The effect of nitrogen fertilization on forest blueberries

In a randomized prospective trial with hens it is shown that artificially fertilized forest blueberries are toxic. In a high dose (1.7 1/hens) the birds died within 72 hours (p less than 0.01). In a lower dose (0.33 1/hens) all survived but a lifelong change in the egg production occurred implying defects of the shells (p less than 0.0000001). It seems that fertilizers change the microflora in the ground, which releases soluble aluminiumnitrate which is absorbed in the berries. Aluminium poisoning has been found to have clinical significance in dialysis patients and probably also in senile dementia. In smaller doses it can be difficult to establish this relation as the symptoms can have a latency period of more than 10 years.