Foaming fertilizer?

Question

I live in a suburban subdivision, but my house backs up to a cornfield. I'm not a country girl at all, but have a general idea of agriculture, and can usually figure out what the farmer is doing back there. A few weeks ago he tilled up the soil, and last week it appeared that he was either tilling again, or actually planting the seeds.

However he just came around and sprayed the field with some kind of fluid. The far ends of the spray arms are leaving some kind of white foam every 20 yards or so, which I'm sure is just a malfunction in the equipment, not intentional.

Last year he grew soybeans, so I'm assuming what he planted last week was corn, but nothing is growing yet.

So, what is he spraying..Fertilizer? Weed Killer? Rodent Repellant?

Answer 1

The foam is nothing more than detergent.  The blobs of foam mark the area that has been sprayed and is used to guide the driver on his return pass.  They don't want to overlap but neither do they want to miss an area.

Answer 2

I've been a comercial chemical/fertilizer applicator for 15 years. The foam is nothing more than soap, most likely alcohol based, it's harmless. I've used it to wash my hands in a pinch, also works well for washing the machine off. How long it lasts depends on humidity, temperature, mixing ratio, etc, but I've never seen it last more than a couple of hours unless it's close to freezing outside, then I've seen it last overnight. It's used to mark where fertilizer/chemicals have been applied. The driver will keep one edge of the booms (spray arms) on the foam while driving to the other end of the field. Most applicators have gone to GPS guidance and/or auto steering now. But, the machine wasn't malfunctioning, it was intentional.

If the crop was already planted but not emerged yet, he was probably spraying a pre-emergent herbicide. It prevents weeds from germinating. If the crop wasn't planted yet, it could have been fertilizer only, or a combination of fertilizer and a pre-emergent herbicide.

Answer 3

Yeah, the blob of foam every few yards is a marker to show where the spray stopped so he don't overlap or skip an area. I'm not sure of the make up of the foam but it is pretty substantial because it can last for days. Sometimes it is pink instead of white. But it is harmless.