Nitrogen accumulation in sole and mixed stands of sweet-blue lupin (Lupinus angustifolius L.), ryegrass and oats

Abstract

Nitrogen fixation was measured in monocropped sweet-blue lupin (Lupinus angustifolius), lupin intercropped with two ryegrass (Lolium multiflorum) cultivars or with oats (Avena sativa) on an Andosol soil, using the ISN isotope dilution method. At 117 days after planting and at a mean temperature below 10°C, monocropped lupin derived an average of 92% or 195 kg N ha-1 of its N from N~ fixation. Intercropping lupin with cereals increased (p < 0.05) the percentage of N derived from atmospheric N 2 (% Ndfa) to a mean of 96%. Compared to the monocropped, total N fixed per hectare in intercropped lupin declined approximately 50%, in line with the decrease in seeding rate and dry matter yield. With these high values of N 2 fixation, selection of the reference crop was not a problem; all the cereals, intercropped or grown singly produced similar estimates of N 2 fixed in lupin. It was deduced from the ~SN data that significant N transfer occurred from lupin to intercropped Italian ryegrass but not to intercropped Westerwoldian ryegrass or to oats. Doubling the ~SN fertilizer rate from 30 to 60 kg N ha ~ decreased % Ndfa to 86% (p < 0.05), but total N fixed was unaltered. These results indicate that lupin has a high potential for N 2 fixation at low temperatures, and can maintain higher rates of N 2 fixation in soils of high N than many other forage and pasture legumes.

Grain legume–cereal intercropping: The practical application of diversity, competition and facilitation in arable and organic cropping systems

“…Improved cultivars of faba bean and lupin might be alternative grain legumes to pea with a higher seed protein concentration and stronger stem strength but probably with the some of the same obstacles as peas, such as weak competitive ability towards weeds 20 . Intercropping experiments with faba bean and cereals have shown similar advantages 9 , 21 , 22 , but knowledge of the effect of intercropping lupin and cereals for maturity is limited 23 .…”

Comparison of interspecific competition and N use in pea–barley, faba bean–barley and lupin–barley intercrops grown at two temperate locations

“…Pea-barley intercropping compared with sole cropping has shown a more efficient use of environmental sources for plant growth, especially nitrogen (N) Jensen 1996), increased N concentration in intercropped barley grains compared with sole cropped barley (Jensen 1996), higher proportion N derived from fixation (Pfix) in intercropped pea compared with sole cropped pea (Izaurralde et al 1992;Jensen 1996;Jensen 1998), greater yield stability than sole cropped pea (Jensen 1996) and increased competitive ability towards weeds compared with pea sole cropping . Intercropping experiments with faba bean and cereals have shown similar advantages (Martin & Snaydon 1982;Jensen 1986;Danso et al 1987;Bulson et al 1997), but knowledge of the effect of intercropping lupin and cereals for maturity is limited (Pa´lmason et al 1992).…”

Intercropping of Corn with Soybean and Lupin for Silage: Effect of Seeding Date on Yield and Quality

“…Lupin has been used as a livestock feed ( Hill 1977) and may be better suited to the colder climates of higher latitudes than soybean ( Pate et al 1985). Intercrops of lupin and cereals have shown positive effects on yields, and lupin may also be used as a green manure for soil conservation ( Lopez‐Bellido and Fuentes 1986, Palmason et al 1992). A second soil conservation strategy that could be applied to corn silage is the use of underseeded forages such as red clover and ryegrasses ( Scott and Burt 1987, Scott et al 1987, Bruce et al 1991).…”