TY - JOUR

T1 - Narrow-leaved lupine as an N source alternative to grass-clover swards in organic vegetable rotations

AU - Katroschan, Kai Uwe

AU - Stützel, Hartmut

N1 - Publisher Copyright: © 2017 Informa UK Limited, trading as Taylor & Francis Group. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2017

Y1 - 2017

N2 - Legumes represent an important N source in organic vegetable rotations. Since the amount of N2 fixed as well as N mineralisation from legume biomass are highly variable, N availability does often not match the requirements of following crops. The production of grain legume seeds followed by their temporary storage and application as N fertilizer may represent a flexible and controllable alternative to traditional legume green manures. In two field experiments, narrow-leaved lupine was investigated as N source for subsequent white cabbage and beetroot and was compared to two grass-clover treatments, in which cut herbage was either removed from the sward or remained as mulch. Symbiotic N2 fixation was highest for cut grass-clover, averaging about 350 kg ha−1. Mulching reduced N2 fixation by on average 57%. Lupine N2 fixation was largely comparable to that of mulched grass-clover swards. Net N mineralisation from grass-clover residues within the year of their incorporation was positively related to the percentage of clover (R2 = 0.93). Application of coarsely milled lupine seeds on plots previously cropped with lupines resulted in an N supply for cabbage being higher or equal to that after mulched grass-clover. Residual effects on the N supply for beetroot, grown in the third rotational year following white cabbage, averaged −2 and 28 kg N ha−1 for lupine and grass-clover, respectively. In conclusion, lupines may provide a highly flexible N source alternative to frequently mulched grass-clover swards. Further attention should be directed towards the utilization of cut forage legume herbage as mobile N source.

AB - Legumes represent an important N source in organic vegetable rotations. Since the amount of N2 fixed as well as N mineralisation from legume biomass are highly variable, N availability does often not match the requirements of following crops. The production of grain legume seeds followed by their temporary storage and application as N fertilizer may represent a flexible and controllable alternative to traditional legume green manures. In two field experiments, narrow-leaved lupine was investigated as N source for subsequent white cabbage and beetroot and was compared to two grass-clover treatments, in which cut herbage was either removed from the sward or remained as mulch. Symbiotic N2 fixation was highest for cut grass-clover, averaging about 350 kg ha−1. Mulching reduced N2 fixation by on average 57%. Lupine N2 fixation was largely comparable to that of mulched grass-clover swards. Net N mineralisation from grass-clover residues within the year of their incorporation was positively related to the percentage of clover (R2 = 0.93). Application of coarsely milled lupine seeds on plots previously cropped with lupines resulted in an N supply for cabbage being higher or equal to that after mulched grass-clover. Residual effects on the N supply for beetroot, grown in the third rotational year following white cabbage, averaged −2 and 28 kg N ha−1 for lupine and grass-clover, respectively. In conclusion, lupines may provide a highly flexible N source alternative to frequently mulched grass-clover swards. Further attention should be directed towards the utilization of cut forage legume herbage as mobile N source.

KW - apparent net N mineralisation

KW - grass-clover sward management

KW - lupine seed meal

KW - Lupinus angustifoliusL

KW - symbiotic N fixation

KW - vegetable crop rotation

UR - http://www.scopus.com/inward/record.url?scp=85011303915&partnerID=8YFLogxK

U2 - 10.1080/01448765.2017.1285250

DO - 10.1080/01448765.2017.1285250

M3 - Article

AN - SCOPUS:85011303915

VL - 33

SP - 125

EP - 142

JO - Biological Agriculture and Horticulture

JF - Biological Agriculture and Horticulture

SN - 0144-8765

IS - 2

ER -