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Soil water plant relationship

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SHIVAJI SURYAVANSHI

The document discusses the relationship between soil, water, and plants. It covers several key topics: - The importance of water for plant growth and physiological processes like germination, photosynthesis, and transpiration. Water is necessary for these processes and makes up a large percentage of fresh plant tissues. - The movement and storage of water in soil, including gravitational, field capacity, and hygroscopic water. Plants can only access water within a certain soil water potential range. - The mechanisms by which plants absorb water from soil, including passive absorption via transpirational pull and active absorption using energy. Absorption is influenced by root properties and environmental factors. - How nutrients move from soil to plant

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SOIL WATER PLANT RELATIONSHIP Prof. S.R. Suryavanshi, Asst. Professor of Agronomy, Dr. D.Y. Patil College of Agriculture, Talsande
INTRODUCTION Air Water Minerals O.M • Soils are the natural media that support the growth and activities of many kinds of plants, animals and micro-organisms which play a vital role for the existence of life on earth. SOILCOMPONENTS
FUNCTION AND PROPERTIES OF WATER • Water is a chemical compound of hydrogen and oxygen. • Water together with dissolved nutrients forms the soil solution from which plants get nutrients. • Water helps to maintain turgor pressure of plant cells. • Water is an integral component of photosynthetic relation. • Water serves as a universal solvent. • Water is very important for soil formation. • Water is an important component of plant cell and constitutes about 80-90% of the fresh weight of herbaceous plant parts and over 50% of the fresh weight of woody plants.
ROLE OF WATER IN GROWTH AND PHYSIOLOGICAL PROCESSES • Almost every plant process is affected directly or indirectly by water supply. Germination Growth Photosynthesis Respiration Transpiration Stomata opening and closing Flowering and Fruiting Fruit ripening and Dormancy
Soil water plant relationship
ROLE OF WATER IN SOIL FUNCTIONING Soil Formation Soil Fertility Regulating soil temperature
CLASSIFICATION OF SOIL WATER 1. Gravitational water: It is of little use because it stays in soil for very short period of time. It is present in soil at water potential greater than -0.1 bar and is always in acces of field capacity. 2. Field capacity: . At field capacity water is held in soil at water potential -0.1to -0.3bar. 3. Capillary water: it is present in soil at water potential -0.3 to -31 bar. However, plant can use capillary water upto - 15 bar. 4. Hygroscopic water: Water that is held very tightly with soil solids at a water potential lower than -31 bar.
Classification of water with respect to plants or biological point of view 1. Available water: the available water is estimated as the difference between soil water content at field capacity and permanent wilting point. 2. Permanent wilting point: It is generally the soil water held at less than 15 bar. It is the lower limit of available water beyond which water is adsorbed so strongly that plants cannot absorb it fast enough to meet their water requirements. 3. Unavailable water: Water held at water potential less than -15 bar and bound to soil particles so tightly that is not available to plants.
Reference State  The reference state must have following characteristics; 1. It is pure. 2. It is free ,no adsorption at soil matrix. 3. It has pressure equal to atmospheric pressure. 4. It is at same temperature as that of soil water. 5. An arbitrary reference elevation must be set at a specific height.
Factors affecting free energy of water Matric forces Osmotic forces Gravitational forces
Soil Water Potential It is the difference between free energy of soil water and that of pure water in a standard reference state is called soil water potential. Characteristics of soil water potential; 1. Relative 2. Negative 3. Continuity 4. Driving force 5. Variability 6. Dynamic
MOVEMENT OF WATER THROUGH SOIL 1. Saturated Water Flow: It is the movement of water under saturated soil condition and is mainly determined by two major forces; • Hydraulic force • Hydraulic conductivity • Hydraulic force: It is the driving force that controls water movement through soil under saturated condition. It originates from gravity. It is the ease with which soil pores permit water movement.
MOVEMENT OF WATER THROUGH SOIL 2. Unsaturated Flow: It is the movement of water in soil through capillary pores. Unsaturated flow depends upon two factors; Hydraulic conductivity Driving force • Driving force in case of unsaturated flow is generally the matric forces. Unsaturated flow is inversely proportional to matric forces. Water flows from wet region (low metric forces) to dry region (high matric forces).
MOVEMENT OF WATER THROUGH SOIL 3. Vapour Movement: Water vapours move from one point to another in response to the difference in vapour pressure. • Water vapors moves from moist soil where soil air is nearly saturated with water vapours high vapour pressure to a dry soil where vapour pressure is somewhat lower. • Vapour movement in soil is very small and has limited practical significance to meet crop water requirement. • In a dry soil vapour movement may be considerable significance in supplying moisture to drought resistant plants.
HOW PLANTS ARE SUPPLIED WITHWATER • Two major phenomena are generally responsible for plant access to water. 1. Capillary movement of soil water to plant roots 2. Growth of plant roots into moist soil
Capillary movement • When plant rootlet absorb water they reduce moisture content and thus result in reduction in water potential in immediate surroundings of plant roots. In response to this lower water potential, water tends to move towards plant roots. • The rate of water movement depends on Magnitude of potential gradient Hydraulic conductivity of soil
Growth of plant roots to moist soil • Capillary movement of water is complemented by rapid rate of root extension. • The primary limitation of root extension is a small proportion of soil with which roots are in contact. • Roots soil contact commonly accounts for less than 1% of total soil surface area. • Complemented operation of capillary and root extension is more effective to move water from soil to plant roots
WATER ABSORPTION BY PLANTROOTS • The transport of water from soil to plant roots and to atmosphere takes place in following three steps; 1. Water is first absorbed from soil by root hairs and other epidermal cells in or near the root zone of young root tissue. 2. Lateral conductance across young root tissue epidermis pericycle into xylem duct and vertical conductance within xylem vessel into leaves. 3. Passage of water across leaf tissue through the process of transpiration into atmosphere.
MECHANISM OF WATERABSORPTION There are two mechanisms of water absorption 1. Passive absorption 2. Active absorption
Passive Absorption • In passive absorption uptake of water by plants is generally controlled by transpirational pull generated at leaves surface due to loss of water into atmosphere. • During passive water absorption suction force originally generated at leaf surface moving down through a continuous column of water is transmitted to root system and is responsible for the absorption of water from soil.
Active Absorption • Absorption of water by plant roots due to activity of living roots and usually involving the expenditure of energy. • When there is high concentration of salts in soil, due to adsorption of water molecules to salt ions water potential of soil solution becomes low as compared to root cells. • Under these conditions plant roots have to synthesize and accumulate different kind of osmolytes (Proline, glycine batane, sucrose and mannitol) into root cell sap. • Due to accumulation of these osmolytes in the root cell sap water potential within cell sap decreases and water starts to move from soil to plants along water potential gradient.
FACTORS AFFECTING WATERABSORPTION 1. Absorption efficiency of roots 2. Availability of water and soil type 3. Concentration of soil solution 4. Transpiration 5. Soil Temperature 6. SoilAeration
Nutrient Movement From Soil To Plant Roots • Before taken up by plants the nutrients must reach from soil to root surface. It takes place by three processes. 1. Mass Flow 2. Diffusion 3. Root interception
Mass Flow • It is the transport of soil solution containing nutrients to plant roots caused by water potential gradient developed due to loss of water through transpiration or evaporation. • Contribution of mass flow to carry nutrients to plant roots varies with following factors: Nutrient in consideration and its concentration in soil solution Water consumption or requirement of plants. Plant species and plant age Time of the day and season Soil moisture content
Diffusion • It is the transport of nutrients to root surface along the concentration gradient. P,K, S, Fe and Zn move through diffusion. • The transport of nutrients to plant roots through diffusion is high when plant uptake exceeds nutrients supply through Mass flow. • Depletion zones develop along the root surface depending upon following factors • Uptake by roots • Replenishment of soil • Mobility of ion by diffusion
Root Interception • It refers to the exchange of Ions between root surface and soil minerals surface through the physical contact between root and soil. • The quantity of nutrients that can come in direct contact with plant roots is the amount in the volume of soil equal to volume of root. • Roots can contact 1-3% of available soil nutrients but normally 1%. • Root interception can be increased by mycorrhizal infection.
Factors affecting nutrient movement to plant roots • Factors affecting nutrient movement to plant true fruits can be grouped into three categories. • 1. Nutrient related factors • 2. Plant related factors • 3. Soil related factors
Nutrient Related Factors Nutrient under consideration Concentration of nutrient in soil solution Form of nutrient in soil
Plant Related Factors Plant species and varieties within species Plant age Root type Presence or absence of root hairs Root length Root induced changes in rhizosphere
Soil Related Factors Soil texture soil structure Soil aeration soil temperature pH Eh Organic matter Microbial activities Soil moisture
Percolation : Percolation is the downward movement of water through saturated or nearly saturated soil in response to the force of gravity. Seepage : Seepage is the infiltration (vertically) downward and lateral movements of water into soil or substrata from a source of supply such as a reservoir or irrigation canal. Permeability : Permeability is the characteristic of a pervious medium relating to the readiness with which it transmits fluids.
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Soil water plant relationship

  • 1. SOIL WATER PLANT RELATIONSHIP Prof. S.R. Suryavanshi, Asst. Professor of Agronomy, Dr. D.Y. Patil College of Agriculture, Talsande
  • 2. INTRODUCTION Air Water Minerals O.M • Soils are the natural media that support the growth and activities of many kinds of plants, animals and micro-organisms which play a vital role for the existence of life on earth. SOILCOMPONENTS
  • 3. FUNCTION AND PROPERTIES OF WATER • Water is a chemical compound of hydrogen and oxygen. • Water together with dissolved nutrients forms the soil solution from which plants get nutrients. • Water helps to maintain turgor pressure of plant cells. • Water is an integral component of photosynthetic relation. • Water serves as a universal solvent. • Water is very important for soil formation. • Water is an important component of plant cell and constitutes about 80-90% of the fresh weight of herbaceous plant parts and over 50% of the fresh weight of woody plants.
  • 4. ROLE OF WATER IN GROWTH AND PHYSIOLOGICAL PROCESSES • Almost every plant process is affected directly or indirectly by water supply. Germination Growth Photosynthesis Respiration Transpiration Stomata opening and closing Flowering and Fruiting Fruit ripening and Dormancy
  • 6. ROLE OF WATER IN SOIL FUNCTIONING Soil Formation Soil Fertility Regulating soil temperature
  • 7. CLASSIFICATION OF SOIL WATER 1. Gravitational water: It is of little use because it stays in soil for very short period of time. It is present in soil at water potential greater than -0.1 bar and is always in acces of field capacity. 2. Field capacity: . At field capacity water is held in soil at water potential -0.1to -0.3bar. 3. Capillary water: it is present in soil at water potential -0.3 to -31 bar. However, plant can use capillary water upto - 15 bar. 4. Hygroscopic water: Water that is held very tightly with soil solids at a water potential lower than -31 bar.
  • 8. Classification of water with respect to plants or biological point of view 1. Available water: the available water is estimated as the difference between soil water content at field capacity and permanent wilting point. 2. Permanent wilting point: It is generally the soil water held at less than 15 bar. It is the lower limit of available water beyond which water is adsorbed so strongly that plants cannot absorb it fast enough to meet their water requirements. 3. Unavailable water: Water held at water potential less than -15 bar and bound to soil particles so tightly that is not available to plants.
  • 9. Reference State  The reference state must have following characteristics; 1. It is pure. 2. It is free ,no adsorption at soil matrix. 3. It has pressure equal to atmospheric pressure. 4. It is at same temperature as that of soil water. 5. An arbitrary reference elevation must be set at a specific height.
  • 10. Factors affecting free energy of water Matric forces Osmotic forces Gravitational forces
  • 11. Soil Water Potential It is the difference between free energy of soil water and that of pure water in a standard reference state is called soil water potential. Characteristics of soil water potential; 1. Relative 2. Negative 3. Continuity 4. Driving force 5. Variability 6. Dynamic
  • 12. MOVEMENT OF WATER THROUGH SOIL 1. Saturated Water Flow: It is the movement of water under saturated soil condition and is mainly determined by two major forces; • Hydraulic force • Hydraulic conductivity • Hydraulic force: It is the driving force that controls water movement through soil under saturated condition. It originates from gravity. It is the ease with which soil pores permit water movement.
  • 13. MOVEMENT OF WATER THROUGH SOIL 2. Unsaturated Flow: It is the movement of water in soil through capillary pores. Unsaturated flow depends upon two factors; Hydraulic conductivity Driving force • Driving force in case of unsaturated flow is generally the matric forces. Unsaturated flow is inversely proportional to matric forces. Water flows from wet region (low metric forces) to dry region (high matric forces).
  • 14. MOVEMENT OF WATER THROUGH SOIL 3. Vapour Movement: Water vapours move from one point to another in response to the difference in vapour pressure. • Water vapors moves from moist soil where soil air is nearly saturated with water vapours high vapour pressure to a dry soil where vapour pressure is somewhat lower. • Vapour movement in soil is very small and has limited practical significance to meet crop water requirement. • In a dry soil vapour movement may be considerable significance in supplying moisture to drought resistant plants.
  • 15. HOW PLANTS ARE SUPPLIED WITHWATER • Two major phenomena are generally responsible for plant access to water. 1. Capillary movement of soil water to plant roots 2. Growth of plant roots into moist soil
  • 16. Capillary movement • When plant rootlet absorb water they reduce moisture content and thus result in reduction in water potential in immediate surroundings of plant roots. In response to this lower water potential, water tends to move towards plant roots. • The rate of water movement depends on Magnitude of potential gradient Hydraulic conductivity of soil
  • 17. Growth of plant roots to moist soil • Capillary movement of water is complemented by rapid rate of root extension. • The primary limitation of root extension is a small proportion of soil with which roots are in contact. • Roots soil contact commonly accounts for less than 1% of total soil surface area. • Complemented operation of capillary and root extension is more effective to move water from soil to plant roots
  • 18. WATER ABSORPTION BY PLANTROOTS • The transport of water from soil to plant roots and to atmosphere takes place in following three steps; 1. Water is first absorbed from soil by root hairs and other epidermal cells in or near the root zone of young root tissue. 2. Lateral conductance across young root tissue epidermis pericycle into xylem duct and vertical conductance within xylem vessel into leaves. 3. Passage of water across leaf tissue through the process of transpiration into atmosphere.
  • 19. MECHANISM OF WATERABSORPTION There are two mechanisms of water absorption 1. Passive absorption 2. Active absorption
  • 20. Passive Absorption • In passive absorption uptake of water by plants is generally controlled by transpirational pull generated at leaves surface due to loss of water into atmosphere. • During passive water absorption suction force originally generated at leaf surface moving down through a continuous column of water is transmitted to root system and is responsible for the absorption of water from soil.
  • 21. Active Absorption • Absorption of water by plant roots due to activity of living roots and usually involving the expenditure of energy. • When there is high concentration of salts in soil, due to adsorption of water molecules to salt ions water potential of soil solution becomes low as compared to root cells. • Under these conditions plant roots have to synthesize and accumulate different kind of osmolytes (Proline, glycine batane, sucrose and mannitol) into root cell sap. • Due to accumulation of these osmolytes in the root cell sap water potential within cell sap decreases and water starts to move from soil to plants along water potential gradient.
  • 22. FACTORS AFFECTING WATERABSORPTION 1. Absorption efficiency of roots 2. Availability of water and soil type 3. Concentration of soil solution 4. Transpiration 5. Soil Temperature 6. SoilAeration
  • 23. Nutrient Movement From Soil To Plant Roots • Before taken up by plants the nutrients must reach from soil to root surface. It takes place by three processes. 1. Mass Flow 2. Diffusion 3. Root interception
  • 24. Mass Flow • It is the transport of soil solution containing nutrients to plant roots caused by water potential gradient developed due to loss of water through transpiration or evaporation. • Contribution of mass flow to carry nutrients to plant roots varies with following factors: Nutrient in consideration and its concentration in soil solution Water consumption or requirement of plants. Plant species and plant age Time of the day and season Soil moisture content
  • 25. Diffusion • It is the transport of nutrients to root surface along the concentration gradient. P,K, S, Fe and Zn move through diffusion. • The transport of nutrients to plant roots through diffusion is high when plant uptake exceeds nutrients supply through Mass flow. • Depletion zones develop along the root surface depending upon following factors • Uptake by roots • Replenishment of soil • Mobility of ion by diffusion
  • 26. Root Interception • It refers to the exchange of Ions between root surface and soil minerals surface through the physical contact between root and soil. • The quantity of nutrients that can come in direct contact with plant roots is the amount in the volume of soil equal to volume of root. • Roots can contact 1-3% of available soil nutrients but normally 1%. • Root interception can be increased by mycorrhizal infection.
  • 27. Factors affecting nutrient movement to plant roots • Factors affecting nutrient movement to plant true fruits can be grouped into three categories. • 1. Nutrient related factors • 2. Plant related factors • 3. Soil related factors
  • 28. Nutrient Related Factors Nutrient under consideration Concentration of nutrient in soil solution Form of nutrient in soil
  • 29. Plant Related Factors Plant species and varieties within species Plant age Root type Presence or absence of root hairs Root length Root induced changes in rhizosphere
  • 30. Soil Related Factors Soil texture soil structure Soil aeration soil temperature pH Eh Organic matter Microbial activities Soil moisture
  • 31. Percolation : Percolation is the downward movement of water through saturated or nearly saturated soil in response to the force of gravity. Seepage : Seepage is the infiltration (vertically) downward and lateral movements of water into soil or substrata from a source of supply such as a reservoir or irrigation canal. Permeability : Permeability is the characteristic of a pervious medium relating to the readiness with which it transmits fluids.