Printable Nitrogen Cycle Interactive Nitrogen Cycle Nitrogen Text Back to Intro Page GLOBAL WARMING ATMOSPHERE N2O NO N2 PLANT LOSS INDUSTRIAL FIXATION N2 FIXATION SYMBIOTIC NON-SYMBIOTIC MESQUITE RHIZOBIUM ALFALFA SOYBEAN BLUE-GREEN ALGAE AZOTOBACTER CLOSTRIDIUM LIGHTNING, RAINFALL PLANT AND ANIMAL RESIDUES HABER BOSCH (1200°C, 500 atm) 3H2 + N2 2NH3 MATERIALS WITH N CONTENT > 1.5% (COW MANURE) FERTILIZATION MATERIALS WITH N CONTENT < 1.5% (WHEAT STRAW) AMINO ACIDS NH3 AMMONIA VOLATILIZATION AMINIZATION ORGANIC MATTER HETEROTROPHIC R-NH2 + ENERGY + CO2 BACTERIA (pH>6.0) FUNGI (pH<6.0) IMMOBILIZATION Pseudomonas, Bacillus, Thiobacillus Denitrificans, and T. thioparus R-OH + ENERGY + 2NH3 N2O2MINERALIZATION + NITRIFICATION MICROBIAL/PLANT SINK 2NH4+ + 2OHFIXED ON EXCHANGE SITES NO2- OXIDATION STATES NH3 AMMONIA -3 NH4+ AMMONIUM -3 N2 DIATOMIC N 0 N2O NITROUS OXIDE 1 NO NITRIC OXIDE 2 NO2- NITRITE 3 NO3 NITRATE 5 pH>7.0 R-NH2 + H2O AMMONIFICATION NH2OH NO3POOL DENITRIFICATION LEACHING TEMP 50°F LEACHING NITRIFICATION 2NO2- + H2O + 4H+ Nitrobacter LEACHING VOLATILIZATION NITRIFICATION LEACHING + O2 Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees LEACHING pH 7.0 +O2 Department of Plant and Soil Sciences Oklahoma State University ADDITIONS LOSSES OXIDATION REACTIONS REDUCTION REACTIONS Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Plant and Animal Residues Lightning, Rainfall Fertilizer Plant Loss Volatilization R-NH2 + Energy + CO2 Organic Matter R-NH2 + H2O N2, N2O, NO Plant/Microbial Sink R-OH + Energy + 2NH3 NO3- Pool 2NH4+ + 2OHSoil exchange sites Leaching 2NO2- + H2O + 4H+ Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Symbiotic Rhizobium Alfalfa Mesquite Soybean Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Plant and Animal Residues Non-Symbiotic Azotobacter Cyanobacteria Clostridium Fertilizer Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Haber-Bosch (1200C, 500 ATM) Lightning, Rainfall Plant and Animal Residues 3CH4 + 3O2 + 2N2 4NH3 + 3CO2 Fertilizer Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Plant and Animal Residues Lightning, Rainfall Fertilizer Plant Loss Organic Matter Volatilization Small Percentage N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Soil Exchange Sites Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Plant and Animal Residues Oxidation of N N2 + 3O2 2NO3Fertilizer Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Plant and Animal Residues %N > 1.5 %N < 1.5 (Animal Manure) (Wheat Straw) Fertilizer Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter Temperature above or below 50°F? N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Plant and Animal Residues Lightning, Rainfall Fertilizer Volatilization Heterotrophic Aminization R-NH2 + Energy + CO2 Plant Loss Fungi pH < 6.0 Bacteria pH > 6.0 Ammonification Organic Matter Immobilization pH > 7.0 R-NH2 + H2O N2, N2O, NO R-OH + Energy + 2NH3 Immobilization Plant/Microbial Sink + H2O 2NH4+ + 2OH- NO3- Pool Soil exchange sites Back to Main Cycle Back to Temperature Choice Leaching 2NO2- + H2O + 4H+ Back to Intro Page Interactive Nitrogen Cycle Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Amino Acids Plant Loss Organic Matter NH3 N2, N2O, NO NH2OH NO2N2O2Thiobacillus, T. Thioparus, Pseudomonas, Bacillus, and Dentrificans Back to Main Cycle Immobilization NO3- Pool Plant/Microbial Sink Mineralization & Nitrification Denitrification Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Back to Temperature Choice Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter Immobilization N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching 2NH4+ + 2OH- Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink Thiobacillus, T. Thioparus, Pseudomonas, Bacillus, and Dentrificans Back to Main Cycle NO3- Pool Denitrification Leaching Back to Intro Page Interactive Nitrogen Cycle Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter NH3 N2, N2O, NO NH2OH NO2- Plant/Microbial Sink N2O2- NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Lightning, Rainfall Fertilizer Plant and Animal Residues Volatilization Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Plant and Animal Residues Lightning, Rainfall Fertilizer Volatilization Heterotrophic Aminization R-NH2 + Energy + CO2 Plant Loss Ammonification Organic Matter pH > 7.0 R-NH2 + H2O N2, N2O, NO R-OH + Energy + 2NH3 Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Interactive Nitrogen Cycle N2 Fixation Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Atmosphere Department of Plant and Soil Sciences Oklahoma State University Industrial Processes Haber-Bosch (1200C, 500 ATM) Lightning, Rainfall Plant and Animal Residues 3CH4 + 3O2 + 2N2 4NH3 + 3CO2 Fertilizer Volatilization Heterotrophic Aminization R-NH2 + Energy + CO2 Plant Loss Organic Matter N2, N2O, NO Plant/Microbial Sink NO3- Pool Back to Main Cycle Leaching Back to Intro Page Nitrogen Information Form taken up plant Enzymes that require N Mobility Concentration in plants Deficiency symptoms Effect of pH on availability Soil pH deficiency Nutrient interactions Role of N in plant growth Fertilizer sources Role of N in microbial growth References • NH4+ • NO3- Back to N Text Main Page Back to Intro Page • Soil – NH4+; NO – NO3- ; Yes • Water Soluble • Not influenced by soil colloids • Plant – Yes Back to N Text Main Page Back to Intro Page • Chlorosis in older leaves • Under severe deficiency lower leaves are brown, beginning at the leaf tip and proceeding along the midrib Back to N Text Main Page Back to Intro Page • None due to nitrate’s mobility Back to N Text Main Page Back to Intro Page • N assimilation into amino acids for protein and amino acid synthesis • Component of chlorophyll • Vegetative growth Back to N Text Main Page Back to Intro Page • Necessary for the synthesis for amino acids Back to N Text Main Page Back to Intro Page • Nitrate reductase • Nitrite reductase • Nitrogenase Back to N Text Main Page Back to Intro Page • Wheat 1.7 to 3.0% – Grain 2.0% – Forage 3.0% – Straw • • • • • • Corn 2.7 to 3.5% Soybeans 4.2 to 5.5% Grain sorghum 3.3 to 4.0 % Peanuts 3.5 to 4.5 % Alfalfa 4.5 to 5.0% Bermudagrass 2.5 to 3.0% Back to N Text Main Page Back to Intro Page • Low pH – None • High pH – None at pH > 8 – At pH > 7 NO2- accumulates Back to N Text Main Page Back to Intro Page • Si: enhances leaf erectness neutralizing the negative effects of high N supply on light interception • P: symbiotic legume fixation needs adequate P, or a N deficiency can result • Mo: component of nitrogenase, therefore could have Mo induced N deficiency in N2 fixing legumes • Fe: Necessary for nitrogenase and ferredoxin, legume hemoglobin, deficiency reduces nodule mass, and nitrogenase Back to N Text Main Page Back to Intro Page ammonium sulfate ammonium chloride ammonium nitratesulfate ammoniated ordinarysuperphosphate monoammonium phosphate ammonium polyphosphate calcium nitrate sodium nitrate urea-sulfate urea-ammonium phosphate Back to N Text Main Page anhydrous ammonia ammonium nitrate ammonium nitrate with lime ammonium phosphatesulfate diammonium phosphate ammonium thiophosphate potassium nitrate urea urea-ammonium nitrate urea phosphate Back to Intro Page • Burford, J.R., and J.M. Bremner. 1975. Relationships between the denitrification capacities of soils and total, water-soluble and readily decomposable soil organic matter. Soil Biochem. 7:389-394. • Marschner, H. 1995. Mineral Nutrition in Higher Plants. Academic Press, London. • Tisdale, S.L., W.L. Nelson, J.D. Beaton, and J.L. Havlin. 1993. Soil Fertility and Fertilizers. MacMillan Publishing Co., New York, N.Y. Back to N Text Main Page Back to Intro Page