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In the February edition of the Guelph Service Bulletin, we will announce a small change in the way our reports are sent and celebrate the International Year of Soils by discussing soil fertility. We will also list the upcoming trade shows where you can meet SGS representatives.


In an effort to keep our services as cost effective to our customers as possible, we will no longer send copies of reports to secondary recipients but only to the original submitter, unless exceptional circumstances deem necessary. We apologize for any inconvenience that this decision may cause and encourage you to contact us with any questions you may have.


2015 is the International Year of Soils, with recognition given to the importance of soil's role in sustaining human existence, and the necessity of ongoing stewardship.

In 2011, the International Plant Nutrition Institute released the results of their North American Soil Test Survey, where it was shown that the percentage of soil samples testing below critical values is increasing while the percentage of samples testing high is decreasing. This indicates an overall average decline of soil test values. This trend occurred across nearly every Canadian province and American state. In Ontario, we consider 20 ppm P (by sodium bicarb extract) and 120 ppm K (by ammonium acetate extract) to be critical values. Anything registered below these values require additional nutrients to optimize crop yields.

In the years since the results of this survey, the value trends have continued. View our graphs that represent the percentage of samples in various soil test ranges from 24 agricultural counties in Ontario, as submitted to SGS. We can see that, in 2014, 53% of these soil samples were less than the established critical value of 20 ppm P, and 54% were less than 120 ppm K. The mean value has also declined from 33ppm P in 2010 to 26 ppm P in 2014. For Potassium, the mean has dropped from 153 ppm to 127 ppm.

The results are not necessarily surprising, as we have been blessed recently with large yields, which removes more nutrients from the soil. However, it is also paradoxical: how are we achieving greater yields with lower average fertility? As well, it begs the question, “Where would yields be if soil fertility had not been trending lower?”

The winter months offer an excellent opportunity to review soil reports, track trends, and plan to update soil data where necessary. Although the routine of sampling in the fall after wheat harvest is optimal, a spring soil test is better than no soil test at all if updates are required. Contact SGS to arrange or pre-book soil sampling this spring.


SGS is excited to sponsor, exhibit and/or attend the following events in January:

For further information, please contact:

Jack Legg, CCA-ON
Branch Manager, Agronomist
503 Imperial Rd. N., Unit 1
Guelph, Ontario N1H 6T9
t: +1 519 837 1600