Vanished yield potential

How much yield is lost every year because we don’t apply the knowledge from the past?

Huber, McNeil, Zimmer, and others have reported regularly achieving 400+ bu per acre corn yields during the ’70s and ’80s. What happened? How was that yield potential lost? Why are we going backward? Why haven’t we made more progress?

From my podcast interview with Gary Zimmer:

John: What is something that you believe to be true about modern agriculture that is very different from the mainstream view?

Gary: When I was at Brookside, back in 1976, I visited a farm in northern Illinois that was growing 375-bushel corn, with a public variety of corn from the University of Illinois, on forty-inch rows. You could stick your hand in the ground clear to your elbow. Of course it got my attention.

In the ’90s, in Iowa, there was somebody who grew 400- to 500-bushel corn. That really opened up the doors to say that there’s much more potential.

This is why I find it offensive when people say, “How are we going to feed all these people?”

I say, “Forty percent of our corn goes into making ethanol, and we have the capability to double our yields. And we can do it with a cleaner method of farming.” It’s not that we can’t produce more food. And most people don’t even eat corn and beans. We can do a lot of things if we want to feed people. I think that conventional agriculture, or whatever you want to call it— modern agriculture—is shifting to a biological farming system.

2022-02-08T18:58:05-05:00February 10th, 2022|Tags: , , , |

Plant flexibility and unhealthy brace roots

Copper is known to provide flexibility to plant structures. Stems become flexible, plants can bend in high winds, and stand back up afterward, without any breaking or lodging. Twigs and branches become more flexible and don’t break as easily. Spurs and fruit clusters become less fragile and breakable. Crops that are sometimes known for ‘brittle’ leaves like broccoli don’t have the leaves snap off as easily. Fruit skin becomes more flexible and very slightly stretchable, allowing for fruit expansion right at maturity with additional moisture without cracking and splitting.  Copper provides all of these benefits because it enhances the formation of lignins in the structural tissue. We have observed all of these benefits occurring in the field.

When grain crops have adequate copper, they develop very flexible stems. A corn plant should be able to bend when gripping the stalk immediately above the ear until the tassel brushes the ground, with no strain, and stand right back up again. This gives grain crops a lot of resilience to severe weather stress and physical abuse.

This also means plants do not need so-called ‘brace roots’. At least not to ‘brace’ themselves. ‘Brace’ roots only show when the plant’s vascular tissue is plugged immediately below the node. As soon as the vascular tissue begins plugging, plants quickly send out emergency bypass roots at the node, above the plugged transport pipeline. When the pipeline plugs again one node higher, the plants send out another set of brace roots. The worse the plugging is over the season, the more sets of brace roots a corn plant will extend.

Vascular tissue (xylem) plugging seems to occur when plants are absorbing a great deal of oxidized iron, sometimes aluminum, and seems to be associated with herbicide use. The more herbicides that have been used historically, the worse plugging and brace root expression seems to become.

This means brace roots are in reality a negative signal of plant health.

In cases of extreme vascular plugging, there is so much growth from the node, individual roots are not even visible, but the growth is in a continuous band. In cases where the soil has a toxic accumulation of herbicide, the brace roots may grow down toward the soil surface, and then curve back and point upward again, as they seek to avoid the toxic soil.

It is possible to grow corn crops with no brace roots. A grower sent me this photo of a buffer strip between an organic field and herbicide sprayed field. The buffer is cultivated for weed control. I didn’t personally visit, so my best guess is the cultivated side on the right has had one set of brace roots buried from soil movement. In any case both of these crops have either only a single set, or no brace roots.

Have you observed corn with a continuous band of brace root growth, or where the brace roots turn up and away from the soil? I would love to see your photos and share them.

P.S. We have a big announcement coming tomorrow. Stay tuned!

2020-08-24T19:02:13-05:00August 25th, 2020|Tags: , , |

Dead Canadian thistle in a corn crop

An organic farm in Pennsylvania had challenges with Canadian thistle in one pasture section. One-fourth of the farm was in intensively managed rotationally grazed pastures for a five to seven-year period before shifting to other crops, and then going back to pasture.

After the pasture sod was plowed down,  biological amendments were applied and tilled in, and corn was planted. The corn and thistles both grew quickly. Cultivation cleaned out the thistles between the rows, but those in the row escaped. When I visited the fields in mid-summer, the crop was approaching the dent stage, and the Canadian thistle that survived the cultivator were all dead. Samples of the dead plants were sent to a lab to identify if any usual pathogens caused the weeds to die, but no known pathogens were identified.

The corn crop went on to make 32+ tons per acre of silage.

This field is now back in pasture for several years, and the thistles have not returned. Do you have any idea why they may have died?

2020-07-13T14:50:14-05:00July 14th, 2020|Tags: , |

Treating corn rootworm with nutrition

In Spring 2013 an organic grain crop grower in central Pennsylvania called, very concerned about corn rootworm in his organic corn crop. About 15%-18% of the seedlings  were noticeably delayed behind the other plants, and the rootworm larvae were spreading to the larger plants as well.

At this point, we had less experience managing insects with nutritional applications than we do today, and I was uncertain how much of a difference a nutritional application would make.

With the caveat that I don’t have experience with this situation, and I am unsure if the recommendation will work, I suggested a foliar application of AEA products that contained magnesium, sulfur, boron, cobalt, molybdenum, seaweed, humic substances, crab shell,  shrimp shell, and some other goodies.

The intent of the foliar was to rapidly convert all the existing free amino acids, nitrates, and ammonium which might be present in the plant sap into peptides and complete proteins. An additional goal was to trigger an immune response within the plant through the induced systemic resistance (ISR) pathway so the plant produces higher levels of phytoalexins which can disrupt the digestive system of the insects and shut them down.

The grower applied double our recommended rates. (You don’t know any farmers that have ever done that, right??)

Forty eight hours after the application, scouting showed that all the rootworm larvae were dead.

The crop went on to produce a full yield of 230+ bushels.

Since then, we have experienced similar success on many different types of insects in different crops. It is possible to not only prevent insect damage, but healthy plants will actually kill insects that persist feeding on them.

What I find particularly interesting in this example is that the insect was below ground, and could not have been directly exposed to the foliar application. This is a certain indicator that the plants nutritional profile was changed as a result of the foliar application, which produced the resistance response we were looking for.


2020-06-23T11:23:38-05:00June 26th, 2020|Tags: , , |

Change nutrition management for spider mite resistance

Plants have the capacity to kill insects and mites feeding on them when they are healthy enough. These potential pests don’t show up in fields at random, but only when the plant has a nutritional profile they can utilize as a food source. When you change the plants nutritional integrity with agronomy management practices, you also change the crops susceptibility to insects and pests of all types.

Spider mites are often associated with hot and dry conditions. Spider mites are not attracted to high temperatures specifically. They are attracted to plants with abundant levels of free ammonium in the plant sap.

Elevated levels of ammonium often occur in high temperature environments when plants shift from photosynthesis dominant to photorespiration dominant. When this shift to high photorespiration occurs, plants are no longer getting enough energy (sugars) from the photosynthesis process (which has slowed down or halted). To sustain themselves, they begin catabolizing proteins to use as an energy source.

The protein catabolism during photorespiration in high temperature environments usually results in the accumulation of ammonium in the leaf, which can result in the crop being susceptible to spider mites, only when the plant does not have the needed nutrients and enzyme cofactors to convert the ammonium back into proteins at night, or as soon as carbohydrate energy become available. The critical nutrients for this conversion process are magnesium, sulfur, boron, molybdenum, adequate carbohydrates in the plant, and occasionally nickel.

In these photos, you can observe the results of a nutritional correction applied through an overhead pivot on a corn crop in SW Kansas in 2015. Spider mites were present in large numbers, and the local crop scout recommended a miticide application immediately.

The pivot took 48 hours to treat the entire circle with nutrients. In the sections that had been treated 24 hours earlier the spider mites were noticeably sluggish and moving slowly. In the section that had been treated 48 hours earlier, the spider mites were completely dead. The local crop scout assumed a miticide had been applied, but this was not the case.

Healthy plants can be completely resistant to all diseases and all insects when supported with the correct nutrition and the correct microbiome.

Of course, applying more ammonium fertilizer than plants can convert to proteins in a few days is also a great attractant for spider mites, thrips, and other related pests that are thought to like ‘warm conditions’.

2020-06-23T07:17:16-05:00June 23rd, 2020|Tags: , , , |

We can produce enough food to feed 15 billion people with 30% less land with 1960’s tech, if we want to.

This quote from the podcast interview with Don Huber is powerful and important.

We were shooting for 400 bushels in 1979 and 1980, and now we’re struggling with 250 bushels.

John: Don, in 1979 you were producing 350-plus bushels of corn per acre in a biological soil ecosystem. Today, growers are struggling to produced 250 bushels of corn. We don’t even have a conversation about growing 350 bushels of corn on a commercial field scale. There are a few notable exceptions, but not on a large-scale production system. What happened with that knowledge? Where did it go? Why was it not adopted on a much broader scale?

Don: We started saying we had too much production. We needed to focus on different things. At our land grant universities, a lot of that research and the long-term commitments that breeding programs require for the expression of that genetic potential was closed out. Materials were just given to the private companies to develop their experiment stations.

The universities were happy to not have that long-term commitment. They could then respond to the political pressures, and their programs started being limited to three to five years—for the competitive grant programs on a federal scale. And most of our breeding programs were funded through the Hatch Program and the Smith-Lever Program, which would give the states a constant amount of money on a formula basis for those long-term agricultural developments, which are the reason why we have success in our agricultural programs. They were built on those long-term, continuous programs that were pretty much abandoned as we started looking at the bells and whistles in science rather than at the end product.

Again, we were producing more than we knew what to do with. I don’t know what we’d do with all the corn that we currently produce if we weren’t producing so much ethanol. I mean, that’s the way to use your crop: find a new market for it. Certainly, population growth is a long way from requiring our current production. We could produce enough food for about fifteen billion people with about 30 percent less land—if we wanted to really do that, if we really needed to do that—with the technology that we had in 1964.

We were shooting for 400 bushels in 1979 and 1980, and now we’re struggling with 250 bushels. But sometimes you have to reinvent the wheel. That part of the system was not considered important, and the resources were fractured. In a breeding program, you don’t just turn it on and off with each little whim or political idea that comes along. It’s a long-term program. When we turned all of that material over to the private companies, their interest was the bottom line. There’s a tremendous amount of material that could be manipulated. But as far as that long-term commitment, there hasn’t been any of that.

Genetic engineering certainly has not improved the long-term effects; you get the idea that we can do it all in a laboratory just by switching this system on or inhibiting this particular system. We forget that it’s still a system—an ecology that has to be managed—if any of it’s going to be of value to us. It’s a thought process that’s involved, as well as the necessity. But also, the desire—the innovation—drops out when you forget that you’re a part of a very dynamic, beautiful system that was all put together—when you start focusing on only one thing. Silver bullets may take care of a varmint, but they don’t provide stability in the system. 

2020-05-19T19:18:25-05:00May 20th, 2020|Tags: , , , |

Visual indicators of calcium and boron deficiency in corn

When the soil biology does not provide enough calcium during rapid vegetative growth stages, cell division continues imperfectly, resulting in the common leaf ‘zippers’ on corn and other grass crops.

The location of the zipper can also indicate whether boron is inadequate. Adequate levels of boron produces the effect of moving nutrients and water through the plant and leaf quickly to the outer edges. When the zippering effect occurs at the edge of the leaf, it may indicate there is not enough boron present to move calcium to the leaf edge. When zippering occurs in the middle of the leaf, boron may be adequate, but calcium remains low.

When enough calcium is present to remove the zippering effect, plants get significant growth energy from the abundant calcium, and nitrogen requirements drop. This is one reason some farms grow high yielding, high test weight corn with only .35 – .5 lb of N per bushel measured in the system.

PS. We added a new feature on the blog, all posts are tagged, and you can browse the tag index here.

2020-06-24T07:12:27-05:00May 11th, 2020|Tags: , , , |

Untapped yield potential on corn

How much can you increase photosynthesis levels beyond what is considered ‘normal’ today? Beyond what is common?

How much higher might national corn yields be, if the right incentives were aligned to produce the desire for higher corn yields? Could we have a 350 bushel national average yield? Don Huber suggests we had the capacity to do so with knowledge that existed in the 70s if we had the collective desire.

From our interview on the podcast episode here.

John: What is the potential for plants to increase the volume of photosynthesis?

Don: The potential is 100 percent. I mean, fivefold, tenfold—depending on where we are now and what plant we’re talking about. There a number of different ways to do that.

I mentioned plant morphology, but you can also do it by increasing light intensity. You got a lot of leaves on a garden plant—a mature corn plant at tasseling time—that aren’t getting very much sunlight. They’re not photosynthesizing at their potential because of that lack of sunlight. That’s where morphology comes in.

Plant spacing—we can increase the number of ears on a corn plant. There is tremendous work being done at Purdue, for instance, in corn breeding/genetics—they’re producing five and six ears on a corn plant. If you increase the efficiency of that plant, you don’t need as high a population. You can minimize that crowding and that shading effect.

We can reduce the allelopathic effect of our plants. To increase the population in corn, it’s very critical to have even germination. If you delay germination six to eight days, you automatically reduce the size of your ear by the allelopathic effect—that auto-intoxication effect of the root exudates on an adjacent plant—by as much as 80 percent.

John: Wow!

Don: When the John Deere MaxEmerge planter came out, I remember how it was almost an instant success because it increased the soil-seed interface—the contact that gave you that uniform emergence, to minimize that allelopathic auto-intoxication suppression that you otherwise had from those higher populations. We got an increased corn population and maintained full yield potential without the allelopathic chemicals reducing the overall production potential of that particular plant.

There a number of things we could do if we needed to. Right now we’re concerned about a surplus. The biggest thing is that necessity is still the mother of invention. But there’s plenty of potential there.

In one of our brainstorming sessions at Purdue we asked Charles Tsai what the biochemical genetic potential of a corn plant was. And a couple of weeks later, when we were all together, he said “I’ve got your answer.” We were shooting for 350, 400 bushels in our research. We knew that a lot of our better farmers—back in the late ’70s—had the potential for 550 or even 600 bushels. We were trying to design some systems for them to achieve that on a field basis.

And Charles sat down, and we said “Well, is 600 bushels a realistic figure?” And he said “You’re all pessimists. The biochemical genetics of the corn plant are about 1100 bushels.” That’s what we could do if we managed the environment and the plant in a proper manner and provided the expression.

We probably won’t come close to achieving that until the necessity is there. The limiting factor is the innovation of man. And as long as we’re doing okay—as long as we don’t have that burr under our saddle to look at both the genetics and the environment—we won’t have the need to maximize the expression of that genetic material.

John: What yields did you end up achieving on your yield trials?

Don: We could get 400 bushels. We had farmers that were getting 350. Of course, the average was still 75 bushels. They were doing three or four or five times what the average was on a major piece of land. They were able to do it because they recognized that they were managing an ecology. They started out with the soil. They had a beautiful soil.

I remember visiting Herman Warsaw’s farm. You could take a steel probe and you didn’t have to lean on it. You just pushed it in the soil three feet. He had that system working very well. In some of his neighbors’ fields you’d get the probe down three or four inches and you’d have to really put some pressure on it. To get it down a foot and a half you’d be driving it in.

I can’t tell you how many of the old ping tubes are still sitting out there in the field. Those were tubes that you could drive into the soil to collect soil samples—at three and four feet. And we had to get it into our soils using a sledgehammer. Then the problem was pulling it out. You would tear the metal off of the tube with a jack, and finally you’d just crimp it over so that it wouldn’t tear up the tire, and then you left it. A lot of them are still sitting out there in those fields because we didn’t have that concept— the soil wasn’t a major part of the management program. In general, we would look at the nutrients and forget that all parts of the ecology needed to be managed—to have better percolation, to have biology, to have air exchange—and most things have to take place if you want to capitalize on the genetic potential of the plant.

John: What were the plant populations that growers were using to achieve 350-plus bushels per acre?

Don: You had the old Pioneer 3532 seed—a hybrid that picked up 95 percent of its nitrogen by tasseling time and then merely recycled it. On sandy soils it was a great hybrid because you couldn’t maintain your nitrogen availability in those sands. It would take it up and store it, but it had a yield potential of about 125 bushels at 24,000 plants, which was our standard at the time. But you could increase the population of that particular variety because it didn’t have the allelopathic effects from the root exudate with high population. It had a fixed ear. So, as you increased the population, you still maintained that same ear length. It wasn’t big like your higher-yield hybrid, but it was very stable and it tolerated high populations. So they got the yield up by increasing population.

With our other varieties—our high-yielding varieties that were hybrids—there you had a flex ear that related to the environment more dynamically. The higher the yield potential, the more nitrogen you want as ammonium. For the 3532 variety a 50-50 ratio of ammonium/nitrate was optimum for it. And you get into the higher yield and the 250- to 300-bushel yields, you want 75 to 80 percent of your nitrogen as ammonium and only 10 to 20 percent as the nitrate source of nitrogen, because you want as much photosynthesis as possible to go into the kernel. When the plant utilizes nitrate nitrogen—and most plants can utilize either form equally well—it takes 15 to 20 percent of your photosynthate to reduce nitrate nitrogen back to the amine form so that the plant can utilize it.

And so the higher your yield potential, the more ammonium nitrogen you want—to provide those amino acids for that growth, and your enzymes and everything—and less nitrate nitrogen. We always found that there was a benefit to some nitrate nitrogen because it serves as a buffer—both to limit the drain on carbohydrates—if you have a high uptake of ammonium nitrogen, nitrate will tend to balance that—but also as a stable form of nitrogen. If you run short, then you can use some of that photosynthate.

If you have molybdenum and your other nutrients available, you have part of the function of your nitrate and nitrite reductase enzymes. Again, you have a different physiological pathway. And if you’re saying, “Well, I’m going to get most of mine from an ammoniacal source,” you may forget that you also have to have molybdenum for some of those other enzymes that aren’t quite as dynamic or quite as involved as they are if you’re relying more on the nitrate source.

Those are some of the things you could do to enhance that overall photosynthetic efficiency—the form of nitrogen is going to influence your soil biology and your buffering capacity in those areas.

2020-04-25T14:20:06-05:00April 27th, 2020|Tags: , , , |

Pesticides as a cause of soil degradation

Many agronomists and farmers with three or four decades of experience describe how soil health deteriorated quickly when herbicide and pesticide use became mainstream. Michael McNeill shares his observations.

From the Regenerative Agriculture Podcast with Michael McNeill:

John: And when you say you have about 165,000 acres that you work on today, what is the scope of the work you do on each of these farms?

Michael: Most of it is working with soil health and soil fertility, and helping growers select the right genetics for the fertility programs that they’re working with. Soil health is becoming a bigger and bigger issue for me to deal with. When I first started, it wasn’t a really big issue. It’s huge now. And so I’m devoting more of my time now to soil health than I ever thought I would.

John: I’d love to talk about that a little bit—when you say that soil health didn’t used to be a big issue, and now you’re spending a lot of time on it, what changed with soil health? How are you managing it differently today than you were twenty or thirty years ago?

Michael: Well, it’s interesting that you would ask me that, John. The other day I was cleaning out a drawer in my desk, and I found some old pictures that I had taken back in 1972 or 1973 of crops that were growing. I had some close-ups and some overviews of the field. The thing that I noticed was how healthy the plants were. There were no disease lesions on them anywhere. The corn plants were just perfect. And the whole field was that way.

It’s really hard to find a field today that is that way. I was looking at the weeds that were growing along the fence rows, and they were big and healthy and looked great. They don’t look so good today, comparatively speaking. And you say, “Well, maybe that’s a good thing!” No, it’s not. The whole area that we’re farming is unhealthy. It makes me ask the question—what’s changed?

To me, the big difference from that era until today is that farmers have been drawn into big ag. You need to use herbicides. You don’t want to use a cultivator. You have to farm more land. So you use herbicides, but herbicides are doing things to the soil, because they’re all chelators. So now the plants become a little bit imbalanced in the nutrition that they’re taking up, and you find more disease—you find more insect pressure. So you start using fungicides and insecticides—more chelators, more poisons being dumped onto the ground. And you’re pretty impressed with how they work. The field is perfectly clean, and weed free—excellent. The diseases were dramatically reduced. The fungicides worked really well. The corn borers and some other of the insects that were issues went away. It was magic. The chemistry was totally magic—it looked beautiful.

But as time went on, the chemistry started poisoning the good things that were in the soil. And so, today, I’m called out to look at farms where the guy’s production has dropped off dramatically and the soil is virtually dead.

John: When you say the production has dropped off dramatically, what have you observed?

Michael: Looking at ten-year crop insurance records, the guy was getting 190 to 210 bushels per acre and had around a 200-bushel 10-year average. Excellent, excellent yields. Now it’s getting 70- and 80-bushel yields. That’s dramatic, and it will put him out of business very quickly.

John: That is very dramatic.

Michael: This isn’t just happening on a little field here, a farm there. I’m seeing 8,000- and 10,000-acre farms that this has happened to. And that really, really woke me up. I started seeing this about five years ago. I’ve been working with these growers who are asking me whether I can help them remediate that. Can I help bring the farm back? And in a three- to four-year period, we’ve had pretty good success. I would say we’re back now at where we were when this crashed.

The farmers are excited that they can now take it to a different level—to the 250-bushel range or greater. And they can see growth and potential and doing what they’re doing. They’ve moved away from GMO crops, and they’ve particularly moved away from glyphosate.

Corn root system development

We routinely harvest only a fraction of the genetic potential our crops are capable of. Few of us actually know what a really healthy crop actually looks like anymore. Here is an image that describes what is possible.
This is a photo of corn root system from Al Trouse, from a demonstration conducted at the National Soil Laboratory at Auburn University.
The photo and notes below were shared by Jim Martindale from Cursebuster, who heard Al Trouse’s presentation to a group of Brookside consultants approximately 1979 or 1980.
In this demonstration, soil was sifted into a growth chamber so it would have a uniform density (other than gravitational pull). In this growth chamber with uniform soil density, the seminal roots reached the bottom of the chamber (6+ feet) in a few days.
Growing roots extend very rapidly though the soil until they encounter any change in soil density. When they encounter either an increase or decrease in soil density, they temporarily stop extending, and then slowly begin growing once more. If the soil density is uniform, they will extend very rapidly during the root systems establishment phase. Each growing root tip will extend for 72 hours, and stop growing after that period. The rapidly growing tips grew to the bottom of the growth chamber in 72 hours or less.
During the establishment phase, plants expand their seminal root system as widely and deeply as possible. This phase lasts for about 40 days, until the ear embryo begins to form. The outer root system boundaries are established during this phase. Future root growth does not expand past the established borders. What might this mean for cultivation close to the 40 day mark? Disturbing root systems at this point doesn’t seem like a wise idea.
Once the embryo begins to form, the root system shifts to the expansion phase, where fine roots emanate from the seminal root mass that has already been established, and fill the zone inside the established boundaries. This root system expansion period lasts until pollen drop. After the plant has dropped pollen, no additional root system development takes place.
The normal precipitation rate for Auburn University for the growing season was added with no fertilization.
Yields were estimated at 400 bushel per acre at normal plant density.
Each of the large blocks in the photo below ris 12 inches, total depth from the surface is 78 inches.
We have lots of upward potential left. I have never seen a corn plant in the field with a comparable root system.
2020-03-26T07:07:14-05:00March 26th, 2020|Tags: , , , , |
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