कम्पोस्ट में अमोनिया

01Where it comes from

Ammonia is nitrogen on the move. Urea, chicken manure, cotton seed cake and every other nitrogen source breaks down during Phase I, and the nitrogen leaves the material as ammonia. This is normal. DMR reports compost at the end of Phase I holding about 800 to 1,000 ppm, with pH pushed up to roughly 8.2 to 8.5.

The size of your ammonia problem is therefore decided long before the tunnel. DMR notes that a mix carrying more than 1.75 percent nitrogen loses more of it as ammonia, and that such compost attracts yellow moulds, ink caps and olive green mould.

02Smell is not concentration

DMR states plainly that we generally cannot smell ammonia below 10 ppm. Read that carefully. Your nose can tell you ammonia is present. It can never tell you the level is low enough. Those are different statements, and crops are lost on the difference.

A nose also tires. After a few minutes in the corridor you stop noticing a smell that has not changed. That is olfactory fatigue, and it makes the second sniff less reliable than the first. Never deliberately breathe compost air to test a batch. Ammonia is an irritant gas and a tunnel is a confined space.

03Four questions before you decide

When someone reports that the compost still smells of ammonia, do not reach for a chemical and do not add a day. Ask four questions first, because each one changes the answer.

Which stage is this: end of Phase I, mid conditioning or after cooling? What method produced the reading: an instrument, a detector tube or a nose? Where was the sample taken: front, back, top, middle or plenum? Has cooling started, since a warm mass releases ammonia that a cooled mass holds back? A reading without those four facts cannot support a spawning decision.

• Stage
• Method
• Sample location
• Cooling status

04What it looks like after spawning

If ammonia is still there at spawning, the compost tells you within days. Spawn runs slowly or stops in patches. DMR lists ink caps, the black inky Coprinus mushrooms, under presence of ammonia and high nitrogen in compost. It ties Oedocephalum mould to ammonia and amines that were not eliminated during pasteurisation and conditioning.

By then nothing in that batch can be repaired, so the lesson belongs to the next one. Check the formulation nitrogen you actually stacked, the oxygen supply during conditioning, and whether your ammonia evidence was honest or convenient.