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The effect of orchard soil management on the uptake of nitrogen by established apple trees
Author(s) -
Atkinson David,
Johnson Martin G.,
Mattam David,
Reuben Mercer E.
Publication year - 1979
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740300206
Subject(s) - orchard , nitrogen , horticulture , agronomy , chemistry , biology , organic chemistry
Nitrogen‐15 was supplied as K 15 NO 3 to mature Cox/M.26 apple trees grown in conventional wide herbicide strips, with overall herbicide or with complete grass cover. Uptake was measured, following placement, either at 10 cm depth within the tree rows or at 10 or 25 cm depth in the alleys between the rows. Uptake of 15 N in the strip treatment was always much greater from the strip than from the grassed alley, while with the overall herbicide trees, uptake was highest from the tree row in June but from the alley in August. With overall grass, uptake was highest from the alley. Management treatments did not affect the total N content of the leaves, so results were similar whether expressed on an atom % or pg μg g −1 DW basis. In the herbicide strip treatment, application of fertiliser nitrogen at rates between 0 and 126 kg ha −1 had little effect on either the amount or the pattern of 15 N uptake. Recovery of added 15 N tracer by the trees during the year of treatment varied from 2 to 25% depending upon treatment, position and depth of injection. Absorption of 15 N appeared to be greater in mid‐summer than in spring or autumn. Pattern of N uptake was affected by interaction between soil water status, periodicity of root growth and total N demand.