plant nutrition powerpoint presentation.pptx

plant nutrition

1. Crop nutrients Introduction , history, Primary and secondary nutrients

2. The nutrients are chemical elements which are absorbed by the plants in more or less quantity to transform light energy into chemical energy and to keep up plant metabolism for the synthesis of organic materials. Feeding of plants with nutrients is termed as nutrition. Growth and production of the plants are governed largely by the nutrition.

3. Why is Mineral Nutrition Important? In most natural soils, the availability of mineral nutrients limits plant growth and primary productivity. Nutrient limitation is an important selective pressure and plant face many special changes related to the need to acquire and use mineral nutrients efficiently. “Plant nutrition” specifically does not refer to photosynthesis.

4. History In the early 18 th century van Helmond and woodward conducted experiments, and demonstrated that; C and O form air and water lead to the formation of plant matter Growth of plant is dependent on some peculiar terrestrial matter.

5. History Justus Von Liebeg (1840) proposed the ‘Law of Minimum’

6. History De Sausssure (1800 ) worked on the variability in ash (dry matter) of plants grown in different soils, and suggested that some elements were universally present in all plants while others were not. Justus Von Liebeg (1840) arrived at the conclusion that carbon, hydrogen and oxygen were supplied from air while potassium and phosphorus from soil. He proposed “ law of Minimum” according to which growth of a plant is not dependent on the one nutrient which is present in the minimal quantity.

7. ESSENTIAL ELEMENT An element required by plants for normal growth, development and completion of its life cycle, and which cannot be substituted by other chemical compounds. Classified based on quantity required: Macro nutrients (>100mg/kg of dry weight) Micro nutrients (<100mg/kg of dry weight) Both are equally important.

8. SOIL NUTRIENTS MACRONUTRIENTS Nitrogen Phosphorous Potassium Calcium Magnesium Sulphur NON MINERAL ELEMENTS Carbon Hydrogen Oxygen MICRONUTRIENTS Manganese Copper Zinc Molybdenum Boron Chlorine Iron

9. Criteria of essentiality Proposed by Arnon and Stout (1939). An element is considered as essential- When plants cannot complete vegetative or reproductive stage of life. When this deficiency can be corrected or prevented only by supplying this elements. When this element is directly involved in the metabolism of the plant.

10. Nutrient requirements Nutrients are required for plant processes to function 1) Transpiration - It is a process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapour and is released to the atmosphere. 2) Respiration – It is the opposite of photosynthesis, which is a biological process performed by a green plants that creates oxygen and releases it into the air. during respiration plants absorb free molecules of oxygen and use them to create water, co2 and energy,

11. 3) Photosynthesis – it is process used by plants and other other organisms to convert light energy into chemical energy During this process in green plants, light energy is captured and used to convert water , co2,and minerals into oxygen and energy rich organic compounds.

12. Nutrient Loss Nutrients are lost in many ways - Depleted by plants Used by micro organisms Leached because of watering Conversion to gaseous form

13. Root absorption takes place as Active absorption takes place as an exchange phenomena and requires energy. Most plant nutrients are absorbed in this manner. Passive absorption is a part of the transpiration cycle (mass flow). Water and some dissolved solutes are absorbed by this process.

14. In the passive part , the movement of low-molecular-weight solutes (e.g. mostly ions, organic (amino) acids, sugars) from the external solution into the cell walls of roots. This process is driven by diffusion or mass flow. In the active part ion uptake takes place due to the movement of ions from the soil solution into the plant root against a concentration gradient. This is followed by the solute transport across membranes.

15. Gas exchange Gas exchange take place through the stomata found in leaves. Carbon dioxide required for photosynthesis and oxygen required for plant respiration are exchanged through leaves.

16. Uptake of nutrients in plants Mineral uptake is the process in which minerals enter the cellular material, typically following the same pathway as water. The most normal entrance portal for mineral uptake is through plant roots. During transport throughout the plant, minerals can exit xylem and enter the cell that require them. Mineral ions cross plasma membranes by a chemiosmatic mechanism. Plant absorb mineral as in ionic form; nitrate, phosphate and potassium ions, all have difficulty crossing a charged plasma membrane.

17. Forms of nutrients absorbed by plants:

18. Mechanisms of nutrient uptake Prior to absorption, nutrients reach the root by 3 mechanisms; Mass flow – movement with the water flow. Most prominent. Diffusion – movement in response to a concentration gradient. Slow process. Root interception – root extension. Very important to find new nutrient sources.

19. BASED ON TRANSPORT: MOBILE NUTRIENTS- Can be translocated within plants from older to actively growing tissues. Deficiency symptoms appear in older growth. N, P, K, Mg. IMMOBILE NUTRIENTS - Cannot be translocated within the plant. Deficiency symptoms occur in the new growth. Ca, S, B, FE, Zn, Cu, Mn .

20. Several terms namely, Deficient, Insufficient, Toxic and Excessive are commonly used to describe levels of nutrient elements in plants.

21. Deficiency of an element Deficiency will result in the decrease in normal growth of the plants, affect the crop yield and produce more or less distinct deficiency symptoms. Typical deficiency symptoms are not often clearly defined. Masking effects due to the other nutrients, secondary cause like disease, herbicide toxicity or insect infestation can confuse field diagnosis.

22. Insufficient levels When the level of an essential plant nutrient is below the required amount for optimum yields or when there is a imbalance with other nutrients it is considered insufficient. The symptoms of this condition are seldom clearly visible, resulting poor yield.

23. Toxicity levels Toxicity level will often cause nutrient imbalances and will result in poor plant growth, delayed maturity, stunted and spindly growth and also show visible symptoms of chlorosis or necrosis.

24. Excessive when the concentration of an essential plant nutrient is sufficiently high to result in a corresponding shortage of another nutrient.

25. REFERENCES: A Handbook of Soil Fertilizer and Manure by P. K. Gupta. Crop Nutrition- Principles and Practices by Rajendra Prasad. Nutrient Management in Fruit crops by Dr. B. S. Chundawat

26. HEALTHY SOIL, HEALTHY PLANT