Sandy Soil

[Gardeneer]

Recently I moved to NC, its most southern tip in Columbus county, very close to SC.
According to one soil survey the native soil is 93% sand. But what is SAND ? Broken pieces of some rocks. So is the CLAY !! But apparently it takes longer time for the sand to become fine power but it happens or can happen !
So they describe some sandy soils "Sandy Loam".
In my case it is quite sandy. I did a quick test. It turned out about 20% humus and the res SAND and LOAM.
What is the remedy ? I have made about 500 sq-ft garden . Cannot afford to buy bagged stuff, there is no place nearby to sell bulk compost.
WHAT I AM DOING :
1) raked /collected as much fall leaves I could, about 10 loads of tarp.
2) raked /collected as much pine needle I could, about the same as leaves.
3) there was a big pile of wood ash accumulated over the years by the previous owners, about 16 wheelbarrow loads of ( 5 cu-ft each = 3 cu-yrd), mixed with some humus.
After turning and removing Bermuda grass roots, I layered leaves, pine needles and spread the ash/humus on top and let it over winter. Come spring, I will till the whole thing. Hopefully by the the leaves and the pine straw are broken down.
In the meantime I am looking to find stuff like cotton seed meal, alfalfa ... compost.
I will have to optimize my resource and will further amend each planting hole with fancy and more costly material like peat moss.

It is not over and I am not done yet. That is why I am here seeking advice

[AlittleSalt]

Just answering a small part of what you wrote above - Sand takes a lot of weathering to turn in to silt, and silt eventually weathers into clay. This explains it to a point https://en.wikipedia.org/wiki/Soil_texture

Sand comes from weatherization of the rocks, minerals, and elements in any given area. But in the case of sand and silt - it can be brought in from a long way away in the form of sand/dust storms. We have sand storms blown in from west Texas. Whatever that sand and silt is composed of may not be what is natural for this part of Texas. One way or another, it becomes part of our soil. Silt is blown in - in sand/dust storms easier because it is smaller in diameter and lighter in weight than sand.

I know that really didn't answer your question, "But what is SAND ?" scientifically, but to know exactly what your sand is made up of would take a diagnostic test to determine what your soil is made of.

As a means of comparison, the soil in my Texas garden is mostly a silty loam. If you dig down a couple feet, you'll find different colors of clay soil. It is actually kind of fun seeing the different colors of clay here when digging deep enough. Red clay is what you find most here, but you can find brown, yellow, white, and blue clay. I'm guessing the red clay comes from iron rock. Iron rock is found here everywhere. The brown clay probably comes from the sandstone that we have so much of. As far as white, yellow, and blue clay - I'm saving that to learn about at a later date.

As far as dried leaves go, they actually decompose faster after mowing/mulching them and turning them into your soil. I don't have scientific findings - I just know it happens out of experience.

[Cole_Robbie]

Manure from the nearest animals tends to be the most economical soil improvement, often it is horse manure. If you use manure, test it first for herbicide contamination by sprouting a bean in a cup of it.

Sand is the opposite of clay in regard to water retention. It's a good pairing for most manure composts because they can hold too much water. Clay is better about holding nutrients long-term, especially phosphorous, which is more relevant if you are applying pelleted fertilizer. It washes away faster in sandy soil.

[Gardeneer]

Thanks guys.
There are no animals down here, nearby. The area is in a flood plain. The crops grown are strawberry, soybean, sweet potato, corn and cotton.

Yes Robert, it seems that some of the top layer of sand becoming silt ( dark brown ). But far from becoming clay. When I dig a foot or more there is yellow sand.
I figure if they can grow strawberry, soybean, sweet potato, corn and cotton , I can grow tomatoes, peppers, okra and few other thing.
Look at the picture below. Amazingly the grass is doing well.
one
nc-gar 2.jpg
two
nc-gar 4.jpg

I have done a non-scientific soil profile check on the garden soil. I will take a picture and post it later/

[Worth1]

That is some really nice loose rich well drained sandy loam soil, it isn't even close to sandy soil in the sense I think of sandy soil.
You could grow anything in that soil with little effort.

Worth

[Gardeneer]

Here is a picture of my soil structure test.
Took some from the garden add water to it,shook it quite a bit and let it sit.
After 2 days I made few small holes at the bottom and let it drain over night.
The I cut a window and the take a pie like slice out of it.
Now you can see the profile.
soil-prof.jpg
there is a layer of humus on the top. The rest of it is sand Or call it sandy loam.

[Worth1]

Okay that looks more sandy than the other pictures showed.
But still not as bad as the fine blow sand we have here in places.
Worth

[PureHarvest]

First thought: you can not physically remove bermuda grass from digging and tilling. You most likely just root pruned it and it will branch from every point you broke it off and it will still continue its spread to take over the world. There are so many stolons and rhizomes that are still in the soil that will take off next year. It is unreal.
I would spray an area 2x the size I want to grow in if it was bermuda. Probably too late now as it is dormant most likely. Spring dormancy break and late summer before entering dormancy is the time to spray.

Your soil. You can not not change the texture of your soil. You can change the structure and % organic matter. By all means add organic matter and do cover cropping. Do not till it in (mixes up the structure). Keep adding layers to the surface, and move the material aside as you plant, then scoot it back.
Leaves or grass or hay layered over the garden will smother weeds and maintain the top layer (A horizon) which is where your organic matter is located in which makes the topsoil or plow layer. It will also help the sandy soil retain moisture.
If you do a cover crop in fall, come spring, do not till it in. Mow it down 2-3 weeks before planting and leave the clippings on to keep weeds from coming up.
You already have topsoil, mixing organic materials into the soil is a waste of your energy. Layer it on top. Look at a natural prairie or forest. Things are never mixed. Layers are added on top and the soil is always covered. Roots grow down and die off or slough off layers. Crowns die, blades die and layer on top. Worms find this area the most desirable. Things are not all mixed up and the soil rhizosphere is able to become complex when it is not tilled and the organic matter then oxidized.
Then you just need to come along and supply some ingredients to supply the needed nutrients for the crop. You can do the organic route or CORRECTLY supply the PRECISE amounts of soluble ferts at the right time in the right forms and not "kill" your soil or the world. That's your call.

Organic route as far as N needs: Alfalfa pellets at 5% Nitrogen:
Tomatoes in a sandy soil will need 120 lbs per acre of nitrogen per year added. You have 500 sqft. That is .01 acre. .01 x 120lbs = 1.2 lbs of N for your garden. 1.2/.05 (5% N in alfalfa) =24 lbs of alfalfa pellets for all your N needs for your 500 sqft garden. It will not be available right off the bat, so needs to be added well ahead of planting, or soluble fert needed at plant out. Of course that does not address the K that you will need nor other nutrients. My loamy sand also needs 150 lbs/ac of K added every year, and I keep an eye on Cal and Mag along with micros. Just had a test done last month. Last one was done 2014. Still needs K. The pH and Cal, P, Copper, Boron, and Mag are unchanged in 2 years.
Alfalfa pellets will not "build" your soil, just add nutrients. Plant roots via cover crops, not tilling, and leaving a cover of plant material on the surface (in that order) are the top things you can do to improve your soil health. People underestimate the value of living and dying roots year round from fall and summer cover crops and your main crops. Much more contribution there than what is above ground, especially if you use a mixture such as Rye/Radish/Clover. Use a dwarf clover or go with an annual plant in your walkways in summer. Smother the walkways in the fall with leaves/clippings and plant into the walkways in the spring. No spraying needed. Tilling anywhere along the way defeats a lot of these efforts.
HEAR ME tillers, not saying your method doesn't work or you're a bad gardener. This is what I would do in my loamy sand (but also did with my clay back in the day and never had to use a tiller). Let the biology do the job for you.

[Gardeneer]

Originally Posted by PureHarvest

First thought: you can not physically remove bermuda grass from digging an tilling. You most likely just root pruned it and it will branch from every point you broke it off and it will still continue its spread to take over the world. There are so many stolons and rhizomes that are still in the soil that will take off next year. It is unreal.
I would spray an area 2x the size I want to grow in if it was bermuda. Probably too late now as it is dormant most likely. Spring dormancy break and late summer before entering dormancy is the time to spray.

Your soil. You can not not change the texture of your soil. You can change the structure and % organic matter. By all means add organic matter and do cover cropping. Do not till it in (mixes up the structure). Keep adding layers to the surface, and move the material aside as you plant, then scoot it back.
Leaves or grass or hay layered over the garden will smother weeds and maintain the top layer (A horizon) which is where you organic matter is located in which makes the topsoil or plow layer. It will also help the sandy soil retain moisture.
If you do a cover crop in fall, come spring, do not till it in. Mow it down 2-3 weeks before planting and leave the clippings on to keep weeds from coming up.
You already have topsoil, mixing organic materials into the soil is a waste of your energy. Layer it on top. Look at a natural prairie or forest. Things are never mixed. Layers are added on top and the soil is always covered. Roots grow down and die off or slough off layers. Crowns die, blades die and later on top. Worms find this area the most desirable. Things are not all mixed up and the soil rhizosphere is able to become complex when it is not tilled and the organic matter then oxidized.

Alfalfa pellets at 5% Nitrogen:
Tomatoes in a sandy soil will need 120 lbs per acre of nitrogen per year added. You have 500 sqft. That is .01 acre. .01 x 120 = 1.2 lbs of N for your garden. 1.2/.05 (5% N in alfalfa) =24 lbs of alfalfa pellets for al you N needs for your 500 sqft garden. It will not be available right off the bat, so needs to be added well ahead of planting, or soluble fert needed at plant out.
Alfalfa pellets will not "build" your soil in my opinion, just add nutrients. Plant roots via cover crops, not tilling, and leaving a cover of plant material on the surface (in that order) are the top things you can do to improve your soil health.

Thanks Pure Harvest.
On the Bermuda grass, I found the roots shallow on the surface and I removed as much as I could find. In spring preparation I will remove any that has escaped.
No, they are not dormant. They are as green as can be (elsewhere )
Yeah, I cannot change my soil. All I am doing is increasing the percentage of organic/humus matter, just to improve moisture retention.
I am not going to apply alfalfa and cotton seed meal. Those are just fertilizer. I will just use synthetic fertilizers like 10-10-10 ,, 13-13-13 and some 24-0-0- My aim is to add organic mater. I keep collecting more top soil in the wooded areas produced manyy many years of fallen leaves and decayed vegetation (Humus ).
duting plant out time I will further amend planting holes to get a good bang for my resources (peat moss, FloorDry, Compost).
I will fix it. Several years ago I created close to 1000 sq-ft garden in GA re clay that could get as hard as rock. It is hard work.

[Sydney Grower]

Hi Gardeneer,

I live on old sandhills near the coast and I have come to see sandy soil as a real advantage as a base to start working from. I have raised beds and I use Chickens to build the soil and rotate them around 9 small gardens to improve the soil after every crop. After 5 years of this system my soil is amazingly good. The only things I add in are home made worm castings, a small amount of lime and a bit of rock dust (hardly any extra expense). I mulch each bed with 2 inches of sugar cane mulch which the chickens dig into the soil at the end of the season.

Can you get some animals to help with your soil and to give you added benefits like eggs/meat?

[Gardeneer]

Thanks Sydney Grower
I think I now know that the native soil, though sandy, is not all that bad. Next property on both side were soybean fields. There are lots of corn fields, cotton, sweet potato ,... Hundreds of acres. They just plant in the native soil, as it is not possible to amend in that commercial scale.

So considering, with my amendments , my garden is going to be just fine.
My garden beds will sleep over the winter months ( Nov, Dec, Jan, Feb ). Come March I'll wake'm up. and till, add more amendments ( if needed ). To help keep the soil moist, I have lots of pine needles to mulch with. The area gets good amount of rain in the summer, but even without the water hose is right there. I have learned not solely rely on rain.

[brownrexx]

I don't do this myself but many organic gardeners lay corrugated cardboard on top of the soil and then pile their mulch on top. They say that this really conserves moisture, helps build the soil and that the earthworms love eating the cardboard. You can Google lasagna gardening to read about layering methods.

I sort of tried this one year and didn't like it but I'm told that my mistake was in not wetting the cardboard really well before adding the mulch on top. Now I just mulch heavily with straw and am very happy with this method. I have clay soil here.

[Zone9b]

I read this thread with interest. I garden in Central Florida where the soil is said to be 70% sand and 30% silt. I used to garden directly in the native soil but without much success. Then I switched to Raised Beds filled with 100% compost from yard waste. This improved my results greatly. However, I recently have been thinking that it may be possible to amend the native soil to equal the performance of my RBs. The real question is in growing of vegetables where nematodes are not an issue; such as Brassicas, and varieties of plants which have been bred to be resistant of nematodes, is it reasonable possible to bring FL native soil to a point where it would be a easier and more cost effective method and produce results as good as or better than using raised beds filled with a non soil media, such as compost?
Of course one could create a test case and give it a go but others' advice could be of huge value before venturing out with one's own experiments.
Thanks
Larry

[Cole_Robbie]

Don't the nematodes just crawl up into your raised beds? Maybe they are not as bad in Central Florida as in South Florida.

My parents lived in Gainesville for a while. I once stopped at someone's roadside stand in front of their house in the country and bought a few tomatoes. I was excited about them because they were homegrown, which in Illinois means they would taste good. As it turned out, they were the worst tomatoes I ever tasted, like a mouthful of pink sand. It had to be that sandy Florida soil.

[Zone9b]

Originally Posted by Cole_Robbie

Don't the nematodes just crawl up into your raised beds? Maybe they are not as bad in Central Florida as in South Florida.

My parents lived in Gainesville for a while. I once stopped at someone's roadside stand in front of their house in the country and bought a few tomatoes. I was excited about them because they were homegrown, which in Illinois means they would taste good. As it turned out, they were the worst tomatoes I ever tasted, like a mouthful of pink sand. It had to be that sandy Florida soil.

When I read Gainsville I thought this is going to be interesting but "Mouthful of Pink Sand". That's pretty funny but it don't help much.