In November of 2017, a long-time Corn Belt no-tiller came upon a shocking scene: One of his no-till fields was being chisel plowed by a misinformed tractor driver, working for a multi-thousand acre operator who thought the field was among some of his newly rented ground.
Before the no-tiller was able to put a stop to this disastrous tillage situation, 80 acres of a 100-acre field had been chisel plowed. For 30 years, this field had been no-tilled or strip-tilled to corn and soybeans. It had also been seeded 6 weeks earlier to a mixture of cover crops.
Part of a 3,200-acre continuous no-till operation, these highly productive silt loam soils commanded a cash rent of $215 per acre, The field had a 10-year average of 210 bushels of corn per acre and 62 bushels per acre of soybeans.
Since the veteran no-tiller asked to remain anonymous, we’re not identifying him or his location. But these facts are important, as other no-tillers or strip-tillers may someday be facing a similar situation. As you will read later, some no-till veterans and educators believe it may take as long as 6 years to remedy this unfortunate tillage mistake.
Bad, Bad Deal
After recovering from the initial shock, the veteran no-tiller wondered how to remedy the situation. With considerable no-till crop and cover crop residue remaining in the roughly tilled field, it was too late to correct the situation that fall. The following spring, the grower disced and field cultivated the 80 acres of chisel-plowed ground to spread the residue and level the field before no-tilling soybeans.
As it turned out, his soybean yields a year later were surprisingly the same for the 80 acres where the unfortunate chisel plowing had taken place as on the remaining 20 acres that had been no-tilled for 31 years.
While there was no yield differentiation, there was a dramatic increase in costs. The no-tiller had invested $28 per acre in cover crop seed and application costs. There was also the spring tillage cost, which equaled $16.30 per acre for discing and $10.10 per acre for field cultivating based on university farming rates.
This added up to $54.40 per acre in unnecessary expenses, or a total of $4,352 for the 80 chisel-plowed acres.
“Trespassing Due to Chisel Plowing”
Since the no-tiller also had a 5-year Conservation Stewardship Program contract at $18 per acre per year for the 100-acre field, he worried that he might be forced to forfeit these government payments. Despite the contract violation, the county NRCS staff authorized the $1,440 per year ($7,200 over 5 years) payment, listing the reason as “trespassing due to chisel plowing.”
“There were $4,352 in extra costs for the chisel plowed acres…”
In addition, the grower wondered about the value of sequestered carbon that was lost into the atmosphere after three decades of achieving an ideal physical, chemical and biological environment in his no-tilled soils.
Following this unfortunate incident, the veteran no-tiller asked the No-Till Farmer editors if we knew of any research that covered a similar situation.
No Easy Solution
To gather ideas on how to remedy this one-time soil destruction event, the No-Till Farmer editors shared this unfortunate situation with several long term no-till advocates:
John Grove is a University of Kentucky soil scientist in Lexington, Ky.
Randall Reeder of Hilliard, Ohio, is a retired ag engineer from Ohio State University. (His comments include assistance from David Brandt, a veteran-tiller and cover cropper from Carroll, Ohio; Bill Richards, a long-time no-tiller from Circleville, Ohio; and Don Reicosky, a retired Agricultural Research Service soil scientist and carbon sequestration authority from Morris, Minn.)
Guy Swanson of Exactrix Global Solutions in Spokane, Wash.
Dan Towery, the owner of Ag Conservation Solutions in Lafayette, Ind.
Q Has any research ever been done on a similar situation?
Grove: Somewhat similar work has been done in Australia, Spain and Sweden, but has limited value for North American conditions. I’ve only found two somewhat-related U.S. studies in Nebraska and in Ohio, but neither exactly fits this situation. For example, the Ohio study was a comparison between continuous no-till and the use of a disc every 3-4 years.
Q What’s your estimate of the amount of soil health damage done to this field?
Towery: With no-till and strip-till for 30 years, the organic matter (OM) in the top 3 inches of soil could have increased by about 0.05% per year, or a total of 1.5%. I’d expect some tied up nitrogen (N) would also have been available the following year, but it wouldn’t be needed with no-tilled soybeans.
Swanson: Similar scenarios occur with field fires in the western states, but the soil damage from tillage isn’t as dramatic. Chemfallow and wheat stubble fires have burned up to $150 per acre of good nutrients and released sequestered carbon into the atmosphere.
Compare a soil OM test from previous years with a current one. You can make a case for the loss of N, phosphorus, potassium, micronutrients, carbon and OM.
Grove: Given the limited scientific evidence, it’s difficult to estimate. Check the crops with a yield monitor for 2-3 years to determine if reduced soil health led to lower yields.
Q How many years will be needed to bring the soil quality in the chisel plowed area back to its previous level?
Reeder: Dave Brandt and Bill Richards believe it will take 5-6 years to restore the soil.
Towery: There’s definitely a reduction in OM and hard-to determine carbon losses. While the soil’s aggregate stability will decrease after tillage, it takes a fairly intense test to measure, such as the procedure Cornell University uses in their soil health program.
Swanson: You can gain back the soil structure more quickly with a cover crop or by switching to winter wheat and applying manure from nearby hog farms. It will take at least 3 years to get this field back to full no-till production.
Grove: Two of the Nebraska sites were re-examined 5 years after the one-time discing. At that point, there was little discernible yield impact from tillage.
Changes in soil properties depend on the soil, the landscape and the tillage tools used. Soils that are largely sandy, silty or clay take longer to recover lost aggregate stability than mixed texture soils. Erosion-prone soils will take longer to recover.
What About Carbon Payments?
Suppose farmers who are doing continuous no-till are paid for carbon sequestration. Then a new landowner plows the field after 20 years of no-till, which would release several decades of sequestrated carbon.
Does the new landowner have to pay back the carbon payments for those 20 years? Since much of today’s cropland is rented, it’s likely more complicated than you might think.
Aggressive tillage will result in a reduction in soil aggregate size and a larger loss of carbon. Given that the tillage included chisel plowing, discing and field cultivating, the decrease in soil aggregate size will be pretty intense in the top couple of inches of soil nearest the surface.
The good thing to remember is that crop residues, roots, shoots, manure and cover crop growth will have the largest and quickest impact on the upper few inches of soil.
While carbon loss from a single tillage operation is difficult to measure, the top couple of inches of soil may have lost as much as 90% of its labile carbon. While it does not account for a great deal of total soil carbon, it’s part of the overall soil organic carbon content that has the fastest turnover time and highest loss to the atmosphere.
Q What else should be considered in determining the decrease in soil value?
Reeder: The biological loss is impossible to estimate. How long will it take to restore fungi, microbes and earthworms? Having living roots growing all year long and adding manure could accelerate the change.
Towery: A soil’s aggregate stability decreases with tillage, which means there are fewer pores for storing water. Chisel plowing may cause a soybean yield drop of 3-7 bushels per acre in a year when summer moisture is in short supply.
Grove: Water retention, nutrient level and oxygen transmission values are associated with soil properties that contribute to the field’s assessment for crop production while providing a favorable environment for root growth and function. Since erosion causes physical losses of both nutrients and OM, this chisel-plowed ground may not be as suitable for water infiltration as when it was no-tilled.
The loss of crop residue can lead to increased water evaporation, greater crusting of the exposed soil surface and nutrient losses from the residues. This can lead to a loss of porosity in the soil particles that are responsible for draining excess moisture and transmitting water to the crop root system.
Q How does a no-tiller best handle being in violation of a CSP contract?
Towery: Just like this grower did, contact your local NRCS and figure out the options.
Swanson: While I’m not sure government employees will really care since it was an accident, they might be interested in gathering more data. A grower might request extra dollars for more extensive testing or get extension or Agricultural Research Service staffers involved.
Grove: The no-tiller might ask for NRCS approval to change conservation and cropping practices to bring the field more quickly into government compliance.
Q Should the no-tiller pursue legal action against the operator who did the chisel plowing?
Towery: The 80 acres were tilled by mistake, and the only ones who would make any money on a lawsuit would be the attorneys. If there was miscommunication between this large-scale operator and the tractor driver, ask how this happened. If the operator did not provide GPS maps clearly showing which fields were to be chisel plowed, the responsibility is more on the big acreage operator than the tractor driver.
Reeder: The other party should pay the extra costs. An additional 20% of fertilizer may also be needed to compensate for lost nutrients over the next 5 years.
Q What value over time would you place on this unfortunate situation?
Towery: At a minimum, the $54.40 per acre expense for 80 acres is $4,352 that the no-tiller should be paid.
Grove: Let the yield monitor be your guide and assume any unnecessary differences due to this one-time event would be over by the fifth year. Here’s an example based on the Nebraska research.
Let’s say the yield loss is 8% the first year. Then I’d assume a 6% yield loss the second year, a 4% loss the third year, a 2% loss the fourth year and 0% loss during the fifth year.
Reeder: The one-time direct costs are $28 per acre for cover crop seed already applied before the chisel plowing took place and $26.40 per acre for secondary spring tillage before no-tilling soybeans. Future costs will be for practices required to restore the soil properties to their previous physical, chemical and biological status.
Swanson: The value lays in what can be learned — not how much money the grower made or lost. If this ever happens to you, ask your state’s land grant university to do a case study. You will do yourself and society a lot more good than trying to get the attorneys working on a problem that can be settled with correct information and the development of a good long-term friendship.
Q What would you recommend that this no-tiller do?
Towery: It’s a judgement call, but here are several options:
- Put it behind you and do nothing. It’s almost impossible to put a value on the loss of soil quality due to unnecessary tillage trips.
- Ask for $4,352 to cover the cost of the cover crop seeding and the two spring tillage trips. This would be very reasonable and hopefully would send a message to the large-acreage operator to get his act together.
- Ask for “potential” yield loss values for 2019 and 2020 resulting from their trespass, loss of soil health properties and mental anguish over this unfortunate tillage trip. A $8,000 payment could be defended.
- I’d still want to know who is responsible. If it is a big acreage grower, who is picking up new acres by offering higher cash rents, then ask for $8,000-$10,000. While it may be difficult to find an attorney who would take this case, it probably wouldn’t go to court, as the operator may be willing to offer something to make the situation go away.
Reeder: Here is a 6-year plan that can likely restore the OM and soil structure to its previous condition, while adding fertilizer to maintain crop yields:
Use an aggressive cover crop mix each year. The exact mix will be different when ahead of no-tilled corn or soybeans, but $50 per acre per year should cover seed and application costs.
Yields should remain about the same, but will likely require 20% additional fertilizer for the next 5 years. The chisel plowing released nutrients that would otherwise have been released slowly.
To gain more days for cover crop growth, switch to short-season corn hybrids or soybean varieties that can be harvested a couple of weeks sooner. However, it’s impossible to predict whether a slightly lower corn or soybean yield would be compensated by additional value due to carbon buildup, more soil nutrients and improved soil structure from extended cover crop growth.
If it’s available, apply a high rate of manure on a green cover crop to more quickly increase OM, accelerate biological activity and replace some of the needed chemical fertilizer.