Dr. Dan Talks Agronomy
By Dan Davidson
DTN contributing agronomist
World records don't just happen at home. Globally, soybean growers are using contests to break yield barriers and that's evident in Brazil.
The Brazilians launched a national yield contest in 2008-09 that encompasses five regions and more than 1,000 entrants annually. In the contest, a farmer and agronomist team work together on a set of management practices to improve yield. One yield winner is selected from each of five regions.
Brazilian farmers measure yield in bags per hectare and 112 bags equates to about 100 bushels. If a yield contest team believes they have a yield of at least 90 bags, it is reported and officials audit practices and witness the harvest. When the contest started in 2009, no one broke 100 bags per hectare. Since then, nearly every winner is breaking the 100 bags per hectare mark, which means today, many contest winners are routinely producing 100 bushels per acre or more. The record yield was 126 bushels per acre in 2015 and 107 bushels per acre this year.
One thing these yield contestants have in common with U.S. yield winners is they are willing to experiment with inputs. The main thing that generally sets Brazilian growers apart is they manage soybeans up through R6 while in the U.S. we routinely stop at R3.
KEYS TO SUCCESS
We tend to think of Brazil as having a hot and humid tropical environment that is prone to heat stress, soybean rust and insect pressures such as the invasive Old World bollworm.
Henry Sako, agronomist and technical coordinator for the Strategic Committee over Soybean Development in Brazil (Comite Estrategico Soja Brasil) says winners in Brazil generally use the best genetics, plant in narrow rows and apply foliar products.
"The varieties being planted are good, but are also commonly grown by all farmers," said Sako. "It means everybody has the same (genetic) potential, but to reach those high yields depends on how the farmers deal with their environments."
Sako also believes good seed vigor, bigger seed sizes and seed treatments are important factors to get the crop off to a good start. Even planting is also as important in soybeans as corn, he added. Brazilian farmers also plant in narrow rows of about 15 to 20 centimeters (6 to 10 inches) to capture more sunlight. Still, they generally hold populations to the equivalent of about 120,000 to 140,000 seeds per acre.
PROTECT THE PLANT
"Air temperature and relative humidity during the crop season are highly favorable conditions for diseases development and proliferation. Fungicide spraying, starting at vegetative stages, when the pressure diseases is still low, has become a standard practice among all Brazilian soybean farmers," Sako said.
The use of biostimulants and foliar nutrition is more inconsistent. "Use is based on individual preferences based on a variety of different reasons. But it's a common practice," he said.
Building fertility deep in the soil profile is also key. "High soybean yields are mostly explained by the soil fertility available below the 40 cm (1.3 foot) depth. Soybean yield above 120 bags/ha (7.2 t/ha or 107 bu/A) correlates well to soil base saturation in the lower profile," Sako said.
"Oxygen supply, water movement and low soil resistance to penetration are essential to soybean root growth and yields. The less the resistance, the better the yield performance.
"Fields with a competition history have higher potential. Soils have been built up over the growing seasons, involving remediating soil acidity and making fertility corrections and including crop rotations," he said.
Dan Davidson can be reached at AskDrDan@dtn.com
© Copyright 2016 DTN/The Progressive Farmer. All rights reserved.