Some fodder beet crops become deficient in nutrients (see photos below) from January to May, despite good applications being made at planting and canopy closure.
In 2013, DLF Seeds conducted tests which suggested that crops can be responsive to nitrogen or potassium applications in late January and February, or both. Responses were certainly large enough to be economic, with yield gains up to 5.8 t DM/ha and profit increases up to $2600/ha.
Indications of the need for fertiliser can be leaf colour and accelerated death of older leaves. The most economic rates of application seem to be 100-150 kg/ha of urea or potash (potassium chloride), normally spread by helicopter.
in 2017 over 70% of fodder beet crops in Canterbury were deficient in nutrients click here to read more.