TECHNICAL PAPER #26
UNDERSTANDING MULTIPLE CROPPING
Dr. Glen M. Wood
Charles A. Francis
Armin R. Grunewald
1600 Wilson Boulevard, Suite 500
Arlington, Virginia 22209 USA
703/276-1800 . Fax: 703/243-1865
Understanding Multiple Cropping
[C]1985, Volunteers in Technical Assistance
This paper is one of a series published by Volunteers in
Assistance to provide an introduction to specific
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
people choose technologies that are suitable to their
They are not intended to provide construction or
details. People are
urged to contact VITA or a similar organization
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
The papers in the series were written, reviewed, and
almost entirely by VITA Volunteer technical experts on a
Some 500 volunteers were involved in the production
of the first 100 titles issued, contributing approximately
5,000 hours of their time.
VITA staff included Maria Giannuzzi
as editor, Julie Berman handling typesetting and layout, and
Margaret Crouch as project manager.
The author of this paper, VITA Volunteer Dr. Glen M. Wood,
Agronomist and Professor of Plant and Soil Science at the
of Vermont. The
reviewers are also VITA Volunteers.
A. Francis, international program director at the Rodale
Center in Pennsylvania, has worked on intercropping for the
10 years. He was
previously a staff scientist at the Centro
Internacional de Agricultura Tropical (CIAT), near Cali,
and a professor at the University of Nebraska.
Grunewald bas 33 years experience as a soil scientist with
U.S. Agency for International Development and the U.S.
of Agriculture. He
has performed consultancies in several developing
VITA is a private, nonprofit organization that supports
working on technical problems in developing countries.
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to
maintains an international Inquiry Service, a
specialized documentation center, and a computerized roster
volunteer technical consultants; manages long-term field
and publishes a variety of technical manuals and papers.
UNDERSTANDING MULTIPLE CROPPING
By VITA Volunteer Dr. Glen M. Wood
Multiple cropping, simply defined, is the growing of two or
crops on the same field during the same year.
When the crops are
grown one after another the term "sequential
cropping" is applied.
If the second or later crops are the result of regrowth of
the first crop, then the term "ratoon cropping" is
cane (Saccharum spp.), sorghum (Sorghum spp.), and even rice
(Oryza sativa L.) can be ratoon cropped.
Crops that produce no
regrowth, as in the case of most annuals, cannot be ratoon
When two or more crops are grown simultaneously on the same
of land the term "intercropping" is
appropriate. Such crops may
be mixed planted, that is, the plants of different crops are
intermingled; or they may be sole (pure stand) planted in
rows, that is, the plants of each crop are grown in separate
rows or strips (wide rows).
When one crop is interplanted
with a second crop as the first crop approaches maturity,
practice is termed "relay cropping." All of these
come under the general heading of multiple cropping.
All forms of multiple cropping have the potential to utilize
soil more efficiently, resulting in greater production from
given unit of land.
This is especially true in tropical or subtropical
areas of the world with wet and dry seasons.
for irrigation is available, exploitation of the abundant
energy in the dry season is possible.
Double, triple, and even
quadruple cropping has dramatically increased food
some countries--making them exporters instead of importers
food crops. Less
dramatic increases can also result from other
forms of multicropping.
Beans (Phaseolus vulgaris L.), for example,
can complete their life cycle in dry periods, if fertilized
and relay planted in corn or maize (Zea mays L.) toward the
of the wet season.
The exploding world population continues to place a severe
on existing land resources and their ability to provide
food. Any technology
that can result in increased food production
from present land holdings has great potential for easing
around the world.
Some researchers consider multiple cropping the
most important of today's agricultural practices.
Both high and
low technology societies can profit from greater use of
Multicropping is not a new agricultural technique.
the practice has been found in Egypt dating back to 300
Maya Indians in Central America and the Incas in South
practiced both sequential and intercropping.
II. SYSTEMS OF MULTIPLE CROPPING
Sequential cropping, to be used most effectively, requires
use of fertilizers, high yielding plant varieties, pest
high planting rates, mechanization, and, where appropriate,
Sequential cropping of plants with relatively short growing
seasons offers better total annual use of land than does a
single crop system.
It is particularly important to use the
improved, early maturing, high yielding varieties.
varieties, these improved types do not lodge, or fall over
to the ground, when heavily fertilized and also produce more
grain per unit of fertilizer applied.
Pest control, as well as
irrigation and fertilizers, allows them to yield more nearly
their full potential.
Mechanization, or the use of appropriate mechanical
allows the farmer to perform promptly all the operations of
preparation--planting, pest control, and harvesting--so that
next crop in sequence is not delayed and a portion of the
season wasted. In
the United States and other more temperate
regions of the world where growing seasons are shorter,
planting is widely used.
With the use of specially designed
equipment and early maturing varieties, crops can be
planted in the stubble of a previous crop without any
This ensures a minimum of delay and full use of
the available growing season.
Leaving the stubble in place also
minimizes water and wind erosion and affords protection for
newly emerging seedlings.
The use of day-neutral varieties--those not requiring a
day length to flower and set seed--allows the farmer to grow
at any time of the year, regardless of latitude, if growing
conditions are favorable.
The availability of water for irrigation
permits full use of the dry season.
Early maturing varieties may also suffer less damage from
As a general rule, the most serious crop loss due to weeds
during the first third of the life cycle.
An exception occurs
where late maturing varieties compete better with barnyard
(Echinochloa crusgalli L. Beauv.).
Although crop rotation with
different crops will generally result in better pest
may be feasible to rotate different varieties of the same
having different disease and insect resistance and better
to compete with weeds.
Sometimes natural predators of pests
(biological control) build up to more effective levels when
crop follows same crop.
The buildup of the pests with continuous
cropping is perhaps more likely to happen, however, and thus
rotation with different crops is preferred.
The principles involved in ratoon cropping, a form of
cropping, are different from other types of multiple
because of such factors as the presence of a well developed
system, earlier maturity, and the perennial nature of the
Although the term may be applied to perennial pasture
is considered more appropriately used with respect to field
such as sugar cane, sorghum, banana (Musa sapientum, M.
cotton, kodra millet (Paspalum scrobiculatum), pineapple
(Ananas comosa), and rice.
The advantages of ratoon cropping include the following:
1. reduced cost of
production through savings in land preparation
and care for the
2. reduced crop
cycle: crop planted less often, so replanting
cycle is longer;
3. better use of
4. higher yield per
unit area in a given period of time;
5. less use of
irrigation water and fertilizer than main (original)
crop because of
a shorter growing period; and
6. simple and
effective way to provide windbreaks for vegetable
On the other hand, ratoon cropping has a number of
1. later crops have
lower yields than the first crop;
2. buildup of
3. buildup of
4. increased disease
5. greater cost per
6. where heavy
equipment is used, the soil may become hard,
drainage and lack of oxygen for roots;
7. loss of crop
density (number of plants per unit of land);
8. growth of
volunteer seedlings inferior to sown variety.
Intercropping requires only 60-80 percent of the land to
the production of monocropping systems.
Traditional farmers in
many parts of the world-have practiced intercropping in
forms for many centuries.
This form of multiple cropping, which
generally involves the growing of rain-fed crops in
uses available resources and permits farmers to maintain low
often adequate and relatively steady production.
Intercropping can take any of three forms--strip planting,
planting, or mixed planting.
The form chosen should be based on
crops grown and such factors as ease of planting, weeding,
also may be affected. Intercropping is
suited to those situations where labor is abundant and land
is not. If it is to
be successful economically, the sum of the
competition of the interplanted species should be less than
the species are grown alone.
Crops of different maturities have
varying peak requirements for water, fertilizer, light, and
space. Thus, there
may be less competition between different
crops than there is in a sole planting of identical plants.
Moreover, disease and insect infestation of intercropped
tends to be less.
For example, virus diseases may spread more
easily through adjacent plants than to those separated by
and frequently non-susceptible, neighboring plants.
spread disease are also thwarted or at least slowed. Insects
tend to be less attracted to plants that are intermingled
other species than to those in solid stands of the same
Interplanting of some crop species, however, may be harmful
because of allelopathic effects.
Allelopathy is defined as "any
direct or indirect harmful effect that one plant has on
through the production of chemical compounds that escape
environment."(*) The harmful compound may take varied
as volatile chemicals produced by roots, or leached from
Dead or decaying plant tissues may also be a source of
that the nitrogen released from legumes
is not considered a form of allelopathy.
Some common combinations are maize-bean, maize-soybean
max L. Merr.) , maize-rice, maize-sorghum, sorghum-millet,
potato (Ipomoea batatas Lam.) in sugar cane (Saccharum
L.), and cotton (Gossypium sp.) with peanuts (Arachis
L.). The net result
of such combinations can vary widely from
productive to unproductive compared to sole planting of the
crops. Factors such
as fertilization schedule, seeding rate and
spacing, selection of variety and type of plant, e.g., dwarf
versus normal (maize), bush versus pole (bean), as well as
other cultural factors can markedly influence results.
The overall advantages of intercropping include the
increased protection against erosion;
2. insures against
3. spreads labor
and harvesting more evenly during the growing
season and helps
minimize storage problems;
4. helps allocate
space for crops required in small quantities,
production of many commodities in a limited
5. results in
efficient use of resources by plants of different
systems, and nutrient requirements;
6. where legumes
are grown with grasses (or other non-legumes),
benefit from the nitrogen fixed by the
7. inhibits the
spread of diseases and pests since not all
are susceptible to the same extent to the
(*) B.R. Trenbath, "Plant Interactions in Mixed Crop
Multiple Cropping, Edited by M. Stelly (Madison, Wisconsin:
American Society of Agronomy, 1976).
Disadvantages, on the other hand, are:
planting and harvesting are difficult;
2. it is more
difficult to apply needed fertilizers and other
chemicals as in
sole cropping; and
with intercropping is more complex and difficult
to manage than
with sole cropping.
Relay intercropping is a common practice in wet-dry climates
where the wet season is not sufficiently long for two full
corn is the wet season crop, with beans interplanted
as the corn approaches maturity.
With relay planting,
greater crop density and protection against wind and water
are achieved. Since
the first crop has reached maturity, its
demands on soil moisture and fertility are minimal as
aging and deterioration of leaves occur.
The relay interplanted
seedling crop likewise places small but increasing demands
soil. As the first
crop gradually fades out of the picture and is
finally removed entirely through harvest, the sequential
continues to advance and the transition is completed.
Multiple cropping in some form can help get the maximum crop
production from fixed land holdings, particularly in
and tropical areas of the world.
Both low and high technology
societies can profit by adopting one or more of the various
Even small farmers who lack the capital
to purchase inputs (e.g., equipment, fertilizers,
but generally have abundant hand labor, can find the
some form of multicropping to be to their benefit.
Multiple cropping places heavy demands on the soil and
successful unless the crop is supplied with adequate
Where the extra fertilizer is not available, a few crops
fertilizer needs may be planted (such as cassava [Manihot
and plantain [Plantago sp.]).
Many marginal farmers find the
purchase of inorganic fertilizers beyond their means, even
obtainable, and should not consider intensive multicropping
More limited multicropping can be practiced where
amounts of animal manure and/or composted plant materials
Minerals provided by burning cleared land have
only temporary value.
On the other hand, many systems of multicropping
originated under subsistence farming and can be made to
work using available sources of fertilizer.
Placing fertilizer in
bands between plants or directly in the planting hole are
ways of making more efficient use of fertilizer at
possible, legumes should be planted for their ability to
nitrogen from the air and convert it into forms available to
The advantages of multicropping include greater use of
solar energy in the dry season, improved pest control,
insurance against crop failure, better nutritional balance
families because a wider variety of foods is produced, and a
stable farm income.
As in any departure from traditional methods, some cautions
hazards may be encountered in switching from mono- to
Farmers should consider their options carefully and seek
help if necessary from local extension agencies or from
assistance services such as VITA.
BIBLIOGRAPHY/SUGGESTED READING LIST
Allen, L.H., Jr.; Sinclair, T.R.; and Lemon, E.R.
Relationships in Multiple Cropping Systems." In
Cropping, p. 171. Edited by M. Stelly. Madison,
Society of Agronomy, 1976.
Andrews, D.J., and Kassam, A.H. "The Importance of
World Food Supplies." In Multiple Cropping.
Edited by M.
Stelly. Madison, Wisconsin: American
Beets, Willem C. Multiple Cropping and Tropical Farming
Colorado: Westview Press, 1982.
Litsinger, J.A., and Moody, K. "Integrated Pest
Systems." In Multiple Cropping, p. 299.
Edited by M. Stelly.
Madison, Wisconsin: American Society
Metcalf, D.S., and Elkins, D.M. Crop Production, Principles
York, New York: MacMillan Publishing Co.,
Nasr, H.G. "Multiple Cropping in Some Countries of the
Multiple Cropping, pp. 117-118. Edited by M.
Wisconsin: American Society of Agronomy,
Oelsligle, O.D.; McCollum, R.E.; and Kang, B.T. "Soil
Tropical Multiple Cropping." In Multiple Croppping,
p. 281. Edited by
M. Stelly. Madison, Wisconsin:
of Agronomy, 1976.
Okigbo, B.N., and Greenland, D.J. "Intercropping
Systems in Tropical
Multiple Cropping, p. 63. Edited by M.
Wisconsin: American Society of Agronomy,
Pinchinat, A.M.; Soria, J.; and Bazan, R. "Multiple
America." In Multiple Cropping, p. 53. Edited by
Madison, Wisconsin: American Society of Agronomy,
Pluknett, D.L.; Evenson, J.P.; and Sanford, W.G.
In Advances in
Agronomy, p. 285. Edited by N.C.
Brady. New York,
New York: Academic Press, 1970.
Rice, E.L. Allelopathy. New York, New York: Academic Press,
Thomas, G.W.; Curl, S.E.; and Bennett, W.F. Food and Fiber
Danville, Illinois: Interstate Printers and
Thomas, G.W., and Phillips, S.H. "Multiple
Cropping--Ace in the
The 1981 Yearbook of Agriculture--Will There Be
Enough Food?, p.
68. Edited by J. Hayes. Washington, D.C.:
Printing Office, 1981.
Trenbath, B.R. "Plant Interactions in Mixed Crop
Cropping. Edited by M. Stelly. Madison, Wisconsin:
of Agronomy, 1976.
Wrigley, G. Tropical Agriculture: The Development of
Faber and Faber, 1969.