Two experts share their perspectives on regional soils, soil health, and fertility management.
Adapted from the March 30 East Kootenay Soils Webinar delivered by Mike Malmberg, MSc & Hilary Baker, PAg
As we head in to the spring, it is important to understand the nutrient levels in your soil and in turn, what type of fertilizer you will need. Take a look at some of the takeaways from KBFA’s soil technical series the past few weeks.
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Want to see the whole thing? No problem — we’ve got them recorded! Check out the East Kootenay presentation HERE and the West Kootenay presentation HERE.
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Test your soil!
· Optimize economic returns.
· Optimize crop production.
· Build soil health.
· Maintain levels of plant available nutrients.
· Improve the nutritional balance of the growing media.
· Avoid pollution and environmental degradation.
· Understand nutrient deficiencies, pH imbalances, and excess soluble salts.
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How do I take a soil sample?
Soil testing can be done any time your soil isn’t frozen or overly wet. You will want to take 10 random soil cores from the specific area you are wanting to test (e.g., field or pasture unit, lawn, garden bed) if the area is small (under 2 acres) and 20 to 25 samples for a larger field.
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Materials:
· Spade or trowel
· Container (0.25 cup is ideal)
· Small bucket
· Marker & label
· Plastic bag
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Methods:
· Insert the spade or trowel to the desired depth in soil, making an opening.
· Create a soil slice about ½ inch thick by reinserting the spade next to the initial opening.
· Remove your tool and leave the slice intact. Take a 1 inch wide strip from the centre down the entire length.
· Remove grass, stems, thatch, and stones from the sample.
· Use the container to measure out your sample size. Once measured, put the sample in your bucket. Repeat at the other testing holes.
· Mix all the samples thoroughly to get one uniform sample.
· Label your sample bag (date, pasture, number of samples [# combined], your name), fill your sample bag with the tested soil.
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Avoid:
· Field entrances
· High traffic areas
· Field corners or turnarounds
· Old buildings
· Feeding areas
· Livestock watering areas
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Where do I send the soil to be tested?
There are six companies in BC that will test soils, and several others outside of the province. You can find a Nutrient Testing Laboratory on this Government of BC Factsheet.
You will need to include a submission form with your soil sample. Submission forms can generally be found on the website, or by calling the testing lab directly.
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What does a soil test look like and how do I read it?
Here is a soil test that was sent to Interior Seed and Fertilizer, and analyzed in Edmonton AB. The managers goal is to build nutrients in his East Kootenay soils to a level to maintain soil health. He operates a grazing operation on dryland pasture.
This lab uses nutrient extraction and analytical methods specifically developed for western Canadian soils. These use standards methods for testing soil in Western Canada.
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Take a look at an example…
Interpreting this soil test:
Nitrogen
Nitrate nitrogen is what is called plant available nitrogen. For this soil sample, nitrate nitrogen is very low. This is normal for a fall sample, because soils cool down, microbial activity decreases and soil microbes use available nitrogen.
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Phosphorus
Phosphorus levels are very low. Phosphorus is important during the seeding year, and for optimum production.
In the Kootenays, over time applied phosphorus can become unavailable to plants. Soils generally have high pH, high calcium and high magnesium. Plant available phosphorus is not stockpiled in the soil, particularly for soils with these properties.
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Potassium
Potassium levels are high in the soil test (over 190 ppm or 380 lbs/acre). Potassium is an inexpensive fertilizer nutrient. Potassium deficiencies are easy to visually see on the plants.
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Sulfur
Sulfur is listed as marginal, or near deficient. When sulfur is low, other plant nutrients are not utilized effectively. Sulfur, applied in elemental form is not available to plants immediately. Elemental sulfur must be modified to sulfate form by soil microorganisms, which takes about 1 growing season.
Ammonium sulfate fertilizer (21-0-0-24S) delivers sulfur in sulphate form and is available to plants immediately.
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Recommendations Given for this Soil Test
· Apply a blend of fertilizer that will give the following nutrients for the current year
o N at 20 lbs/ac
o P205 at 20 lbs/ac
o S at 10 lbs/ac
o Boron at 1-2 lbs/ac
· If you do not wish to fertilize next year
o Increase N and P205 in the current year to save costs in Y2 and Y3
§ N at 60 lb/ac**
§ P205 at 30 lbs/ac **
o **This is only applicable for dryland sites
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How Often Should I Test my Soils?
· Every 2 to 3 years until results stabilize.
· Every 3 to 4 years for maintenance.
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Additional Resources
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Current Value of Common Plant Nutrients
Cost per pound of Nutrient (2021)· N: $0.72/lb· P205: $0.74/lb· K20: $0.51/lb· S04: $0.42/lb· S(ele): $0.28/lb· B: $9.41/lb
Fertilizer Guidelines for Forage
Soil Test Phosphorus and Potassium Guideline
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KBFA Soil Resources
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References
Agrium. (n.d.). Forage Nutrient Management for Maximum Productions. FarmWest. Calgary, AB. https://farmwest.com/wp-content/uploads/2020/09/AgriumForageManual.pdf
Alberta Agriculture, Food and Rural Development. (2004). Alberta Fertilizer Guide. Agri-Facts. Agdex 541-1.
Alberta Agriculture, Food and Rural Development. (1998). Crop Nutrition and Fertilizer Requirements. Agri-Facts. Adex 540-1.
Alberta Agriculture, Food and Rural Development. (2005). Fertilizing Grass for Hay and Pasture. Agri-Facts. Agdex 127/541-1.
Alberta Agriculture, Food and Rural Development. (2001). Fertilizer Requirements of Irrigated Alfalfa. Agri-Facts. Agdex 561-18.
Alberta Agriculture, Food and Rural Development. (2013). Phosphorus Fertilizer Application in Crop Production. Agri-Facts. Agdex 542-3.
Koenig, R.T., Nelson, M., Barnhill, J., Miner, D. (2002). Fertilizer management for grass and grass-legume mixtures. Utah State University. All Archived Publications. Paper 9. http://digitalcommons.usu.edu/extension_histall/9
Weil, R.R., Brady, N.C. (1990). The Nature and Properties of Soils (10th Edition). Chapters 11, 12, 16. Maxwell MacMillan International.
