In addition to being a valuable protein and energy source in animal feeding, grain legumes benefit the cropping system, via biological fixation of atmospheric N2 - a fundamental process for maintaining soil fertility in organic farming systems. Other positive effects in the crop rotations are recycled N-rich crop residues and the break-crop effects in the often cereals-rich rotations. Thus, important environmental benefits can be obtained when including legumes in rotations and forage production systems while on the same time increasing productivity, reducing the use of fossil energy and thereby overall emissions of greenhouse gases. In addition to these effects, an increased cultivation of legumes would reduce dependence on protein imports (mainly soybeans) and the associated negative effects (long transport, deforestation of tropical forests). Nevertheless the area of legumes in the European cropping systems is very low (around 5% of grain legumes and even lower in Denmark), while it is far higher (around 20%) in the USA.
The aims of the project are to: - determine the potential for grain legume production in organic cropping systems on different soil types,
- identify eventual obstacles to the grain legume production,
- evaluate methods, e.g. intercropping with cereals, to overcome some of the obstacles, for in-creased production of high quality grain legumes seeds, and
- give recommendations for species and cultivar choice depending on production system, soil type and use of grain legumes seeds in the organic animal production.
Grain legume crops should preferentially appear frequently in the rotation in order to cover the protein supply for feed together with optimum N2-fixation inputs to the cropping system. However, in such system weed control can cause problems. Intercropping of grain legumes with cereals is suggested as an integrated strategy utilizing complementary interspecific competitive interactions
Intercropping is defined as the growth of two or more plant species simultaneously in the same field during a growing season. Due to agricultural intensification in terms of plant breeding, mechanisation, fertiliser and pesticide use during the recent 50 years intercropping has disappeared from the Danish cropping systems. The plant production in organic farming systems resembles in many ways conventional systems, e.g. the growing of monocrops, because farmers adopt the methods, which are familiar to them, when converting to organic farming. Intercropping is the practical application of ecological principles, such as diversity, competition and other natural regulation mechanisms. More specifically intercropping offers the potential of: i) improving the use of limited resources (nutrient, water, light and land), ii) increasing the input of N2-fixation in the cropping systems and iii) improving yield stability, due to self-regulation in the crop (Willey, 1979). Successful implementation of intercropping strategies will give the organic farmer a better insurance against total crop failure and will safeguard the farmers earnings
Selected publications:
Hauggaard-Nielsen, H, Jørnsgaard, B, Kinane, J and Jensen ES (2008) Grain legume-cereal inter-cropping – The practical application of diversity, competition and facilitation in arable and organic cropping systems. Renewable Agriculture and Food Systems 23(1), 3–12
Ghaley, Bhim B.; Hauggaard-Nielsen, Henrik; Jensen, Erik Steen; Høgh-Jensen, Henning (2005) Intercropping of wheat and pea as influenced by nitrogen fertilization. Nutrient Cycling in Agroecosystems, 73: 201-212
Hauggaard-Nielsen, H, Andersen MK, Jørnsgaard, B and Jensen ES (2005) Density and relative frequency effects on competitive interactions and resource use in pea–barley intercrops Field Crops Research, 95: 256-267
Participants:
GENESIS involves a multidisciplinary research team (agroecologist, weed scientist, crop scientists, agronomists, animal nutritional physiologists, entomologist, plant pathologist, microbial ecologist, plant nutritional physiologist) from Copenhagen University Life, Faculty of Agricultural Sciences Aarhus University and Risø DTU to carry out the tasks.
Role:
Risø DTU is responsible for nitrogen cycle assessments involving 15N stable isotope techniques as well as field experimentations involving crop diversification using intercropping strategies.
Resources:
GENESIS is linked to the Danish Research Centre for Organic Farming (DARCOF) and funded under the research programme DARCOF II with the remit to produce knowledge that can support increased production and a closer relationship between the inherent and organic qualities of organic foods (2000-2005).
Duration:
GENESIS is funded to run from 2000 through 2004.
Web page:
GENESIS has a webpage for further information at www.darcof.dk/research/darcofii/i5.html
Employees involved:
Per Ambus (Mass spectrometry and 15N analysis) and Henrik Hauggaard-Nielsen (field experiments, intercropping strategies and N2-fixation estimates)
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