Abstrakt
Nitrogen (N) nutrition is a major means of controlling growth and fruiting of trees. In EU Countries, society’s expectations and political decisions have pushed for the adoption of sustainable ways to manage orchards. Guidelines for N management aim to limit fertiliser applications under threshold limits, in order to reduce N losses. Increasing the effectiveness of the recycling of the N present in the orchard is a basic step to reduce external N inputs. The availability of the stable isotope 15N as experimental tool has made possible significant advances in the knowledge of the fluxes of N at tree and orchard
level. This paper discusses the N fluxes occurring within the tree both between the years and within the year (root-shoot-root N recycle) and their role in the vegetative and reproductive cycle of fruit trees.
Bibliografia
Coleman G. D., Englert J. M., Chen T. H. H., Fuchigami H., 1993. Physiological and environmental requirements for poplar (Populus deltoids) bark storage protein degradation. Plant Physiol. 102, 53–59.
Cooper H. D., Clarkson D. T., 1989. Cycling of amino-nitrogen and other nutrients between shoots and roots in cereals – A possible mechanism integrating shoot and root in the regulation of nutrient uptake. J. Exp. Bot. 40, 753–762.
Dong S. F., Scagel C. F., Cheng L. L., Fuchigami L. H., Rygiewicz P. T., 2001. Soil temperature and plant growth stage influence nitrogen uptake and amino acid concentration of apple during early spring growth. Tree Physiol. 21, 541–547.
Fife D. N., Nambiar E. K. S., 1984. Movement of nutrients in Radiata pine needles in relation to the growth of shoots. Ann. Bot. 54, 303–314.
Frak E. W., Millard P., Roux X. Le, Guillaumie S., Wendler R., 2002. Coupling sap flow velocity and amino acid concentrations as an alternative method to 15N labeling for quantifying nitrogen remobilization by walnut trees. Plant Physiol. 130, 1043–1053.
Grassi G., Millard P., Wendler R., Minotta G., Tagliavini M., 2002. Measurement of xylem sap amino acid concentrations in conjunction with whole tree transpiration estimates spring N remobilization by cherry (Prunus avium L.) trees. Plant Cell Environ. 25, 1689–1699.
Grassi G., Millard P., Giacchini P., Tagliavini M., 2003. Recycling of nitrogen in the xylem of Prunus avium trees starts when spring remobilization of internal reserves declines. Tree Physiology 23, 1061–1068.
Guak S., Neilsen D., Millard P., Neilsen G. H. 2003. Determining the role of N remobilization for growth of apple (Malus domestica Borkh.) trees by measuring xylem – sap flux. J. Exp. Bot. 54, 2121–2131.
Jeschke W. D., Pate J. S., 1991. Modelling of the partitioning, assimilation and storage of nitrate within root and shoot organs of castor bean (Ricinus communis L.). J. Exp. Bot. 42, 1091–1103.
Jeschke W. D., Pate J. S., 1992. Temporal patterns of uptake, flow and utilization of nitrate, reduced nitrogen and carbon in a leaf of salt-treated castor bean (Ricinus communis L.). J. Exp. Bot. 43, 393–402.
Malaguti D., Millard P., Wendler R., Hepburn A., Tagliavini M. 2001. Translocation of amino acids in the xylem of apple (Malus domestica Borkh.) treea as a consequence of both N remobilization and root uptake. Journal of Experimental Botany 52 (361), 1665–1671.
Marschner H., 1995. Mineral nutrition of higher plants. 2nd edition. London, Academic Press, 889.
Marschner H., Kirkby E. A., Cakmak I., 1996. Effect of mineral nutritional status on shoot-root partitioning of photoassimilates and cycling of mineral nutrients. J. Exp. Bot. 47, 1255–1263.
Millard P., 1996. Ecophysiology of the internal cycling of nitrogen for tree growth. J. Plant Nutr. Soil Sci. 159, 1–10.
Millard P., Proe M., 1992. Storage and internal cycling of nitrogen in relation to seasonal growth of Sitka spruce. Tree Physiol. 10, 33–43.
Millard P., Wendler R., A Hepburn., Smith A., 1998. Variations in the amino acid composition of xylem sap of Betula pendula Roth. trees due to remobilization of stored N in the spring. Plant Cell Environ. 21, 715–722.
Neilsen D., Millard P., Neilsen G. H., Hogue E. J., 1997. Sources of N used for leaf growth in a high density apple (Malus domestica) orchard irrigated with ammonium nitrate solution. Tree Physiol. 17, 733–739.
Niederholzer F. J. A., DeJong T. M., Saenz J. L., Muraoka T. T. Weinbaum S.A., 2001. Effectiveness of Fall vs. Spring Soil Fertilization of Field-Grown Peach Trees. J. Am Soc. 126(5), 644–648.
Neilsen D., Millard P., Neilsen G. H., Hogue E. J., 2001. Nitrogen uptake, efficiency of use and partitioning for growth in young apple trees. J. Am. Soc. Hort. Sci. 126, 144–150.
Pate J. S., 1975. Exchange of solutes between phloem and xylem and circulation in the whole plant. [In:] Transport in Plants. I. Phloem transport. Eds. M.H. Zimmermann and J.A. Milburn. Springer Verlag, Berlin, 451–473.
Quartieri M., Millard P., Tagliavini M., 2002. Storage and remobilization of nitrogen by pear (Pyrus communis) trees as affected by timing of N supply. Eur. J. Agron. 17, 105–110.
Rosecrance R. C., Johnson R. S., Weinbaum S. A., 1998. The effect of timing of post-harvest foliar urea sprays on nitrogen absorption and partitioning in peach and nectarine trees. J. Hort. Sci. 73(6), 856–861
Rufat J., DeJong T. M., 2001. Estimating seasonal nitrogen dynamics in peach trees in response to nitrogen availability. Tree Physiol. 21, 1133–1140.
Sanchez E. E., Righetti T. L., Sugar D., Lombard P. B., 1991. Recycling of nitrogen in fieldgrown ‘Comice’ pears. J. Hort. Sci. 66, 541–546.
Tagliavini M., P. Millard., Quartieri M., 1998. Storage of foliar-absorbed nitrogen and remobilization for spring growth in young nectarine (Prunus persica var. nectarina) trees. Tree Physiol 18, 203–207.
Tagliavini M., Millard P., Quartieri M., Marangoni B., 1999. Timing of nitrogen uptake affects winter storage and spring remobilisation of nitrogen in nectarine (Prunus persica var. nectarina) trees. Plant and Soil 211(2), 149–153.
Tagliavini M., Quartieri M., Millard P., 1997. Remobilised nitrogen and root uptake of nitrate for leaf growth, flowers and developing fruits of pear (P. communis) trees. Plant and Soil, 195, 37–142.
Warren C. R., Dreyer E., Adams M., 2003. Photosynthesis – Rubisco relationships in foliage of Pinus sylvestris in response to nitrogen supply and the proposed role of Rubisco and amino acids as nitrogen stores. Trees 17, 359–366.
Weber P., Stoerner H., Gessler A., Schneider S., von Sengbusch D., Hanemann U., Rennenberg H., 1998. Metabolic responses of Norway spruce (Picea abies) trees to long-term forest management practices and acute (NH4)2SO4 fertilization: transport of soluble non-protein nitrogen compounds in xylem and phloem. New Phytol. 140, 461–475.
Weinbaum S., van Kessel C., 1998. Quantitative estimates of uptake and internal cycling of N-14 labelled fertilizer in mature walnut trees. Tree Physiol. 18, 795–801.
Youssefi F., Brown P. H., Weinbaum S. A., 2000. Relationship between tree nitrogen status, xylem and phloem sap amino acid concentrations, and apparent soil nitrogen uptake by almond trees (Prunus dulcis). J. Hort. Sci. Biotech. 75, 62–68.
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