Why soil testing is important

As I mentioned in my last post about the miracle fruit, Synsepalum dulcificum, there is a need for soil testing when plants look unhealthy. I know, to the average homeowner it sounds ridiculous and in a way, I totally agree. Soil tests can run anywhere from $7 to over $15 a sample depending upon whether you use a private laboratory like A&L Labs or the state Extension Service (I'm in Florida, so UF is my extension). It may seem useless but here's why I tell people its not.

Reasons why soil testing is important:
1. You can't see nutrients, only plant responses.
2. Not every plant responds to the same nutrients in the same way. Some plants require more nutrients than others (we call these "heavy feeders" i.e. corn and tobacco that need lots of nutrients like nitrogen).
3. Fertilizing can be expensive.
4. Fertilizing is bad for the environment if it gets into waterways (i.e. lakes).
5. Soil fertility is a good indicator of soil biota (the organisms that occupy the soil: bacteria, fungi, and protozoans).

And to be completely fair:

Reasons why soil testing isn't important:
1. Soil testing is performed in a lab which means its based upon scientific principles and theories (its by no means absolute).
2. Results vary by lab. For example, there are three methods to measure Phosphorus- we know them as the Bray and Kurtz,  the Mehlich, and the Olsen methods. Depending upon what part of the country you live in, the method varies.
3. Interpreting soil test reports can be difficult.
4. Soil tests can be expensive (but not as expensive as fertilizer) if you have a large piece of land or land that has many slopes, soil types, etc.
5. Dealing with the people in the lab can be a nightmare.

I'll be working in the next week posts on explaining soil testing in further detail. Its not an easy concept to grasp mostly because its all theoretical (yes, its science) but its also an invaluable tool for any gardener, landscaper, or professional. Don't fret if soil testing isn't your thing either, I like to write about what's growing in my garden too.

Here's a picture of a soil sample I took earlier this afternoon that I left out to dry overnight on a newspaper (most soils are dried before testing). I'll allow this sample to dry a few days before I send it off.