Legacy effects of leguminous green manure crops on the weed seed bank in organic crop rotations
Autor: | Ilse A. Rasmussen, Jørgen E. Olesen, Bo Melander |
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Rok vydání: | 2020 |
Předmět: |
0106 biological sciences
broadleaved weeds Cash crop lucerne 010603 evolutionary biology 01 natural sciences Crop Green manure grass weeds grass-clover seed decay 2. Zero hunger Ecology Composting and manuring Weed management 04 agricultural and veterinary sciences 15. Life on land Crop rotation Weed control Agronomy seed bank depletion 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Environmental science Animal Science and Zoology Soil fertility Arable land Weed Agronomy and Crop Science |
Zdroj: | Agriculture, Ecosystems & Environment Melander, B, Rasmussen, I A & Olesen, J E 2020, ' Legacy effects of leguminous green manure crops on the weed seed bank in organic crop rotations ', Agriculture, Ecosystems & Environment, vol. 302, 107078 . https://doi.org/10.1016/j.agee.2020.107078 |
ISSN: | 0167-8809 |
DOI: | 10.1016/j.agee.2020.107078 |
Popis: | Leguminous green manure crops are important for accumulating nitrogen by means of biological nitrogen fixation and for building up soil fertility in organic arable cropping systems. Whole-year green manure crops are also known to deplete the soil weed seed bank, e.g. by decaying and predation, but there is uncertainty about the magnitude of the legacy effect after termination of the green manure crop. This study sampled soil for weed seed bank assessment upon termination of a two-year leguminous green manure crop and then one, two and three years afterwards. The samples were taken from two five-year crop rotations (2011–2015) in a long-term organic crop rotation experiment in Denmark. One rotation (O2) had a two-year green manure crop followed by three years of annual cash crops, and the other rotation (O4) consisted only of annual cash crops, with four crop sequences in both rotations represented every year. In general, the weed seed bank of rotation O2 was 54 % lower than O4, with 5475 seeds m−2 versus 11,967 seeds m−2. Similarly the aboveground amount of weed biomass in O2 was lower than in O4 over the course of the five years. The legacy effect of the green manure crop showed a negative exponential rise in weed seed numbers with the increase in years after termination of the green manure crop. A biennial leguminous green manure crop can mitigate weed problems in organic annual crops. This effect adds to the benefits of including nitrogen fixing leys in crop rotations with limited access to animal manures. |
Databáze: | OpenAIRE |
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