It is very common in agriculture to deploy nutrient at a time that suits the work cycle, rather than when it is needed by the crop. Often this means applications of organic fertilisers and bagged fertilisers at the same time, early in the crop, putting out 80 or 90% of the crop's required nutrient at the time when it just does not need it.
Take Maize as an example - the work of the late Don Schriefer highlights that the crop has critical trigger points and needs over 50% of its NPK nutrient between knee high and shoulder high development.
For cereals such as barley and wheat, how often has it been seen that a fantastic looking crop fails to properly fill grain? This can be avoided by simple testing at the right time to establish if the crop is running out of steam.
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