NUTRIENT CYCLE. - udaykumar

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nutrient cycle

Transcript of NUTRIENT CYCLE. - udaykumar

  • 1. NEARLY 30 Y0 40 ELEMENTS REQUIRED FOR PROPER GROWTH AND DEVELOPMENT OF LIVING ORGANISM , MOST IMPORTANT OF THESE ARE C, H, O, P, K, N, S, Ca, Fe, Mg, B, Zn, Cl, Mo, Co, I, AND F. THESE ELEMENTS FLOW FROM ABIOTIC TO BIOTIC COMPONENTS AND BACK TO THE NON LIVING COMPONENT AGAIN IN A MORE OR LESS CYCLIC MANNER. THIS IS KNOWN AS NUTRIENT CYCLES.

2. THERE ARE THREE TYPE OF BIOGEOCHEMICAL CYCLE 1.HYDROLOGIC CYCLE OR WATER CYCLE 2.GASEOUS CYCLE 3.SEDIMENTARY CYCLE 3. SEDIMENTARY CYCLE MINERAL ELEMENTS REQUIRED BY LIVING ORGANISMS ARE OBTAINED INITIALLY FROM INORGANIC SOURCES. AVAILABLE FORMS OCCUR AS SALTS DISSOLVED IN SOIL WATER. MINERAL CYCLES ESSENTIALLY CONSIST OF TWO PHASE 1.THE SALT SOLUTION PHASE 2.ROCK PHASE 4. PHOSPHORUS IS A MAJOR CONSTITUENT OF BIOLOGICAL MEMBRANES, ENERGY RICH COMPOUNDS AND NUCLIE ACIDS. IN ADDITION MANY ANIMALS ALSO NEED LARGE QUATITIES OF THIS ELEMENT TO MAKE SHELLS, BONES, AND TEETH. 5. PLANTS AND ANIMALS OBTAIN PHOSPHORUS FROM THE ENVIRONMENT. PHOSPHORUS IS A COMPONENT OF NUCLEIC ACID, PHOSPHOLIPDS IT OCCURS IN THE SOIL AS ROCK PHOSPHATE, CALCIUM PHOSPHITE, FLUROPATITE (Ca10Fe2(PO4)6), IRON PHOSPHATE, ALUMINIUM PHOSPHATE. 6. PHOSPHORUS OCCUR IN THE SOIL IN FIVE FORMS : P1 (STABLE ORGANIC) P2 (LABILE ORGANIC) P3 (LABILE INORGANIC) P4 (SOLUBLE) P5 (MINERAL FORM 7. THE CYCLE STARTS WITH THE ROCKS, THE SEDIMENTARY ONES. THEY HAVE THE PHOSPHORUS IN A FORM CALLED APATITE Ca5(PO4)3OH. 8. THE SEDIMENTARY ROCKS MERELY ADD PHOSPHORUS TO THE CYCLE , THEY ARE NOT ACTUALLY PART OF THE CYCLE 9. THE SEDIMENTARY ROCKS WILL THEN WEATHER DOWN FROM STORMS AND SUCH WHICH MOVE THE APATITE INTO THE SOIL 10. THE PLANTS THEN USE THE PHOSPHORUS IN THEIR REPRODUCTIVE STRUCTURE, SUCH AS DNA AND RNA. 11. AND THE PHOSPHORUS GOES THROUGH THE FOOD CHAIN 12. SOMETIMES DUE TO RUN OF THE PHOSPHORUS ENTERS AREA OF WATER. IT IS GOES THROUGH THE MARINE FOOD CHAIN 13. PHOSPHORUS ALONG WITH MANY OTHER MINERAL ELEMENTS REACHES THE OCEAN AND SETTLE DOWN AS SEDIMENT. A GOOD PROPOTION OF PHOSPHORUS LEACHES DOWN TO DEEP LAYERS OF SOIL. IN THIS WAY, MAJOR PROPOTION OF PHOSPHATE BECOME LOST TO THIS CYCLE BY PHYSICAL PROCESS, SUCH AS SEDIMENTATION AND LEACHING. BIOLOGICAL PROCESS SUCH AS FORMATION OF TEETH AND BONES ALSO KEEP PHOSPHORUS LOCKED UP FOR SOME TIME 14. SULFUR IS ONE OF THE ESSENTIAL ELEMENT OF LIFE SYSTEM AND ITS MAJOR RESERVOIR LIES IN THE EARTHS CRUST TOGETHER WITH OCEANIC SEDIMENT. IT ACTS AS A COMPONENT OF SEVERAL COMPOUND LIKE AMINO ACID, PROTIEN,ENZYME etc. NATURAL FUEL LIKE COAL AND OILS ALSO HAVE SOME SULFUR (1-30%) 15. WHERE IS SULFUR FOUND ?? IN ROCKS UNDERGROUND IN SULFUR SALTS AT THE BOTTOM OF THE OCEAN 16. MINERALISATION OF ORGANIC SULFUR TO THE INORGANIC FORM HYDROGEN SULFIDE (H2S). OXIDATION OF SULFIDE AND ELEMENTAL SULFUR AND RELATED COMPOUNDS TO SULFATE (SO4). REDUCTION OF SULFATE TO SULFIDE MICROBIAL IMMOBILIZATION OF THE SULFUR COMPOUNDS AND SUBSEQUENT INCORPORATION INTO THE ORGANIC FORM OF SULFUR 17. WEATHERING OF ROCKS RELEASE STORED SULFUR SULFUR COMES INTO CONTACT WITH AIR AND IS CONVERTED INTO SULFATE IONS THE SULFATE IS TAKEN UP BY PLANTS AND MICROORGANISM, CONVERTED INTO ORGANIC FORMS 18. ANIMALS CONSUME ORGANIC MOLECULES CONTAINING SULFUR, SULFUR MOVES THROUGH THE FOOD CHAINTHE DEATH AND DECOMPOSITION OF ORGANISMS RELEASE SULFUR ONCE AGAIN IN SULFATE FORM AND SOME OF IT BECOME PART OF THE BIOMASS OF MICROORGANISM 19. VOLCANIC ERUPTIONS, BREAKDOWN OF ORGANIC MATTER IN SWAMPS AND TIDAL FLATS, AND THE EVAPORATION OF WATER, ESPECIALLY SEAWATER, RELEASE SULFUR DIRECTLY INTO THE ATMOSPHERE SULFUR EVENTUALLY SETTLES TO EARTH OR COMES DOWN WITH RAINFALL 20. Human Activities The burning of fossil fuels and processing of metals releases huge quantities of sulfur into the atmosphere Human activities are responsible for onethird of all sulfur emissions and 90% of all sulfur dioxide emissions Sulfur dioxide emissions lead to acid rain as sulfur dioxide and sulfur trioxide reacts with water to form H2SO4