[Zippy]

I notice on eBay there are soil testing kits for about £3 covering pH, K, N and P but only two tests of each in the pack - I would need 3 or 4 of these!

I have used litmus paper to test for pH (much cheaper per test), but can anyone recommend the additional tests for nutrients? Surely if you are adding these organically or from a packet you should be pretty confident that these are all ok?

[pushrod]

I notice on eBay there are soil testing kits for about £3 covering pH, K, N and P but only two tests of each in the pack - I would need 3 or 4 of these!

I have used litmus paper to test for pH (much cheaper per test), but can anyone recommend the additional tests for nutrients? Surely if you are adding these organically or from a packet you should be pretty confident that these are all ok?

If you want to test i would investigate different packs that can do more tests. It can be useful to check nutrient levels as you don't know how much of each has been depleted by a particular crop. It can also help explain why something did worse one year than on a previous occasion. Having said that i have a multi test kit that i have not used in the last x years 

[Salmo]

The test kits for pH that are sold in garden centres with the tablets and test tubes are what you need. Acidity is the important one although soils can be too alkaline for some crops. These tests are better than litmus. The probe type things are unreliable in my experience.

The way that you sample the soil is important. Just taking a trowell full and doing a test can be misleading as you may hit a spot where there is a lump of organic matter, or not. If you divide your plot by rotation do a test for each part. Take a bucket and walk over the area digging trowell fulls to about six inches deep as you go. Thoroughly mix up the soil and then do tests on that to give you a good average.

If a soil is very acid some of the important nutrients such as phosphate can be tied up and unavailable to the plants even if they are present in the soil. This if more likely to happen in peaty or clay soils although light sandy soils can become very acid.

Allotment plots are so messed about with fertilisers and all sorts of compost that you are unlikely to get meaningfull results with other nutrient tests and I would not bother with them. As a general rule heavy soils are usually short of phosphate and have plenty of potash. Light soils are usually the opposite.