Particles of iron oxide and iron in the soil, perhaps also on the stalk, spikes and grains: cathodic reduction and pyrolysis, the particles could be partially melted.
Chembe ya chuma na chuma oxide katika udongo, Labda pia juu ya ufito spikes, na nafaka: cathodic kupunguza na pyrolysis, chembe Inaweza kuwa sehemu ikayeyuka.