Title: INTERCROPPING FABA BEAN WITH WHEAT TO IMPROVE YIELDS, NITROGEN RECOVERY AND WEED CONTROL
1INTERCROPPING FABA BEAN WITH WHEAT TO IMPROVE
YIELDS, NITROGEN RECOVERY AND WEED CONTROL Mike
Gooding, Rachel Ruske, Elena Kasyanova, Rebecca
Owen Crops Research Unit, School of Agriculture,
Policy and Development, The University of
Reading, Early Gate, Reading, RG6 1PD, UK. email
m.j.gooding_at_reading.ac.uk
Funded by a EU shared cost project (INTERCROP)
under the 5th Framework Programme of RTD, Key
Action 5 Sustainable Agriculture
2Introduction
- Intercropping cereals with grain legumes can
improve - resource-use,
- weed control in the grain legume,
- nitrogen concentration in the cereal
- (Bulsen et al. 1997 Haymes and Lee 1999
Hauggaard-Nielson et al. 2006). - Faba bean plus wheat intercrops have particular
promise - due to the relative ease with which the crops
can be separated after harvest, - thus wheat with high nitrogen concentration
marketed separately from the bean (Bulsen et al.
1997).
3Additive intercropping wheat with faba bean
1. Nitrogen concentration ( DM)
4Two field experiments repeated in each of the
2002/03, 2003/04 and 2004/05 growing seasons on
sandy loam soil after a cereal
Treatments randomised in four blocks
Experiment 1 Spring-sown faba bean (B) cv. Meli
and spring wheat (W) cv. Paragon in replacement
sowing rate (seeds/m2) combinations of B52,
B39W100, B26W200, B13W300 and W400, and an
additive combination of B52W400.
Experiment 2 Winter-sown faba bean cv. Clipper
and winter wheat cv. Malacca sown in replacement
combinations of B32, B24W100, B16W200, B8W300 and
W400.
5Spring sown intercropping Mean of three years
6Winter sown experiment
7Winter sown intercropping Mean of three years
0
8
16
24
32
0
8
16
24
32
Faba bean sowing rate (seeds/m2)
400
300
200
100
0
400
300
200
100
0
Wheat sowing rate (seeds/m2)
8Land equivalent ratios
9Discussion
We confirm that wheatfaba bean intercrops can
increase LER for grain dry matter and nitrogen
yields. Total nitrogen harvested in the grain
was, however, only increased relative to the
cereal sole crop, and weed control was only
improved relative to the legume sole crop. The
winter experiment showed less benefit of
intercropping for yields and weed control. This
may have been because of the dominance of the
bean crop. Haymes and Lee (1999) reported a
similar problem and suggested resorting to an
older, taller cultivar of wheat to achieve a more
equal balance between the component crops.
Older wheat cultivars, however, have low
harvest index and reduced Hagberg falling numbers
(Gooding et al. 1999), and a better solution
maybe to identify shorter winter bean cultivars.