The fate of15N labeled nitrogen applied to mature citrus trees
- 163 Downloads
The efficiency and balance of nitrogen from one year's application was studied in a long-term fertigation experiment. Enriched nitrogen fertilizer, K15NO3, was applied to a 22-year-old Shamouti orange tree with a history of high N applications (N3) and to an N-starved tree (N1). The distribution of N in the different parts of the trees and in the soil was determined after the experimental trees were excavated.
Similar total recovery of the labeled fertilizer N was found in the trees and soil in both treatments (N1−61.7% N3−56%). However, the distribution between tree and soil was different. The amount of recovered residual fertilizer in the soil was much larger in the N3 treatment than in N1. The highest percentage of fertilizer N was found in the new organs,i.e. fruits, twigs and leaves. The roots and branches took up only 6–14% from the labeled fertilizer.
Only 20.9% of the leaf N and 23.4% of the fruit N in the N3 tree originated in the labeled fertilizer, indicating translocation of N from older parts of the tree to new growth.
Evidence was found of storage of N in the wooded branches, while the roots contained a surprisingly small part of labeled fertilizer.
Key wordsCitrus sinensis Dry matter distribution Fertigation Hamra soil Leaf area index Mediterranean climate Nitrogen distribution Nitrogen recovery Nitrogen uptake Oranges Shamouti
Unable to display preview. Download preview PDF.
- 1.Bielorai H, Dasberg S and Erner Y 1985 Long-term effects of partial wetting in a citrus orchard. Proceedings of the Third International Drip/Trickle Irrigation Congress. (Fresno, CA.) ASAE, 2, 568–574.Google Scholar
- 2.Bremner J M 1965 Total nitrogen.In Methods of Soil Analysis, Part 2. Ed. C A Black Agronomy 9, 1149–1178.Google Scholar
- 3.Camerson S H and Compton O C 1945 Nitrogen in bearing orange trees. Proceedings of the American Society of Horticultural Science 46, 60–68.Google Scholar
- 4.Castle W S 1978 Citrus root systems: their structure, function growth and relationship to tree performance. Proceedings of the International Society of Citriculture 1978, 62–69.Google Scholar
- 5.Cohen S 1983 Light relations of an orange canopy. Ph.D. thesis, Hebrew University of Jerusalem, Israel.Google Scholar
- 7.Embleton T W, Jones W W, Labanauskas C K and Reuther W 1973 Leaf analysis as a diagnostic tool and guide to fertilization.In Citrus Industry, III, Ed. W J Reuther. 183–211.Google Scholar
- 8.Feigenbaum Sala and Hadas Aviva 1974 Methods of sample preparation for15N determination in soil extract by emission spectrometry. Soil Sci. 117, 168–170.Google Scholar
- 9.Feigenbaum Sala, Seligman N G and Benjamin R W 1984 Fate of nitrogen-15 applied to spring wheat grown for three consecutive years in a semi-arid region. Soil Sci. Soc. Am. J. 48, 838–843.Google Scholar
- 10.Hauck R D and Bremner J M 1976 Use of tracers for soil and fertilizer nitrogen research. Adv. Agron. 28, 219–266.Google Scholar
- 11.Iwakiri T and Nakahara M 1981 Nitrogen fertilization programs in Satsuma mandarin orange groves in Japan. Proceedings of the International Society of Citriculture (Tokyo, 1981), 571–574.Google Scholar
- 12.Kalma J D 1969 Some aspects of the water balance of an irrigated orange plantation. Ph.D. thesis, Hebrew University of Jerusalem, Israel.Google Scholar
- 14.Legaz F, Primo Millo E, Primo Jufera E and Gil C 1981 Dynamics of15N labeled nitrogen nutrients in Valencia orange trees. Proceedings of the International Society of Citriculture, Japan, 1981, 575–582.Google Scholar
- 15.Legaz F and Primo Millo E 1984 Influence of flowering, summer and autumn flushes on the absorption and distribution of N compounds in citrus. Proceedings of the International Society of Citriculture, (Sao Paulo, Brasil, 1984) (In press).Google Scholar
- 16.Legg J O and Meisinger J J 1982 Soil nitrogen budgets.In Nitrogen in Agricultural Soils. Agronomy 22, 503–560.Google Scholar
- 17.Titus T S and Kang S M 1982 Nitrogen metabolism, translocation and recycling in apple trees. Hortic. Rev. 4, 204–246.Google Scholar
- 18.Weinbaum S A, Klein I, Broadbent F E, Micke W C and Murauka T T 1984 Effect of time of nitrogen application and soil texture on the availability of isotopically labeled fertilizer nitrogen to reproductive and vegetative tissue of mature almond trees. J. Am. Soc. Hortic. Sci., 109, 339–343.Google Scholar