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.
Similar content being viewed by others
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.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
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
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02372273