Pine or any other wood mulch breaks can tie up the nitrogen to a limited extent. I'm linking to a previous 2010 thread where Dawn and Larry discuss this issue. It's very helpful.

Susan

Here is a link that might be useful: Adding Nitrogen to Wood Mulch

Sammy,

If you had mixed the mulch into the soil, maybe it would be responsible for the lower N, but that's about it. It would not be the explanation for your high P and high K.

Testing for nitrogen in soils is very tricky and, for that reason, some testing labs no longer even test for available nitrogen. The levels of available nitrogen can fluctuate a lot, being greatly influenced by both rainfall and soil temperatures. You could have a soil test in January show low nitrogen and could test the same soil in June and have much higher levels even though you added nothing new to the soil.

While it always is good to have a soil test done so you can get a general overall idea of what is going on with your soil, a nitrogen test in January or February is largely irrelevant for warm-season plants that won't be planted for weeks or months yet. The best time to get an accurate reading of available nitrate levels is when the plants are actually growing in the soil because that is the only time the test will tell you how much nitrogen is available right then. There is a difference between how much nitrogen is in the soil too, and how much of it is in an available form the plant roots can access. Or, if you have applied nitrogen to your soil and you want to ensure you have enough nitrogen in that soil, then you apply the nitrogen, water it in and wait a week or two and then send in a soil sample. A soil sample at that time tells you how much nitrogen is available to the plants right then when they need it. While some commercial growers will test their soil after nitrogen applications, it is not practical for home gardeners to do so, especially for those raising plants in pots. You cannot dig up the soil around your plant to send it in and get it tested.

Pine bark fines are a major ingredient in many soil-less planting mixes and the controlled-release-fertilizers used in many of those bagged, commercial mixes are formulated to compensate for whatever the pine bark fines will tie up. I haven't found any soil-less mix that works better than Al's 5-1-1 mix and it has a high percentage of pine bark fines. However, most people who use it are either adding in a controlled-release-fertilizer or they are fertilizing weekly (or more often) with a water-soluable fertilizer depending on their specific plants' needs. You cannot use the 5-1-1 mix for much of anything unless you are fertilizing in some shape, form or fashion because the ingredients themselves are not high in available nutrients.

I know this whole soil thing must be very frustrating for you, but when you grow in containers, it comes with the territory. Since the roots are "trapped" in the container and must grow only in whatever the container provides them, proper fertilization is key to success and it can be very easy to over- or under-fertilize. That's one reason the Miracle Grow (and other similar brand) fertilizers with a controlled release fertilizer are so widely used--because they take the guesswork out of growing in containers. Once the growing medium in a container is out of balance in terms of nutrients, it can be hard to fix. Once you start trying to fix things, every ingredient you add has the potential to solve your problems but also to create new ones simply because the growing medium is confined to such a relatively small area.

Dawn

I've had my soil tested by the Ag agent a couple of times. In fact in 2010 I had it tested again. The BIG test with the micros included (cost about twice as much). I tested 4 different areas that have served different purposes over the past 20 or so years. The soil results were remarkably the same as 20 years ago. Low in N, very high in P, K. No lack in the minor nutrients. The only thing that was different on the 4 sites was the PH. My highly amended raised bed was 6.8 while the other sites registered 7.3. Our heavy clay soil retains P,K tenaciously and it is hard (impossible?) to deplete it. Our soil is somewhat similar to the heavy clay soil around the Dallas area, and they have a similar problem. Using fertilizers with additional P,K can actually be damaging to the plants. The addition of Pine Bark mulch may deplete the nitrogen somewhat as it breaks down, but unless you are dumping a truck load of the stuff in one place, a simple addition of a 1/4 cup of Urea will solve the problem......Maryl

Thanks, Mary. Urea is one of the suggestions that the OSU paper gave me. However, some if not here then on the Antique Rose Forum suggested that it is too cold to measure nitrogen. Once it is warmer, the nitrogen will do its thing and become higher.

I do wish that at some point in my life, I had studied just a little bit of horticulture. There is so much I do not know, and I cannot really understand so much, because I do not know the basics.