Field 1
pH: 5.8
P: -2
K: 2+
Mg: 4
P205: 44Units/ac
K2O: 48Units/ac
Gran Lime: 252.9kg/ac
Field 2
pH: 5.4
P: -2
K: 2+
Mg: 4
P205: 44Units/ac
K2O: 48Units/ac
Gran Lime: 455.2kg/ac
Field 3
pH: 5.6
P: 1
K: 2+
Mg: 5
P205: 56Units/ac
K2O: 48Units/ac
Gran Lime: 354.1kg/ac
Field 4
pH: 5.6
P: 2-
K: 2+
Mg: 5
P205: 44Units/ac
K2O: 64Units/ac
Gran Lime: 354.1kg/ac
Will probably leave the lime until after the first cut, or possibly 2nd cut. Trying to cut earlier this year. Approx 3000G/ac slurry has been applied since samples were taken.
Assuming the slurry is giving 18-15-90 applied at 3000G/ac (6-5-30 per 1000Gallons) where does that leave me for fertiliser requirements?
From reading
https://www.teagasc.ie/media/website/animals/dairy/FertilisingGrassSilage.pdf I need 100-24-120 for index 2 soils. So they recommend 3 bags/ac of 27-2.5-5.0. This will provide 81-7.5-15 and including the slurry at 18-15-90, brings total to 99-22.5-105.
So, it looks like I'm now okay for K2O - so I just need to increase P by 44-15=30units/ac. So I need:
N: 100 - 18 = 82
P: 44 - 15 = 30
K: 48 - 90 = -42 (excess)
So, do I need a NP fertiliser (plus Sulphur) in ration of 82:30 or 2.5:1?
Thanks.