Welcome to the tenth instalment of our Know your Soils series sharing practical tips for monitoring the soil health on your land. Keep an eye out for our bitesize videos and fact sheets on simple tests you can do yourself on farm.
“If you can’t measure it, you can’t improve it.”
When and how often should you do soil tests?
Soil test calendar created by the Soilmentor team
Taking the first steps on your soil monitoring journey involves some essential decision making! Firstly, which soil tests are right for your farm as well as when and where you are going to do them?
Certain tests are best done at certain times of year, and like most things in farming, this is due to the weather. On the calendar you can see the key soil tests, when and how often to do them. Choose a minimum of 3 of the key tests and ideally do them all on the same day.
Deciding when and how often to do the tests
Deciding which fields to test
If you want to get an overview of how your soil is doing choose fields which are managed differently, for example, one arable field, one permanent pasture, one herbal ley and so on.
A few farmers have wanted to better understand how soil changes across their rotation, or under cumulative years of a herbal ley. In both these cases, choose one field from each part of the cycle to look at how the soil changes over time.
If you are concerned about the performance of different fields choose to test a couple of your worst fields and a couple of your best and then try different management practices to improve the worst ones so they look more like the best.
Choose fields where you can experiment with different management practices and make changes, so that the results from your soil tests can inform what to do next. If you found poor soil on a field under a restrictive stewardship scheme it could be frustrating that you can’t do anything about it.
Most importantly, only choose as many fields as are manageable and which are easily accessible, ideally not too far from each other. Planning to test 3 fields and doing it is better than planning to test 6, feeling overwhelmed, and not doing any!
Where to do the tests on the field
As a basic rule you want to do each test a minimum of 3 times on each field to get a representative sample. It’s important to not do them too close to the edge of the field too. Certain tests such as the plate meter are better conducted more randomly – for these you can also try walking a W in the field and testing along it.
If you want to get the most accurate representative sample do 1 test every 8 acres in a field, but sticking to the rule of 3s is easier and will give you good results too!
Once you’ve decided on the location of your sample sites within each field, you can add the exact GPS location of the sites into the Soilmentor app, so you can make sure to return to the same sites for a more accurate comparison next time you go out testing! Read more about this feature here.
To remind yourself of the different soil tests you can choose from, and how to do them, see the full list here.
Here is a PDF of the Soil Test Calendar which you can print
See our free online soils guide for soil tests you can do at home and find out how our app Soilmentor helps you record & learn how your soil is changing.