Looking for the right formula to grow high-yield corn crops in Ontario
Monday, October 7, 2013
Two Ontario farmers are trying radical ways to push their corn yields to beyond 300 bushels an acre and their methods are being watched with interest south of the border
by DON STONEMAN
Accompanying a first-time visitor to his farm, the first thing 2011 corn-yield champion Dean Glenney does, ironically, is to dive into the soybean headland on his field. He spreads the towering soybean plants apart to reveal what he believes is key to his extraordinary yields – middens.
Middens are piles of corn leaves and stalks assembled by earthworms and Glenney says they will be pulled down the worm holes over time to be used as food by colonies of Lumbricus terrestris (dew worms), which live in burrows deep underground. Glenney's goal is to grow crops while disturbing the earthworms' tunnels, and their work, as little as possible. They've been good to him, after all.
In 2011, Glenney harvested more than 300 bushels of corn from a 25-acre plot on his Haldimand County farm to win a province-wide contest sponsored by Dupont-Pioneer. That's double the average for a county rarely referred to as "highly productive."
For 20 years, Glenney has been planting corn following beans, putting the corn seed directly into the row where soybeans were grown the previous year while disturbing the surrounding soil as little as possible. "If I could, I would use a pea shooter to put the seed into the ground," says the engineer and pilot, who scouts his fields from the air with a motorized parachute.
He calls his planting technique "fencerow farming" because he seeks to emulate the growth boost he noticed when farm fields were expanded a generation ago and previously unplowed fencerows, together with the well-structured soils under them, were put to crop for the first time. At first, he hand-steered down the rows, which was less successful than he would have liked. These days he uses RTK GPS technology. "I give 50 bushels an acre to the GPS," Glenney says.
He plants 30-inch twin rows of corn using a heavily modified White planter, alternating six twin rows of corn with a same-width strip of soybeans and drives down the soybean strips to spray the corn. The twin rows give him "a double chance" – if one of the corn plants fails to flourish, for whatever reason, the other fills the missing space.
Most of the corn acres are planted at a rate equivalent to 36,000 plants to the acre. Glenney has increased populations to 38,000 in test plots for this year's corn-yield contest. There are also some plots planted to 32,000. Each acre of corn gets a total of 200 pounds of N, 55 of P and 78 of K along with 0.25 pounds of zinc, 21 pounds of sulphur and 4.2 pounds of magnesium.
The fertility program is based on the right placement and the right timing of nutrients to supplement what the soil is doing on its own. Phosphorus and potash are applied as dry fertilizer banded with the planter and Alpine 6-24-6 with some zinc goes on the seed. Thirty gallons of the 28 per cent nitrogen is banded with the planter and another 30 gallons is side-dressed when the corn is 20 inches tall. No fertilizer is spread except for lime. This year, as an experiment, Glenney applied an additional 15 gallons of 28 per cent at tassel with dropped nozzles into the standing corn. "You have to keep the crop growing all the way to maturity. This year a lot of fields that had all the nitrogen applied at planting were shutting down in early August."
Based on his 2012 average of 280 bushels, the added fertilizer works out to 0.71 pounds/bushel of nitrogen, 0.20 pounds/bushel of phosphorus and 0.28 pounds/bushel of potash, roughly half of soil test recommendations. (See Fertilization Table A.)
Glenney has modified or discarded the coulters on his planter many times. His next plan is to get rid of coulters entirely and install spikes that will disturb the soil even less.
His yields have been increasing steadily since reaching 236 bushels per acre in 2005. He hit 272 in 2010, 299 in 2011 and 301 bushels last year, despite the drought that gripped his area. He credits the soil's water-holding capacity for part of this. An application of three inches of irrigation water with a gun at a critical juncture added only seven bushels an acre across his fields and was hardly worth it.
Glenney says the last 100 bushels of corn per acre on his farm are grown in September. "You've got to keep (corn) growing right up to frost," says Glenney. "I want that plant to continue growing as long as there is sunshine to grow." The number of kernels and rows has already been determined but the kernels continue to grow and get heavier and the cobs get bigger around.
Bucking current trends
Keeping machinery traffic to the same areas is part of Glenney's program. His John Deere 9560 STS combine has 24-inch wide tires, the narrowest he could get. His sprayer tractor has 11-inch tires. Glenney tries to use the same paths to run all implements through fields. This year, he bought a three-point hitch-mounted sprayer, replacing a 30-year-old pull-type model. He will cut the number of tires going through his fields by half at spraying time.
Glenney is fighting against current trends in agriculture. He describes vertical tillage as "useless." His use of narrow tires and deliberate following of old tracks is the technological opposite of the current movement to put ever-wider tires on machines to reduce the pounds per square inch on the ground while passing. He espouses using the same tracks over and over again with all implements – from pre-planting corn stalk chopping (he chops in the spring rather than fall, so as to avoid putting down a mat that keeps the ground chilled) all the way to harvest. Dairy farmers should use their RTK and autosteer to run their forage wagons to the fields and back over the same tracks, he suggests.
Soil scientist George Lazarovits, research director at A & L Biologicals Agroecology Research Services Centre in London, thinks Glenney's success is due to more than just soil structure and worms. He suggests that soil science has been ignored as a fundamental function of crop yields and is just now coming to the forefront. Grain Farmers of Ontario (GFO) is providing funding for two growing seasons ending this fall at the Glenney farm, which he is comparing to a conventionally tilled farm in the same neighbourhood, on the same soils.
A December 2012 report to GFO says: "One of the key hypotheses of the project is that the cultural practices used (at the Glenney farm) have enriched the microbial communities in soil that can enhance the nutrition of corn plants through biological activities such as nitrogen fixation, P solubilization and by creation of disease-suppressive environments that protect roots from pathogens and pests."
Mid-season soil tests show more nutrients in the field than at the start of the growing season. Lazarovits says tests show corn stalks on Glenney's farm contain far fewer different strains of bacteria, and more of the same bacteria, than on a nearby conventionally-tilled farm that is also being tested. The report goes on to say that "the present work aimed to investigate microbial community profiles/diversities and to isolate/compare potential beneficial microorganisms in various samples collected from the two production sites."
An hour's drive west of the Glenney farm, on the sand plains of Norfolk County, a very different project to maximize corn yield is also underway.
Todd Boughner is taking extraordinary measures to boost corn yields far beyond normal levels by burying watering tape 14 inches into the ground to allow for subsurface irrigation.
The piping for the farm was installed after fall harvest in 2012. The soil was limed, deep ripped and worked well. Then 7/8th-inch drip tape pipes were installed 44 inches apart (an admittedly arbitrary number that the installation team devised) using RTK guidance, says Boughner. Header pipes were installed 48 inches deep, using an old trench type ditching machine.
The 75-acre corn field is irrigated in six separate zones at critical times in the season. Six hours of run time with the pump put nearly a quarter inch of water into the root zone of the plants. The water flow is measured and documented for each zone. Water is applied at critical times in the corn-growing season.
Boughner works with Judge Family Farm which manages irrigated corn for a number of area producers. Kevin Judge, the farm manager, describes this as "an entirely new way of managing your crop." Water use is reduced to one quarter compared to overhead spray-gun applications, because the full value of the water is getting to the plant roots without evaporation loss.
Using water efficiently
Irrigating is more than just about yield. It is also a contributor to crop quality in a dry year. However, water-taking permits are required. "It is an important part of farming now" on the sand plain, Boughner says.
The University of Guelph is monitoring Boughner's field and its own plot at the Simcoe Research Station. The project is funded by Farm & Food Care Ontario, which administers monies from the Water Resource Adaptation and Management Institute. The corn project got $70,000 for one year and the project operators are looking for more money to continue monitoring the project, according to environmental co-ordinator Bruce Kelly. Funding was also provided for drip-tape applications and studies for apples, peaches and grapes, as well as corn.
The goal is to prove that sub-surface drip drainage works and also that we can use less water more efficiently, says Peter White, irrigation research technician. He aims to maintain soil moisture at 80 per cent of the maximum that is available to the crop. Soil under the corn crop of 10 plots on 2.5 acres at the research station is being monitored for moisture at different depths and distances from the tape and the emitters, which are 24 inches apart. As well, there are moisture testers 36 inches down.
"We don't want to put too much water on," White says. If water is going down 36 inches, "that would mean you are leaching nutrients out. It has been easy to do that."
Even in a wet year in Norfolk, irrigation is necessary, he says. Water has been applied on at least 15 days between the hot spell in July and the last week in August.
The crop is also being spoon-fed nitrogen through the pipes – about 10 pounds of N per acre every week. According to research from the United States, White says, "25 per cent of the cob is still in jeopardy (at the end of August) and you need to finish it off as much as you can."
White says that "we realized early on we had a pH problem" and that the soil was deficient in zinc and magnesium. The crop is getting a supplement called Magical Max, a calcium supplement with magnesium and zinc. "It was amazing how fast the crop that was behind caught up to the other stuff."
The 2012 corn-yield-challenge winner, who bested Dunnville's Glenney with 318 bushels, was Randy Vanden Heede, a Judge Family Farm custom farming client and a corn supplier and a former tobacco grower who now grows corn, rye and ginseng west of Simcoe.
In 2012 and again this year, Vanden Heede irrigated his corn with a traveller nozzle. In mid-August, according to Vanden Heede, the Judge farm's crop consultant said the corn treated with the overhead gun and the corn with sub-soil irrigation were neck and neck as far as development was concerned.
Vanden Heede says his crop gets one to 1.5 pounds of N per bushel of yield and P and K according to soil tests. He irrigates when his moisture meter indicates moisture content is down to five per cent on the sandy knolls. (His experience is that soil moisture will be at 10 per cent at the same time on the lower loamier ground in the same field.) At $1,200, the moisture reader is expensive, but he amortizes it over his high-value ginseng acres as well.
Vanden Heede plants his corn when the soil temperature reaches 10 C at a population of 35,000 plants per acre, on 30-inch rows.
Growing corn on sand has its shortcomings, Vanden Heede says. Nitrogen applications must be high, because there is little organic matter in the soil. In a rainy year, he says, "we do leach. But at least it is not drowned out and dead" as were some fields elsewhere this spring that retained moisture.
This year, he applied 28 per cent N liquid fertilizer in the field when the corn was 4.5 feet high, using a sprayer with drop pipes. The crop also received two applications of a fungicide, one from the sprayer and one from an airplane when the crop was taller.
Vanden Heede is watching the Boughner farm project with interest. He sees the advantage of "fertigating" through the pipes, as well as applying water.
Watching from Illinois
Fred Below, a plant biologist with the University of Illinois, listens to a description of the high corn-yield production techniques at both the Norfolk and the Haldimand farms with great interest. He thinks sub-surface irrigation and planting on top of the previous year's crop are doing the same thing: they help the corn plant to put roots deep into the ground fast.
Watering 14 inches deep pulls down the corn roots to the water source in the sandy soil. Planting on top of the soybean row in the clay allows corn roots to go deep. "The previous crop has done the exploration," Below explains.
Soybeans have a taproot and corn has fibrous roots, but digging soil pits in the field will likely reveal that the corn roots have gone straight down the paths of the soybean roots.
Below is a strong proponent of planting corn in 20-inch rows and is surprised that 300-bushel yields are being achieved with 30-inch rows, at least until he hears that both farmers are also banding fertility close to the crop.
"Spoon feeding" the crop at the right time is critical, Below says. Even a 250-bushel crop of corn must suck up 150 pounds of nitrogen between V12 (10 leaves) and R1 (silking). That's more than seven pounds a day. And that N intake needs to be even higher for a 300-bushel yield.
Crop uptake of phosphorus needs to be even sharper during that critical period. Below wonders if the soil tests developed in the 1960s need to be recalibrated to deal with the far higher corn yields now typical on most farms. A technical article Below co-authored and published earlier this year in Better Crops with Plant Food begins by stating that current fertilization practices "developed decades ago may not match uptake capabilities of modern hybrids that contain transgenic insect protection and are grown at population densities higher than ever before."
Judge and Boughner allow that on-farm ponds and experience with the technology from former tobacco farmers is a reason irrigation is an ideal technology to use on the sand plains of Norfolk.
Plant biologist Below says high yields and high plant populations go hand in hand. Fifty years ago, the average corn yield in the United States was half what it is now and farmers were planting 16,000 seeds per acre, roughly half of the average plant populations in 2013.
He describes a 200-bushel-an-acre crop as a 32,000-plant final stand, each plant with 550 kernels and each kernel weighing 250 milligrams. A 250-bushel yield needs 36,000 plants an acre, with 600 kernels on every plant, and each kernel weighing 255 milligrams. "If I change the kernel weight one milligram, that is a bushel," Below says. The loss of one kernel per plant costs 4/10ths of a bushel.
"It is an unbelievable challenge to go from 250 bushels to 300 bushels," he says. It takes 45,000 plants per acre with 565 kernels per plant and each kernel weighing 260 milligrams. Yet Vanden Heede grew 318 bushels with a 32,000 planted population and Glenney did nearly the same with 38,000 plants.
"I believe 20-inch row spacing is the future," Below says. It gets more plants in a smaller area. A grower needs better weed control from the beginning and the plant needs to be fed, not the soil.
Plants that emerge a day or two later with standard planting and fertilizing technology "are left behind. They never catch up" and produce a small cob, if any. With high-tech fertilizer banding under the rows, Below says, "there are virtually no plants left behind. Apparently plants sense their fertility earlier than we realize and they make irrevocable growth decisions. It is all about rapid growth right from the start and you can never make up for lost yield."
In field testing, Below sees a 14-20- bushel-per-acre yield increase just by banding fertilizer. Add high plant populations and fungicide and yields increase by 45-50 bushels per acre.
While there is much emphasis on getting nitrogen to corn plants, Below thinks phosphate may be a limiting growth factor. At flowering, the plant has to suck up as much phosphate again as it already had to that point. Eighty per cent of the phosphate is removed from the field with the grain. It is probably the single most limiting element for high yields.
"Where I band phosphate, sulphur and zinc, I see an enormous improvement and early growth of the crop. I wouldn't believe if it I hadn't seen it myself." BF
Extraordinary commitment and constant vigilance
How would someone start to farm as Dean Glenney is doing? "Don't plow up the hayfield," he advises. "Plant right into it. You will get reasonable yields and they will increase from there." But Glenney doesn't see that his program is being emulated. A lot of farmers have come to see what he is doing, "and they keep on plowing."
He says that achieving these yields as he does it takes extraordinary commitment and a constant watch over the crop. Glenney comes from a dairy background, where top production depends upon heading off cows from having "bad days." From there, he went to berry production, where there is no market for less than top-quality fruit. No one wants wormy sweet corn, he points out. Like a berry farmer, he now goes to the trouble of scaring away birds, which would attack his corn fields, ripping open cobs and leaving a path for disease.
It may be no coincidence that Simcoe's Randy Vander Heede, who won the Dupont-Pioneer corn contest last year, also has lots of experience growing high-value crops. BF