# Compost Soil Test



## OnyxsLawn (Mar 15, 2018)

I was interested how the compost i've been using would look on a soil test so I sent some in with my soil test for my yard. everything is very high. the high pH is a little worrying especially because I thought compost usually ends up acidic. I've been growing grass in the compost alone just fine for the last 2 months. Should I avoid using this as a topsoil for my reno?


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## g-man (Jun 15, 2017)

Compost is outside my comfort zone. This was tested as a C1 or as a soil by A&L? From my limited knowledge, this compost is not finished in it process. It first goes acidic, then alkaline and then back to just below acidic.


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## viva_oldtrafford (Apr 4, 2018)

This stuff is going to hold a ton of water (OM% is 31! CEC is 32!) - it will get wet and stay wet for a long time. I would not use this.


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## Ridgerunner (May 16, 2017)

I, too, have little familiarity with the methods and results used for testing compost. I can tell you that the methods used for testing soil (dirt: primarily consisting of sand/silt/clay-mineral parent material with a relatively low % of OM) are not correlated or calibrated for testing something like compost. I've read that once soil OM exceeds 20%, that the results from common soil testing methods aren't very useful in predicting nutrient sufficiency levels. Based on that, I'd think that using those methods to test pure compost would produce results that wouldn't have much useful application. I've only ever seen a couple of compost reports and they all reported nitrogen, phosphorous, potassium etc. as a % by weight. Like the analysis for a fertilizer. They also tested and reported for things like heavy metals and pathogens, things that a gardener wouldn't want in their tomatoes.


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