Best Q&A from Agronomy Update 2026 - Part One
A huge thank you to the 654 participants who joined us for Agronomy Update 2026 on January 13-14! It was great to see over 500 of you engaging in the webinar throughout the event. We hope the information provided serves as a valuable resource for your on-farm decision-making this season.
To support your continued learning, speaker slides are now available on the Agronomy Update website. Feel free to refer to them as resources.
The speakers and the audiences had great discussions in the Q&A section during the webinar. The following highlights the best Q&A from your peer producers, agronomists, and industry experts.
This is Part One of the best Q&A from Agronomy Update. The discussions in Integrated Pest Management will be shared in the next e-newsletter. Stay tuned!
Abiotic stress – Heat and drought
From Session: How is Australia Managing Heat and Drought Stress in the Cropping System? – Dr. James Hunt
Q: How much yield potential is reduced with increased stress tolerance genetics, if any?
A: Non if done properly! Australian breeders haven't specifically selected for stress tolerance genetics - they have just made crosses selected for yield in stressful environments! High yield across environments (low G x E or adaptive plasticity) is the best form of stress tolerance. Hard to beat breeders just selecting for yield in a target environment!!!
Q: Beyond just 'escaping' heat through early sowing, are there specific management tactics, such as late-season nitrogen placement or stubble management, that you’ve found can physically cool the crop canopy during a 30°C+ heat wave?
A: The best way of cooling a canopy is to make sure it has water. So growing rotational crops that leave a bit of water available for wheat canola (vetch hay, oat hay, lentils) and conserving as much moisture as possible over the summer fallow are the best things we can do. Not over-applying N is also important. There is a real negative interaction between drought, heat and excessive N (excessive N = wheat protein >12%)
Q: For Southern Alberta farmers facing dry seedbeds, how deep can we reliably seed these new long-coleoptile varieties compared to our current standard, and does this depth affect the plant's ultimate tolerance to heat stress later in the season?
A: It depends a lot on soil type. On sandy soils, long coleoptile cultivars can be sown up to 10 cm deep and still get good % emergence. On our clay loams, we lose a lot of plant establishment if we sow that deep, even with long coleoptile cultivars.
Soil testing and soil fertility
From Session: Soil Sampling and Analysis Interpretation – Dr. Jeff Schoenau
Q: For the range in the recommendations, how much of that error is due to environmental factors versus lab measurement errors typically? Are there certain techniques that are less error prone that I can watch out for?
A: It has been my experience that the greatest reason why a recommendation does not “hit the mark” is not because of lab measurement errors, but more often a problem with inadequate sampling technique, sample handling and different actual growing season/available moisture experienced than what was predicted and used in the recommendation model. All labs I am familiar with have very good strict analytical quality control/quality assurance measures they follow.
Q: Our sample results come back as "P" and "K" rather than P2O5 and K2O. I assume those need to be converted to P2O5 and K2O to properly translate that to a recommendation? 15 lbs/ac of P might seem deficient, but if we look at it as 34 lbs/ac of P2O5 then it's not so bad.
A: Very relevant question and I wish I had more time to cover this in the presentation. As you note, the sample results from the soil test come back typically as lbs per acre or ppm of P and K. However, you do not need to convert these yourself to equivalent lbs of K2O or P2O5 per acre in the soil. The interpretation table as shown in my slide no. 8 and the recommendation models are based on P and K concentrations or supply rate in the soil. However, recommendations are generated as recommended pounds of P2O5 and K2O to be consistent with how the nutrient contents in the fertilizer products are expressed which is %P2O5 and % K2O.
Q: Did I miss a quick discussion on bulk density to help convert the soil data?
A: Good question, I did not have time to get into. Yes, to most accurately quantify the amount of nutrients in a volume of soil in lbs per acre or kg per ha, actual bulk density should be used in the calculation along with the weight per unit weight concentration rather than using the “fudge factor” of 2 I gave, which assumes a bulk density of 1.3 grams per cc.
Q: How many samples do you recommend as a representative sample per acre for a soil with high spatial variability?
A: Unfortunately, I did not have the time to get into specific soil sampling strategies, but I would say that an 80-acre field with undulating topography would require across that area 15 or more cores for the composite sample to adequately represent the true mean of the field.
Q: Which micronutrients are most often misinterpreted on standard soil tests, and which ones should we be most skeptical of when a lab report shows a "deficiency"?
A: The challenge in testing soil for micronutrient deficiency, I think, lies not so much in a failure of the soil to predict availability under “normal” conditions, but the fact that micronutrient availability in the field can be very sensitive to environmental and soil conditions, such as temperature and moisture, which are hugely variable and fluctuate. This can explain why a soil may test “deficient” yet no response is observed. The conditions were such in the field that the soil was warmer and moister than normal which enabled that micronutrient to move much more readily to the roots. Or for a highly mobile micronutrient like chloride, the sample was taken after a period of high leaching but by the time the crop was seeded the water was moving back upward in the profile carrying the chloride with it. I would say mobile micros like B, Cl would be ones to watch for change over time.
Q: How many lbs of N,P,S release can we reasonably assume per % of OM in a dark brown soil zone?
A: Phosphorus and sulfur are difficult to assume because a portion of their mineralization occurs from ester bonded forms through activity of enzymes like phosphatase and sulfatase with variable activity induced by deficient conditions in the rhizosphere. For nitrogen, I think that an assumption of 1% of organic N mineralized over the growing season would be ballpark, but it could be a pretty wide range around that. For a 0-15cm surface soil layer, this would equate to about 10 kg N/ha released per percentage of organic matter.
Q: Sulphur levels can vary widely in soils. Do you feel that composite sampling can accurately tell you the amount you may have available on your land or is it giving you a false sense of that average level if you have 1 or 2 hot spots throwing out your S average available across your land? Suggestions and thoughts to ensure your not shorting yourself especially in canola production.
A: Indeed, sulfur is often the most variable nutrient across a farm field in western Canada, especially in soils where there is salinity at or close to the surface in patches (salts that cause salinity in W Canada are sulfate salts). As you note and I agree, a composite sample does not tell you much about the S status as it actually exists across the field because one or two hot spots can skew the composite sample to a high level, yet S deficient areas could exist that limit production in significant portions of the field. That is why if traditional non zonal composite sampling has been used, S may be recommended for a high S demanding crop regardless of what the soil test from the composite sample says to be on the safe side.
From Session: The Impact of Different Crop Types and Rotations on the Soil Microbial Community – Dr. Bobbi Helgason
Q: Some companies are beginning to offer soil biology testing. What are your thoughts on this testing and what would you recommend when using this type of testing?
A: I think that on-farm data are needed to build the knowledge needed to support using soil biological profiles as useful indicators. However, interpreting the results cam be daunting with the knowledge we have today (I am thinking of DNA based tests). In terms of detailed microbial community composition, our understanding of who is "good" and who is "bad" is only beginning to develop and is highly influenced by the environment.
Q: If I wanted to begin managing the below-ground microbiome and microbiology of the soil profile, what measurable tests/observations can I make and what should I look for?
A: Soil organic matter content - is it increasing or decreasing - is a great indicator. Soil carbon respiration under standardized conditions is another useful indicator of overall microbial activity that is readily accessible (e.g. Solvita or other). Consistent assay conditions and monitoring over time will give the most value (compared to a one-time check).
From Panel: Management of Low and High pH soils – Dr. Miles Dyck, Rob Dunn, Karen Skarberg
Q: Can you touch on post remediation expectations regarding the expected time before PH levels begin to drop again and potential factors that could cause levels to drop sooner than they should
A: The rate of pH decline depends on soil buffering capacity (clay, organic matter), nutrient management (fertilizer rates, manure rates) and crop rotation. At the UofA Breton Plots (grey soils), we found the greatest rates of pH decrease following liming (0.1 pH units per year) were in treatments that received nutrients exclusively from fertilizers (urea, elemental S, potash, phosphate) with legume forages in the rotation. Legume forages remove a lot of Ca from the soil which increases acidification rates. The lowest rates of pH decline (0.02 pH units per year) were observed in treatments where most nutrients were supplied by composted cattle manure.
Q: Have you ever heard of any correlation between sulphur fines and an increased rate of pH decrease?
A: I'm assuming you mean ammonium sulphate (AMS) fines (21-0-0-24). I haven't heard of it personally, but AMS does produce acidity when applied to soil. As a rule of thumb, it takes 5 lb of lime to neutralize 1 lb of S applied as AMS. https://nrcca.cals.cornell.edu/nutrient/CA5/CA0537.php
Q: If you have variable 5-5.5s, what is the economic target if we are spreading lime to correct? 6.3 - 6.5 or all the way to 7.
A: Good question. The target pH depends on what type of crops you want to grow. If you are planning to grow a lot of pulses, maybe a target pH of 6-6.5 is good. For Canola and cereals, 5.5-6.0 may be acceptable. Liming all the way to 7.0 would be expensive and you likely won't get a yield benefit above 6.5.
Q: Has there been any research done on using any Humic products and the affect they might have on pH?
A: North Dakota included a humic product in their trials with pH, soil P and wheat (Buetow, 2022). No benefit in that study.
Q: If synthetic fertilizers (especially ammonium fertilizers) cause soils to become more acidic over time, what else are they doing to the soil? Specifically, the soil health and microbiology of the soil?
A: Fertilizers are not the only sources of acidity. Even decomposition of organic matter and crop residues produces acidity. As soils become more acidic, the composition of the microbial communities will likely change. Generally, fungi prefer acidic conditions over bacteria, but some bacterial genera are adapted to acidic conditions. However, changes in soil microbial community composition (diversity) may not affect soil functions like nutrient cycling. Different organisms are active at different pH ranges.
More about soil health. The USDA definition of soil health is: Soil health is defined as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. Even acidic soils can sustain plants, animals and humans. So it is a bit subjective and depends on which plants (crops) we want the soil to sustain.
Q: There has been some research on pelleted lime being more effective vs regular lime and the potential of being able to reduce rates of lime when used pelleted. Most of this research has been done in the US. Has this been looked at in Alberta soils? Any thoughts?
A1: Particle size is a huge factor in the time factor with lime. Smaller particle size = faster response.
A2: Yes to the importance of particle size. Pelleted lime was one of the products used in Mark Wagner's study at 3 sites (UofL), but at equivalent rates to other types.
Have more questions about the topics above? Feel free to reach out to Agronomy Update 2026 planning committee, by contacting Ruoxi Xia at rxia@albertagrains.com. We will help direct your questions to the experts. Also, feel free to reach out directly to the speakers. Their info can be found on Agronomy Update 2026 Agenda.