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winstonsblues

soil amendment vs. fertilizer

winstonsblues
10 years ago

From the soil test I did, I know I need to boost nitrogen from low to high and phosphorus from medium to high, and I also need to lighten the soil up. From some extension website, it seems I need 6.4 lbs. of an organic amendment such as humus/manure that is labeled .05-.05-.05.... but 6.4 lbs. isn't really enough to loosen the soil up is it? Will it hurt to increase the lbs. substantially? Also, if I go with the organic stuff, will the slowness of it mean I need to also use a synthetic fertilizer since the nitrogen level is starting at low?

Comments (11)

  • slowpoke_gardener
    10 years ago
    last modified: 9 years ago

    Winston, how large of a spot are you talking about. I feel that it is hard to use too much organic matter. I have used many kinds of fertilizers and they all did what they were supposed to do, I favor the organic kind, but will use Miracle Gro of 27-0-0 for a quick fix. The only problem I have had by using too much organic matter is my plants blowing down when we get rain and a little wind because of the ground being too loose.

  • winstonsblues
    Original Author
    10 years ago
    last modified: 9 years ago

    very small, 8x5 maybe?

  • chickencoupe
    10 years ago
    last modified: 9 years ago

    Winston, Larry is correct.

    By "slow" for nitrogen via organic matter I'm assuming you've experienced using a source of organic material that didn't have enough nitrogen. If it's organic, it's immediately available to the plant roots. I've experienced my organic nitrogen source being old and the nitrogen depleted. I know because the plants didn't green up quick enough though they enjoyed the bacterial infusion from the organic material. In these cases I depend on my trusty rabbit food - alfalfa pellets or alfalfa hay. I buy the compressed bales of alfalfa hay from Atwoods and when ripping off a section of hay all this glorious alfalfa dust appears. I sweep it up and use it as a nitrogen source. Other organic sources are usually within arms reach, too.

    Go weed the garden or mow the yard. Stuff the weeds and grass clippings in a bucket of rainwater for 12 hours or more (add a touch of molasses, while you're at it). Strain. Drench soil with "tea". There. Nitrogen added. it's the same as using a cover crop but a bit quicker.

    Or you can keep a supply of alfalfa rabbit pellets on hand. Crush them up in a coffee grinder. Add it to liquid, though before putting on plants. It can go thermal and burn. Great for fueling up a cold compost, too. This is just one short-cut. You'll find the one that you prefer. Kitchen scraps? Brew them up into a tea if you toss out lots of beans or greens.

    You can use these short cuts while waiting on the beneficial progress of using green manures as cover crops. It takes time for a cover crop or a legume to break down into the soil and convert nitrogen ready for plant roots. Dawn writes of this a lot. In the meantime, you already have vast sources of quickly decaying nitrogen sources to utilize.

    I hope this is what you were referring. I love organic gardening.

  • wbonesteel
    10 years ago
    last modified: 9 years ago

    6.4 lbs of compost and composted manure per square foot? Sounds about right, if you're dealing with un-amended clay. There's no such thing as too much compost, imo. Mix in 6-7 lbs, now and you'll be adding more every year, if not a couple times per year. Keeping in mind that I have four or five compost heaps to play with

    I'd mix in a couple of inches of builder's sand or perlite after you mix in the compost - but that's just my opinion.

    With that much compost, the pH will drop a bit, but that's ok, if you're at 7.0 now.

    Another way to raise the nitrogen is with blood meal. Same wrt bone meal and phosphorus. A little goes a long way, in either case. Read the directions before you use them. If you use composted manure, you won't need too much blood meal, if any, in your case.

  • winstonsblues
    Original Author
    10 years ago
    last modified: 9 years ago

    Thanks to you all so much for the info :) That puts my mind to rest.

  • Okiedawn OK Zone 7
    10 years ago
    last modified: 9 years ago

    Did you do a soil test by sending in a soil sample to a soil lab or did you use those little test kits you buy at the store? If you used a soil lab, they'd tell you exactly how much to add, and I'd probably do what they said. If you used a little soil test kit purchased from a store, those things are notoriously inaccurate and I wouldn't do anything to my soil based on what one of those showed.

    Testing for nitrogen can be very tricky. Nitrogen is highly mobile in soil and sometimes doesn't show up well in tests, particularly when the soil is tested when temperatures are cold. Some labs no longer test for nitrogen for this reason, or they are careful to note that nitrogen can test differently in the same soil at different times of the year.

    Much depends on whether you're starting with soil that leans heavily towards being clay or sand or if you're starting out with a nice sandy loam that already has good tilth. You have to tailor what you are adding to your soil to whatever type of soil you start out with.

    It probably is an oversimplification to say this, but the answer to most soil issues is simply to add more organic matter to the soil. I don't worry about how much nitrogen, phosphorus or potassium are in my soil. I just add enough organic matter to give the soil good tilth and, in general, the organic matter contains enough N-P-K to enable plants to grow well in that soil, and it also contains all the micro-nutrients (aka trace elements) like magnesium, molybdenum, copper, boron, manganese, iron, zinc, and sulfur that plants need. Too often, gardeners focus on the N-P-K in their soil and never give the micro-nutrients a single thought. If you just focus on adding organic matter to your soil, it will tend to have everything the plants need to grow well and the more you improve the soil by adding organic matter regularly, the more fertile it will become.

    Because I started with dense red clay in most parts of the garden, I added 6 to 8" of organic matter (not all at once--I would rototill a couple of inches into the existing soil, then pile more on top of the ground and rototill it in, etc., until I had added 6-8") to break up the soil. All I was aiming for at that point was to break up dense red clay that was perfect for making red clay pots but not so perfect for growing ornamental and edible plants. The first few years I tried to add a variety of different materials to make up for what I perceived as deficiencies in my soil---adding sulfur to lower the pH, blood meal to increase nitrogen, soft rock phosphate to increase the amount of readily available phosphorus, etc. Once I felt like I had the soil where I wanted it, all I have done since then, for the most part, is add organic matter and let it do its job.

    I don't bother with soil tests because my plants will tell me if they have a problem, and you will learn pretty quickly what different symptoms indicate. For example, if nitrogen is too low, you will see decreased plant vigor, sluggish growth and yellowing of the oldest leaves on the plant. If phosphate is too low, you'll see poor flower and fruit production. If your soil has inadequate levels of calcium, your plants will be very susceptible to disease and may have tip die-back at the top of the plant. If your soil is low in potassium, you may see winter kill of plants that ought to be able to survive the winter or increased susceptibility to diseases. If your soil is low in zinc, you'll often see huge amounts of weeds. It can take time to learn what the different symptoms you observe are telling you, but once you learn how to "read" your plants, you will know if you have healthy, nutritious, well-balanced soil....or not, and it isn't as hard as you'd think to read the plants and decipher what they're telling you.

    The best way for me to explain what I try to do to my soil would be to say that I am trying to recreate the forest floor inside my garden. When we walk through our woodland, do we see perfectly brown or brownish-black topsoil? No, of course not. We see all kinds of organic matter lying right there on the ground decomposing---leaves, twigs, sticks, bark that has sloughed off trees, deadfall limbs or even entire trees that are rotting and decomposing right there on the forest floor. You may see the decomposing remains of insects, birds, reptiles or small animals. It all decomposes where it fell. No one goes into the woods and tries to plow, rototill or dig all that organic matter down into the soil. Over time, various creatures that dig into the soil (anything from microorganisms that are invisible to the human eye to ground-burrowing insects, earthworms, armadillos, skunks, possums, etc.) will carry the nutrients from the soil surface deeper into the soil, and so will rainfall. The forest enriches its own soil naturally and is self-sustaining, so I just work as hard as I can to add amendments to the soil surface in my garden and let them decompose and be worked into the soil over time. This doesn't mean that I never rototill my soil---I would, in fact, like to stop rototilling and do no-till-gardening, but I am an impatient gardener and like to get the organic matter down deeper in the soil more quickly that it would get there without rototilling. In areas where we have some sandy-silty soil, I don't feel the need to rototill it as much as I do the dense clay either.

    Just in the last couple of weeks, I've been going back and adding a couple of inches of compost on top of each raised bed. There is no need for me to rototill it into those beds and, in the case of something like the bed where asparagus and strawberries grow, it would be impossible to till it into the soil without destroying the plant roots. The compost will feed the soil and the soil will feed the plants and you won't see me out there in the garden with a Miracle-Grow sprayer in my hand unless I see a fertility issue that needs a quick fix, which in my garden is extremely rare.

    Remember, too, that just because plants need a certain amount of various nutrients, that does not mean that more of any nutrient is better. Excessive amounts of various nutrients can have an adverse impact on plant growth, often because too much of one nutrient can prevent a plant from taking up and using a different nutrient. All too often, people overfeed their plants N-P-K because it is too easy to buy fertilizers with too much of those elements in them, and then they think they've taken care of their plants' nutritional needs so they don't add anything to the soil (like compost, for example) that adds the micronutrients all plants must have in order to thrive. When was the last time a gardening friend told you "I am going to add some boron to my soil?" (grin) That's an extreme example and my point is that if you just add organic matter to your soil, you likely won't see a boron or copper deficiency. Copper, by the way, becomes unavailable to plants when there is excess nitrogen in the soil so it is common in some places to see copper deficiency symptoms in plants, but the issue more often is that the soil is overly rich in nitrogen and not that the soil lacks copper.

    Many gardeners focus so heavily on adding nitrogen to their soil, particularly via synthetic fertilizers, that they end up with big, beautiful, leafy plants with foliage so dark green that the leaves almost look blue-green, that they send up doing more harm than good with all that nitrogen. I went to a house once that had three gigantic tomato plants, spaced about 10-12 feet apart from one another. They were huge and their color was so dark that from a distance I thought they were three cedar trees. Up close they looked incredibly lush, thick and gorgeous. It was summer and guess what was missing? There wasn't a single fruit or flower on those plants. Call me crazy, but I thought most people grow tomato plants in order to have tomatoes! Obviously the person who had planted and tended those plants had overfed them nitrogen, and they did it, I am sure, with the best of intentions. They just hadn't learned, yet, that there is such a thing as too much nitrogen.

    My advice is to add all the organic matter you want to your soil, and it is best if it comes from a variety of sources. Compost (and particularly home-made compost) is my favorite and because we are in a rural area with tons of space I keep multiple large compost piles working all the time, but I add tons of chopped and shredded leaves to the top of each bed as mulch every year, and as they decompose, they too feed the soil. Sometimes I add purchased cow manure to the beds, or mushroom compost. In the early years, I added tons of pine bark and hardwood mulch directly to the soil. I didn't care if the bark and hardwood tied up nitrogen as they decomposed because I knew there were other ways I could add nitrogen to the soil to compensate for that occurrence. What I cared about at that point was breaking up the dense, red, highly compacted clay. Remember that plant roots do not grow, technically, in soil. They actually grow in the air space in between soil pores....so to have great plant growth, you need to break up soil that is tight or highly compacted so that the roots can move about freely. I've had friends lament and moan and groan and talk about their horrible clay soil, only to discover they don't have clay at all---they just have sandy loam or a sandy-silty blend that is so compacted that it resembled clay until they broke it up and added organic matter to prevent it from being compacted back into hard layers of soil again.

    Gardening is an adventure. People have done it for thousands of years, largely without all the synthetic fertilizers available the last 60 or 70 years. It is possible to garden without ever buying an actual fertilizer product, although I think most people nowadays amend the soil to improve it and then also use limited amounts of the fertilizer of their choice, whether it is organic or synthetic in origin.

    Focus on giving the soil what it needs, which mostly is lots of organic matter, and the soil will feed the plants. Actually, I should say the plants will take what they need from the soil. They cannot absorb nutrients that aren't there, but once you add organic matter to the soil, most if not all of what they need will be there in the soil just waiting for the plants to use it.

    In a hot climate like ours, organic matter in the soil decomposes quickly and gets used up quickly, so you must continually add new organic matter to the soil on a regular basis. The easiest way is by mulching and letting the much decompose in place. As it decomposes, it feeds the soil beneath it. I also mulch all my pathways heavily and then, in late winter, I scoop up all the decomposed mulch from the pathways and dump it onto the adjacent growing beds. I then put down a new layer of mulch---usually some combination of grass clippings, old spoiled hay, and leaves that have been chopped up by the lawnmower and caught in the mower's grasscatcher bag. I add mulch throughout the growing season, both to the surfaces of the growing beds and to the pathways. The mulch suppresses weeds, and it helps keep the soil beneath it cool and moist, but the main reason I regularly add more mulch is because it is like doing composting in place. To me, it is so much easier to use my pathways as a sheet composting site than to have a compost pile 100' away and to have to carry one wheelbarrow load after another of compost into the garden. It all goes back to the forest floor analogy---Mother Nature doesn't go through the forest and clean up all the 'garbage' that has fallen to the forest floor, pile it up someplace, let it decompose, and then carry the compost back to the forest---it all happens in place. I try to garden in such a way that most of my soil improvement (after the initial effort to break the ground and add 6-8" of organic matter rototilled into the soil) takes place from the top down as organic matter used as mulch decomposes in place.

    Don't be afraid that you'll be adding too much organic matter to your soil. Unless you are in the rainiest part of OK, which is eastern OK, where rainfall is often 40-60" or more a year, you likely cannot add enough organic matter to create a problem. In some of the rainiest parts of OK, I do think a person could add so much organic matter that their soil holds too much moisture for too long, but for most of us, that's not going to be an issue. Most of us deal with the opposite issue of not having enough moisture for much of the growing season.

    Sometimes we humans overthink things and try too hard. The truth is that enriching soil is pretty simple---just add compost. Making compost is also something that some people put huge amounts of effort into---adding this to the pile, adding that---turning the pile, watering it, etc. I am a lazy composter. I pile stuff up. It rots. I use it. Could it be any simpler? No, but it can be a lot more complicated. I feel like my life is busy enough and complicated enough without me making my composting and soil amending complicated. I try to keep it simple. For me, if I try to make gardening too technical and too complicated, it sucks all the fun out of gardening. Above all else, in order for it to be rewarding, gardening has to be fun. I try to focus more on having fun and less on doing things that are technically and perfectly correct.

    Dawn

  • luvncannin
    10 years ago
    last modified: 9 years ago

    Wonderful posts and a lot of great info here. Thanks y'all.
    kim

  • slowpoke_gardener
    10 years ago
    last modified: 9 years ago

    Winston and Kim, I keep a hard copy file on the things I like to grow. The file came from the Arkansas Agriculture Cooperative Extension Service. I expect all states have the same type of info. My " Understanding the Numbers on Your Soil Test" is #FSA 2118. I expect my hard copy is older than the one online because it seems to be in more detail, but the one on line is very helpful. The information you find on the Oklahoma site may be better, but I don't know the numbers for those reports.

    Larry

    P.S. I pick up these reports free at the extension offices, I expect you can also.

  • luvncannin
    10 years ago
    last modified: 9 years ago

    Larry I wish my ag offices had info. They look at me funny when I ask. The focus here is cotton and wheat. They don't really even consider gardening.
    I have learned how to Clip so that helps a lot to be able to keep an informative post handy.
    kim

  • winstonsblues
    Original Author
    10 years ago
    last modified: 9 years ago

    Wow! Thank you so much for explaining so much of your process, Dawn :) I guess I have had such awful attempts before, I just want to do everything perfect this time lol. We are in SW OK just 30 minutes from TX, so you would think that the soil would be clay... and it is everywhere... we had it terrible at a different urban area here... but the yard here seems to have more going on. If it is clay, it definitely isn't the red stuff. I did notice the dirt being more compacted than I had expected after it rained and dried last time, but I think it is just that lack of organic matter, as you said. I also didn't understand mulching well enough the other times I tried gardening. So, dig in the organic stuff, mulch with organic stuff. Alright, simple enough :) Thanks again :)

  • Okiedawn OK Zone 7
    10 years ago
    last modified: 9 years ago

    Kim, I think that if you Google the subject you're interested in along with the words Texas Agri-Life Extension, you'll find the types of documents that we used to be able to pick up at Ag Service Extension offices in Texas back in the good old days. Then you can save them to a file online where they are easy to find again, or print them out. OSU's fact sheets all have been online since at least the late 1990s or early 2000s.

    Winstonblues, You're welcome. You're going to have a garden in southwestern OK? Wow. You are brave. Look at Lauren's thread entitled "help" and you'll see I linked the Fine Gardening article about using the jar soil test to determine how much of your soil is clay, sand, silt, etc. That will give you an idea really fast about how much clay remains in your soil. Maybe you have a sandy loam or a clayey loam. Our soil on our property changes every few feet, so we have areas with dense clay, sandy clay, sand, a sandy-silty mix, etc. There's one area that seems to be largely a really fine silt and it is awful. It won't hold enough water for anything to grow, and wet silt is like quicksand.

    As the crow flies, we are only about 9-10 miles north of the TX/OK state line at I-35. By roadway, I guess we are probably 15-20 minutes from Texas on a good day. We are in the part of Love County that sticks down into Texas sort of like a finger, so we actually have Texas to our east, south and west. I watch the weather for Cooke and Montague Counties in TX as much as I watch our own weather in south-central OK because their weather is much like ours, and almost all our worst severe weather moves into our area from those TX counties to our south and southwest.

    Organic matter added to soil and used as mulch can fix almost anything wrong with the soil, but you may have to resort to cloud seeding to get enough rain to keep your garden happy. : )

    Dawn

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