Are exposed piles loosing nutrients?

[dcluck]

I was told by someone at one of the nurseries I frequent that rains will wash nutrients out of exposed compost piles and into the surrounding soil. Makes sense to me, but it seems that a lot of people who compost have bins which leave their piles exposed. Are we really getting weaker compost with open bins? Any thoughts or links to other info would be appreciated since I'm considering building a new bin setup.

~Dave

[CaptainCompostAL]

Not really. It depends. Mild rains don't hurt open compost piles. Floods and constant heavy rains can reduce your available nitrogen levels from the pile, slightly over time.

Keep in mind that the carbon forms (carbohydrates, cellulose, humus, etc.) in your compost piles acts as a soil/compost magnet and sponge. It can hold over 1/2 it's weight in excess moisture, and it can buffer, balance, and chelate nutrients in the pile or around the root zone around growing plants.

Whatever minor nutrient losses occur over the composting cycle, are easily recovered by your mulches, legume cover crops, or tea brews during the growing season.

[darn7pin]

dcluck,

I no longer worry about my piles losing any nutrients, I just rotate my piles from one bed to another each year. My theory is that any nutrients that leaches out of piles as they cook, goes straight down into the bed and that way something planted there in the future will make use of it.

Ed

[BlackForestComposter]

I would be more concerned about the piles going anaerobic if they get that soaked.