Compost temperature

Now we are approaching the end of the summer, many people are confronted with the problem of keeping compost temperatures under control, especially in the first few days after filling. To begin with, it is obviously important that during warm weather the compost is supplied as cold as possible. Unfortunately growers do not have much influence in this respect. You can make sure the room to be filled is sufficiently chilled by cooling the night before filling. As the room is empty, this shouldn't use too much energy, but cold shelves and walls may be just enough to keep compost temperature under control.

The compost can also be compacted slightly more firmly for a short while during the warmer months. This will speed up the exchange and make temperature control easier.  As filling machinery has been placing compost far more loosely in recent years, it is not often a problem to temporarily fill in a more compact manner. And in many cases (the already drier) compost in summer is more voluminous anyway.

It is then essential to closely watch the intermediate layer in the first week after filling, and namely for water absorption in the upper layer of compost. This layer must not become too sticky!

The next step to take after filling, is not to wait until compost temperature rises, but start cooling immediately. Even if the compost is only 18-19 degrees Celsius after filling, cool the air down to 15-16 degrees. The experience with compost in the past period is that the peak will come anyway and anticipating any extreme temperature rise is a more efficient way of controlling it.

Sprinkling is the next logical step, and a few extra litres of water during a hot period can't do much harm.

Be careful when cooling using outside air.  As all the heat from the compost has to evaporate via the casing soil, it makes no sense to cool using outside air if the wet bulb sensor temperature outside is higher than the room temperature. Some computer controls react automatically here, others will have to be adjusted manually.

John Peeters, C point