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Decatur, IL

I'm thinking about getting some compost from a local compost site. It's made from leaves, grass and some horse manure. They gave me the test results from a sample pulled in Nov. '07. It looks like it just shows heavy metals, pH and % moisture. The results are as follows: Cadmium .63 ppm, Chromium 14 ppm, Nickel 12 ppm, Copper 28 ppm, Lead 48 ppm, Zinc 120 ppm, Arsenic 5.8 ppm, Mercury .062 ppm, Selenium <0.63ppm
pH 7.34, % moisture 41%. Are these within acceptable limits? I'm thinking about getting a sample myself and sending it to Midwest Labs . How extensive of a test do I need (NPK,ammonia,Ca,Mag,etc.), or would a C:N ratio be enough with what I already know? Thanks for the help, Charlie

2/8/2008 9:37:53 PM

Sparks, NV

thats great

2/8/2008 10:30:08 PM

Roselle, IL GJGEM@sbcglobal.net

Some of those numbers look a little scary. Not sure what the safe limits should be, but I would like to see as close to "0" for Lead, Arsenic,& Mercury.- especially if you plan to eat anything- Midwest is a great lab to check the rest- Charlie I'm expecting big things out of you this year!

2/8/2008 11:03:43 PM

Decatur, IL

The report amounts were actually in mgm/Kgms. I just converted to ppm. The lead results would be .048 mgm/Kgm for instance. Don't know if this is less confusing to most people.

Thanks for the words of encouragement, George. I'll try my best. I'm hoping I can keep the disease problems under control, along with other distractions.

2/9/2008 12:19:03 PM

Decatur, IL

Sorry, I made a really big boo-boo. I'm thinking backwards, as usual. 1 ppm=1mg/kg, so my results are actually .00063 mg/kg Cadmium,.014 Chromium, .012 Nickel and so on. These should be well within the limits for soil and compost, I believe.

2/9/2008 12:43:41 PM

southwest MO

Lead is naturally present in all soils, generally in the range of 15 to 40 parts lead per million parts of soil (ppm) or milligrams per kilogram (mg/kg).

2/14/2008 3:46:58 PM

southwest MO

The most serious source of exposure to soil lead is through direct ingestion (eating) of contaminated soil or dust. In general, plants do not absorb or accumulate lead. However, in soils testing high in lead, it is possible for some lead to be taken up. Studies have shown that lead does not readily accumulate in the fruiting parts of vegetable and fruit crops (e.g., corn, beans, squash, tomatoes, strawberries, apples). Higher concentrations are more likely to be found in leafy vegetables (e.g., lettuce) and on the surface of root crops (e.g., carrots).

Since plants do not take up large quantities of soil lead, the lead levels in soil considered safe for plants will be much higher than soil lead levels where eating of soil is a concern (pica). Generally, it has been considered safe to use garden produce grown in soils with total lead levels less than 300 ppm. The risk of lead poisoning through the food chain increases as the soil lead level rises above this concentration. Even at soil levels above 300 ppm, most of the risk is from lead contaminated soil or dust deposits on the plants rather than from uptake of lead by the plant

2/14/2008 3:50:26 PM