In Western Canada, 284-bushels-per-acre corn can win a competition. But in the United States, you’ll need 521 bu. to get the win.
Georgia corn grower Randy Dowdy grew 521 bu. per acre three years ago to win top spot in the National Corn Growers Association yield contest.
The big crop was grown on a no-till, strip-till irrigated field.
Rules say a contest plot must be at least 10 acres, planted to one hybrid only and those 10 acres can come from any place within a larger field, according to a story in Progressive Farmer magazine.
Dowdy said he adheres to Liebig’s Law of the Minimum, which describes how a plant’s growth is controlled by the scarcest nutrient available and not, as some people think, by the total amount of nutrients available.
The availability of the most abundant nutrient in the soil is only as good as the availability of the least abundant nutrient in the soil.
In other words, if magnesium is in short supply, you can pile on the NPK but it won’t help the yield. The field needs magnesium. Once the magnesium requirement is satisfied, zinc might be the next limiting factor. And on it goes.
Dowdy’s interpretation of Liebig’s Law of the Minimum is to continue attacking the limiting factor in each field. He applies the principle to nutrients, and also to seed population, skips, doubles, compaction, crop protection, water, drainage, harvest and variety selection. He said the minimum always causes plant stress, and thus reduces yield. In focusing on fixing the minimum, he reduces stress and increases yield.
Dowdy urged other growers to try new hybrids. Depending on the soil and variety, he puts down anywhere from of 28,000 to 56,000 seeds per acre. He waits until the soil temperature is 13 C and the forecast is for continued warming.
He likes to see emergence within eight days to 10 days. He sticks to a seeding depth of two inches. He expects to see the first spikes within 75 to 110 growing degree units and the entire field to emerge uniformly within 10 GDU.
Constant scouting is the only way to find and address all those minimum factors. Tissue samples are a primary source of data. Tissue testing starts at 350 GDU, just as the young crop begins drawing nutrients through the roots, and continues through R4 and R5.
He strives to maintain sufficient nutrient levels, depending on crop stage. Sufficient at one stage may not be sufficient at another.
Dowdy’s total production costs in 2016 were US$2.74 per bu. He sold corn that year for $4.30 to $4.70 per bu. His growing season began with a flood that destroyed 700 acres of corn. That dump provided a benefit on his better-drained ground, through an ideal growing season and no big disasters.
His website is: www.growbigcorn.com.
“I do all I can do, but at the end of the day it’s all providential. The good Lord smiled on us,” he said.