Båth, Birgitta
(2000).
Matching the availability of N mineralised from green-manure crops with the N-demand of field vegetables.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae. Agraria, 1401-6249
; 222
ISBN 91-576-5754-8
[Doctoral thesis]
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Abstract
This work assesses the possibilities of reducing N-losses from green-manure crops in cropping systems with iceberg lettuce and leek, by matching the availabilty of N mineralised from green.manure crops with N-demand of field vegetables. The influence of the choice of green-manure species (A), combination of species (B) and time of incorporation (C) was examined by analysing the temporal pattern of N-mineralisation from green-manures, and the N-uptake and root growth of the vegetable crops. In one of two field experiments, the effect of autumn and spring incorporated Persian clover, white clover and yellow-sweet clover was examined (A, C). In the other field experiment, the effect of inter-row red clover strips incorporated at different times during the cropping period was investigated (B). Net N-mineralisation from a mixture of perennial ryegrass and red clover was evaluated in an incubation experiment (C). Uptake of N by perennial green-manure species kept N protected in the green-manure tissues until incorporation into soil and thus prepared the way for a match between N- availability and N-demand. The amount of N incorporated differed with green-manure species. However, because the chemical composition influenced the percentage of N mineralised, no effect of species could be observed in the temporal pattern of N- mineralisation or crop yields. Different combinations of species in the incubation experiment and time of incorporation in the field did, however, influence the temporal pattern of N-mineralisation. Combining red clover with rye grass resulted in net N- immobilisation followed by a net N-mineralisation rate that temporarily exceeded that of clover alone. However, a similar pattern was not observed when inter-row red clover strips of different ages were incorporated into the soil. The change in temporal pattern of N-mineralisation from red clover was instead proportional to the intervals with which the red clover strips were incorporated. This synchronisation effect was counteracted by uptake and transfer of N in crop rows by the clover strips between rows. In treatments with the latest time of incorporation the competition between the vegetable crop and clover strips together with low intensity and lateral spread of vegetable roots contributed to low N-upta
Authors/Creators: | Båth, Birgitta | ||||
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Title: | Matching the availability of N mineralised from green-manure crops with the N-demand of field vegetables | ||||
Series Name/Journal: | Acta Universitatis Agriculturae Sueciae. Agraria | ||||
Year of publishing : | January 2000 | ||||
Number: | 222 | ||||
Number of Pages: | 29 | ||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||
ISBN for printed version: | 91-576-5754-8 | ||||
ISSN: | 1401-6249 | ||||
Language: | English | ||||
Publication Type: | Doctoral thesis | ||||
Full Text Status: | Public | ||||
Agris subject categories.: | P Natural resources > P35 Soil fertility F Plant production > F01 Crop husbandry F Plant production > F04 Fertilizing | ||||
Subjects: | Not in use, please see Agris categories | ||||
Agrovoc terms: | trifolium pratense, trifolium repens, trifolium resupinatum, melilotus officinalis, green manures, allium ampeloprasum, lactuca sativa, brassica oleracea, vegetable crops, nitrogen fixation, mineralization, nitrogen cycle, soil fertility, nutrient availability, leaching, sweden | ||||
Keywords: | field vegetables, green-manure species and combinations, N-availability, N-demand, root development, time of incorporation | ||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-5421 | ||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-5421 | ||||
ID Code: | 33 | ||||
Department: | (NL, NJ) > Dept. of Soil Sciences (until 081001) | ||||
Deposited By: | Staff Epsilon | ||||
Deposited On: | 13 May 2002 00:00 | ||||
Metadata Last Modified: | 02 Dec 2014 10:01 |
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