Nutrient Testing

Discussion in 'Plants: Science and Cultivation' started by sciencelover, Jan 3, 2010.

  1. sciencelover

    sciencelover Member

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    I am doing a science project on the effects of Pacific Northwest invasive plants on the nutrient levels in the soil. I am using a CIL Soil Testing Kit, and was wondering what the symbols for the levels (N1, N2, N3 etc.) mean. Is 1 low in Nitrogen or high in Nitrogen?
     
  2. togata57

    togata57 Generous Contributor 10 Years

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  3. sciencelover

    sciencelover Member

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    Thank you, and now my question is, is this test reliable enough? All of my test results came up as deficient in all the nutrients I tested. If I took my soil samples deep in the forest, where there is no presence of fertilizer and such, do the results sound right, or plausible for the area? I guess I should have asked these sorts of questions before I started my project, but I'm new at this, so I guess I've made a few mistakes :). I'll just have to work around them.
     
  4. togata57

    togata57 Generous Contributor 10 Years

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    Hey---we all gotta start somewhere! Doing things is the only way to learn. And, to quote Big Bird: Asking questions is a good way to find answers!---Perhaps some of our Forum forest mavens could give you some insight as to whether your results are freakishly outrageous, normal, or not.

    Good luck to you, sciencelover! You have the first and most important element of this puzzle already: your desire to know. Adopt as your own the mongoose motto: Go And Find Out.
     
  5. sciencelover

    sciencelover Member

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    How would I speak with a "Forum forest maven"?
     
  6. togata57

    togata57 Generous Contributor 10 Years

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    I am surprised that they have not spoken with YOU as yet!
    Suggest M.D. Vaden, lorax, Lila...how about it, folks? Ron?
     
  7. sciencelover

    sciencelover Member

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    Thank you! Hopefully my research will serve me well, and I can become more knowledgeable in biology and botany!
     
  8. M. D. Vaden

    M. D. Vaden Active Member 10 Years

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    Got your note.

    I'm not sure of the answer. Its used a lot, because Google display a lot of results for N1, N2, N3.

    Guess one of the results will have a little extra to explain. Give it a try and see if you find one. I quickly browsed about 15 web pages.
     
  9. sciencelover

    sciencelover Member

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    Thank you, but actually, I am more concerned about the questions below the first, as togata57 answered that question for me.
     
  10. lorax

    lorax Rising Contributor 10 Years

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    Togata, I was in Quito! I'm back and I'm paying attention, I promise.

    It's entirely plausible that your test results are correct for a primary-forest soil sample. There are a lot of variables that determine the N-levels in soils, the most obvious being the forest type. Predominantly pine or eucalyptus forests, for example, have notoriously "poor" soils (ie, they're deficient in most minerals) because the trees are such heavy feeders, and because they make the soils so acidic that it inhibits a lot of secondary growth. It might shock you to know, too, that soils from the deep Amazon forests are also pretty depleted, especially in areas that are seasonally or permanently flooded. Here, the poorness of the soils comes from being constantly soaked and rinsed, and because the dense canopy of primary forest prevents light from hitting the floor, reducing secondary growth to only the hardiest of shade-lovers. There are also a number of other variables for tropical forests that aren't relevant to you - for example, many tropical trees produce phytotoxic substances in their leaves, which specifically inhibit growth of other plants (the Mahogany family is notorious for this) - and when these fall and form the leaf mulch (which is the main point of nutrient in a rainforest, since the base soil is usually red clay) they keep other things, like the Fabaceae (notorious N-fixers) from growing.

    Here's some questions for you, since these things all have a bearing on soil quaility.

    What is your dominant forest type in Utah (conifers, deciduous, mixed?) What's your most common tree in the area where you took the samples? Did you take humus (leaf mulch) or base soil? What colour was it? What smell does the soil have? What flavour? What is the pH of the soil? (this is a very easy test to do if you have distilled water and pH strips - suspend about 1 tbsp of your soil in the water, allow it to stand for about an hour, shake well, and test.)
     
  11. sciencelover

    sciencelover Member

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    Lorax,
    I actually did my testing on Vancouver Isalnd, British Columbia, Canada, because in Utah, the ground is covered in about 5 in. of snow, even in the valley. The dominant forest type in British Columbia is evergreen coniferous forest. I have to say, I honestly don't know what the most common tree in the area was, as I even had a hard time identifying my samples, even with the help of E-Flora B.C. The deciduous trees in the area had all lost their leaves, so I couldn't tell you the names of those, but conifers were definitely more prominant. I used the base soil, 10 cm under the plant. The soil of the area was black when it was collected because of the very rainy weather, but it was a darkish brown once dry. I also wouldn't know how to describe the smell of the soil, but musty I guess. Flavor? I took six samples and here are my results of each test:

    Invasive plants:
    Spurge Laurel: pH, 7.0. Nitrogen, N1. Phosphorus, P2. Potassium, K1
    Scotch Broom: pH, 6.0. Nitrogen, N1. Phosphorus, P3. Potassium, K1
    Thistle: pH, 7.0. Nitrogen, N1. Phosphorus, P3. Potassium, K2.

    Native Plants:
    Oregon Grape: pH, 6.0. Nitrogen, N2. Phosphorus, P1. Potassium, K1.
    Waxberry: pH, 6.5. Nitrogen, N1. Phosphorus, P1. Potassium, K2.
    Huckleberry: pH, 7.0. Nitrogen, N1. Phosphorus, P1. Potassium, K2.

    As you can see, all of my plants are shurbs, or bushes. This is where I didn't know what to do. What can I conclude from this?
     
  12. lorax

    lorax Rising Contributor 10 Years

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    Well, you can conclude a few things: Broom, Oregon Grape, and Waxberry either prefer acidic soils, or purposefully make the soils around them acidic. Oregon Grape fixes Nitrogen. Plants with lower P and K ratings are absorbing more of these minerals, whereas higher P and K ratings mean that the plants aren't feeding as heavily.
     
  13. sciencelover

    sciencelover Member

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    So the invasive plants have higher levels of phosphorus, but wouldn't that be... better for the surrounding native plants? Don't invasive plants inhibit native plants?
     
  14. lorax

    lorax Rising Contributor 10 Years

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    Yes, but more by their presence and aggressive growth habits than by any effect they may have on the soils! Generally, invasive plants are faster growers or have more effective seeding techniques than natives, which means that they spread faster and grow more, eventually simply displacing the native plants. A prime example of this is Acacia horrida in Ecuador, which has all but displaced the native Anadenanthera colubrina trees because it occupies the same niche, but is a faster grower with a more broadly-spreading canopy - in effect, it simply outgrows and outshades the native tree.

    In the case of, say, thistles, they've got both an extremely efficient system of seed distribution and a tendency to reproduce from root fragments. They're also opportunistic and will happily grow in soils that are depleted, which makes them a greater threat to the pickier natives. Additionally, native plants are often finely adapted to a particular set of soil, light, and moisture conditions which means that they're less adaptable to change.
     
  15. sciencelover

    sciencelover Member

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    So could I conclude that the affect of invasive plants on soil does not indirectly affect native plants?
     
  16. lorax

    lorax Rising Contributor 10 Years

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    Yes, with a few reservations. Certain invasive plants (vetch and other legumes, for example) are actually beneficial to the soils vis a vis native plants - they fix Nitrogen, which is important to growth and may in fact accellerate the growth of natives. However, the detriment of the fast growth and easy spread of invasives generally outweighs their benefit to the soils and thus the native plants.
     
  17. sciencelover

    sciencelover Member

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    I guess I should have done more research before... Ahhhhh! So my project is basically irrevelant?
     
  18. lorax

    lorax Rising Contributor 10 Years

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    Not necessarily. I think it's actually come to a pretty neat conclusion, namely that invasive plants have little impact on available soil nutrition. To be really definitive, though, you'd have to do a more in-depth soil analysis to include the trace minerals (this involves taking samples to a soil-testing lab, which is beyond the scope of your current experiment). There might be something going on that your tests haven't accounted for or detected.
     
  19. sciencelover

    sciencelover Member

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    That's true, and I guess, me being a ninth-grader it's the best I can do at the current time, especially because I have to do all the testing myself. That's the thing about having our project start in winter: plants are really hard. So of course I had a week in a place where it wasn't snowy, so this is what I have to work with. I am interested in this though, so maybe over the summer, I'll take some more soil tests and do a large variety of plant species. Well, enough excuses! Thanks for helping me come to an educated conclusion! I think next year I'll have a much better idea of how science fair projects work. :)
     

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