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Soil test results

Liz
11 years ago

I'm planning on renovating my lawn next fall. I will probably test the front yard next year, but I was curious, so I jumped the gun and decided to run a soil test on my back yard now. Results are in. I have sandy loam (no surprise there) with 3.8% organic matter, which they said was high for sandy loam. pH is 6.22, optimal, so they said no lime should be used. As for fertilizer, they said to apply a ratio of 1-2-2, at a rate of 1 lb. of N per 1000 sq. ft.

I'm not planning on fertilizing at all next spring, since I'd just be feeding weeds. I'm thinking more about what to do at the time of seeding.

I'd like to go organic. I couldn't find any organic fertilizer with that exact ratio, but Dr. Earth Bud and Bloom Booster (4-10-7) isn't too far off. How much should be applied to my 15,000 sq. ft. lawn? Would it be sufficient to simply add compost? Why is the N requirement so low, anyway? I thought lawns mostly need N, since we don't want flowers or fruit.


3.8% organic matter seems low to me, but Rutgers didn't say so. What am I to make of this? Is it possible to have too much organic matter? I was planning on adding 3" of compost, or a mix of compost (spent mushroom substrate, probably) and topsoil. But it's expensive stuff. Do I need that much?

It seems my soil test has led to more questions than answers!

Comments (20)

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    I have found over the years that a level of organic matter in the 6 to 8 pecent range is what works best for the different soils, sandy loam, sand, clay, that I have worked with. 3.8 is just barely adequate. It is possible to have too much organic matter, I have seen soils with close to 20 percent OM that stayed too wet for too long and the plants trying to grow there simply ended up with root rot.
    What do you expect the "topsoil" to be? "Topsoil" is simply the top 4 to 6 inches of soil from someplace. It may be something worthwhile or it might be more of a deteriment. Be very careful when thinking of buying something called "topsoil" or even "garden soil" since there is no criteria for what they are. Have in mind what you want and accept only that.
    Think about the recommendation for spreading 1 pound of Nitgrogen per 1,000 square feet, a fairly negligable amount, not anything I would be concerned about. Work at getting the amount of organic matter in your soil up and that should be enough.

  • maplerbirch
    11 years ago
    last modified: 9 years ago

    I had always heard that phosphorus is needed only at seeding time, if at all. Why does Rutgers believe that so much P and K is needed for lawnsand that 3.8 OM is high for sandy loam. I'd think that in sand it would be even more unlikely to have too much OM. Root rot wouldn't be an issue with that much drainage, would it?
    Seems that the soil test, does indeed create more questions than answers, as stated. :)

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    Think about this. One pound of fertilizer per 1,000 square feet is a pretty negligable amount in reality, but those numbers are a ratio. Rutgers is telling you that if you do spread some fertilizer about you need about twice as much P an K as N, but concentrate on the organic matter rather then what I would consider a drug, a steriod, a fertilizer that only has N, P, and K.

  • maplerbirch
    11 years ago
    last modified: 9 years ago

    Mycorhizzae Fungi will eventually get the P that is already existing in the soils.
    3 inches of compost is definately a lot and personally I'd use just a quarter inch to cover the seed right now. You have years ahead to add more compost rather than all at once, IMO.
    Compost actually has P in it,doesn't it?

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    All organic matter, not just compost which is made of lots of organic matter, has all of the nutrients plants need to grow although not in easily measured forms that synthetic fertilizers have. Over the years here, just by adding compost and other forms of organic matter (shredded leaves) my soil tests have gone from a pH of 5.7 and low optimal levels of P, K, Ca, Mg to a pH of 7.2 and high optimal levels of those nutrients.
    If those nutrients did not come from that organic matter then the soil had to have made them, and I am unaware of how inert soil particles could do that.

  • maplerbirch
    11 years ago
    last modified: 9 years ago

    I remember a product being advertised as having all 72 micronutrients and it was sand dust, pulverized to the extent that plants could now access those nutrients. :)

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    Sand is an inert mineral and has no nutrients to share with anything. Pulverizing sand will not release nutrients that are not there to begin with.
    Keep in mind that there are people out there that are selling magic elixars with the sole purpose of seperating you from your money. If the ads sound too good to be true they are.

  • dchall_san_antonio
    11 years ago
    last modified: 9 years ago

    I remember a product being advertised as having all 72 micronutrients and it was sand dust, pulverized to the extent that plants could now access those nutrients. :)

    That's like Kentucky Fried Chicken's eleven herbs and spices. When you read the KFC patent for the process, all he uses is salt and pepper.

    dr.liz, if you want to move to organic care, you need to force yourself to unlearn most of what you know about fertilizer and lawn care. The NPK ratios don't amount to anything in the organic world. Listen to kimmsr. He said his soil has improved to perfection simply doing what he does...which is all organic. I never like speaking for him but I do it all the time. This time I think he would say that he has never looked at the NPK of any fertilizer since going organic. (that is his cue to come tell me I'm wrong - that's okay). Certainly I can tell you I don't even buy commercially bagged fertilizer. NPK means N-O-T-H-I-N-G to me. What I care about is protein content and cost. Ratios smatios. I could not care less. Any real organic fertilizer will deliver what you need in the right proportions. Having said that you should know that I exclude liquid fertilizers from the realm of "real" fertilizers. Liquid fish fertilizer? You would need to apply about 8 gallons per 1,000 square feet to get the protein content of 20 pounds of alfalfa. I don't know what you might be a doctor of but most people gasp at the cost of 8 gallons of liquid fish fertilizer, whereas 20 pounds of alfalfa pellets costs about $5. But actually now that I look that up, 8 gallons of liquid fish costs about the same as a cubic yard of compost delivered. Once again, compost loses in the cost benefit analysis.

    But I'm digressing. Pay no attention to the NPK of your fertilizer. If you really want to stop the urge, go to your local feed store and buy a bag of alfalfa pellets (rabbit chow). Alfalfa is sold as feed, not fertilizer, so it carries a protein label instead of an NPK label. Immediately you will stop looking at the NPK. Scatter the pellets on your lawn at a rate of 20 pounds per 1,000 square feet. The more you use the better the results. The more often you use it, the better the results. One of the gurus on another forum experimented with trying to overdo his organic fertilizer. Every weekend he applied 40 pounds per 1,000 square feet of a combination of Milorganite and soybean meal. At the end of the season he had applied well over 1,000 pounds per 1,000 square feet. I would caution you to not jump in too hard with organics at first. Start with 10 pounds per 1,000 of whatever you use. Otherwise the soil microbes will not be properly populated in the soil and the odor may not be to your liking. Once you get the soil tuned up, it will take the heavier amounts with no odor. It is nothing like a manure smell - it smells a little like ammonia, because that is what it is.

    Compost is very expensive and has very little protein left in it. The cost of compost in my neighborhood amounts to $75 per 1,000 square feet. The cost of alfalfa pellets is $4 per 1,000 square feet. In my opinion the alfalfa is 100x more valuable in terms of protein, so my choice is clear.

    Hope this helps.

  • maplerbirch
    11 years ago
    last modified: 9 years ago

    So where did the 72 micronutrients that we believe plants need, come from originally if not from parent rock? :)

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    Plants evolved over many eons and probably the original plants did not need all of the micronutrients they do today. Some of the nutrients plants need are manufactured in the leaves by photosynthesis while others are pulled from the soil, where both the mineral component (the results of erosion of rocks) and the organic component (the result of plants dying and contributing what the have to the soil via the action of the Soil Food Web) are waiting for the wee critters of the Soil Food Web to both convert them into nutrients the plants can use but also through a symbiotic relationship with certain fungi (the mycorrhizal relationship) to be fed to those plants.
    Not all the nutrients plants need are available from rocks.

  • Blanket
    11 years ago
    last modified: 9 years ago

    1. Homeowner, why don't you seed your yard this year with a variety of clovers, white, red and crimson. Don't fertilize, let the clovers grow up, then cut them like a lawn as high as you can set the mower. Do that every now and then to thicken up the lawn and let the clover clippings stay on the ground. After a year or two, till that into the ground. Even better, get some leaf mold or compost, add a little Milorganite (the only fertilizer you would need given your description), and then till it in. Then pick a grass you like and go with it. Try and get your grass seed from a breeder. Try to avoid the old seed that they sell in big box stores. It's garbage.

    2. Brings me to a point brought up by another person. The reason Rutgers does what it does is it is using specific breeds of grasses. It doesn't use lousy grass from Scotts or Pennington. These elite grasses are literally engineered to be grown in "so much P and K." So do it.

    3. A pound of N in 1,000 square feet really truly is nada. Clover will put more N into your soil than buying it and spreading it.

    4. Never forget we live on a planet orbiting through different regions of space. It's certain space dust settles in peoples' yards from meteors and asteroids. That can always explain intrusion of new minerals that you can't account for. Especially since we are in an active solar cycle. Use common sense.

    5. KFC is just OK. Popeyes rocks.

    6. As you can see, at least one person, possibly two completely can ignore the rest of the planet's fixation on NPK. And succeed. Decide whether you are that, or are you the person who asked about NPK? N is handled by clover. For sure it would fix 1 pound in 1,000 foot square. Just clover. Sandy soil drains fast, so applying something like cottonseed meal to improve your nitrogen would work, but adding fast fertilizer will just leech through the sandy soil. Leastways that's what happens in Florida. Clover seed is way cheaper and more effective over the longhaul than spreading dead plant stuff on your yard. Plus it looks cool and it attracts rabbits. Rabbits are good for yard drama. And isn't yard drama what this forum is really all about? =)

    7. You near the buggy racing part of Jersey? Your best organic will be cottonseed meal. Forget the dead rabbits food (living, uncaged, rabbits like clover, not alfalfa). Give your ground what the studs feed on. It's much higher in protein, and your Rutgers extension people can help you. They know horses and lawns. Some of the best turf people in the turf industry are at Rutgers. They know what they are talking about.

    8. Compost tea is a superb way to pull SOME of the good stuff out of compost and leaf mold, but do you really have warm enough weather up there to do it right? There's a reason moonshine came from the hills around me. Warm summers, lots of overstory. You don't want to buy compost, it's been sanitized beyond belief. But stables do have fresh manure, and it makes a tea that smells almost as bad as wet cottonseed meal. But I don't know about the public health impact of getting elbow deep in equine poo.

    Here is a link that might be useful: The Grass Horse Web (GHW), as God intended

  • maplerbirch
    11 years ago
    last modified: 9 years ago

    kimmsr, you have a catch 22 situation with the "ancient plants" not needing micronutrients(probably) yet they appear in the decayed bodies of the very same plants.
    From there we have modern plants using the nutrients that were manufactured in the leaves by photosynthesis.
    Which nutrients might those be?

    We all know that P exists in rocks all over the world. How about K? Fe, Mn or Ca? I really don't know.

    I see fairly desolate mineral soils made up of rocks, clays and sands with little or no OM in it just about 2 feet below the surface around here. Trees, I believe, are our best source of the some organic minerals, from leaf compost and their roots are deep in that mineral soil.

    For those reasons I respectfully disagree. :)

  • Blanket
    11 years ago
    last modified: 9 years ago

    What plants need to survive may be evolving in reaction to our environment and might need more micronutrients in the past 100 years or so than in the past million. Not sure. That's pretty fast reaction time, but I'm not an earth scientist. It could be. Regardless, how plants live and die hasn't changed.

    Plants produce their food from photosynthesis. To aid this miraculous process, which God started as anyone can read in the very first chapter of the Bible, plants pull what they need from the soil AND from the air. What's in the soil and air come from very nearby biochemical reactions on a nano level and from very far away, from even beyond the atmosphere. In between those extremes, you have minerals and other soil constituents in constant flux depending on animal life, wind patterns and atmospheric conditions in your microenvironment. Well, maybe that sounds like earth science, but really, not an earth scientist. Given available information, all this should just be common sense if one removes the blinders of bigotry.

    So it's entirely possible the off topic discussion about where minerals comes from can be brought back to the NJ yard that's supposed to be the focus of this lawn discussion. In her case, NJ is near enough to the shore to be impacted by migratory birds, wind patterns and industrial sharing. God knows, NJ has more oil refineries than golf courses, so there's all sorts of stuff in the air that can change from one year to another depending on the wind. If she has what she has, really all she needs is to build up the top surface of soil. NJ is called The Garden State for a reason. It has great soil all over the place. Microbes don't weigh a lot and do move in the wind just like OM and minerals (less so). You can't talk about the microenvironment without more information.

    So in general, can't everyone agree that a yard full of clover would remedy the homeowner's situation. Let that grow like green manure to build the soil, THEN add leaf matter and THEN add soil amendments? And do what you can to attract birds and their guano. Birds contribute greatly to the habitat, which then impacts the microscopic world of the soil surface.

    Here is a link that might be useful: National Geographic, The Food Chain

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    Algaes, mosses, lichens were among the first plants and they were followed by others.
    Plants manufacture nutrients by photosynthesis and by uptaking soil borne nutrients.

    Here is a link that might be useful: Plant Evolution

  • dchall_san_antonio
    11 years ago
    last modified: 9 years ago

    At the risk of sounding like I might agree with wet blanket, I do have to say that clover is an unsung alternative to traditional lawns. Before the selective herbicides became so popular in the 1960s, clover was included in most lawn seeds. When clover invades a lawn and forms clumps, it is unattractive; however, when it is seeded evenly, it has a very lush look. If you decide to start down that path, do some research on the various varieties. Some grow taller and faster than others leading to the uneven, clumpy appearance again. You would also need to get seeds which are inoculated with the bacterium which provides the nitrogen boost blanket describes. Otherwise clover will not add nitrogen. There are two drawbacks to clover. The flowers attract bees and the plant stains clothing if you roll around in it. Bees can be charming or hazardous depending on you and your situation. Stains come out with modern soaps.

    Just as clover is an offbeat suggestion for a lawn, I would take the rest of what blanket says with a grain of salt. He has mentioned cosmic dust several times on other posts. He says it is common sense. I presume he relies on it as a soil amendment. I don't. My lawn needs a more concentrated source of nutrients.

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    Clover could be a good lawn, but there are places, where homeowners associations rule, that prohibit clover in the lawn because it is a "weed".

  • Blanket
    11 years ago
    last modified: 9 years ago

    In Florida, an amendment was made to the state constitution to prohibit any homeowner association from preventing any homeowner from installing a Florida Friendly yard, which often has no grass at all. It is a model of legislation, and a great way for all of us to bridge our differences and promote broad guidelines for the regular guy. As someone who has worked with legislative staff on a regular basis from an objective stance, neither Nazi organic environmental socialst or gun-totin' condo developer magnate, I'd love to see more coverage of what Florida has done. Other states should find a way to let homeowners do smart things like planting clover for a few years to rebuild their soil.

    Here is a link that might be useful: Florida Friendly legislation

  • Kimmsr
    11 years ago
    last modified: 9 years ago

    If in the process of trying to maintain well established organic growing principles from modification by people that wish to dilute those principles I become a "Nazi organic environmental socialst" then I will be just that.
    Anyone that says using any synthetic material is acceptable to an organic grower is wrong and is not an organic grower. Using any synthetic fertilizer or weed or insect poison in the garden means that garden must then be organically worked for a minimum of 3 years, 5 would be much better, before you can call it organic again.
    Anyone that would come to an organic gardening forum and advocate using synthetic materials should not be listened to for a minimum of 5 years.

  • Blanket
    11 years ago
    last modified: 9 years ago

    I just can't help it.

    Here is a link that might be useful: Ecofascists are people, too (and Merry Christmas!!)

  • dchall_san_antonio
    11 years ago
    last modified: 9 years ago

    blanket, do you see any irony in calling yourself objective and calling us Nazis?

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