Homesteader
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I have been doing some digging through and figured I would share it. It seems to me as a cannabis smoker cadmium is our most concern as a heavy metal due to its uptake from plants being much greater than lead and arsenic etc. but as a soil maker lead is a great concern as well when mixing and handling dirt and amendments. Amendments of most concern would be rock phos and super phos but also crustaceans or oyster shell due to their ability to immobilize heavy metals.
"Cadmium availability is influenced by several soil properties. Plants uptake cadmium through their roots, but uptake is lowest when soil pH is higher (6.2); organic carbon (organic matter) levels are higher and levels of soil calcium (Ca), iron (Fe) and zinc (Zn) are adequate"
"Cadmium is concentrated in particular parts of plants. As a general rule, leaves contain the most Cd, followed by storage roots and tubers, and then seeds or grain and fleshy fruits. Fleshy leaf crops (lettuce, spinach) tend to have higher levels than pumpkin, cucumber etc. Storage root crops (garlic, parsnip, carrot, beetroot, onion, potato) can also all contain significant levels of cadmium, depending on levels present in the soil."
"Superphosphate (super) is manufactured by attacking a rock phosphate rock source material with sulphuric acid."
"Earlier superphosphate was made from rock phosphate from Nauru which had high levels of C0d0 contamination i.e. 600mgCd/kg P in the superphosphate."
Guanos are generally low in cadmium but all manures contain at least trace amounts in varying quantities.
http://soiltech.co.nz/articles/Cadmium_Article_April_2013.pdf
http://www.cadmium.org/environment/level-of-cadmium-in-the-environment
" It appears that cadmium is the heavy metal of greatest concern in fertilizer. In a Washington State Department of Agriculture study that considered the plant uptake of arsenic, lead, and cadmium (coincidently, the only three metals that California regulates), cadmium was found to be of the greatest concern because cadmium builds up in the soil and plants can take it up. Some plants, such as lettuce, were found to contain more cadmium in the plant when more was available in the soil. In one study area, there was a clear linear relationship between cadmium in soil and cadmium in plants. Arsenic and lead were not taken up by plants in the same way as cadmium. "
Cadmium
Cadmium accumulation in crops
"Cadmium availability is influenced by several soil properties. Plants uptake cadmium through their roots, but uptake is lowest when soil pH is higher (6.2); organic carbon (organic matter) levels are higher and levels of soil calcium (Ca), iron (Fe) and zinc (Zn) are adequate"
"Cadmium is concentrated in particular parts of plants. As a general rule, leaves contain the most Cd, followed by storage roots and tubers, and then seeds or grain and fleshy fruits. Fleshy leaf crops (lettuce, spinach) tend to have higher levels than pumpkin, cucumber etc. Storage root crops (garlic, parsnip, carrot, beetroot, onion, potato) can also all contain significant levels of cadmium, depending on levels present in the soil."
"Superphosphate (super) is manufactured by attacking a rock phosphate rock source material with sulphuric acid."
"Earlier superphosphate was made from rock phosphate from Nauru which had high levels of C0d0 contamination i.e. 600mgCd/kg P in the superphosphate."
Guanos are generally low in cadmium but all manures contain at least trace amounts in varying quantities.
http://soiltech.co.nz/articles/Cadmium_Article_April_2013.pdf
http://www.cadmium.org/environment/level-of-cadmium-in-the-environment
" It appears that cadmium is the heavy metal of greatest concern in fertilizer. In a Washington State Department of Agriculture study that considered the plant uptake of arsenic, lead, and cadmium (coincidently, the only three metals that California regulates), cadmium was found to be of the greatest concern because cadmium builds up in the soil and plants can take it up. Some plants, such as lettuce, were found to contain more cadmium in the plant when more was available in the soil. In one study area, there was a clear linear relationship between cadmium in soil and cadmium in plants. Arsenic and lead were not taken up by plants in the same way as cadmium. "
Cadmium
Cadmium accumulation in crops
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