Finding and Fixing Soil Compaction

When it comes to spring seeding, there can be challenges on the weather and soil conditions fronts.  Areas in Ontario that often struggle with planting conditions had crops planted under good soil conditions and in record time this spring, while other areas, even some with lighter soils, experienced delays due to rainfall.

With the wet, cool conditions through much of the seeding period, some planting occurred into slightly to moderately wet soils. Soil compaction happens when heavy loads are driven on soils that are too wet to carry those loads. Those same soils in mid-season, when conditions are typically drier, would often handle the weight that overwhelmed soil strength in the spring, resulting in soil compaction. Numerous compaction events over the last few years have really demonstrated the difference in soil load strength in wet versus dry soils. The St. Clair Regional Soil and Crop Association, in partnership with the Ontario Soil Compaction Team, is hosting a compaction event in Rutherford, Ontario on August 7th. (https://www.eventbrite.com/e/st-clair-region-soil-crop-improvement-association-compaction-event-tickets-1263916701879)

Patience must be employed to help avoid compacting and damaging soils.

The biggest challenge with going too early is the impact that big equipment and fast speed can have. The implements tend to be heavier and covers many acres per day. Even starting a half day too soon in terms of soil moisture, can lead to a lot of acres being damaged.

To date, crops have looked relatively good because the weather has, for the most part and across much of the province, provided excellent soil moisture for crop growth. However, last week in the 2nd heat wave of the summer, corn began curling up and soybean leaves flipped over, trying to fend off the heat and lack of soil moisture. This is when the damage from compaction in the spring really starts to appear. Now is the time to get out in the field and diagnose the problems in parts of the field that are showing stress. There are many factors that impact crop growth, and they don’t tend to happen alone. Soil compaction created at planting or previously with manure, fertilizer, tillage, and planting equipment will contribute to crop impacts through loss of soil pore space, which impacts water infiltration, air movement, gas exchange, nutrient cycling, pest control, and crop growth and development. (Figure 1)

Examples of what soil compaction can look like on soybeans.
Figure 1. Example of what soil compaction can look like on soybeans.
Examples of what soil compaction can look like on corn.
Figure 1b. Example of what soil compaction can look like on corn.

When diagnosing soil compaction, one thing to look for is straight lines of poor crop development in the field that are the tire paths of the implements. The lines might not be perfectly straight or smooth because of the interaction with other natural conditions, including rainfall, variation in soil moisture, disease, weeds, insects, topography, etc. The way to check how much compaction is part of the issue is to use the two most important tools that should be in every farm truck: a shovel and a tile probe (or compaction meter) (Figure 2).  You can contact your local drainage contractor to likely knows where to purchase tile probes.

Start with the tile probe and in areas of visual crop impairment, push the probe into the ground steadily, looking for areas and depths that are harder to push through (Figure 3). Do not use the tile probe on wet soil, because the soil strength is reduced by the lubricating effect of soil moisture between soil particles. This reduces the interparticle friction between soil particles and lets the probe slide easily through otherwise compacted layers. Get a feel for the extent of the area where compaction occurs.

Figure 2. Compaction Tools every farmer should have in the truck (Essential compaction tools include a shovel and a tile probe, soil probe, or compaction meter).
Using tile probes and compaction meters to find compacted soils.
Figure 3. Using tile probes and compaction meters to find compacted soils.
Using tile probes and compaction meters to find compacted soils.
Figure 3. Using tile probes and compaction meters to find compacted soils.

It is also often good to take the shovel and dig a hole below the depth where the resistance was detected. Look for smearing, dense layers, plow pans, etc. (Figure 4). The next two important steps are determining how widespread and how deep the compaction is. Knowing this allows you to manage the soil compaction that is causing crop issues without having to apply the remedy to the entire field. Compaction tends to occur in discrete patches because of the variation in soil texture, moisture, and strength across the field. To fix the problem, fix the problem areas only. It’s a strain on time and fuel to do the whole field if it doesn’t need it.

Figure 4. Digging a hole to examine compacted layers found with the tile probe

To lower your risk of soil compaction, lower the load, lower the tire pressure, and lower the soil moisture before traveling across the fields.

The most common decision to remedy compaction is to apply tillage. Tillage depth should be only a couple of inches below the determined depth of the compaction layer. The tillage should be done when the soil is dry. Dry soil shatters and is less likely to smear. Confine the remediation to the area of the field that really needs it. Longer-term solutions involve crop rotations, cover crops, changes in tillage practice (less is more) and others. Consult Field Crop News (https://fieldcropnews.com/soil-compaction/)for more information on soil compaction.

OMAFA Weather Summary: Thurs July 17—Wed July 23, 2025

LocationHighest Temp (°C)Lowest Temp (°C)Rain for Week (mm)Rain Since April 1st (mm)GDD0C April 1stGDD5C April 1stCHU May 1st
HARROW       
202527.912.215.3321.8183812911857
202427.411.60.3319.2199214212037
202328.914.015.1288.8177912201788
10 YR Norm (2011-2020)29.217.714.1351.1182912611950
RIDGETOWN       
202529.09.90.8240.8174411991738
202427.49.71.8433.0188413161916
202327.812.031.3379.6168711361662
10 YR Norm (2011-2020)29.015.917.9300.0171911561816
SARNIA       
202529.611.514.9382.6169611561654
202428.311.51.0374.2186713031878
202328.913.024.5276.3164510961582
10 YR Norm (2011-2020)29.217.218.4318.3167611151765
LONDON       
202528.19.27.4272.7166011361684
202428.510.41.5464.5185912891900
202327.512.211.4337.1168011301659
10 YR Norm (2011-2020)29.216.220.2323.2169511361793
BRANTFORD       
202530.79.73.8312.3168811551672
202428.810.61.6391.4180512391849
202328.011.78.6294.5167011191650
10 YR Norm (2011-2020)30.015.411.1281.7167911231759
WELLAND       
202529.99.63.5211.2173911971754
202427.211.80.3391.9186512961928
202327.113.814.8300.9168911321665
10 YR Norm (2011-2020)28.716.911.2302.0170111411802
GODERICH       
202528.48.31.2217.5158910591587
202427.19.21.0262.5168011221697
202326.911.919.6236.6153910061499
10 YR Norm (2011-2020)26.915.318.9269.115289781607
ELORA       
202527.88.019.3300.0155310321554
202427.38.53.6345.5168011231726
202327.410.137.7307.7154010061513
10 YR Norm (2011-2020)27.813.615.2316.515229761597
MOUNT FOREST       
202528.18.010.9258.6155010311546
202426.28.32.6332.4166011071704
202327.111.05.1296.7153710081514
10 YR Norm (2011-2020)27.113.919.5318.315029641593
BARRIE       
202527.46.61.7223.7154410221556
202426.19.94.2500.9162010671675
202326.911.024.0383.315279921508
10 YR Norm (2011-2020)27.313.911.9284.214839481568
PETERBOROUGH       
202528.37.011.1243.3159410631594
202428.89.50.0346.6167211141700
202327.89.035.7300.3157110241509
10 YR Norm (2011-2020)28.612.810.9278.015439971602
KEMPTVILLE       
202529.36.914.7242.3166611321682
202428.111.91.2376.4176212041829
202329.311.213.8315.0168511441645
10 YR Norm (2011-2020)29.015.314.8306.3161910741704
SUDBURY       
202527.95.638.8296.413498601399
202424.810.221.3398.814999711567
202326.79.131.6401.014429491460
10 YR Norm (2011-2020)27.313.013.5293.413748901493
EARLTON       
202528.16.921.4303.313048321364
202426.67.79.4344.714789571542
202327.57.711.5253.014269321445
10 YR Norm (2011-2020)26.711.318.3266.212798171395
SAULT STE MARIE       
202528.77.714.2265.213038061293
202423.610.011.2384.713728291359
202326.110.323.8260.613718751347
10 YR Norm (2011-2020)26.411.823.4297.112277441276
THUNDER BAY       
202527.07.953.6311.912027341268
202427.36.20.6278.112767571256
202326.77.014.8198.712567841297
10 YR Norm (2011-2020)26.311.116.1294.011957211257
FORT FRANCES       
202527.04.648.0313.013898851451
202428.16.26.4345.213448151356
202326.610.536.1230.514259461510
10 YR Norm (2011-2020)27.311.118.2286.213218291417

This weather summary is compiled by OMAFA using Environment Canada weather station data provided by Agriculture and Agri-Food Canada. Data quality is verified but accuracy is not guaranteed and should be used for general information purposes only.  For additional locations and weather analysis, visit the OMAFA Pest and Weather System (PAWS)