Economics of tillage

tractor tilling a field.

Yield differences from soil tillage are more often the exception rather than the norm. This is particularly the case for soybean yields, as well as rotated corn systems.

Due to the costs associated with soil tillage and the number of extra passes on fields, reducing soil tillage is a great way to cut costs, labor and soil erosion, while promoting soil health and getting the same crop yields.

Farmers see an immediate benefit to leaving crop residues on the soil surface in regions with annual rainfall less than 20 inches due to soil moisture conservation. However, farmers are often reluctant to farm with more crop residue in Minnesota and the eastern Dakotas, where higher precipitation, cool springs and short growing seasons are common.

The primary concern is the potential for slower crop growth and reduced yield due to cooler, wetter soils in the spring. Crop residue management is even more challenging when corn follows corn, or on poorly drained soils with a high clay content.

Higher residue doesn’t mean lower yields

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Annual weather affects yield more than tillage

bar graph illustrating yield per year and residue for corn.
Figure 11: Average yields and surface residue for four tillage systems in Minnesota (DeJong-Hughes & Vetsch). *In 2004, no-till had much lower yields (LSD=3 bushels per acre), with no effect in 2005.

An earlier study in 2004 and 2005 across southern and west-central Minnesota compared on-farm corn yields at 13 sites for chisel plowing plus spring field cultivation, strip-till, one-pass spring field cultivation and no-till.

Tillage treatments had a larger effect on corn yields during 2004, when air temperatures were cooler than normal, than during 2005, when air temperatures were warmer than normal (Figure 11).

In a cool spring, corn with no tillage yielded six to nine bushels per acre less than corn that received tillage. However, in a warmer-than-normal year, no-till yielded the same as the other tillage systems.

The benefits of no-till included:

  • An average of 2.7 times more residue than chisel plowing with a field cultivation (Figure 11).
  • Lower costs per acre for equipment costs, tractor wear and tear and labor.

Averaged over two years, corn yields were similar among the chisel-plowed and strip-tilled fields while strip-till had twice the residue. These results are similar to those observed in long-term small-plot tillage trials in Waseca, where very little differences in yields have been observed among tillage systems in a corn and soybean rotation.

The perception remains that more residue will lower yields, but today's planters and drills have options to handle high levels of crop residue. These include row cleaners and coulters that clear residue from the seed row and ensure good seed-to-soil contact and a warmer seedbed. Equipping the planter with starter fertilizer attachments increases the chance for consistent yields in high-residue systems.

Tillage costs

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Fuel use

Reducing tillage means fewer trips across the field, conserving fuel, time and labor, and cutting machinery maintenance. The power requirement and fuel used for tillage equipment varies depending on

  • Equipment design

  • Number of row units

  • Components used

  • Soil properties

  • Shank or disk depth

  • Field conditions

  • Operator adjustments

Fuel use rises with tillage intensity, depth and increased number of passes. Effectively pulling aggressive tillage implements, such as a disk ripper or moldboard plow, requires that tractors use lower gears and consume more fuel. Using a lighter, less aggressive tillage implement can save fuel costs by operating the tractor in higher gears.

In a 2013 study at Iowa State University, fuel use reduced 18 to 34 percent when operating the tractor in a higher gear and at a reduced engine speed while maintaining travel speed.

In the same ISU study, raising disking depth from 5 inches to 3 inches saved 6 percent in fuel use. However, dropping tillage depth from 9 inches to 18 inches in continuous corn almost doubled fuel use, with no added yield advantage.

Another way to lower fuel costs is to eliminate a primary tillage pass or two secondary tillage passes.

In a 2015 study, researchers compared fuel usage with different tillage implements (Table 6). Moldboard plowing with two passes of a spring field cultivator would use 546 gallons more diesel ($1,910 at $3.50 per gallon) than a shallow disking and 406 gallons more diesel ($1,420 at $3.50 per gallon) than strip-till over 1,000 acres.

Table 6: Fuel use and cost

Operation Fuel use per 1,000 acres Fuel cost per 1,000 acres: $3.50 a gallon Fuel cost per 1,000 acres: $2.50 a gallon
Shallow disking 35 gallons $123 $88
Field cultivation 73 gallons $256 $183
Strip-till 175 gallons $613 $438
Moldboard plow + 1 field cultivation 508 gallons $1,778 $1,270
Moldboard plow + 2 field cultivations 581 gallons $2,034 $1,453

In 2015, researchers from the University of Manitoba partnered with the Prairie Agricultural Machinery Institute to calculate the cost of four tillage systems. The study compared

  • Two passes with a double disk (DD)
  • Two passes with vertical-till at a 6-degree angle (high-disturbance or VT 6)
  • Two passes with vertical-till at 0 degrees (low-disturbance or VT 0)
  • One pass with strip-till (ST)

All were pulled by the same tractor, on a sandy loam soil in corn residue. Residue levels after tillage were more than 60 percent for strip-till and low-disturbance vertical-till and under 30 percent for double disk and high-disturbance vertical till.

There were no differences in soybean yield due to tillage (data not shown). The study could use tractor and tillage costs alone to calculate a total cost per acre.

Both vertical-till units could effectively run at a higher speed compared to either the strip-till or double disk. This equated to more acres tilled per hour by vertical till, with 7 more acres an hour than strip-till, and 10 more acres per hour than double disk (Figure 12).

Fuel usage ranged from 1,020 gallons to 1,540 gallons over 1,000 acres, with strip-till using the least amount of fuel (Figure 13). This is due to effective corn residue management with only one pass of the strip-till equipment. Strip-till used 34 percent less fuel than high-disturbance vertical till.

bar graph with tractor icons illustrating the number of acres per hour being tilled and the type of tillage system being used.
Figure 12: Acres tilled per hour using a work rate efficiency of 80 percent for four tillage systems on sandy loam soil near MacGregor, Manitoba.
bar graph illustrating fuel usage.
Figure 13: Fuel usage in gallons for four tillage systems on a 1,000 acre farm near MacGregor, Manitoba

Landlord benefits

Across Minnesota and North Dakota, almost half of cropland is being rented by the operator. More than 74 percent of that land (23 million acres across Minnesota and North Dakota) is owned by landlords who have limited to no connection to the land (Table 7).

Table 7: Rented crop acreage statistics for Minnesota and North Dakota

State Total cropland Rented cropland Rented cropland owned by non-farmers Rented cropland owned by non-farmers
Minnesota 26 million acres 45% 78% 8.1 million acres
North Dakota 39.3 million acres 49% 74% 14.3 million acres

Generally, land owners that have a stake in the land’s earning potential have more of an interest in soil health and conservation practices. A Utah State University study of absentee owners of farms or wooded acreage found that absentees express high environmental concern, especially those who used the land for recreation.

When asked whether conservation is important on their property, 88 percent responded yes to soil, 56 percent said yes to wildlife and 66 percent said yes to water. However, the land owner may not be knowledgeable about their options or how to find programs or farmers who share their goals.

While farmers and landowners may have conflicting views regarding conservation and production practices, using no-till or strip-till improves the long-term productivity of the soil and can represent both environmental and economic benefit for the land. It’s worth a conversation with the land owner about the benefits of reduced tillage for preserving their land legacy.

Jodi DeJong-Hughes, Extension educator and Aaron Daigh, soil scientist, North Dakota State University

Reviewed in 2018

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