2024 Aeration Project

Objective

This year we worked with a producer in Yellowhead County looking at the use of an aerator on pastureland. The implement used was a 2022 Ranch Worx SL Series single drum pull-type aerator. We wanted to look at the efficiency of an aerator in hopes of eliminating the need for completely reworking the land. Aeration is all about improving soil structure, enhancing water infiltration and increasing oxygen availability. Soil aeration is also necessary for aerobic microorganisms. Given that this land is located in the gray luvisol soil zone, compaction may be a concern as it does have a higher clay content and poor drainage. There are several methods of aeration, mechanical, which are spike aerators and subsoilers/rippers. Rippers and subsoilers  are used for deep tillage to break up hardpan layers. There is also biological and natural aeration, biological uses deep rooted cover crops to get through the compacted soil. Natural aeration is using grazing management, rotating the livestock preventing over compaction. Another natural aeration option is controlled traffic farming, it is designed to keep machinery in designated lanes on the field.

Incorporating aeration into a management plan is understanding it’s different than tilling. Aeration is minimal soil disturbance, and its purpose is to improve air and water movement and reduce compaction. Tilling is a more aggressive soil disturbance, it physically breaks up and mixes the soil, designed for preparing the seed bed and incorporating amendments.

The process of aerating can be done in fall to catch winter snow as a reserve for the next year or in spring, allowing the crops to be less stressed in the event of a dry growing season accessing that moisture reserve.

In theory, when using aeration as a tool to break up compaction and encourage better soil structure, improvements should be seen. Every field will be different, but understanding what method of aeration would work best in your area should help improve your land.

PARTNERS

·         Bob Mitchell

·         Yellowhead County

Corn planting on June 5th

METHODS

The original intention was to use the aerator on both hay land and pasture, both the sites chosen will be cut as hay in 2024. Two fields were chosen to compare. A flagged-out block in both fields will not be aerated, the rest of the field will be aerated.

Field 1 was completely worked about 8 years ago and has been hayed every year since. The site will be aerated and harrowed in the first week of June.

Field 2 has not been worked in 25 years and will be aerated only. It was aerated on May 4th.

As of July 31st, the area only received 2 inches of rain, so no changes were observed on either field. We came back on Sept 30th to take fall soil samples; no visual differences were observed. Aeration will occur in mid-October in field 1 and the hopes are to see a difference in the land in 2025. Some short-term improvements that can be seen within weeks of aeration, less water pooling on the surface and less surface crusting, the top layer should be softer. More mid-term improvements, weeks to months after aeration that may be seen, better root growth, improves microbial activity which leads to better organic matter breakdown. Long term improvements; improved soil aggregation, higher yields and better overall plant health.

RESULTS

These are the spring soil analysis results for Field 1. The organic matter varies quite a bit from the 2 samples (depths) taken in the field. The samples were taken prior to aerating. The pH ranges from 6.3 to 7.3 for both depths, which is the most desirable for mineral soil. The cation exchange capacity (CEC) is also within range for this soil zone. CEC and pH are closely related as they both affect nutrient availability, soil structure and overall fertility. This field prior to aerating seems to within an ideal range for nutrient availability and has a good foundation for microbial activity.

This is the spring soil analysis results for Field 2. This site has not been worked for 25 years. It has quite low organic matter, which is expected when the field has not been touched for an extended period. Noticeable characteristics, pH is lower than 6, could lead to nutrient deficiencies. Low pH will also affect the CEC, the values for this field are on the low side for this soil type, typically gray luvisols have higher CEC due to more clayey soils. Another example of what is to be expected with no land disturbance.  We may potentially see an improvement in the future soil health and yield after multiple aeration passes.

This is the fall soil analysis for Field 1. All soil parameters registered very little change. Organic matter dropped slightly in both depths, and the nitrate-nitrogen also dropped. It is unlikely that we will see any distinct changes overall in the first season. Perhaps observations in the second or third years will show some improvements. No samples were taken for Field 2, as it was decided there were not enough differences observed.

Aerated plant tissue samples from Field 1 were collected in the fall of 2024. The analysis provides a snapshot of the physiological status of the plants at the time of sampling. Laboratory results indicate a deficiency in sulfur, while nitrogen, potassium, phosphorus, and magnesium levels were found to be sufficient. The field's location within a gray luvisolic soil zone likely contributes to the observed sulfur deficiency, as this soil type is commonly characterized by low sulfur availability. It is also noted that poor root development or inadequate drainage could lead to a sulfur deficiency.

Non-aerated plant tissue samples from Field 1 were collected in the fall of 2024. The analysis reflects the nutrient status of the plants at the time of sampling. Results indicate a deficiency in sulfur and a low concentration of magnesium, while levels of other assessed nutrients were within sufficient ranges. A deficiency on sulfur and low magnesium could be due to poor drainage, in which aeration may be helpful.

Pollinator blend being floated on, on May 29th

This blend was also designed to encourage bees to the area. We partnered with the Alberta Native Bee Council to set up and monitor a bee trap over the summer, this is a province wide project.  The trap was installed in a location that was protected from disturbance, and every 2 weeks it would be emptied. Samples were stored in the fridge and sent to the Bee Council at the end of the season. The goal for this project is to get an idea of the wild bee populations throughout the province. With a survey covering a large geographic area they can acquire a single season snapshot of bee populations. A special thanks to Raymond Chittick who donated his time to float the blend on our site.

FINAL THOUGHTS

We will continue monitoring the aerated and non-aerated fields throughout 2025 to assess long-term soil and plant responses. It is unlikely that significant differences will be observed during the first season of aerating, continuous monitoring will be essential.

Aeration is a non-chemical soil management practice that enhances root development by alleviating compaction. Additionally, it improves water infiltration and drainage, reducing surface runoff and mitigating soil erosion. By promoting nutrient cycling, aeration increases the bioavailability of essential nutrients for plant uptake. As outlined above, we anticipate observable differences between the two treatment blocks; however, measurable impacts may require several years to fully materialize.