Nitrogen applications until the cabbages are harvested

LAN is the preferred fertiliser for post-plant fertilisation of the cabbage crop. It contains nitrate that is available to the crop but unfortunately also easily leached from the soil

- Bill Kerr

The ammonia half of nitrogen is able to be taken up by cabbage plants, but because it is positively charged, it is attracted to the soil colloids and therefore not freely available to be taken up, as it is not in the soil water until converted to nitrate by bacteria. Nitrate is negatively charged and therefore repelled by the soil colloids into the soil water.

LAN therefore has the advantage of having half immediately available and half with delayed availability, thereby providing a measure of safety.

Experience helps to get the nitrogen fertilisation right, but until that stage, we need to err on the side of perhaps overdoing it just to make sure that it is sufficient.