Morbloom isn't organic
... Arsenic and lead levels in most agricultural fertilizers are very low. Occasionally,
relatively high levels of lead can be found in some micronutrient fertilizers, but the
application rate of those products is so low that it does not significantly contribute to lead
soil levels. In addition, compared to cadmium, the transfer of arsenic and lead from soil
to crop is minimal. ...
...Application of lead to a Sultan silt loam up to 40 times the Washington fertilizer
standard had no effect on fresh or dry weight lettuce yield, i.e. phytotoxicity was not
observed at any application rate.
• Lettuce lead concentrations increased with increasing application rates of granular
zinc.
• Liming did not affect lead uptake by lettuce.
• Soil extractable lead was lower in soil treated with granular zinc than with soluble
lead salt.
• The average Tc was small (0.005); indicating a low potential for plant uptake of lead...