October or November is the ideal time to start preparing a fertiliser plan.
Discuss your soil testing requirements with your advisor as soon as possible, so that test results will be back in time for making out an autumn and spring fertiliser/slurry programme.
A fertiliser/slurry plan combined with recommendations and farmyard assessment form a complete Nutrient Management Plan.
It is easy to take short cuts when putting a Nutrient Management Plan in place but these short cuts could be very costly.
This plan should include using a map of your farm (the area aid map, for example), showing where recent soil samples have been tested.
Any areas that haven’t been tested in the past few years can be identified and tested so that an overall farm nutrient status can be established.
Testing different parts of your farm every few years is unsatisfactory, because it is unlikely to ever give you sufficient information for a complete fertiliser plan.
Proper soil sampling is essential and should be carried out according to the correct instructions.
Based on your soil test results and your system of farming, a 4-5 year lime/fertiliser and slurry plan can be made out for your whole farm.
As this exercise is the basis of efficient and environmentally friendly farming, you should make every effort to get it right.
Make sure the selection of your soil sampling areas is correct and well identified on the map.
Advisors can help you with these tasks and give you recommendations in an informative and easy-to-follow format.
If good records are kept, the plan will normally need little adjustment for five years.
Soil tests will not show how much N should be used.
This will depend on farm output, crop history, soil type etc.
Early autumn P, K and lime applications are beneficial on areas that are deficient in these nutrients.
Otherwise, sufficient P and K can usually be applied through the proper use of N compounds throughout the grazing season.
Soil testing is the most cost effective tool to optimise use of fertiliser and slurry.
Yet it is one of the most neglected practices on Irish farms.
But bad soil sampling is worse than no sampling, because it can give misleading results.
For example, if samples from areas that have been treated differently in the past regarding slurry applications, silage cutting etc. are sampled together, the results might indicate that the area is OK for lime, P or K, but the reality would be quite different.
Fertiliser recommendations are based on samples taken to four inches deep.
Samples taken to any other depth are misleading, because most of the nutrients are in the top layers.
At least 25 cores should be taken in a W-pattern in the area to be sampled. Avoid sampling for P and K within 10 weeks of fertilising with P and K, and within 12 weeks of slurry application, or within 18 months of liming. Avoid sampling around gaps or areas where cattle gather.
Farmers using soil corers should get good advice on proper soil sampling and recording methods. A lot of bad soil sampling has been done in the past due to corers being handed out without instructions.
Ideally, testing laboratories should have a well trained person to take the samples.
This should not cost very much extra, if there was a reasonable minimum number of samples per farm.
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