Notes From the Field

Rock phosphate comes in a big white plastic bucket, pelleted with molasses. A dark, crumbly, fine, sweet-smelling substance, with the texture and consistancy of smashed-up lava rock. Application consists of sprinkling it around the base of your fruits, vegetables, and native perennials. Repeated watering wears away the molasses "coat," and the phosphate is taken up and absorbed by the soil.

Rock phosphate's 0-3-0 profile had me confused at first. Why use a weird, expensive, and hard-to-find organic substance when 20-20-20 is readily available at Home Depot? Hell, if phosphorous is required, why not just buy a box of triple super phosphate (0-45-0) and be done with it?

A1: Any fertilizer number above 10 indicates the probable refinement of a natural source, with all the additional energy costs and pollution that the refining process implies.

A2: Highly refined fertilizers "flush" through humus really fast. Most of your expensive 0-45-0 ends up sitting in the drain saucer underneath your tomatoes, instead of lingering in the soil.

A3: Chemical fertilizers kill beneficial microorganisms that are otherwise present in the soil, making fruits and veggies fed on them more susceptible to disease.

A4: Plants aren't meant to be glow-in-the-dark green and freakishly elongated. Organic fertilizers, composts, and carefully built-up soils are better in the long run than the "quick fix" of chemicals meant to accelerate a single growing season.

I didn't really set out to be a strident organic gardener, but the logic justifying organic fertilizers' use is pretty unassailable. Plus, fish fertilizer (5-1-1), bone meal (1-11-0) and liquid kelp (1-1-5) look and smell way better than 20-20-20's icy blue poisonous crystals.
- posted by cjb @ 9:14 AM