Friday, June 13, 2014

Milorganite's Potassium and Operation

I've received two more Dear Reader questions!

Question:  does Milorganite really work?

Answer:  yes.  However, if you're used to the mode of operation of synthetic fertilizers, you may not think so at first.  It takes two to three weeks (in normal weather) to decay into the soil and begin to feed the plants, and the level of feeding it supplies is never as extreme as a synthetic.  Any growth spurt you get will be very minor, and mostly fueled by the small amount of free nitrogen in Milorganite.  Other fertilizers, like soybean meal, have no free nitrogen and won't set off any spurt of growth at all.

Most organic fertilizers have a slowly building positive effect over time as you use them.  The first year, the grass and gardens just look better.  That improves the second year.  And so on.  Eventually, growth is always at the optimal level for the time of year because food is always available when the plant wants it.  That takes some time, however.

Question:  Milorganite has no potassium, correct?

Answer:  incorrect, actually, but you can think of it as 0 if you want.  Milorganite is 5-2-0, which means that the potassium (the third number) doesn't consistently measure at 1% or greater. That doesn't mean zero potassium, merely that it's less than 1% of the mass.  If I remember correctly, Milorganite is just under 1%.

Whether you need potassium or not is something only a good soil test can tell you.  In my case, my soils have entirely sufficient levels and no more is required at the present moment.


No comments: