Recommended
More Related Content
Similar to N P K Nutrition Principles
Similar to N P K Nutrition Principles (20)
Recently uploaded
Recently uploaded (20)
N P K Nutrition Principles
- 1. N P K Nutrition Principles Dr. Rai Mukaram
- 2. Site Specific Management: Accounting for spatial variability
- 3. Nutrition Principles Nitrogen Cycle Factors Affecting Availability Sources Forms Taken up Role in Plants Nitrogen Key Presentation Points
- 4. Role in Plants • Protein • Nucleic acid • Chlorophyll • Carbohydrate utilization Four nitrogenous bases – adenine (A), thymine (T), guanine (G), and cytosine (C) are components in the DNA double helix.
- 5. Forms Plants Uptake Ammonia • Plants uptake both forms. • Uptake NO3 - the most. • NO3 - is mobile, NH4 is not. • NO3- prefers acidic pH. • NH4 + prefers neutral pH. • Combination is better. Which form is vulnerable to leaching losses? Nitrate
- 6. Nitrogen Cycle • N in soil enters, exits, and changes forms in many ways. • Can you name some of the processes and pools in N cycles? mineralization, immobilization, nitrification, denitrification, nitrogen fixation, nitrogen leaching…
- 7. NITROGEN CYCLE Denitrification N2 Biologicaland Chemical FixationAtmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant) N states NO3 Nitrate ion NO2 Nitrite ion NO Nitric oxide oxide N20 Nitrous oxide oxide N2 Dinitrogen gas Various states of N
- 8. NITROGEN Denitrification N2 Biologicaland Chemical Fixation Atmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant) N from air is fixed by microbes and lightning. N Fixation NITROGEN Nitrogen Fixation
- 9. Denitrification N2 Biologicaland Chemical FixationAtmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant)N from Organic Matter N is released from organic matter decomposition. Mineralization Mineralization
- 10. Denitrification N2 Biologicaland Chemical FixationAtmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant) N from NH4 When the process reverses with plant and microbial uses Immobilization M ineralization
- 13. Fertilizer Nitrogen • Nitrogen fertilizer should be added to the soil when the crop will use it, adding excess N will cause losses that may harm the environment. • Nitrogen is expensive and using only what the crop needs for adequate growth is important - • THUS it becomes important to give N - CREDITS for previous management (legumes, manure or other organic additions with low C:N ratios). Wheat with N response
- 14. Nitrogen soil testing • Mobile nutrient • In drier areas use a fall or spring nitrate- N soil test. • In humid areas, use spring nitrate-N test or table value based on previous crop and organic matter.
- 15. Nitrogen soil testing • After arriving at N recommendation then credits need to be taken for: – Previous crop – Previous manure applications or sludge – 2nd year after alfalfa
- 16. More on The story behind residual nutrient credits to growers
- 17. NH2 Upon decomposition plant animal residues, N-containing molecules are released from Chlorophyll DNA and RNA Protein } NH2
- 18. Chlorophyll DNA and RNA Protein } NH2 N molecules from this amino group NH2 NH2 NH2 When organic matter decomposes, N-containing molecules are released from H H combine with H to produce NH3 and NH4 NH3 + H = NH4 - Ammonium
- 19. Chlorophyll DNA and RNA Protein } NH2 First they make this gas, then NH2 NH2 NH2 NH3 H H+ H + NH4 AmmoniumAmmonia (gas) = The simple steps in the mineralization process are now complete. The process is also called ammonification. When organic matter decomposes, N-containing molecules are released from
- 20. Denitrification N2 Biologicaland Chemical Fixation NH3 + H+ = NH4 Clay Fixation and Release NO3 N2 N2O Immobilization (use by the plant) NITROGEN Oxidation of NH4 to NO3 is nitrification. Nitrobactor Nitrosomonas Nitrification NO2 Two kinds of bacteria are involved in two steps.
- 21. Denitrification N2 Biologicaland Chemical Fixation NH3 + H+ = NH4 Clay Fixation and Release NO3 N2 N2O Immobilization (use by the plant) NITROGEN In water-logged soil, NO3 transforms to gaseous N, and this loss to air is denitrification. Nitrobactor Nitrosomonas Nitrification NO2 Steps: NO2--NO--N2O and N2
- 22. Denitrification N2 Biologicaland Chemical FixationAtmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant) NITROGEN Clay Fixation and Release of NH4
- 23. Denitrification N2 Biologicaland Chemical FixationAtmospheric Nitrogen, 78% NH3 + H+ = NH4 Clay Fixation and Release NO3 Leaching N2 N2O Immobilization (use by the plant) NITROGEN Nitrate Leaching
- 24. Sources of N in Wheat • Organic – residue breakdown (slow) • Organic manures (N content varies) • Commercial – Urea – Ammonia – Monoammonium phosphate (MAP)/diammonium phosphate (DAP) – Potassium nitrate – URAN (urea + ammonium nitrate) solutions – Ammonium nitrate More discussion in Sections 4 and 5
- 26. P Nutrition Principles How the materials will be presented P-cycle Key Factors Sources Forms uptake Role in plant P
- 27. P Essentiality • Second most important nutrient • Its concentration in soil solution is low • Low solubility • Low availability • Low mobility Nutrient Amount in Solution (mg/L) NO3 - 60 NH4 + -- H2 PO4 - , HPO4 2- 0.8 K+ 14 Ca2+ 60 Mg2+ 40 SO4 2- 26 are key characteristics for better management
- 28. Role in Plants • ATP • DNA/RNA • Enhance crop maturity • Root growth Can you justify how P is important in these
- 29. Role in Plants • ATP • DNA/RNA • Enhance crop maturity • Root growth P is a critical component of cell’s energy currency, ATP
- 30. Role in Plants • ATP • DNA/RNA • Enhance crop maturity • Root growth P containing sugar phosphate is the backbone of DNA
- 31. Orthophosphate ions: H2PO4 - & HPO4 2- Plant Available Forms 7.2 pH Availability is pH dependent Both species are even at this pH
- 32. Phosphorus Cycle • Not involved in atmospheric exchanges • Cycles among various pools – Soil solution – Organic matter – Inorganic minerals • Interaction among pools is complex. • Knowledge of each pool is necessary.
- 33. Phosphorus Cycle Secondary Minerals Fe & Al PO4 CaPO4 Nonlabile P Primary Minerals (Nonlabile P) Solution P H2PO4 - HPO4 2- Microbial- P bacteriaFungi nematode Plant residue Labile P Adsorbed P Dissolution Dissolution Precipitation Adsorption Desorption Immobilization Mineralization Fertilizer-P Soil Organic Matter Microbial P (Nonalabile P) (Labile P) 1. Soil Solution: plant uptake poolAdsorption and DesorptionPrecipitation and DissolutionMineralization and Immobilization SOIL SOLUTION POOL INTERACTIONS
- 34. Phosphorus Cycle Secondary Minerals Fe & Al PO4 CaPO4 Nonlabile P Primary Minerals (Nonlabile P) Solution P H2PO4 - HPO4 2- Microbial- P bacteriaFungi nematode Plant residue Labile P Adsorbed P Dissolution Dissolution Precipitation Adsorption Desorption Immobilization Mineralization Fertilizer-P Soil Organic Matter Microbial P (Nonalabile P) (Labile P) Crop residue and organic matter release P by mineralization Various factor affects rate of mineralization including C/P ratio Net immobilization (available for plant uptake) at C/P >300 ORGANIC POOL INTERACTIONS What is good – high or low C/P? Why?
- 35. Organic-P, quick facts • P of organic matter range between 1% and 3% • Organic P is ~50% of total P in soil • Organic P decreases with soil depth • Organic-P increases with increased organic-C (the C/P, likewise N and C/N)
- 36. Phosphorus Cycle Secondary Minerals Fe & Al PO4 CaPO4 Nonlabile P Primary Minerals (Nonlabile P) Solution P H2PO4 - HPO4 2- Microbial- P bacteriaFungi nematode Plant residue Labile P Adsorbed P Dissolution Dissolution Precipitation Adsorption Desorption Immobilization Mineralization Fertilizer-P Soil Organic Matter Microbial P (Nonalabile P) (Labile P) INORGANIC POOL INTERACTIONS Inorganic P fixed or released by primary and secondary minerals
- 37. P • Soil test for P (Bray pH<7.4 of soil) • 0-5 ppm = very low • 6-10 ppm = LOW • 11-15 ppm = med • 16-20 ppm = high • > =21 ppm = very high • No reason to have soil test > 21 • environmental problems when P >16 • ppm x 2 = lbs/acre P deficient tomato
- 38. Soil P • Crops need more P than is dissolved in the soil solution at any one time, therefore, this P in the solution phase must be replenished many times during the growing season. • The ability of a soil to maintain adequate levels of phosphorus in the solution phase is the key to the plant available P status of the soil. The solid phase P is both organic and inorganic Solid P Phase Solution Phase Root Hair P deficiency reduces root growth
- 39. Inorganic-P, quick facts • Low concentration & solubility of P due to slow release and fixation • Minerals mainly with Ca, in alkaline soils • Minerals with Fe, Al, and Mg in acidic soils •
- 40. Solubility of P-containing compounds Compound Formula Compound type Monocalcium phosphate Dicalcium phosphate Octacalcium phosphate Tricalcium phosphate Oxy apatite Hydroxy apatite Carbonate apatite Fluorapatite Ca(H2 PO4 )2 .H2 O CaHPO4 .2H2 O Ca8 H2 (PO4 )6 .5H2 O Ca3 (PO4 )2 [3Ca3 (PO4 )2 ].CaO [3Ca3 (PO4 )2 ].Ca(OH)2 [3Ca3 (PO4 )2 ].CaCO3 3Ca3 (PO4 )2 ].CaF2 Calcium Strengite FePO4 -2H2 O Iron Variscite AlPO4 -2H2 O Aluminum • Ca-phosphate - major contributor in alkaline soils • pH determines its availability • Solubility decreases in order of: mono > di > tri calcium phosphates
- 43. K Nutrition Principles K-Cycle Key Factors Sources Forms Taken up Role in Plants K
- 44. P Essentiality Principles • Plant absorbs larger amount of K next only to N • Plant tissue K: ~2.5% to 4.5% leaf dry wt. • Soil K: 0.5% to 2.5% • Most soil K’s are tied up, availability is often limited
- 45. Role in Plants • Enzyme activation • Water relations (stomatal control) • Energy relations • Translocation (sugar transport) • Crop quality Justify how K is important in these
- 46. Role in Plants • Enzyme activation • K activates at least 60 enzymes in cell • K level determines reactions catalyzed by enzymes
- 47. Potassium Fertility (Potash) • Potassium (K+) is a problem on acid soils, soils with low CEC and with irrigation or high rainfall where leaching can readily occur. • Potassium can be stored in the soil from one year to the next • K is not a pollutant - even if leached from soil, K does not cause environmental problems. K deficient corn
- 48. Role in Plants • Water relations – K regulates stomatal opening K is critical to stomatal opening and closure in regulating gas exchanges (CO2 in and H2O out)
- 49. Role in Plants • Energy relations – K is required for production of ATP • Crop quality – Increases root growth – Enhances translocation of sugar – Increase protein content in plant – Reduces lodging
- 50. Forms uptake K+ Soil K Pools and Concentrations Mineral…………..… 5000 – 25000 ppm Non-exchangeable…...….50 – 750 ppm Exchangeable…………..400 – 600 ppm Solution……………...………1 – 10 ppm K-Cycle will show interaction among pools
- 51. K forms - characteristics 1. Mineral – K : Minerals like Mica, Feldspar, K is mainly unavailable 2. Non-exchangeable – K : K in secondary minerals like vermiculite or colloidal-size mica, K is slowly available ……more
- 52. In the non-exchangeable fraction of K Most K trapped K slowly available K is widely exchangeable
- 53. K forms - characteristics 3. Exchangeable-K: K on the cation exchange sites of soil colloids is readily available
- 54. K forms - characteristics 4. Soil solution-K: K is readily available. Range in most cropland soils ~ 1-10ppm. ~80% K plant uptake by diffusion, availability depends of many factors
- 55. Exchangeable K+ K+ K+ K+ K+ K+ K+ K+ Nonexchangeable K+ Plant & animal residues 2:1 Clay minerals Soil solution K+ Plant uptake Desorption Adsorption Weathering 90-98% 0.1-0.2% 1-2%1-10% ErosionLeaching Feldspar Mica Primary minerals K Mineral-K, mostly unavailable, accounts for majority of soil K K Non-exchangeable-K, in secondary minerals, slowly available, 2:1 clay K Exchangeable-K, readily available, K in cation exchange site…
- 56. Exchangeable K+ K+ K+ K+ K+ K+ K+ K+ Nonexchangeable K+ 2:1 Clay minerals Soil solution K+ Plant uptake Desorption Adsorption Plant/ animal residues Weathering 90-98% 0.1-0.2% 1-2%1-10% ErosionLeaching Feldspar Mica Primary minerals K K K Residue K recovery is minor, usually leach out K leaching loss is often substantial
- 57. K Cycle Quick Fact • K transfer from minerals is slow but continuous • Exchangeable and soluble K equilibrate rapidly • Fixed K equilibrate very slowly • Transfer from mineral to other form is very slow, usually unavailable (in one crop year)
- 58. K Fixation – who is involved? • Reentrapment of K ions between the layers of 2:1 clay (illite) is a major reason • The 1:1 clay (kaolinite) do not fix potassium • Major factor affecting K availability – Clay minerals, CEC, nature of cations – Soil moisture – Soil temperature – Amount of exchangeable K, capacity to fix K
- 59. Potassium Fertilizers • Organic sources – K content varies with sources, range in manure is 4-40 pounds • Commercial sources – potassium oxide (K2O) is guaranteed standard for fertilizer K • Potash and Potassium names are used interchangeably • The world’s largest high-grade potash deposit is in Canada END OF SECTION 02 INSTRUCTION
- 60. Tools for detecting nutrient deficiency • 1) Tissue testing -involves a complete and detailed laboratory analysis of nutrient elements in the plant leaves. This is a very accurate way of assessing how much nutrient the plant has actually taken up from the soil. • Recommendations are made on the basis of these test results: – Backed by research – Dependent on plant growth stage and plant part.
- 61. Soil testing • Collecting a soil sample to determine the current nutrient status of the soil.
- 62. Calibration • Process of ascertaining the degree of limitation to crop growth or the probability of getting a growth response to applied nutrient at any soil test level. • Soil test interpretation develops fertilizer recommendations.
- 63. Correlation - process • Exploratory fertilization trial – Greenhouse – a controlled environment with soil homogeneity. • Trials in field with selected soils.