Harvest is well underway across the province, and while cold weather may still be a little way off, now is the time to start planning for fall soil testing, which is a key step in setting up next season’s success.
Soil testing is the foundation of a strong 4R nutrient stewardship plan. Did you know that a soil test is only as good as the soil sample you collect? That means a reliable test starts in the field and it is important for soil sampling to be as representative of the field as possible by avoiding the temptation of using a “one-size fits all” approach to sampling. All fields may not be the same. To get the most from your soil test, select a sampling method that reflects your field and potential variability such as topography, drainage, or eroded areas. If you are having the soil sampling done by a service provider, it is always a good idea to go with them during sampling as you, the producer, know your fields better than anyone else and can ensure the best samples are collected that represent your field or management zones.
For uniform fields, whole-field composite sampling works best. Take 15 to 20 soil cores in a zigzag or “W” pattern. For fields with more variability, consider zone-based sampling by dividing field into management zones, or even grid sampling for precision farming.
Sample when soil temperatures have cooled to below 10°C and be sure to use soil and not air temperature in deciding when to sample. When sampling, remove the top layer of dead leaves and plant materials, use clean tools, and avoid fertilizer bands by sampling between them if the locations of the bands are known.
Sample at the right depth down to at least 24 inches for tests that include mobile nutrients like nitrogen and sulfur. Use a probe or auger, and not a shovel, and avoid using rusty or contaminated equipment. Follow your lab’s guidelines for packaging and handling prior to shipping soil samples to the lab.
Remember: good soil testing starts with good soil sampling. Take the time now to do it right and set the stage for next season’s success.