soil pH, nitrogen, etc.

atoner – posted 25 July 2003 21:14

As I said in my other post today, I bought a newly built house in North Carolina last August. The soil is dense clay with lots of rocks 4+” below the surface with some dark topsoil I added.

I’ve done a few pH and nutrient tests with a kit from Lowe’s, using soil from different places in the yard at different times. The tests always come back with almost no nitrogen, pH slightly basic, and acceptable levels of potassium and phosphorus.

I only put down a little lime this spring, so the basic pH seems odd given that everyone around here says the soil is usually acidic. Plus, I’ve heard grass generally wants to slightly acidic, so I’m bit concerned.

I’ve fertilized three times already, but the lawn seems to gobble up nitrogen quickly. I use a mulching mower.

Any ideas?

Thanks,Adam

Dchall_San_Antonio – posted 26 July 2003 15:27

I’ll try to bite my tongue on what I think about soil testing in general, but you’ll get the drift of it with this next sentence. Forget about using the Lowes test kit. Those things are notorious for giving flaky results. So I suggest you forget anything you think you learned about your soil from the testing. Instead, just start taking the best care of your soil that you can. If you see poor performance in the turf, then you can think about sending a sample to a real lab. But I would not apply any pH adjusting materials (like lime) again unless and until you have a valid soil test that tells you to.

I’m going to suggest an organic approach. The reason I’m suggesting organic is the combination of compost and organic fertilizer will adjust the pH of the soil for you without you having to do anything else. Start by applying a thin layer of compost. A thin layer is NO MORE THAN 1 cubic yard per 1,000 square feet of turf. This is about 1/3 inch and should completely disappear into the grass once you sweep it down with a push broom. If you put down any more than this, you increase the risk of smothering the grass. One of my neighbors smothered his bermuda with compost and it looked like crappe for the next 18 months (it’s since been RoundUpped and replaced with St Aug, the original turf). Accidental smothering is one of the three main reasons why more people don’t use organic methods and materials.

Next, apply an organic fertilizer at a rate of 10 pounds per 1,000 square feet. (Compost is NOT fertilizer, it is a source of microbes and a light mulch.) You can get the commercial branded bags of organic fertilizer for about $1 per pound, or you can go the feed store and get the basic raw materials for about $0.10 per pound. I like ordinary corn meal as my prime fertilizer with alfalfa pellets as a back-up. I bought a 50 pound bag of each this week for $6.50 each. As fertilizers, they cover 5,000 square feet, each. These fertilizers work because the microbes in the soil decompose the protein in the feed and convert that protein into nitrogen for the plants. Mother Nature has been perfecting this process for hundreds of millions of years, so that fact that we recently discovered how it works is remarkable. Normal natural sources of protein are animal urine, dead animals and plants, animal winter coat hair shed every spring, and feathers lost from birds.

As for keeping your bermuda out of the neighbor’s lawn, you might want to go halfseys with him on building a concrete curb between the properties. At the very least, you should separate the two with a ground cover that might overlap on both sides. Otherwise he WILL have bermuda. I have Asiatic jasmine between my neighbor and myself. I have a curb on one side and steel landscaping edging on the other – both are easy to edge against with a string trimmer.

For your bermuda, you should be mowing it at 1/2 (preferred) to 1 inch tall. These should be the lowest settings on your mower. If that seems like scalping it, it will adjust quickly. Bermuda will grow tall if left alone, but it is kind of a nasty turf like that. If you mow it low, it spreads out flat and becomes very soft.

Then water deeply and infrequently to soften your soil and get those roots down deeper. As a matter of fact, this is my first and best suggestion. Deep watering solves most problems. Together with proper mowing, your weed problems are completely minimized.

So in order of importance, deep watering followed by short mowing and organic fertilizer are my three suggestions.

Gratis: If dandelions are one of your weeds, there’s a tool called a Weed Hound at Target for $20. It plucks taprooted plants out as fast as you can step on them. Very slick!

atoner – posted 26 July 2003 21:27

Thanks for the suggestions. I am going to look into getting a real soil test done just to satifsy my curiosity. The pH test is especially difficult with clay soil and those kits because the orange color of the soil makes it difficult to see the indicator.

I’ve started a compost pile that’s already producing a good stinky batch. How do I spread it (or something I buy) thin on the ground?

I definitely agree that I need to get some organic matter and organisms in the ground. There are some areas of the yard that appear very active when I dig in, e.g. they have a smell of bacteria doing their work. However, the bad section in the back doesn’t have that.

Dchall_San_Antonio – posted 27 July 2003 16:17

Compost should not stink. That’s a second reason why many people choose not to do organic gardening – “It smells up the neighborhood!” A good compost pile will have enough “browns” to cover up the smell. Compost should be an organic smell filter. Whenever I find a dead rat, possum, or squirrel in the yard, I bury the body in the compost pile. Even my dog doensn’t seem to know the beast is in the pile. In a hot pile, an animal of any size will completely disappear in 4 days – along with any smell you might have thought you might have. All you have to have is enough browns. Browns are formerly living things that don’t have much in the way of protein in them. That would include straw, tree leaves, newspaper, phone books, cardboard, sawdust, and chipped tree wood. These are things which must be decomposed by a fungus. The fungi come in and do clean-up for the smelly bacteria. Then after the fungi and bacteria are finished, then the actinomycetes come in and do the last bit of odor enhancement so that “finished” compost smells like the floor of a forest.

I collect tree leaves when my neighbors are throwing them out. I’m using fresh horse manure in my pile and you’d never know it. I open a crater in the top of the pile, dump the manure in, and cover it back up with some of the leaves I collected. When I run out of leaves, I don’t stop collecting manure because by then I have plenty of real compost to use on top of the fresh stuff. Composting is really off the topic of this website, so I’ll not turn this into a full tutorial.

The way you spread compost is you have it delivered (you can never make enough for yourself without serious importing of raw materials), fill wheelbarrows and make smaller piles around the yard, and sling it out with a shovel from the piles. The last thing you do is broom it down off the leaves with a push broom. The roll-out compost spreaders always get clogged up with twigs and stuff that haven’t finished composting.

Your bad areas might need a thin layer of compost but for sure need organic fertilizer. That should tune them up.

Another problem with soil tests is that they require distilled water. Most people short cut that step and use tap water with unknown pH and buffers in it. That throws off the test kit so much that all you get is the pH of the water.

Gratis: A third reason people choose not to go organic is that it costs so much. This can be a very valid concern until you learn how to cut the corners. Compost at $0.03/square foot is by far the most expensive thing you can apply. Fortunately most people never need compost despite the marketing pressures in the organic world. Commercial branded organic fertilizer at $0.006/square foot is the next most expensive item. This compares with Scotts at $0.0018/square foot. However, if you look at the ingredients on the sack of organic fertilizers, you’ll find the same things there as are in animal feeds including the really cheap dry dog foods. Animal feeds usually have other things in them, like salt, that you don’t need; but if you look for the main label ingredients at the feed store, you can find them for more like $0.001/square foot. So now we’re talking about comparable prices for organic fertilizer as compared to Scotts.