Information day
Relevant
Oktober 2013
10
Sufficient management critical
for higher soybean yield
RUTH SCHULTZ, SA GRAAN/GRAIN CONTRIBUTOR
Why is South Africa’s soybean yield not as high as, for example that of the
USA, Canada, Brazil and Argentina?
“South Africa’s variable rainfall and climate is one of the disadvantages,
but there are a lot of things that producers are also doing wrong. You can
make a profit out of soybeans, but not without sufficient management
inputs.”
This is according to Stephanie Roberts (research agronomist: Omnia
Fertilizer) who spoke at the soybean information day that was held by
John Deere in partnership with the Protein Research Foundation (PRF)
as well as seed, crop protection and fertiliser companies on 27 and
28 August 2013 in Delmas.
Roberts pointed out that the so-called free nitrogen that is supplied by
the N-fixing bacteria, in fact comes at a heavy cost to the plant in the form
of additional sugars and nutrients demanded by the bacteria. “Although
reasonable yields can be achieved without additional nitrogen fertiliser,
soybeans have a high requirement for phosphorus and potassium. These
must be replaced according to crop removal figures; otherwise the
following maize crop will suffer.”
Roberts also highlighted the following practices for improving soybean
yields:
Cultivars must be adapted to both the latitude and altitude of your
farm. Production areas at the same latitude elsewhere in the world
are at lower altitudes and far warmer than our Highveld region.
Discover what works best on your farm. Try different planting dates
and cultivar types to spread the risk of drought during flowering and
pod fill.
Good seedbed preparation and annual inoculation with N-fixing
bacteria are important.
Soybeans are not competitive growers and weeds must be controlled
early and properly to prevent yield losses.
Quality of soybean seed
Good quality seed is the basis of healthy crop production practices.
“Generally good quality seed is 99,9% genetically the right variety with
high germination and vigour and is free of any damage and diseases,”
Jeremy Munton-Jackson (supply manager: Pioneer) said.
The handling and storage of soybean seed is very important. “If you don’t
handle soybeans carefully, it loses its germination and vigour. It is critical
that the harvesting moisture is correct (between 13% and 15%). If the
harvesting moisture is below 12%, the seed splits and cracks. Also make
sure that you use an appropriate combine, as this is where the majority of
seed damage appears to occur. Once you have harvested the soybeans,
you need to store it at a fairly dry moisture level,” he explained.
“And remember,” he said, “even seed that appears visibly good can
give you a very poor germination percentage. This needs to be tested
beforehand, which is why certified seed is recommended.”
Input from Canada and Brazil
Fabio Schavinski (market planner: John Deere, Brazil) shared some
experiences on soybean production in Brazil.
When it comes to the production of soybeans, Brazil is second in the
world (86 million tons) and the country is also the biggest exporter
thereof. “The production of soybeans in Brazil has grown 328% since
1990. Nowadays 50% is processed inside the country and 50% is
exported to China,” Schavinski said.
The total soybean production area in Brazil is produced under the no-till
system which was first started in 1972, but only successfully took off in
the early 90’s after years of trials to perfect the system. Many producers
started and gave up several times, but today over 25 million hectares are
under no-till. “What producers have learned over the past few years is
that crop rotation is of utmost importance when making use of no-till.”
Patrick Lynch (certified crop advisor from Canada) gave some useful
information to producers on soybean production:
The hardest part of growing soybeans is the establishment thereof.
The soil pH must be above 5,5 - 6 and seeds must be coated with two
inoculants in the first year.
In Ontario, Canada the biggest recent soybean yield increase could
be attributed to the earlier planting of soybeans. Plant early and
quickly.
Research showed that making use of narrower rows will increase
your yield. Row spacing has come down over the years from 91 cm
to 19 cm, with the majority of producers currently using row spacing
between 38 cm and 50 cm.
The adequate population in 50 cm rows is between 400 000/
ha and 500 000/ha depending on the type of soil. Unlike maize,
growers successfully replant soybeans if the population is less than
300 000 plants/ha.
The following are soybean planting myths: Nitrogen makes soybeans
lazy and soybeans do not need fertiliser.
Jeremy Munton-Jackson, Stephanie Roberts,
Fabio Schavinski and Patrick Lynch were some of
the presenters at the soya farmers’ information
day that brought producers vital information on
the complete soybean value chain.
