Soil fumigants and microorganisms – mycorrhiza

To Bob, Keith, Peter, Ian and all Daffnetters.
 
Those interested in beneficial soil microfungi in association with roots and nutrient uptake could Google <mycorrhiza>. Both endomycorrhizal and ectomyycorrizal fungi are really a means of expanding surface area of root hairs to make uptake of nutrients more efficient.
In practice growers might bear this in mind for an area such a disturbed sub-soil which has not previously supported plant growth (as Ian has explained).  Also for sterilised soil.
I use an old microwave to cook soil/grit/leaf mould to provide a clean start for seeds.  I don’t know if this kills off the fungi or not, so far I have not noticed any adverse effects on seedlings or later growth.
 
George Norris,  Scotland