Abstract
Provision of N, P, and Ca to field plants of A. linearis markedly (P<0.05) increased growth and N nutrition in a very acidic nutrient-poor soil. Application of P and Ca promoted a significant increase in %N derived from fixation and amounts of N fixed compared to those receiving no nutrients. N2 fixation measured under field conditions ranged from 3.8 g N plant-1 in unfertilized control to 7.1 g N plant-1 in fertilized plants. Overall, about 85% increase in N2 fixation was observed with P supply. The high N2-fixing activity in P-treated plants was confirmed by their lower (more negative) ∂15N values. Age of plants also influenced growth and symbiotic activity as the ∂15N values, %N derived from fixation, and N fixed were lower in 1- and 2-year-old plants compared to 3-year-old. The contribution of symbiotic fixation in unfertilized A. linearis to the N economy of the ecosystem ranged from 105 kg N ha-1 in 1-year-old plants to 128 kg N ha-1 in 3-year-old plants, clearly indicating the remarkable adaptation of this symbiosis to the very nutrient-poor, low pH conditions of Cedarberg soils.
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Bergersen F J and Turner G L 1983 An evaluation of 15N methods for estimating N2 fixation in subterranean clover-perennial ryegrass sward. Aust. J. Agric. Res. 36, 411–423.
Cho M J and Harper J E 1991 Effect of localized nitrate application on isoflavonoid concentration and nodulation in split-root systems of wild-type and nodulation-mutant soybean plants. Plant Physiol. 96, 1106–1112.
Cocks M 1994 The ecology and N2-fixing ability of selected Aspalathus spp. in the fynbos ecosystem. MSc Thesis, University of Cape Town.
Dakora F D 1998 Nodulation specificity of Aspalathus linearis subsp. linearis, a shrub tea legume indigenous to the Western Cape. In Biological Nitrogen Fixation for the 21st Century. Eds. C Elmerich, A Kondorosi and W E Newton. pp 671–672. Kluwer, Dordrecht.
Dakora F D and Keya S O 1997 Contribution of legume nitrogen fixation to sustainable agriculture in Sub-Saharan Africa. Soil Biol. Biochem. 29, 809–817.
Dakora F D and Le Roux R J 1995 Phosphorus nutrition alters root flavonoid content, nitrogen fixation, and phosphorus partitioning in cowpea. In Nitrogen Fixation: Fundamentals and Applications Eds. I A Tikhonovich, N A Provorov, V I Romanov and W E Newton. p 324. Kluwer, Dordrecht.
Dakora F D, Atkins C A and Pate J S 1992 Effect of NO3_ on N2 fixation and nitrogenous solutes of xylem in two nodulated West African geocarpic legumes, Kersting's bean (Macrotyloma geocarpum L.) and Bambara groundnut (Vigna subterranea L.). Plant Soil 140, 255–262.
Danso S K A, Bowen G D and Sanginga N 1992 Biological nitrogen fixation in trees in agro-ecosystems. Plant Soil 141, 177–196.
Deschodt C C and Strijdom B W 1976 Effective nodulation of Aspalathus linearis by rhizobia from other Aspalathus species. Phytophylactica 8, 103–104.
Dreyfus B L, Diem H G, Freire J, Keya S O and Dommergues Y R 1987 Nitrogen fixation intropical agriculture and forestry. In Microbial Technology in the Developing World. Eds. E J Dasilva, Y R Dommergues, E J Nyns and C Ratledge. pp 7–50. Oxford University Press, UK.
Hansen A P and Pate J S 1987 Evaluation of the 15N natural abundance method and xylem sap analysis for assessing N2 fixation of understorey legumes in Jarrah forest (Eucalyptus marginata Donn ex Sm.). J. Exp. Bot. 38, 1446–1458.
Hogberg P 1986 Nitrogen fixation and nutrient relations in savanna woodland trees (Tanzania). J. Appl. Ecol. 23, 675–688.
Israel DW1987 Investigation of the role of phosphorus in symbiotic dinitrogen fixation. Plant Physiol. 84, 835–840.
Ledgard S F, Freney J R and Bergersen F J 1985 Effect of reference plant on estimation of nitrogen fixation by subterranean clover using 15N methods. Aust. J. Agric. Res. 36, 663–676.
Marumo M 1996 Ecology of the (Brady)rhizobium symbiotic relationship with Fabaceae in the South Western Cape. MSc Thesis, University of Cape Town.
Masutha T H, Muofhe M L and Dakora F D 1997 Evaluation of N2 fixation and agroforestry potential in selected tree legumes for sustainable use in South Africa. Soil Biol. Biochem. 29, 993–998.
Muofhe M L 1997 N2 Fixation and Rhizosphere Ecology of Aspalathus linearis subsp. linearis (Rooibos tea). MSc Thesis, University of Cape Town.
Muofhe M L and Dakora F D 1997 Bradyrhizobium species isolated from indigenous legumes of the Western Cape exhibit high tolerance of low pH. In Biological Nitrogen Fixation for the 21st Century. Eds. C Elmerich, A Kondorosi and WE Newton. p 519. Kluwer, Dordrecht.
Ofori F, Pate J S and Stern W R 1987 Evaluation of N2 fixation and nitrogen economy of maize/cowpea intercrop using 15N dilution methods. Plant Soil 102, 149–160.
Pate J S, Atkins C A, White T S, Rainbird R M and Woo K C 1980 Nitrogen nutrition and xylem transport of nitrogen in ureide-producing grain legumes. Plant Physiol. 65, 961–965.
Peoples M B and Herridge D F 1990 Nitrogen fixation by legumes in tropical and subtropical agriculture. Adv. Agron. 44, 155–23.
Peoples M B, Herridge D F and Ladha J K 1995 Biological nitrogen fixation: investments, expectations and actual contribution to agriculture. Plant Soil 174: 3–28.
Reeve WG, Tiwari R P, Dilworth M J and Glenn A R 1993 Calcium affects the growth and survival of Rhizobium meliloti. Soil Biol. Biochem. 25, 581–586.
Richardson A E, Djordjevic M A, Rolfe B G and Simpson R J 1988 Effects of pH and aluminium on the exudation from clover seedlings of compounds that induce expression of nodulation genes in Rhizobium trifolii. Plant Soil 109,37–47.
Robson A D, O'Hara G W and Abbot L K 1981 Involvement of phosphorus in nitrogen fixation by subterranean clover (Trifolium subterraneun L.). Aust. J. Plant Physiol. 8, 427–436.
Sanginga N, Mulongoy K and Ayanaba A 1986 Inoculation of Leucaena leucocephala (Lam)de Wit with Rhizobium and its nitrogen contribution to subsequent maize crop. Biol. Agric. Hortic. 3, 341–347.
Schulze E D, Gebaauer G, Ziegler H and Lange O L 1991 Estimates of nitrogen fixation by trees on an aridity gradient in Namibia. Oecologia 88, 451–544.
Shearer G and Kohl D H 1986 N2 fixation in field settings: estimations based on natural 15N abundance. Aust. J. Plant Physiol. 13, 699–756.
Shearer G, Kohl D H, Virginia R A, Bryan B A, Skeeters J L, Nilsen E T, Sharifi M R and Rundel P W 1983 Estimates of N2 fixation from variation in the natural abundance of 15N in Sonoran Desert ecosystem. Oecologia 56, 365–373.
Smith F W 1982 Mineral nutrition of legumes. In Nitrogen Fixation in Legumes. Ed. J M Vincent. pp 155–172. Academic Press, Sydney.
Staphorst J L and Strijdom B W 1975 Specificity in the Rhizobium symbiosis of Aspalathus linearis (Burm. fil.) R. Dahlgr. ssp. linearis. Phytophylactica 7, 95–96.
Werner C and Hohl H R 1990 The effects of Ca2C and Mg2C on accumulation and secretion of isoflavonoids by soybean roots. Plant Sci. 72, 181–191.
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Muofhe, M., Dakora, F. Nitrogen nutrition in nodulated field plants of the shrub tea legume Aspalathus linearis assessed using 15N natural abundance. Plant and Soil 209, 181–186 (1999). https://doi.org/10.1023/A:1004514303787
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DOI: https://doi.org/10.1023/A:1004514303787