Soil Analaysis, Chemical content and Trace Elements – November 2021

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I am due to do a 5 yearly analaysis of my orchards and other areas soil. All my soil gets sampled and sent away for a chemical analysis and report. They do offer a comparison to chemicals required for normal Vegetable growing ie brassicas or beans etc, or Fruit growing ie Apple or Pears. They then make suppests of what chemical and amount you need to bring it up to the optimum.

But when you say I am growing Persimmons or Pawpaws or Pecans, they are stumped.

I found the following on the RHS website as very informative, and a base line. I hope they do not mind me borrowing the details. If you want to see the applicable RHS page please check out here.

The following criteria (taken from BS3882: 2007 Specification for Topsoil) can be used as a guide against any analysis report a supplier offers you;

Premium grade

  • pH = 5.5-7.8
  • Phosphorus (P) Index min = 2
  • Potassium (K) Index min = 2
  • Magnesium (Mg) Index min = 1

General purpose grade

  • pH = 5.0-8.2
  • Phosphorus (P) Index min = 2
  • Potassium (K) Index min = 2
  • Magnesium (Mg) Index min = 1

Economy grade

  • pH = 5.0-8.2
  • Phosphorus (P) Index min = N/A
  • Potassium (K) Index min = N/A
  • Magnesium (Mg) Index min = N/A

This describes how acid or alkaline soil is, and is expressed as a number between 0 and 14. Soil with a pH of 7 is neutral, an acid soil has a lower value, and an alkaline soil has a higher one. Most plants grow best in soil that’s within a specific pH range, so it’s useful to know your soil’s pH. Testing kits are easy to use and widely available in garden centres and online.

Note that imported topsoil can sometimes introduce invasive plants, such as Japanese knotweed and couch grass to the garden. Inspect the soil for signs of weed roots or shoots. Weed roots are often white and fleshy, sometimes with a brown covering, unlike the brown, dry, fibrous roots of trees and shrubs.

I will be adding more info shortly with regards to actual chemical content, as there is no mention of parts per million. Maybe I might try and have a read of BS3882: 2007 Specification for Topsoil.