Agriculture Reference
In-Depth Information
Future research priorities
Future research needs include development and evaluation of:
1 affordable no-till equipment (particularly roller-crimpers and other residue management
implements, and no-till planting aids) for small-scale organic farmers;
2 cost-effective practices and strategies to prevent production of weed seeds and reduce weed
growth during the minimum weed-free period (4-6 weeks after planting cash crops);
3 techniques and strategies to improve efficient nutrient use, especially synchrony of nitrogen
supply and crop demand;
4 spatial interseeding of grass and legume cover crops on controlled-traffic raised beds to
optimise both nitrogen efficiency and weed suppression; and
5 strategic crop and tillage rotations, designed to achieve a more desirable balance between
high marketable crop yields and high soil quality or production capacity (sustainability).
We conclude by outlining a strip-interseeding technique that integrates list items (4) and
(5) above (Chen
et
al
. 2004, R. Morse and M.W. Schonbeck, unpublished data, 2004). Growing
legume and grass species in alternating multiple-row zones on controlled-traffic raised beds
can indeed be the best of both worlds. Winter-kill or overwintering legumes are grown on bed
tops in designated zones (grow zones) where subsequent cash crops are to be grown; and over-
wintering high-residue grass smother crops are grown in alleyways and between grow zones
on bed tops to maximise weed suppression. In the following spring or summer, cash crops are
established in the nitrogen-rich grow zones, using either no-till seeders or transplanters, or
non-inversion strip-till implements followed by conventional seeders or transplanters.
Alleyway areas are maintained as a dead or living mulch, resulting in conservation of soil and
water, suppression of weeds and creation of habitat for beneficial organisms.
References
Bàrberi, P. 2002. Weed management in organic agriculture: are we addressing the right issues?
Weed
Research
42: 177-193.
Barker, A.V. and Bhowmik, P.C. 2001. Weed control with residues in vegetable cropping sys-
tems.
Journal
of
Crop
Production
4: 163-183.
Berry, P.M., Sylvester-Bradley, R., Philipps, L., Hatch, D.J., Cuttle, S.P., Rayns, F.W. and Gosling,
P. 2002. Is the productivity of organic farms restricted by the supply of available nitrogen?
Soil
Use
and
Management
18: 248-255.
Bond, W. and Grundy, A.C. 2001. Non-chemical weed management in organic farming sys-
tems.
Weed
Research
41: 383-405.
Brandsaeter, L.O., Netland, J. and Meadow, R. 1998. Yields, weeds, pests and soil nitrogen in a
white cabbage-living mulch system.
Biological
Agriculture
and
Horticulture
16: 291-309.
Bruulsema, T.W., Dibb, D.W., Reetz, H.F. and Fixen, P.E. 2003. Productivity of organic crop-
ping systems.
Better
Crops
87(1): 16-18.
Chen, C., Westcott, M., Neill, K., Wichman, D. and Knox, M. 2004. Row configuration and
nitrogen application for barley-pea intercropping in Montana.
Agronomy
Journal
96:
1730-1738.
Creamer, N.G., Benner, M.A., Stinner, B.R. and Cardina, J. 1996. A comparison of four process-
ing tomato production systems differing in cover crop and chemical inputs.
Journal
American
Society
for
Horticulture
Science
121: 559-568.
Creamer, N.G. and Dabney, S.M. 2002. Killing cover crops mechanically. Review of recent lit-
erature and assessment of results.
Journal
of
Alternative
Agriculture
17: 32-40.
