Need to Make Sand Into Soil

Hello All,
We are have begun to augment our acreage in north easter Arizona. (Approx 40 acreas). We have really really deep sand. Its like a beach honestly, but much finer sand. Its river bottom, in an area where a river used to be many moons ago. Our acreage is up high in the hills with amazing views. Basically we are beginning to shape the property one acre at a time.  We have pinion pine and lots and lots of juniper.

We have lots of cattle roaming in the area and we collect all of the manure as we can. Our plan so far is to add a very very thick layer of manure into the the sand by discing it in lightly. Then adding a great deal of straw that we put through the hopper part of our chipper. We then want to add lots more of organic matter as well, likely in the form of bulk compost soil bought by the truckload from a nearby place that makes it. To top that we want to bed down more straw and let it all just do its thing with daily watering. We also plan on adding wood chips super finely chipped since its a potential resource right on the property.
Thoughts on this plan? We don't want to add chems, but we need to get soil going instead of this sand that holds no water or nutrients because those things have no organic matter to be stored in.  

We have sooooo much dry downed juniper wood all over the property as well that we will lilely do some hugelbeds as borders for pathways and along terraces.

Please share your thoughts.
---Roo

Hello Amanda!

If you have water, just grow your own soil. Start by using mixed annual cover crops that do well in your hot dry region. Millet and teft come to mind, mixed with any annual  legumes you can also grow with them. Before they set seed roll them to terminate the crop, and drill seed your next planting of cool weather mixed annual crops when applicable. You can grow over 10 tons of carbon rich organic matter per acer, per year, and after a year of crowing your own nitrogen rich organic matter, the soil will hold water allow you to grow a more diverse mix of annual crops to further increase your soils nutrient rich soil biome and organic matter. Yes you can truck in tons and tons of organic matter, but seed is much cheeper since you have water available. Make sure your annual mixes have those companion legumes, so they will fix extra nitrogen for the other annuals around them.

Hope that helps!

Amanda, do add all the organic mater, but also consider making and adding Biochar.  It holds water wonderfully for the long term.  

Your plan sounds like it will work.

With what amendments you have I wouldn't bother to disc anything in. I would want to mix manure well with a carbon source; straw or wood chips to make a balanced mulch.

I would plant by putting down a layer of compost drop seeds on top, then bury with mulch.

Sand is a great medium for stuff to grow in, just add water. Let the weeds grow, their roots can be your organic matter. After 6 mths of light irrigation and all that sun you will have weeds 3 feet high and organic matter 1-3 feet down

in my experience sandy soil does not hold organic matter well it just seems to disapear unless you have trees.  composted manure works best for me  to get trees started  manure is probaly your greatest asset in sandy soil and biochar like greg said

its kind of like in the amazon where if you get rid of the trees the soil quickly is leached

Geoff Lawton told a story (I'm sorry I cannot remember where/when I saw it) about a project he did, where a school had been built on a huge mountain of beach sand.  Geoff's team was to add a permaculture landscape.  In spite of all the world-class soil building they did, including bringing in carbon and heavy planting, it just didn't work.  After a few years, they went back, dug up the trees, and mixed in purchased clay.  After replanting, the site became successful.   So there may be limits on how much sand can be handled with just planting, mulching, and animals.  

The experts on here (not me!) may be more able to address your site with a few more details:  You say the sand is "deep", but do you know how deep?  So deep that tree roots cannot reach it?  Is there ever water in that former river, even underground?  Are there currently any live trees growing there?  Are all the junipers dead?  Why did they die?


PS having your wood chips "super finely chipped" is probably not optimal.  You would prefer a variety of textures that do not mat together to exclude water and air, the way the commercial bagged stuff does.

EDIT: This was taken from a similar thread, but it applies.

Hi Amanda.

I think a lot of good points have been raised. I have some more, hopefully as good.

I would build intensively managed, slightly sunken beds, and use those as your islands of fertility that nurture the soil life. I would look at your property and decide where the wind usually blows from, and go to that edge of your property. If there are any on site, I would consider building a low wall on the bed's windward side out of any rocks you can scrounge, and building your slightly sunken bed in its shelter. It will likely act as an airwell, if there are air spaces sufficient to the task, and that will harvest water for your bed.

I would plant trees in this bed, probably something that fixes nitrogen and sheds its leaves, or that will coppice/pollard, such that you can harvest its biomass without losing the benefits of the tree as shelter. Food trees are an option as well, but obviously, choose based on your conditions.

Whatever trees and shrubberies you choose for this bed will slow the dessicating wind, transpire moisture into the air, leaving less carrying capacity to rip moisture away from the rest of your property. The shelter belt guild should also be designed to spread itself with minimal assistance, such that the sheltering effect keeps growing, making your work easier over time.

As to choice of species, I have read that deeply taprooted trees have been used in desert regreening projects where there is a deep watertable, as once the taproot reaches that water, it will thrive without watering, and depending on the species, will pull water up for the rest of the bed. Up north where I am, Sugar Maples perform hydraulic lift, raising the water table locally for themselves and those plants growing around them. Ideally, this is what your choice of tree would do.

Once the shelter bed is established, it will provide shelter for plantings downwind of it, and so on, and so forth.

Water harvesting is pretty key. I would keep in mind the downpours you can get seasonally, as mentioned by Nathaniel, I think, and think about making water harvesting depressions on-contour, rather than swales less-suitable for large volume rain events.

Honestly, if I was being minimalist about the rest of the project, I would put in the water harvesting features (long, shallow basins on contour) and then hill up rows of straw on the downslope side to trap sediment. In areas of increased rates of water flow, I would actually stake small rectangular bales on contour, especially in river beds that tend to look like rivers in rain events.

I think vetiver would be really awesome in rows on contour. If not that, then pretty much anything else that will survive in your climate, planted on contour (preferably on the downslope sides of your water capturing landforms) will hold the soil and sand in place, and nurture those soil critters that do all the actual soil-building work.

I think it crucial to think about not just water harvesting, but also the trapping of sediment from the wind and rain. The vetiver rows on contour (or whatever you choose that works in your area) would act as perfect sediment traps, but just laying some of that mesquite down on contour downslope of water harvesting features would result in sediment building up on the windward and waterward sides.

I also wonder if anyone in the position of turning lots of sand into soil has used bentonite clay or some other hydrophilic powdered clay as amendment to hold water longer and to break up the homogeny of nothing but sand. This in itself should make it easier for soil life to expand outside of the islands of fertility that your beds will represent. Covering that sand outside of your beds with whatever mulch you can, even just enough to block the sun from baking the sand, will reduce the heat island effect.

And as to that, I like Nathaniel's idea about sweet potatoes and watermelon. Anything termed "living mulch" like giant-leaved curcurbits will shade out the soil, too, and provide biomass after harvest. I would build a hot-season guild focusing on sweet potatoes, okra (they are complimentary in the garden), and watermelon, for starters. I would plug in as many companions to those as will fit without getting in eachothers' ways. I have included the link for the List of companion plants that I go to most often. I figure that groups of plants that support eachother will only make your job easier.

All the best to you in your endeavours. Keep us posted, and good luck!

-CK

Amanda Layton wrote:Hello All,
We are have begun to augment our acreage in north easter Arizona. (Approx 40 acreas). We have really really deep sand. Its like a beach honestly, but much finer sand. Its river bottom, in an area where a river used to be many moons ago. Our acreage is up high in the hills with amazing views. Basically we are beginning to shape the property one acre at a time.  We have pinion pine and lots and lots of juniper.

 This is good, that you have trees growing there already gives some roots to the sandy soil.

We have lots of cattle roaming in the area and we collect all of the manure as we can. Our plan so far is to add a very very thick layer of manure into the the sand by discing it in lightly. Then adding a great deal of straw that we put through the hopper part of our chipper. We then want to add lots more of organic matter as well, likely in the form of bulk compost soil bought by the truckload from a nearby place that makes it. To top that we want to bed down more straw and let it all just do its thing with daily watering. We also plan on adding wood chips super finely chipped since its a potential resource right on the property.
Thoughts on this plan? We don't want to add chems, but we need to get soil going instead of this sand that holds no water or nutrients because those things have no organic matter to be stored in.

No matter how much organic material you add to this sandy land, it will never last more than three years unless you add some clay to hold on to that organic matter you add, this includes biochar.
Clay is the glue of nature when it comes to soil building, a lack of any clay means instant leaching of everything.
Your ideas are good, but even if you planted millions of seeds, the organic material, once rolled, chopped or in any state of death will be washed so deep that you will not be able to take any advantages of that organic materal.  

We have sooooo much dry downed juniper wood all over the property as well that we will lilely do some hugelbeds as borders for pathways and along terraces.

Please share your thoughts.
---Roo

Clay is going to be your Need it first item on the soil building front, without some clay everything you add will go away fast, leading to more inputs of organic matter.
Sure you can try R. Steele's suggestions but they will fail, because there is nothing in that soil profile to grab and hold the organic matter in place. That means what dies goes away.
The dead wood, being juniper has lasted because the only break down is from wind blown sand erosion, fungi don't like deserts so much, that makes it very hard to use the hugel model until you have better fungi conditions.
Once you have some clay in the sand, it will be able to become friable soil through heavy plantings, chop and drop/crimp rolling and amendments will be longer lasting in the soil.
These are the conditions that need to be addressed first then you can take advantage of compost teas and fungi slurries to build more microbiome life and really get to good soil.

Redhawk

If you want to build up the soil in a hurry, check around and see if there are any municipal composting programs nearby.  I can buy finished compost for $15 a yard at a nearby facility.

Something to be aware of that I just found out recently on this board.  They have been selling persistent herbicides for awhile now and they persist even in manure from horses that eat feed grown using the herbicide.  I haven't seen anything indicating this is in cow manure yet, but Purina Horse chow apparently test high in the herbicides and many parks, etc. have lost trees because they used either the horse manure, or compost made with horse manure, or compost made with grass clippings, etc. that were treated with the herbicides.

If you get that crap in your soil it will be years before you can grow many types of plants there.

https://compostingcouncil.org/persistent-herbicide-faq/

https://www.motherearthnews.com/organic-gardening/gardening-techniques/persistent-herbicide-compost-zwfz1209zhun

I love your plan -- add tons and tons of biomass.

But it will not serve as a long-term solution.  That carbon will continue to gas-off, and eventually, you'll be left with sand once you stop adding biomass on a regular basis.  When organic material breaks down (as we see when we compost), it continues to decompose until it reaches a state of stability.  This is what we call humus: the black, jelly like substance that no longer decomposes and gasses off.  Unfortunately, less than 2% of the organic material you put into the soil ultimately becomes humus.  Over time, all that wonderful manure and other organic material will result in hardly any humus.

Can you get a dump truck full of heavy clay soil from somewhere?  Even if you only amended your planting beds, that will go a long way toward holding the fertility you plan on building.

Clay molecules are negatively charged, where as sand (which is generally quartz) is neutral.  That means that positively charged nutrients like N, K, and P will be chemically attracted to the clay and will cling there until plants can uptake the nutrients.  Without some clay in the soil, those nutrients will wash right through the soil profile.

I agree with Bryant Redhawk, clay will be important for holding nutrients in that sand. Clay is scientifically proven to hold unbelievable amounts of nutrients due to its molecular make up, and the way those nutrient compounds and molecules interact with the clay on a molecular and or subatomic level, or at least that was my understanding. The clay will make growing your soil much faster, without the constant hourglass effect on your nutrients. All layers of sand eventually have a bottom, but it will definitely be best to not waist time filling up future oil reservoirs with all your precious carbon.

Fukuoka talked about growing grains (rice and barley I think) in alternation with soil building crops. It was important that the rice stalks were left whole, so they didn't break down so fast. Then he would interplant the next crop of things going down, right on top of the freshly cut stocks laid on the ground. This way the layers of newly added ground cover were continuous. I have not done anything like this, but those are the notes I have.

I'll offer an anecdote that may or not be relevant. We started grazing cows on coastal beach sand in winter about 40 years ago. When we started there was only seasonal coastal pioneer vegetation there. Nothing much grew there over the summer at all as the higher evapotranspiration rates and free drainage meant no summer soil moisture. Over the years of eating the vegetation and depositing manure the sand slowly developed a black top profile, and the sand started holding moisture longer into the summer, and pasture composition improved to include C4 grasses, and eventually good C3 grasses and even perennial legumes  We never actively improved the soil or added any fertiliser or seed as it had only been an extremely informal grazing arrangement with the owners. We don't use the land anymore, but it has increased in quality to the point the owners now run horses on it. So my experience has been different to that expressed by some of the people here who have found that sand will not hold organic matter. My experience is limited to my climate of course, a mild temperate climate with 40" rainfall and temperatures that never go outside the range 40-85F, improving hot desert sand is likely a totally different ballgame.

Yeah, the evaporation impact is huge. The person who started this thread is in Arizona--and I am in South Texas, same kind of weather stress. (I am also in ten acres of alluvial sand, much like the author.)  

Here in the crack of summer, the high temperature (110F, sometimes more) fries the plants right out of your pots on the front porch. It's almost impossible to keep the moisture in anything less than five gallons of dirt--no matter what kind of dirt.

My land is covered with small mesquite, which drop their tiny leaves each winter--which is definitely helping the carbon content far more than I have ever done with pickle buckets and a shovel.  But's kind of a newcomer's naivete to look at a piece of land and figure that the trees would somehow "beat" the sand if I stare at it long enough. This year's carbon content looks a heck of a lot like last year's.

So the author is facing a very similar problem: the hope and dream is that you get over that hump, where the ground holds enough water from month to month that plants will stay alive through the season, and then a really amazing life cycle begins. Plant life gets more diverse, biannuals start feeling comfortable, things start looking more hopeful all the way around.

We have to find a way to add it faster than it burns.

I recommend this book on the topic.

Michael Sohocki wrote:naivete to look at a piece of land and figure that the trees would somehow "beat" the sand if I stare at it long enough. This year's carbon content looks a heck of a lot like last year's.

Staring doesnt help much but adding water does. I think ton for ton, dollar for dollar, hour for hour the guy who hauls water for the first two or three years is ahead of the guy who hauls organic matter

So yesterday I dug two holes in a garden bed I barely use. It is on the edge of my garden and gets too much shade to be productive for annual veges. I created the bed a few years ago but never really did anything with it so this year I decided to put in some perennials (black currants and rhubarb) which are more shade tolerant.

It was the first time in about 5 years that I've exposed my original garden soil and it is almost all sand. I've been working with this site to change the soil composition. I've pumped tons of leaves and other organic matter into the beds and it just seems to disappear. It's been frustrating at times and even now the soil is still very sandy and prone to drying out.

My exercise yesterday highlighted for me that all this work really is making a difference. My other grow beds that I'm actively working on have a completely different appearance and texture. And there is a ton of soil life in them compared to this bed. Even though there is no clay whatsoever, the soil is most certainly improving.

Now, I pumped a crazy amount of organic matter in so far. The first year I put 3 ft of leaves on top of each bed to over winter and then buried it in the spring. I mulch with lawn clippings to the point where any more would create an anaerobic sludgy mess. And I add compost that I make on site from used coffee grounds, sawdust, garden debris, wood chips, and composting worms.

My point being that what you think is needed to remediate your sandy soil is a drop in the ocean compared with what you will actually need. In hindsight, I would have initially not grown anything in that garden for the first year, and just piled on the organic matter like one giant sheet composting operation 4 ft deep, inoculated with mycelium and composting worms. That sounds like totally crazy talk but I'm telling you even that will disappear into the soil. If I was rural, I would run chickens on the sheet composting operation too. First year harvest - eggs and mushrooms.

Make gin or whisky with those junipers.

Corn grows fast. If you grow corn for just 2 months and chop and drop it like a mulch, you will have a good accumulation of organic matter. Grow corn again 2 more times like this. Apply a light chicken manure on top or a good compost. This will take 6 months and if you start mid spring, it will be mid autumn after 6 months.

Try broad beans and snow peas for a winter cover crop. chop and drop them when they are 1-2 foot long. This will feed the soil with nitrogen fixing properties.

Next spring, things will be decomposed nicely. You can grow whatever you want.

Thank you all very much! There are lots of great ideas and tons of very useful tips and suggestions which we have considered strongly.
We begin here on July 7th. Wish us luck!

Hi Amanda.  

I think that a good description of the lay or your land, and the location of the trees and any other vegetation as well as where the plots are that you are working would help people give better suggestions.  What is your wind situation?  How much rainfall do you expect in any given year and what times of the year?  At that elevation, do you get lots of snow? How many months, and what months, do you have freezing temperatures? Etc.   If I understand you correctly you are working an area that was a river.  Does it ever get flash floods? Have you talked to the locals about what happens in a large rain event up river?  I've seen some crazy stuff happen in dry river beds in Arizona an Utah when a big storm, miles away, opened up and dumped into a drainage.

I'm going to select from a variety of quotes above, to illustrate what I think might work, because a combination might be in order.  But before I do, I will start by advising you to start smaller than bigger.  The smaller you go, to start with, the more success you will have with your project.  A thin layer of compost, for instance, spread over a large area will not have nearly the same positive impact as that same amount of compost spread over an area a 10th the size, particularly when covered with a thick bed of woodchips mixed with manure.  Get a lot of amendments and concentrate them in a small area.  That is probably my best advice.  I further want to acknowledge the suggestions by Bryant and Marco to get some clay into your sand.  If you can make a clay slurry, it will have a massive impact on your sand's water and nutrient retention, and get some seeds in that damp clay/sand right away.  Dry clay on the surface is not good though.  It will do very little on the surface.  Just so you know.  You want it in small sized particles and you want it into your sand, ven if you just disc clay into your sand, make sure you wet the clay so that it sticks to the sand and begins to form a non/sand aggregate structure.  

For starters, I'll quote you:  

Amanda wrote

We have lots of cattle roaming in the area and we collect all of the manure as we can.

 This is great. Do you have a relationship with the cattle ranchers?  If so, ask if you can pen and feed some of the cattle.  Considering the expense you are putting into hauling in material, you might be well off to buy some hay, and tether some cows (or get a small set of electric fencing) so they can access only a very small area.  Not only will the cows manure and urinate the small area, they will trample in and any organic matter that you laid into the area as well.  Do this on a short rotation, and on the final day, add a lot of desired seed, which the cows also trample in.  The land should look as if a stampede went through.  This will create small anaerobic bacterial pockets in the hoof prints.  These bacteria create slimes that hold water.  Move the cows to another small area nearby and water the area heavily that they were just in, and continue to water any time the area looks like it's not got some dampness until you see sprouting and then continue until you see some good development and then move on to giving water every few days to a week so that the plant roots are chasing the water into the sand.  Similar stuff can be done with pigs instead of cows.  After you get some plants establishing themselves, get more seed in there to sprout up in the microclimate understory of the existing growth.  

 Our plan so far is to add a very very thick layer of manure into the the sand by discing it in lightly. Then adding a great deal of straw that we put through the hopper part of our chipper.

 If you are planning to disc any areas, I would think that it is best to concentrate on doing it in a small area, and only once with a lot of material before adding cattle or pigs to it to get that anaerobic surface water retention.  If you have a tractor, and water, and a chipper I would think it much better to make compost with some of that manure and straw.  The richness of the biology in compost made out of the straw and manure is much more than the sum of it's parts.

We have sooooo much dry downed juniper wood all over the property as well that we will lilely do some hugelbeds as borders for pathways and along terraces.  

 If you are planing to garden intensively for vegetable production, consider burying the wood in trenches with a lot of the freshest manure you can gather and water mixed with it (I mean make it wet) instead of raised mounds which will dry out.  Put the trenches deep enough that the hot sand on top of the trench can not dry your wood.  Make the trench still apparent on the surface, so that it will take a good layer of mulch as you go.  Mix the top layer of sand with organic material and plant a crop in (I'm taking a guess here), September or early October, of mixed hardy species that will serve as a nurse crop/ green manure/ mulch for your spring crop next year.  Since you have water, and you have lots of woody material, you can keep the area damp by not only chipping, and laying that around your plants in the spring (I would also first mix these with manure (1:1) in wet layered deep piles to get the chips more biologically active), but also by laying whole trunks and branches on the ground around the plants, which will hold surface moisture and provide some shade and wind protection.  Another thing that can be done is building ramada type shade structures, so that you limit the intensity of the sun on your ground, and build up woody material vertically in areas to deflect any wind that might be aiding evaporation.

I'll come back with more quotes from other folks and suggestions.      

I started another thread about this elsewhere, but did you happen to watch the Ted Talk by Olensen titled something like "Sand to Soil in 7 Hours"? He describes a "liquid nano-clay" that his father developed that permeates sand, and suddenly people are growing things in deserts. It's worth a google search.

I emailed the company, told them it was a fascinating idea, I'm in South Texas (they're in like Norway or something) and where can I get my hands on some of this stuff?

No reply. They seem to be a little too cool for school.
But still...the idea is out there. Really amazing, if it really works.

I think this is the Ted Talk.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch%3Fv%3Dstc5MUIloP0&ved=0ahUKEwi18au-_-3bAhWozlkKHbcHDAsQtwIIKDAA&usg=AOvVaw34XucuZ8vKBL4xvv12azKq

Liquid nano clay?

okay: cheesy name, fascinating concept--don't shoot, I'm just the reporter....

The problem with incorporating clay into bereft desert sand on a large scale has been (purportedly) that nobody wants to screw around with the handling required (trucks, tractors, tilling, then of course irrigation) that promises no short-term gain. Input costs outweigh the return.

As was said in that Ted talk, people have been trying to figure out a dump-on method for a long time--but the retaining quality of clay dumped over the draining quality of sand had always resulted in a slick, or shell on top of the sand--that didn't yield any biology.

So this old man (an HVAC specialist if you want to know) accidentally figures out a way of making clay refuse to clot on the sand's surface--so you really do just pour it on, and shloop, there it goes--where it binds in the sand and creates water retention. Then when water comes naturally, the first beginnings of life appear, weeds and fungi and so forth. And a carbon and nitrogen cycle begin, and then you've got something worth going out to plant in. Voila, garden in the desert.

Yeah, i know it sounds an awful lot like snake oil. I am also suspicious: maybe a Bernie Madoff pyramid scheme in the making. But I daresay I respect Ted talks for their vetting process (I once got as close as the application to go give one). And sure, you can find a photo somewhere in the world of whatever the hell you want people to see.

...but what if it WAS true....

The only flaw in the concept I could think of is that if you invented self-shlooping clay, when you dumped it on the ground it would just keep on shlooping down out of root range and further and further (as water permits) until it hits something solid. But what do I know.

Michael Sohocki wrote:But I daresay I respect Ted talks for their vetting process

Except this was not a TED talk, it was TEDx. The difference is TEDx is not vetted or organised by TED.
BIG difference.

Ive heard reports this nano clay works, but ive seen pricing around 10k per hectare. Id rather spend that on water and cover crop and get roots in the ground, then plant what you like and keep the change from the 10k

OK, whats a HVAC specialist?

An HVAC specialist, I think, is someone who installs air-conditioning units. HVAC stands for "Heating, ventilation, and air conditioning."

According to Wikipedia, "Heating, ventilation, and air conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality."

I'm pretty sure that an HVAC specialist is the technician who installs such units. The main purpose of these units is to cool the air, but they can also heat the air and filter and circulate the air.

But, I could be mistaken. I've never worked with an HVAC specialist, and don't have such a unit in my home.

Hi Amanda,
I've heard horror stories about mixing clay and sand in our desert region (I'm just south of you in Tucson).  You may be hoping for the best qualities of sand and clay but many people have said that when clay is added they create caliche.  This seems to be more of a problem in some areas of Arizona, maybe due to the calcium concentration in the soil.  Hopefully someone else can comment but caliche is slightly worse than concrete

Brian

It sounds like your "sandy soil" "bad because of:
Water runoff/sheeting during storm events = build swales
Soil itself not holding water = add BioChar it has lots of spongy pore space to hold water, similar to clay
Soil not holding minerals = add BioChar it captures the mineral like Activated Charcoal but loosely enough for plant roots to extract it. While requesting less water
Soil not supporting microbes =add BioChar it has lots of space to host good microbes, who also die and release minerals.
Soil low in Carbon = add BioChar

Where would all this BioChar come from. You could make your own from straw/trash hay. Straw is relatively cheap.

There is the fact that you have to precharge the BioChar or wait 18 months for the existing soil to charge it.
What does charging it mean:
Letting the oil/syn gas that is left in the Char get eaten by microbes or leached
Letting the biochar, capture some mineral from the soil to fill up, added mineral rockdust.
Letting the microbes population exploded so that you have a huge amount being born and dieing to supply manure to your plant roots
Letting the mycelium pop. explode in the pore space so that they can extra mineral to trade with the trees with for sugar
Letting the biochar, capture some water from the soil so that it have some to share with the plants, soil life.

You can probably tell I am a big fan of biochar.

Other than adding swales and carbon(biochar, compost, mulch, straw), you can also add
Cover Crop = DryMass Grasses, Nitrogen Fixers, Tap Root Miner/Aerators, Pest Control(Onion+Mint+Carrot Families)

I have had some success with using a mobile chicken coop over my "you can't have a garden there, its just sand" area. I had deep mulch overwinter under a hoop house with wood chips/leaves/etc and it seems like having it covered over kept wind and rain from instantly washing fertility away. Afterwards was able to plant in cover crop and area has done pretty well, it definitely appears more like soil.

When I lived in east TX I was on sugar sand (gritty when dry and sucking mud when wet) I generally follow John Jeavon raised bed methods and double digging. Water just poured through that sand and even tho it had been a horse pasture for years didn't really have any organic matter. I raised a lot of rabbits for meat back then and got an idea. A couple days before butchering some fryer I started triple digging a bed, that is I set aside the top shovel of soil and then the next shovel of soil separately. I dug out the third shovel of soil and dumped it on the paths. On butchering day I poured all the blood and waste into the trench. Then dug the next trench, covering it with the top 2 shovels of soil and dumping the 3rd shovelful on the paths so a trench was ready for the next butchering day. The next summer I grew corn on that bed. It was 10 feet tall with 2-3 ears on every stalk. I also raised red worms under the rabbit cages and would add 1-2" of worm casting to the top of the bed and to cover broadcast seeds with.

If I were doing it now I would do the same in my intensive garden space but probably use manure and woodchips, fresh in the bottom of the trenches because I don't process that much meat any more.

On open acreage I would do a soil test and concentrate on adding whatever was most absent, then plant a lot of cover crops. Peaceful Valley (groworganic.com) has a lot of different cover crop mixtures. I'm going to try out some dryland non irrigated pasture mixes this year if it will ever rain enough to get anything to sprout! these are mixes of annuals that will grow on the winter rains then go to seed and die when it gets hot and dry.