Summary
The influence of phosphorus application on soil nitrogenase and N2-fixers in tropical paddy soils differing in their properties was investigated in a laboratory incubation study. Application of P stimulated the soil N2-ase in an alluvial soil and in a P-deficient soil under both flooded and nonflooded conditions. The stimulation of N2-ase by P was more pronounced under nonflooded conditions. A corresponding increase in N2-ase occurred with an increase in the P level at least up to 80 ppm level. A depressive effect of P on N2-ase occurred after 16 days under nonflooded conditions when the level of P was increased to 100 ppm. But under flooded conditions the stimulation was almost continuous. Results indicate that the effect of P on N2-ase depended on the water regime, level of P and soil type. Addition of P had a little effect on the population of N2-fixing micro-organisms in alluvial soil. On the contrary, addition of P stimulated the population of Azospirillum and Azotobacter in a P-deficient soil. Data suggested that the alteration in the N2-fixing microbial populations and the levels of available P might be responsible for changes in the N2-ase activity in these soils. Application of superphosphate and dicalcium phosphate stimulated N2-ase activity; while the rock phosphate exhibited an innocuous effect in alluvial and P deficient soils. In Sukinda soil, however, super phosphate slightly stimulated N2-ase at early stages, while other P sources had innocuous effect. Results indicate that the level and source of applied P exhibited differential influence on N2-ase and N2-fixers in tropical paddy soils.
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References
Alexander M 1977 Introduction to Soil Microbiology. 2nd Ed. pp 294–297. John Wiley and Sons, New York.
App A A, Watanabe I, Alexander M, Ventura W, Daez C, Santiago T and De Datta S K 1980 Nonsymbiotic nitrogen fixation associated with rice plant in flooded soils Soil Sci. 130, 283–289.
Charyulu P B B N and Rao V R 1979 Nitrogen fixation in some Indian rice soils. Soil Sci. 128, 86–89.
Charyulu P B B N, Nayak D N and Rao V R 198115N2 incorporation by rhizosphere soil. Influence of rice variety, organic matter and combined nitrogen. Plant and Soil 59, 399–405.
Cholitkul W, Tangcham B and Sangtong P 1980 Effect of phosphorus on N2 fixation as measured by the field acetylene reduction technique in Thailand long-term fertility plots. Soil Sci. Plant Nutr. 26, 291–299.
Daungapatra P and De Datta S K 1969 Urea ammonium phosphate and other phosphorus sources for flooded tropical rice. Intern. Rice. Commun. Newsl. 18, 1–17.
Dommergues Y R and Rinaudo G 1979 Factors affecting nitrogen fixation in the rice rhizosphere, 241–260.In Nitrogen and Rice. International Rice Research Institute, Los Banos, Philippines.
Fiske C H and Subbaraw Y 1925 The colorimetric determination of phosphorus. J. Biol. Chem. 66, 62–65.
Habte M and Alexander M 1980 Effect of Rice plants on nitrogenase activity of flooded soils. Appl. Environ. Microbiol. 40, 507–510.
Khalid R A, Patrick W H and De laune R D 1977 Phosphorus sorption characteristics of flooded soils. Soil Sci. Soc. Am. J. 46, 305–310.
Lewis C E 1970 Response to chopping and rock phosphate on south Florida ranges. J. Range Mgmt. 23, 276–282.
Mahapatra R N and Rao V R, 1981 Influence of hexachlorocyclohexane on the nitrogenase activity of rice rhizosphere soil. Plant and Soil 59, 473–477.
Matsuguchi T 1979 Factors affecting heterotrophic nitrogen fixation in submerged rice soils, 207–222.In Nitrogen and Rice. International Rice Research Institute, Los Banos, Philippines.
Nayak D N, Charyulu P B B N and Rao V R 198115N2 incorporation and acetylene reduction by Azospirillum isolated from rice roots and soils. Plant and Soil 61, 429–436.
Nayak D N, Pasalu I C and Rao V R 1980 Influence of natural and synthetic insecticides on nitrogen fixation (C2H2 reduction) in the rice rhizosphere. Curr. Sci. 49, 118–119.
Okon Y, Albrecht S L and Burris R H 1977 Methods for growingSpirillum lipoferum and for counting it in pure culture and in association with plants. Appl. Environ. Microbiol. 33, 85–88.
Rao V R Kalininskaya T A and Miller U M 1973 The activity of non-symbiotic nitrogen fixation in soils of rice fields studies with15N. Microbiologiya. 42, 729–734.
Rao J L N, Reddy B B and Rao V R 1983 Rhizosphere soil nitrogenase (C2H2 reduction) as influenced by nitrogen management in intermediate deepwater rice. J. Agric. Sci., Cambridge, 101, 547–551.
Vyas M K and Motiramani D P 1971 Effect of organic matter, silicates and moisture levels on availability of phosphate. J. Indian Soc. Soil Sci. 1, 39–43.
Watanabe I, Lee K K and De Guzman M R 1978 Seasonal changes in nitrogen-fixing rate in lowland rice field assayed byin situ acetylene reduction technique. 2. Estimation of nitrogen fixation associated with rice plant. Soil Sci. Pl. Nutr. 24, 465–471.
Watanabe I and Cholitkul W 1979 Field studies on nitrogen fixation in paddy soil, 223–239.In Nitrogen and Rice. International Rice Research Institute, Los Banos, Philippines.
Watanabe I, De Guzman M R and Cabrera D A 1981 The effect of nitrogen fertilizer on N2 fixation in the paddy field measured byin situ acetylene reduction assay. Plant and Soil 59, 135–139.
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Rao, V.R., Rao, J.L.N. & Adhya, T.K. Heterotrophic nitrogen fixation (C2H2 reduction) as influenced by phosphorus application in paddy soils. Plant Soil 92, 125–132 (1986). https://doi.org/10.1007/BF02372273
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DOI: https://doi.org/10.1007/BF02372273