Hauggaard-Nielsen, Henrik; Ambus, Per and Jensen, Erik Steen (2001) Interspecific competition, N use and interference with weeds in pea-barley intercropping. Field Crops Research, 70 (2), pp. 101-109.
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Field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L) were inter- and sole cropped to compare the effects of crop diversity on productivity and use of N sources on a soil with a high weed pressure. 15N enrichment techniques were used to determine the pea-barley-weed-N dynamics. The pea-barley intercrop yielded 4.6 t grain ha-1, which was significantly greater than the yields of pea and barley in sole cropping. Calculation of Land Equivalent Ratios showed that plant growth factors were used from 25 to 38% more efficiently by the intercrop than by the sole crops. Barley sole crops accumulated 65 kg soil N ha-1 in aboveground plant parts, which was similar to 73 kg soil N ha-1 in the pea-barley intercrop and significantly greater than 15 kg soil N ha-1 in the pea sole crop. The weeds accumulated 57 kg soil N ha-1 in aboveground plant parts during the growing season in the pea sole crops. Intercropped barley accumulated 71 kg N ha-1. Pea had to rely on N2 fixation with 90-95% of aboveground N accumulation being derived from N2 fixation independent of cropping system. Pea grown in intercrop with barley instead of sole crop had a better competitive ability towards weeds and soil inorganic N was consequently used for barley grain production instead of weed biomass. There was no indication of a greater inorganic N content after pea compared to barley or pea-barley. However, 46 days after emergence there was about 30 kg N ha-1 inorganic N more under the pea sole crop than under the other two crops. Such greater inorganic N levels during early growth phases was assumed to induce aggressive weed populations and interspecific competition. Pea-barley intercropping seems to be a promising practise of protein production in cropping system with high weed pressures and low levels of available N.
|EPrint Type:||Journal paper|
|Keywords:||Land equivalent ratio (LER); nitrogen fixation; 15N isotope dilution principle; field pea; barley; weed management|
|Subjects:|| Crop husbandry > Crop combinations and interactions|
Crop husbandry > Production systems > Cereals, pulses and oilseeds
|Research affiliation:||Denmark > DARCOF II (2000-2005) > I. 5 (GENESIS) Production of grain legumes and cereals for animal feed|
|Deposited By:||Hauggaard-Nielsen, Senior Scientist, phD, Cand. agro Henrik|
|Deposited On:||03 Oct 2002|
|Last Modified:||12 Apr 2010 07:27|
|Refereed:||Peer-reviewed and accepted|
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