Milorganite vs Grains

[Green]

By the way, Morph:

Do you know what the water soluble N fraction of biosolids is? No one seems to know...

[MorpheusPA]

It varies, a lot. But if you just say half, that's a reasonable guess. So is a quarter or two-thirds.

[Green]

Oh, sorry...I literally meant what it is. My gut feeling says ammonium Nitrogen, based on the response and based on the smell when a low rate is used in hot weather (likely losing much of that fast release N fraction to the air, unfortunately, if not watered in soon after application).

[MorpheusPA]

Oh, sorry! Ammoniacal nitrogen, for the most part, although urea can also be in play in some biosolids.

Most of what you're smelling actually isn't the ammonia salts, which are pretty stable. It's the...dreck portion. Aromatic organics. Not aromantic, although I don't feel particularly like a date after smelling that stuff (and my husband just points toward the shower after I come in from using it).

[Green]

Indeed. I found a document by the PNW Extension, published in 2022, titled "Fertilizing with Biosolids". Pub #508. It contains virtually everything anyone would probably want to know about biosolids, including the nutrient analysis, why it is what is, and much more. In it, they confirm the ammonia N and bit of K.