The dust bowl during the Great Depression was probably due more to a combination of financial, social and climatic problems (very frequent drought) rather than to the depletion of soils. Because if it’s due to the latter, it should have happened also in other parts of the world where there are much more population densities and intensive agriculture than in the US.
Soil depletion is one of the preferred myths of greenies, but like anything from them, it’s a dead wrong misconception. There is a simple index that demonstrates it is bunk : productivity per acre, which has increased year after year for decades, for each and every big crops (corn, wheat, potatoes). Even better (or worse for the malthusians’ lie), productivity per unit mass of fertilizer has also increased, showing that not only farmers are more skilled (not a scoop) but that soils are improving not depleted (by producing more per unit mass of fertilizer, but the atmospheric CO2 fertilization factor plays a big part too).
Your know-how in precision mechanics and materials is fascinating. I have zero doubt about your assessment of their mist generator wearing out.
But I see that the whole character of it has required changes from what it was in the mid-20th-century. The transition to electricity and the petroleum engine as energy sources have affected all of life, especially the chemistry of fertilizers and their production.
I hope that we leave a better world to our children than the one we entered.