Carrie Brauer - CARRIE WAITING FOR CALL FROM STAGGENBORG RE HOW LONG
INTERCROPPING HAS EXISTED. OTHERWISE, READY FOR EDIT.
The earliest inhabitants of the United States used intercropping when they planted corn
and beans in the same field. Today, farmers in parts of Africa use intercropping to make money
and feed their families.
Farmers who use intercropping plant more than one type of crop in the same field at the
same time. This planting method maximizes yields by allowing more than one crop to be
harvested, prevents some soil erosion by putting more plants and roots in the ground and controls
pests by stimulating pest growth and lifecycle completion before planting the main crop.
“Every system’s a little different,” said Scott Staggenborg, an agronomy professor and
INTSORMIL principle investigator at Kansas State University who has worked on intercropping
systems in West Africa. He said intercropping involves more than just deciding to plant a field
with half one crop and half another.
“You have to weigh the choice properly,” he said.
Farmers who intercrop do a lot of planning before planting begins. In “Intercropping
Principles and Practices,” the National Sustainable Agriculture Service says farmers should
consider four things: plant architecture, maturity dates, plant density and spatial arrangement.
Farmers consider plant architecture when they decide which crops they’re going to use.
They consider the crops’ shape, size and how they might interact with each other. For example,
if a producer has a short crop that needs a lot of sunlight, planting it with a taller crop that blocks
the sun wouldn’t work.
Choosing plants that mature at different times staggers harvest and may ease a work load.
For example, in India, sorghum matures and is harvested before the pigeon peas that are
intercropped with the sorghum start flowering.
Plant density affects how much farmers harvest. Farmers decide how much of each crop
to plant depending on which crop they want a better yield from. According to Staggenborg,
intercropped plants always compete in some fashion. Both crops need water and soil nutrients,
but the crops are in one field with a limited water and nutrient supply. As a result, the yield of
one crop is going to suffer. However, Staggenborg believes intercropping has advantages. For
example, farmers in Niger plant cowpeas between rows of millet plants while hoeing weeds in
the millet fields.
“They’re already going through the field,” said Staggenborg. “This way they get a little
bit of a bonus.”
Finally, farmers consider which spatial arrangement to use:
• Relay: Farmers plant a second crop before harvesting the first.
• Mixed: Subsistence farmers in Mexico and Central America use mixed intercropping
when they plant corn, beans and squash with no spatial arrangement.
• Row: Niger’s farmers row intercrop when they alternate one row of one crop (millet)
with one row of another (cowpeas).
• Strip: Farmers alternate several rows of one crop with several rows of another.
According to Staggenborg, strip isn’t always considered intercropping because only
the crops on the edges of the strips interact. The center rows of crops in each strip
grow as if they were in a single crop field.
Intercropping has advantages and disadvantages. In the U.S. planting can be done with
machinery, but mechanized harvest is more difficult. If the crops are similar in size, like cowpeas
and millet, machines may not be able to harvest the crops separately, and the grains might mix.
Niger’s farmers plant and harvest by hand. Doing so is more advantageous. Niger’s
farmers harvest the cowpeas first. Because they were planted later and harvested first, the
cowpea yield is less than the yield if the cowpeas were raised in their own field. But the farmers
still gain a small cash crop to sell at market. The farmers harvest the millet second as a
subsistence grain. Because they harvest the crops separately, no contamination (mixing of the
Sullivan, Preston. “Intercropping Principles and Practices.” National Sustainable Agriculture
Information Service, 2003. http://attra.ncat.org/attra-pub/intercrop.html