Soil Sampling Post Harvest for Fall Applications

By , On , In Best Practices
soil for planting with green blur and sunlight background

Fall’s around the corner and it’s time to start planning ahead for the Spring. Spring and summer are incredibly busy times for growers and although you’re all in need of a much-deserved break, now is the time to start planning for the next Spring. The more you’re able to do now, the better and one of the first things that should be on your mind is soil sampling.

We’ve mentioned the importance of soil sampling in previous blogs and it’s safe to say that we can all agree that it’s now a matter of “when” and no longer “if” we should take soil samples. Soil testing is the most effective approach in understanding the nutrients of your soil and building an effective nutrient program.

We’d like to mention a few points first:

  1. Consistency is key. One of the best practices when approaching soil sampling is consistency. This allows the most accurate results possible. If, for example, you sampled last year in early September, the same approach should be maintained year-to-year.
  2. Routine testing is the key to success. The more you sample and understand the condition of your soil, the better.
  3. Sample dry soils when possible. When the soil sample is overly moist, this can impact the results of the readings.
  4. Soil texture. Make sure you’re sampling different soil textures and crops separately.
  5. Gradient. If your landscape has different topography (hills and plateaus for example), make sure you’re sampling these separately.
  6. Depths. Remember to sample from two depths when possible; 0-15cm (for non-mobile nutrients like P,K,Fe,Zn,Mn,OM and PH) and 16-30cm (for mobile nutrients like NO3-N, chloride and sulfur). This would ensure a more accurate fertilizer recommendation.
  7. Soil biological activity affects nitrogen and sulfur. It is recommended you wait until soil temperatures reach less than 10 degrees centigrade in the fall before sampling. Above this temperature, nitrogen and sulfur are released from organic matter and crop residue.
  8. For some reminders on how to sample, here’s a helpful video you can watch.
  9. For reminders on defining the sample area, you can consult our previous blog here.

Why should you sample in the fall?

There’s a few different reasons why you should sample in the fall, a few are discussed below:

  1. Spring is busy. Spring is a very busy time of the year for growers, where the majority of the grower’s teams are busy out in the fields. By sampling in the fall, you allow more time to create a fertilizer program and start ordering ahead.
  2. Seasonal timing. Sampling in the snow isn’t recommended. It’s cold and wet and collecting samples when the soil is frozen isn’t possible. Spring can be wet and rainy and collecting samples during this time is challenging. Fall is therefore the ideal time to sample; it’s been a few months since your last fertilizer application, so this won’t conflict with the results. Fall soil moisture is in an ideal range, making it the best time to sample.
  3. Time to plan a nutrient program. Sampling in the fall allows enough time to receive results, work with your Growers Support team and develop a nutrient plan before the busy Spring season. It’s not recommended you leave this until Spring, it’s busy enough as is.
  4. Product availability. Many products sell out in the Spring, so by planning ahead, you’re ensuring you get what you need, when you need it. We all know this unexpected supply chain issues can arise, so planning ahead mitigates the risks against this. We usually see lower fertilizer prices during late Fall and early Winter, so it’s a good idea to factor this in too.
  5. Amendments which includes gypsum, lime compost, sulfur and humic acid. When applying on the surface (as we do in tree fruit and grapes), applying in the fall allows the freeze/thaw cycles to incorporate the amendments and leave more time for them to move in the soil profile.
  6. Manure. If you are applying manure to your farm or orchard, results of the soil testing can help you determine which fields will benefit the most from the N, P and K contained in the manure, and may help you strategically locate manure stocking areas for the most efficient spreading on the field that will be receiving manure.

Planning ahead is the key to success. Allowing yourself the time to develop and plan a nutrient program for the Spring, is a close second. This is only possible when you start your sampling now. Through sampling with us, you’ll get a comprehensive look at your soil’s nutrient profile, help with interpreting data and fertilizer recommendations. This helps to save money; spending only on needed nutrients, applying the correct amounts, increasing the chances of achieving higher yields, better soil balance and increased soil health.

We will be offering free soil sample analysis during the months of September and October (2022). Growers who ultimately purchase their Fall and Spring Fertilizers from us, will be eligible for this program. Click here to view this offer. Our Growers Support team is here to assist you and answer any questions you may have, so please reach out to get started.