Composting prickly pear and looking for other compost ingredients in the desert

I am in Southwest Texas in the Chihuhuan desert at 3000' elevation, annual rainfall 10-12 inches coming mainly during summertime, and summer temps that routinely run over 110 degrees for weeks at a time. Leaf litter is almost non existent, and mulch and straw are very hard to come by as they typically cannot be grown locally.

I have started to see compost ingredients in a new light as I look for things to help build soil.

Has anyone tried chopping up green prickly pear cactus as a soil amendment. I am curious to know because the "gel" in cactus is what the plant uses to hold water for long dry periods. Besides being green matter, if the gel kept some of its water holding properties for a time after being cut, it could be very useful to place deeper in hugels or under trees. Thorns are a definite negative, but they too will break down.

My property is very efficient at growing prickly pear cactus and I do not intend to cut them all down.

Comments and thoughts appreciated if others have tried things that were successful.

Kevin, interesting question. I really do not know, but the thought that the gel in a cactus may aid in water retention is interesting. Give it a try and see if you see it working. Any towns nearby that may have a supply of tree limbs or other "trash" that you could get a hold of?

Wyomiles, Nearest town is over 80 miles away so limited access when I go there in the truck. It definitely does not pay to just make a run for limbs with fuel prices so high.

I have noticed that some varieties of cactus tend to collect large quantities of minerals inside the plant matrix -- that can be seen when a cactus plant dies and decays. I don't want to overload my growing areas with this mineral if it is not good for my plants. The mineral has to be water soluble because it made it inside the plant. I guess I will have to get some of the mineral analyzed to see exactly what it is.

I am beginning to collect local cardboard and am trying to figure out the best way to break it down where it can be beneficial to the soil and not look like a trash heap.

Kevin

Kevin Elmore wrote:
Has anyone tried chopping up green prickly pear cactus as a soil amendment.

There was a video on Youtube of some folks transplanting squash into holes amended with cut-up prickly pear pads, but I can't find the video now!

Kevin, I think it would depend on how deep you put the cactus, and what else you have to mix with it. I know that some of my prickly pear pads rooted themselves very easily in mulched, watered beds. You might be able to compost them if the pile got hot enough, such as with manure, straw, etc.

I did manage to make some good compost with chopped up thistles and cow patties near a remote homestead in the mountains of southern Utah, at 6000 ft.

Thanks everyone for the comments. I will do some tests and post results.

Kevin

Hi Kevin!
Interesting challenges you have my friend! I would recommend growing a lot of your compostables. I do know that you are in the desert and not much will grow well but try looking at the natural landscape and seeing what thrives. then propagate it! Also if you have good water access, you can start growing all kinds of fast growing invasives that fix nitrogen and thrive in desert conditions. I myself am trying to farm soil on a sanded over lot in Louisiana. similar challanges. I would scour the Plants for a Future database and then see if you can find any useful plants and where you could buy them. If you grow some desert hardy trees and mulch them over with cardboard and other mulch matter, you will do a lot to keep moisture on your property and increase your capability of growing plants for compost and mulch.
there is an old chinese proverb that goes something like this: "When is the best time to plant a tree?" "yesterday" "When is the second best time to plant a tree" "today"
I deeply believe in the wisdom of this proverb and try to live by it wherever I find myself.
Good luck and stay in touch if you find any seeds that would thrive in Sand and grow lots of biomass. If I find anything as I search on my end, I'll let ya know!
Get excited and Make things grow~!!!

There have been some good points given about growing compostable materials. I know it takes time to get started, but whatever can grow will help build and expand the nucleus.

This morning I read on another thread (I think in the hugelkulture or forest garden section) about someone digging a large, oval-shaped hole, for tree-planting, and filling one side with organic matter (I think they used piles of newspaper, though I know Paul doesn't recommend that), but any kind of OM you can get, for the first hole, then use that to grow mulching materials. They said that even in Arizona, they dug into the pile of newspaper and found it was still moist, and that moisture was helping to feed the young tree.

I have been successful in my dry, high elevation area, in getting comfrey plants to grow in the beds with my young fruit trees, and was able to trim off lots of OM last year from those and other understory plants, like Marshmallow herb, sunflowers, wild spinach, sunchokes that came up too thick, alfalfa and clovers, dandelions, and others. Most of my greens I feed to my small flock of chickens, who turn it into rich fertilizer for my garden.

I have noticed in my garden that it seems to work better to layer the cardboard UNDER my plants, in the bottom of a 2 ft deep sunken bed, and then pile sticks, meadow "hay", leaves or whatever else I can get, over the cardboard. Then the cardboard helps to hold water from sinking too deeply into the deep sand, so the whole bed stays moister. Cardboard, paper, and other mulch materials just laid on the surface tend to desicate in the intense summer sun. I have had "small" compost piles, built inside pallet walls, sit for a whole year and not break down at all. But the sunken beds seem to work much better for holding moisture and breaking down into soil.

As I mentioned previously, sometimes it is possible to gather thistles or other weedy plants: I have even collected dried tumbleweeds and chopped them into compost piles. When chopped into small pieces, and mixed with other stuff like grass, or cow patties, or whatever, in a large enough pile to keep the center moist, with a tarp over it to keep the pile from drying out, compost does happen even here.

Disposable baby diapers have a substance inside them that is highly absorbent. It may not be natural, but I don't believe it is harmful either. I don't know if any pediatric hospitals would have any used ones you could take, but maybe worth asking.

I just came back from Terlingua with a similar thought. The drought of 2011 killed a bunch of lechugilla and some prickly pear species these are browns that need nitrogen to compost. Seems to be so much of it that I have to make use next time i'm down there. The only problem my mind came up with was that removing the dead material would leave a spot to be eroded, right now it protects from the rain sun and wind. Using these spots for a base of compost is an idea or protecting the areas with amended mulch from the site is a posibility.

Kevin Elmore wrote:Has anyone tried chopping up green prickly pear cactus as a soil amendment. I am curious to know because the "gel" in cactus is what the plant uses to hold water for long dry periods. Besides being green matter, if the gel kept some of its water holding properties for a time after being cut, it could be very useful to place deeper in hugels or under trees.

YES, we definitely do it here very commonly.
I just leave the base and the roots, and they will grow again.
I have made a post about it, dunno where it is...

Cut them at rainy season. They will rot. I always cut a pad at least in 2.
If you pile up, they rot better. Just cut what is growing from the cut pads.

If you bury: yes it will hold moisture and you can grow with them.
If they have no light, they will not come out.
With very little cover, yes some of them grow and come out. Very easy to see and cut...

I guess there less nutrient losses when you do not leave the stuff in the air...

Desert soil are usually very fertile and high in mineral. What you do need is away to store water in the soil (daikon/tillage radish) and nitrogen.
A way to reduce evaporation with straw wood chip mulch would also be nice. Maybe you will just have to grow your own straw.
You best bet would be to get a pot and plant a vine in it. Water the pot and then have the vine grow 100ft in every direction.
With just a few of these pots with targeted watering and shade you could provide the entire area with shade and biomass.
Hopefully said vines don't produce too much seeds. If you want a tree and not a vine the figs will get the job done.

Opuntia do the job much better than straw!
They produce the same amount of carbon with 3 times less water!

And straw is not a desert mulch because it is not produced there.
The best mulch is either stones or dry dirt!
What you do not want is compacted soil, because of water going away by capillarity.
Loose earth on the ground do the job.
Easy and cheap.

You could try growing some coyote melon: http://en.wikipedia.org/wiki/Cucurbita_palmata. It grows a lot of biomass on desert soils and you could chop that up as a green manure. It's not that common a plant, in the wild it is usually confined to some wetter spot like a draw or a natural swale. But with a little human intervention to give it some help, you could get a good yield from it.

Hi Kevin
Being a big fan of permies.com, I’ve watched a lot of videos on Permaculture techniques.
In my own garden I tried to build a Hugelkulture bed without any wood logs. Instead I made cardboard box logs, (box inside a box inside another box, then stuffed with newspaper) and stacked them to form the bed. So if you are up to a little experimentation this is how I would try it.
Dig a 4x4x4 foot hole, because underground Hugelkulture seem to do better in the desert, stack the cardboard logs along the outside walls of your hole like you would build a brick wall. Then start dumping in your kitchen waste, shredded mail, newspapers, human waste, tumbleweeds, creosol weed and any other organic waste you can find. When you go into town, fill your truck with saw dust, grass clipping restaurant waste or anything else you can find. Shovel a thin layer of local dirt on top, after each delivery to kill the smell. Don’t make any special trips to town, but when you do make it worth the trip.
Now you’ve filled your hole with two key garden soil ingredients, carbon and nitrogen. Now you need water to break it all down. In the desert you need to direct your house hold waste water, sink and bath water to the hole. The cardboard will soak up the water and hold it as it breaks down the organic materials. It will take about a year for the carbon materials to totally breakdown. Worms and sowbugs will help.
If you build this site in partial shaded areas, (next to the house, out buildings or rock outcroppings) your plants will probably do better.
You could pipe your black waste water to the bottom of the pit and build nitrogen faster, but it would have to sit for a year before you started planting vegetables.
A pit toilet or outhouse could be built over one of these cardboard lined pits, but you will want to throw down some quick lime every once in a while to kill the smell.
Melons and tomatoes grew best the first year, after I built my cardboard Hugelkulture. But wood logs, seem to still work best, in my observations
Biology Bill

Yucca Schidegra is a common ingredient in organic fertilizers and compost tea food sources. It contains steroidal saponins, which stimulate microbe and plant growth.

Rory Turnbull wrote:Yucca Schidegra is a common ingredient in organic fertilizers and compost tea food sources. It contains steroidal saponins, which stimulate microbe and plant growth.

Only this one? Or yucca baccata as well?
The root has saponins as it was used as soap, or also the rest of the tree?
thanks for informing us about the use of saponins I did not know.

I have seen yucca bevifolia in shampoo/soap so I think it may contain saponins, but I dont know if they are the steroidal kind; which appears to be the active reagent behind the biological stimulation. But saponins/soap do lower the surface tension of water, allowing it to penetrate into compacted soil much easier.

From my research, most plants that exhibit "extreme" (fast growth, hardiness, flavor/smell) properties will usually lend those properties through extracts and concentrates (IE kelp, kang kong, nettles, etc..), you just need to make sure they aren't detrimentally allelopathic (toxic to other/particular plants)

Vetiver grass sounds like a great biomass plant that is drought tolerant as well. I wonder if it would be something worth planting for compost or mulch?

http://www.vetiver.org/TVN-Handbook%20series/TVN-series1-1-vetiver%20plant.htm

I use vetiver for mulch and it is great and last long.
I have never used it for compost as I have only a surface natural compost at the moment...

It is drought resistant but may be not in a desert. It is first a marsh plant, and then it is able to adapt, when it has managed to get its roots down (a few feet! may be 10).
I really had to be careful for the planting and lost quite a few plants for lack of watering.
I am fond of it anyway!

Chemical composition of Opuntia ficus-indica (Prickly Pear):

http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl

Yucca baccata: (No Saponins)

http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl

Yucca schidigera: (Saponins)

http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl

Aloe Vera:

http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl

All seem to have extremely valuable properties.

Aloe vera also makes a great rooting compound.

In the article posted below, the author describes vetiver used in Death Valley as follows:

"Vetiver is so good for the desert, we used it to hide air conditioners at the Furnace Creek Inn in Death Valley."

http://www.finegardening.com/design/articles/9-unusual-grasses.aspx?id=106290

Just checking back in with some updates.

So far I have not been able to see any real vivid difference in things planted on top of prickly pear -vs- baseline plots, but I will give it some time. I put the cactus fairly deep in the holes (to keep thorns out of the upper soil zone) so it make take a little time for the roots to get down to it.

I am planning to try Vetiver grass (CHRYSOPOGON ZIZANIOIDES)? Look at Vetiver.ORG for more information on this sterilized super grass. I plan to start a small nursery to grow my own sprigs from, but as Xisca has pointed out extra water will be required to get them established. I have several gullies that are in need of some serious stabilization and since the roots can go SO DEEP it might work.

I have also figured out that Chino Grama can be cut at 2-3 inches height and regrows nicely when we get moisture. Some clumps of Chino can be up to two feet across so I have begun harvesting this grass for mulch cover around fruit trees. I doubt that Chino will handle too many cuttings in a year without suffering and not reseeding, so I am watching for that possiblility as well.

I figured out that Greasewood (Creosote Bush) coppices nicely. I harvest the large limbs to lay down for shade/mulch and it regrows fairly quickly. The leaves will fall off after it dries, but the limbs seem to keep them trapped so they don't blow away in the high winds. I haven't put any Greasewood down in a planting hole yet, but I want to try that one too.

Another bush that coppices nicely is the Whitethorn Acacia. I have place the small branches of this plant down in planting holes. I also have it growing as a shade plant between figs and plums and it seems to be a well behaved plant. It is a nitrogen fixer so that is another bonus. I have found that when I prune the acacia and use the pruners to cut up the trimmings in 1" pieces they lock in place pretty well and form a rough form of wood chip mulch.

I am experimenting with dead clumps of Ocotillo and have found that they are great at locking grass/mulch down in areas where high winds would otherwise blow them away. I have used them this way in several gullies and seen their benefit in locking down soil that is washing away after a heavy shower.

That is all for now.

Kevin Elmore wrote:I am planning to try Vetiver grass (CHRYSOPOGON ZIZANIOIDES)? Look at Vetiver.ORG for more information on this sterilized super grass. I plan to start a small nursery to grow my own sprigs from, but as Xisca has pointed out extra water will be required to get them established. I have several gullies that are in need of some serious stabilization and since the roots can go SO DEEP it might work.

I have done this in a separate post in the right forum for not sharing here...
https://permies.com/t/26103/plants/Feedback-vetiver

There is a way to keep watering under control at the beginning, I did some vetiver snakes in pipes before planting in their place.

"Without detracting from the possibilities described for utilization of Opuntias in the production food and natural additives and the benefits for integrated use of the plant, many other popular uses have been known for centuries. Some of these are only now being studied scientifically. For example, the use of cladodes: to clarify water
(López, 2000); as an adherent for paint when added to lime (Ramsey, 1999); or to increase water infiltration into the soil (Gardiner, Felker and Carr, 1999).

Agro-industrial utilization of cactus pear, FAO, 2013, p.19.

Gardiner, Felker and Carr (1999) reported the first experiments on the use of cactus pear extracts for improving water infiltration in soils. After comparing polyacryl amides (PAM) with an undiluted and a diluted extract of cactus pear cladode, the authors found that use of this extract matched the infiltration rates found using PAM. However, many questions remain concerning this research, including the durability of the effect and how the extracts work in the soil. Again, follow-up R&D is recommended."

Agro-industrial utilization of cactus pear, FAO, 2013, p.99.

Gardiner, D., Felker, P. & Carr, T. 1999. Cactus extract increases water infiltration rates in two soils. Comunn. Soil Sci. Plant Anal. 30 (11–12): 1707–1712

Hi Kevin,
Do you have any updates on your work with Opuntia and creosote?  

Thanks,
Brian

Study on composting prickly pears and morninga:

https://www.degruyter.com/document/doi/10.1515/opag-2019-0023/html

I use opuntia pads in semi anaerobic compost water barrels, it makes a supreme  liquid fert. pack them in tight and fill with water. you dont even have to cover it. within 2 months you have nutrient ready water for all kinds of fruit trees. its a fantastic plant for its ability to grab nutrients from deep down in your soil (like a tree). It works and i cant rate it high enough. everything that i put it on booms. as a bonus, the skins of the pads and fibrous structure of the main trunk retain a fair amount of form.. get it out with buckets when its ready and you have a wonderful liquid feed plus a layer of fibrous compost material for the surface (it wont sprout, its just the internal 'structure' of the cacti), sort of like loofah/sponge gourd

Love that!  ❤️  I'm gonna try it for sure.  Thanks for the tip!

Kevin Elmore wrote:Has anyone tried chopping up green prickly pear cactus as a soil amendment.

This sounds like a great way to propagate new prickly pear cactus. Cut the cactus into pieces and put into a compost pile and each piece makes a new cactus.

Yeah, I'm late to this party (thread), but just wanted to contribute that we've found tumbleweeds to be quite the resource. They are greens when green, and browns when brown, lol, both working for compost. When dry a whole huge pile of them stomps down to hardly any volume and becomes terrific mulchy compost for surface use. What doesn't grow on your land will just roll in and present itself with the winds!

So, this was an interesting question that got me thinking, and then researching.

There's now, though there wasn't when this question was first raised, a good amount of research.

I've compiled a summary and links, with the aid of AI, but here are some pertinent points:

1) Most studies dry and powder the cactus to use as an amendment, but traditional use suggests burying whole pads at the base of shrubs and trees in arid climates to create moisture sponges
2) It works, mostly through the polysaccharides found in the mucilage which affect soil moisture cycles in a similar way to the rhizosphere, i.e. improved water retention, deceased drying, improved aeration, improved structure, and beneficial impacts on soil microbes
3) Improved yields at certain densities, but overuse can create waterlogging and destabilizing swelling effects
4) Long after the mucilage degrades, impacts on the soil structure and microbial populations persist

POTENTIAL USES:

1) Direct mulching demonstrated no toxicity, so you can chop and drop and it will improve moisture retention right at the surface.
2) Dehydration would be pretty straightforward in the desert. Chop the pads up and set them in the sun, or on a drying rack in a breezy areas with dappled shade, which would give you a material much less bulky for transport and storage
3) The dehydrated material could be used as a mulch, or as an amendment, either in chunks, ground, or powdered
4) Makes a great compost which has higher moisture retention properties than compost from most other feedstocks
5) Makes a high-nutrient, high-ash, high-pH char which is similar in composition to manure char, but generally less contaminated
6) Makes a great addition to cob, adobe, bricks, mortars, etc by improving cohesion, moisture resilience, and deterring microbial activity

Here's the research list, if you want to go digging:

**Soil Amendment / Agricultural Uses**
- Powdered cactus pear (*Opuntia ficus-indica*) pruning waste incorporated at 10–40% (w/w) increases soil water-holding capacity and reduces bulk density.  
 https://link.springer.com/article/10.1007/s13165-024-00462-9

- At 20% incorporation, basil plant biomass increases by 21%.  
 https://link.springer.com/article/10.1007/s13165-024-00462-9

- Fresh cactus pear cladodes can be composted into a stabilized product with high moisture content (~65%), favorable C:N ratio, high potassium, and low phytotoxicity.  
 https://link.springer.com/article/10.1007/s13165-024-00462-9

- Powdered cactus pear pruning waste improves plant-available water capacity and reduces bulk density in contrasting soils (e.g., red loamy and black clayey), with benefits for arid/semi-arid regions.  
 https://www.sciencedirect.com/science/article/pii/S2352186424000786

- Nopal (*Opuntia*) cladode components (whole, solid, or liquid), alone or with goat manure, increase soil cation-exchange capacity.  
 https://www.mdpi.com/2073-4395/14/6/1221

- Liquid nopal fractions increase seed germination rates (up to 1.7-fold in carrots) and germination percentage.  
 https://www.mdpi.com/2073-4395/14/6/1221

- Nopal amendments increase plant resistance to water stress by approximately 10–15 days in tomato and carrot.  
 https://www.mdpi.com/2073-4395/14/6/1221

- Nopal amendments increase carrot plant length by up to 100% and yield by up to threefold; tomato production and survival also improve.  
 https://www.mdpi.com/2073-4395/14/6/1221

- Cactus mucilage improves soil aggregation, structural stability, and wheat performance (water use, plant height, grain yield) in clayey and sandy soils.  
 http://colposdigital.colpos.mx:8080/jspui/bitstream/10521/1969/3/Garcia_Favela_B_DC_Edafologia_2013.pdf

- Mucilage of *Opuntia ficus-indica* cladodes improves engineering properties of lateritic soil (reduced plasticity index, permeability, and swell; increased CBR) via bioclogging and biocementation.  
 http://www.techno-press.org/content/?page=article&journal=gae&volume=8&num=5&ordernum=2

- Cactus mucilage (optimal ~6%) improves soil compaction (higher maximum dry density) and cohesion.  
 https://srees.sggw.edu.pl/article/view/10861

**Construction Materials Uses**
- Cactus mucilage has been used since pre-Hispanic times in Mesoamerica as an additive in lime mortars, plasters, adobe, and earthen renders for improved plasticity, adhesion, moisture retention, and water resistance.  
 https://www.sciencedirect.com/science/article/abs/pii/S0141813024059178

- Cactus mucilage improves rheological properties (viscosity, workability, consistency, water retention) of Portland-cement-based, lime, and earth-based building materials.  
 https://www.sciencedirect.com/science/article/abs/pii/S0141813024059178

- *Opuntia ficus-indica* mucilage as a mixing-water replacement increases compressive strength of microconcrete (up to 17% at 100% replacement after 28 days; 9% at 10% replacement after 180 days).  
 https://www.sciencedirect.com/science/article/abs/pii/S0950061824043964

- Mucilage additions improve durability of cementitious materials (reduced water absorption, permeability, shrinkage; corrosion inhibition of steel; lower bioreceptivity).  
 https://www.sciencedirect.com/science/article/abs/pii/S0950061824043964  
 https://www.mdpi.com/2079-6412/11/1/75

- Mucilage enhances mechanical strength, cohesion, and water resistance in lime mortars and raw-earth systems used for cultural-heritage restoration.  
 https://www.sciencedirect.com/science/article/abs/pii/S0141813024059178  
 https://www.mdpi.com/2079-6412/11/1/75

**Persistence of Effects in Soil**
- Soil physical improvements (water retention, bulk density reduction) from cactus biomass or mucilage are observed in short-term experiments (weeks to ~3 months).  
 https://link.springer.com/article/10.1007/s13165-024-00462-9  
 https://www.sciencedirect.com/science/article/pii/S2352186424000786

- Mucilage powder maintains water- and oil-holding capacity during storage for up to 8 months under controlled conditions.  
 https://pubs.acs.org/doi/10.1021/acsomega.4c05691