I'd start a week before each spray timing to give you time to get the results back and then add stuff into the tank.
Be very cautious of just single tests and even one years tests aren't really that good, you really need multiple years of results all taken at similar times through the years to be able to build a true picture of what you need or not.
Remember a tissue test is only a snap shot of that plant on that day test the same plant a week later after a warm spell ect and you'll most likely get a different result.
It took longer than a week to get my test results back from NRM. Usually 10-14 days. I did mine 2 weeks before a planned spray pass to allow enough time to get the results back & buy what I needed to add. Avoid posting samples on Thursday or Friday as they could be sat sweating in a mail sorting office all weekend.
On high pH soils, boron, copper & potash always came up as low. Whether they actually reduce yield is another matter. As Robbie says, you will start to get a longer term picture build up through repeated testing.
It’s up to you. Some do it before every planned spray pass and again with grain samples at harvest. I just did a few samples of each crop on different soil types during stem extension, more for a comparison than anything else.
If you’re a member of a buying group it’s worth asking them if they have an account. An individual gets charged a different rate in some labs.
Maintaining grass quality during mid-season grazing is important. Farmers can maintain quality by entering ideal grazing covers of 1,300 – 1,500kg DM/ha, and grazing down to a residual of 4cm every rotation.
If you are now in a situation where cows are not cleaning out paddocks as well as they should be, leading to the development of steamy grass within the sward, here are some options.
Common options for rejuvenating swards include:
Take a silage cut, probably into bales, remove the material and start again with the aftermath...