So mass flow also high. Thus the plant can uptake more
nutrient from soil via mass flow. And at low temperature
transpiration rate decrease as a result mass flow decrease
and plant uptake less amount of nutrient from soil.

4. ★Humidity:
As the humidity of air decreased, the plan losses more water
through transpiration as a result plant uptake more nutrients via
mass flow. On the other hand when humidity of air increased,
the plant losses less water through transpiration as a result
plant uptake less nutrients via mass flow.
03.Solubility of nutrients :
Nutrients rich soil release significant amount of nutrients to the
soil solution. Due to pressure gradient or mass flow plant uptake
more nutrients. One the other hand nutrients poor soil can not
release significant amount of nutrients to the soil as a result
mass flow decrease.

5. 04.Effects on soil pH:
Nutrient uptake is
largely affected by
the pH of certain soil.
pH influences the
cations and anions of
the solution. P, Zn, Fe
are less available in
alkali soil. Again Al3+
and Mn2+ inhibits the
plant growth in the
acid soil.
Fig: effects on soil pH

6. 01.Plant age:
Comparatively older
plant has more leaf
as well as
transpirationrate
increase .So
supplied nutrients
through mass flow
enhance. In case of
younger plant it’s is
vice-versa.Example
corn plant age.
• Internal factors :

7. 02. Transpiration rate:
If transpiration rate
increase then plant
losses more water from
it’s body. As a result
plant uptake water as
well as mass flow
increase and plant
uptake more nutrients
from soil. In case of low
transpirationrate it is
vice-versa.

8. 03.Nutrient status
of plant :
If plant remain
more nutrients
then it’s required
less amount of
nutrients. As a
result during mass
flow it take less
amount of nutrients
from soil and mass
flow comparatively
decreased.

9. 04. Species and variates:
Water absorption by mass flow depends on the species and
variety of the plants. Such as Eucalyptus absorbs much water
than others. High yielding varieties uptake much water. In this
way, it influences the nutrient uptake.
05.Metabolic activists :
Ion accumulation depends on the expenditure of energy through
metabolic activity like respiration. Thus ion uptake can be affected
by metabolic activity. Such as, with lowering the oxygen tension,
the uptake of potassium and phosphate is decreased.

10. • Above external and internal factors effect
the supplied nutrients by plant root through
mass flow.