U.S. Standard sieves stacked

U.S. Standard sieves Nos. 10 (2 mm) and 20 (841 µm). Sieves are used to determine particle separate size fractions for material quality and mechanical properties evaluation and classification.

Granted, the last two AJ dispatches were heavy hitting on the technical side of things. And apologies to all who skipped reading them which I’m sure is most of you. Now, how about sharing something a little more down to earth for a change?

What I had in mind was a recent encounter with that humble, often neglected but ever so useful soil conditioner, lime. Comes a time in the course of one’s daily rounds when something happens to recall a basic truth, self-evident, incontestable it would seem, yet worthy of relearning. This moment came back to me in November while applying lime to a field that had, according to a certain soil test, gone quite acid with a measured pH of 5.3. The same test came with a recommendation to apply 1 ton/acre agricultural limestone to move the pH back up to where it should be, a mildly acidic 6.0 to 6.2. The telltale moment struck when I realized that the hopper on my Gandy drop spreader was running out much faster than it should have, which was set to run the last calibration I had marked for this particular brand of pelletized lime. Something wasn’t right, so I stopped to investigate. Continue reading