Soil tests and the equipment to do it

Discussion in 'Organic Lawn Care' started by ICT Bill, Jan 9, 2008.

  1. tadhussey

    tadhussey LawnSite Senior Member
    Posts: 294

    The learning curve really isn't that bad. Once you can identify the different organisms it's just a matter looking at sample to see if they're present. You can also do a variety of simple tests to see how they respond to various nutrients.

    The magnification will vary depending on whether you're looking at a soil sample or liquid (compost tea).

    I usually start with the 10x (which is 100x magnification with a standard 10x eyepiece). This allows you to find and view some of the larger organisms like nematodes and flagellates. Then you can go up to 20x on soil samples for greater detail (to determine if a nematode is a bacterial feeder or root feeder for example).

    With compost tea, I like to start at 20x and go up to 40x. 100x is not very useful unless the organisms are already dead, otherwise it's too hard to get them to hold still.

    Here's the microscope I have, though it's much nicer than you would probably want or need for basic testing.
    http://www.microscopeworld-professional.com/detail.aspx?ID=173

    My friend wrote a microscope advisory and has some recommendations for cheap microscopes that could work for this purpose (100-200 dollar range).

    ~Tad
     
  2. cpel2004

    cpel2004 LawnSite Bronze Member
    Posts: 1,416

    Kiril I was looking at using the Kelway just to get a quick snap shot of the soils's ph levels and to find any noticable problems/issues for turf and shrub planting. Would you recommend it?
     
  3. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    I believe that kit is designed for field work.

    Best your going to do far as I know is combined moisture/temp/salinity and perhaps pH

    http://www.aquaterr.net/?id=11

    Of course you know the big ones to check -> soil structure, particle size analysis, compaction, and all other soil factors related to water management.

    Then I would determine the soil series and take a number of cores from locations that represent the predominant hydrozones throughout the property. Then based on the data from the soil series I would run tests to verify how closely it matched. Run any additional tests you determine may be required/useful based on previous test results, plants types in the hydrozones, and as Todd suggested, you may want to throw a sample under a scope to get an idea of what is going on with the biology.

    FYI, my experience has been, with an irrigated property, 7 times out of 10 the majority of observed problems can be directly linked to poor irrigation design and management.

    As you get practiced at it, you can determine alot just from looking at a soil core and the condition of the plants growing in it, but of course you will need to test in order to determine with absolute confidence.

    Yea, not a common deficiency, but it might be good to know if your dealing with an acidic soil.
     
  4. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Yes for turf, no for shrubs.
     
  5. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

  6. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Tad,
    Thank you for your input on microscopes, is there a loop or small one piece one magnification microscope that is 100 or 200X for field work that you know of?
    I believe Tad is being quite modest with his skills and knowledge of microscopes and their use, between he and his family they have forgotten more than I'll ever know.
    Tad, what is the learning curve on being able to recognize bugzzzz in soil samples? would you recommend a class or is it something you can "pick up"?

    This brings up another tool for the field, a decent core sampler, I see them in all different lengths is there one length that is better than another.

    Compaction is almost always an issue here on clay soils is there a tool for testing soil compaction. I have been told, but have not done it myself, to use a piece of rebar, when it stops is where soil compaction starts, seems too simple.

    OK so we go out to a site, If its a new customer measure the site then walk around and take samples with our core sampler, put them in bag and mix so the sample is representative of the site, take a small shovel and dig in an area that looks good and one that looks bad to "see" what is going on. seeing is free and may be one of the best tests we have.
     
  7. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    I'll jump in on this one. Several scopes here that will fit that bill.

    http://www.forestry-suppliers.com/search.asp?stext=microscopes

    Bigger is better for versatility. :) If your only interested in turf, you probably won't need anything beyond 12", 24" should cover everything you would be interested in looking at for landscape management.

    If you want a cheaper soil sampler and don't require a full blown kit, then this one should fit the bill. Personally I would recommend getting both slotted and unslotted 24" stainless steel, but in heavy soils you can probably get away with only a slotted model. Note the handy and cheap sample tubes. :)

    http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=3121

    Rebar is the quick and dirty way. Visual examination of your core sample will also tell you alot, or you can use a penetrometer. There are several different types of penetrometers, Lang probably being the most well known.

    http://www.envco.info/0003Soil/0034Soil_Testing

    If you only want a general picture of your soils, and are going to assume homogeneity, mixing the samples you take will work. If the situation calls for it, I would only mix samples from the same hydrozones and depths your interested in looking at, or don't mix them at all and treat them as discrete samples.

    For example, if you have a limited A horizon, and you mix it with a B horizon, your sample is not going to be an accurate representation of the bulk soil conditions. Ideally you want your sample to represent the effective root zone of the plants in the area being sampled.

    Shovels, post hole diggers, bulb planters all work great for a home owner. You can even make your own soil sampler out of a couple brass or galvanized nipples, however I wouldn't recommend that for a professional.
     
  8. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Kiril
    You are obviously well versed in soil and soil sampling

    When I researching spectrometers last summer I ran across some very high end ones that you pulled behind a tractor that was set up with GPS. It would take samples through the entire field and give reading back that the soil PH was so and so in this area and the N was so and so here. It literally mapped all of the NPK and PH needs for the entire site, you then fed that back in when fertilizing and the GPS rig would only put down NPK from the needs taken earlier. The only problem was that they were EXTREMELY expensive.

    They have field units for smaller sites but they start at $75,000 and up

    It looks like the Swift M2 Micro/Macro Microscope might be a good one for the field just under $700 and goes to 400x and has a rechargable bright LED
     
  9. cpel2004

    cpel2004 LawnSite Bronze Member
    Posts: 1,416

    Kiril what is your background?
     
  10. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Yow, talk about big time ag. I've looked into some GPS and satellite stuff with regard to water management and urban forestry, but haven't seen one of those. Got a link?

    BTW, if anyone is interested in setting up an open source GIS workstation, I have some links you may be interested in.

    That is a nice field scope. If you get it, let me know what you think.

    My formal education covers a variety of fields, but primarily soil science, hydrology, and plant biology, which comprised the bulk of the last 4 years (out of 10) I was in school. I have an A.S. in Computer Engineering and my B.S. is in Soil and Water Science.

    If I had been paying attention to the plant biology courses I was taking, I would have another B.S. in Plant Biology. :cry: Unfortunately I have enough units, just not all the required courses. Perhaps some day I will go back and take the 2 or 3 courses I need.

    I also have been working in the green industry for the past 15 years, primarily with regard to soil, water, plant relations. The bulk of my work typically involves irrigation and soil/water/plant resource management (eg. making right what is wrong)
     

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