This graph from the MGA highlights the growth and nutrient uptake of a maize plant.
From this graph, we can see the peak of nutrient assimilation is the 1st week of August and this is very important when it comes to tracing back preparation for growing the crop. Many farmers will see maize as an ideal spot for dumping slurry in early spring, but slurry contains vast amounts of readily available nitrogen. This slurry would be far more useful being targeted on 1st or 2nd cut silage ground, the ideal manure application for maize would be FYM with its slow release N.
Add to that Nitrogen applications of AN at normally 375 kg/ha and you’re suddenly finding yourself with a crop that is potentially going to be running very short of Nitrogen by late June/July. Ideally a urea based product would be an ideal replacement for AN, with its phased release along with the added bonus of sulphur. My favourite grade for maize would be 38:0:0:19
Nitrogen is the key nutrient for obtaining maximum yield and quality, however too much nitrogen which is common on too many farms may also delay maturity and result in lodged crops. The average maize crop yielding 40 t/ha removes 160 kg N/ha although peak uptake is 210 kg N/ha.
Basic Nutritional requirements for a maize crop at index 3 which most continuous maize ground is: (this will probably shock you)
N requirement = 100 units per acre or 120KG/Ha
P requirement = 16 units per acre or 20kg/Ha
K requirement = 96 units per acre or 110 kg/|Ha
To meet these requirements can be done with the following
3000 gallons of slurry at 6% N=27 P=15 K=90 or
7.5 Tonne FYM acre = N=18 P=30 K=108
In addition DAP at 50 kg and acre or 125 kg/Ha for seed germination due to cold soil temperatures and 100 kg an acre of 38:0:0:19so3 or something similar
There is no exact blueprint, but over-doing maize is simply not necessary
For further information contact one of the forage team and we will be happy to help