You can add organic matter willy nilly though, starting now. Any organic matter, although at least some matter that decays relatively quickly will help sooner. Frankly, sandy soil needs one foot of organic matter before it can be called decent. Perhaps two inches of manure, then ten inches of wood chips. Water, let nature take its course. Here, if you call around or look on craigslist, both manure and chips are free.

Animal manures have been used for eons as fertilizers, but much research of late tells us that when vegetattive waste is added to the manure added to the soil there is less nutrient loss through gassing off to the atmosphere (primarily Nitrogen) or leaching.
Far better then simply throwing manure on soils and tilling it in is to properly compost that manure first.

Here is a link that might be useful: About animal manure

Wherever you can't till (around perennial trees and shrubs), you can put on a thick layer of mulch that's actually two layers: compost or half-composted material underneath, followed by mulch to hide it and keep moisture in. When you water the wicking action of all that will help wet the soil underneath.

I'm curious about your composting problems. If you want to, post your ingredients and results in a separate posting and we can talk about that.

gypsum is an excellant and probably only quick way to condition soil that is break up clay, the calcium seems not to impact, over the years we have still had blossom end rot on pumpkins, capsicum and tomatos.

too many nay sayers at times, we do our thing if it works great if not we try some other way, so far we do pretty good.

gypsum is cheap try it

the very best gypsum is talcum powder appearance and slightly damp.

len aka potatohead(lol)

Here is a link that might be useful: gypsum

len, no offense but I don't believe you have any experience with our soils. The problem isn't breaking up clay. There are hardly any places out here that have clay. It's mostly sand and silt that is loaded with Ca. The OP most likely needs organic matter and lots of it.

Seems like a common issue in southern CA - recall this thread earlier this year ...

Here is a link that might be useful: Soil repelling water

Keep in mind that there can be significant losses of nutrients in improperly stored animal manures, and the longer it sits around the more nutrients are lost.

Here is a link that might be useful: nutrient loss from manures

Have you compared the bad soil to the soil in the good bed? Not just the make up, but how fast it drains, etc. Could it be that there is some layer of, I don't know, something impermeable that is screwing everything up in the one bed? You said that there was a saturated level - is there one in the other bed?
It's not just that the soil in the one bed needs amendments, it's why the nearby bed is just fine - figuring that out may be important.

just a thought. Since these were previously agricultural lands, test the soil for sodium (salt) content which residuals of using chemical fertilizers.

If water is gushing down and bypassing those plants, then the soil is a bit hard packed and require a bit of breaking up. I also recommend using compost to amend the soil, not just in the immediate vicinity of the plants but in as large an area as possible. (don't use fresh manure as they burn, plus contain weed seeds) Organic compost will help trap moisture as well as provide nutrients. Thus far your plants are still surviving that that's good. Dig down and add a bit of compost here and there. Top dress with mulch.

For the meantime as you are amending the soil, see if you can use those drip irrigation system to provide slow and steady water to the trees. I've seen those large plastic bags filled with water that are attached to the trunk of trees which slowly provide water. because it's a drip method, the soil may have chances to absorb the fluid. You might be able to find those there.

>>just a thought. Since these were previously agricultural lands, test the soil for sodium (salt) content which residuals of using chemical fertilizers.

Based on what I've read of fertilizer ingredients, they aren't typically sodium salts. Nitrogen is from ammonium nitrate, P from calcium phosphate, K from potassium chloride, etc. Plus, there is going to be a background level of sodium in any soil, so how would you interpret the results?

no offense nil,

soils ain't soils hey i also suggest swaling or rip to get the moisture down, building mulch or tree rubble berms will do that as well as add organic matter.

gypsum is cheap give it a go, nothing ventured nothing gained, CA does not seem to be the issue at hand it is dying trees due to water running off.

the sandier the soil (sandy soil usually allows water in but it won't retain it, then mulch the whole property rip those swale line. we had sandy loam set like cement when dry cut like butter when wet all i suggested worked in the end the soil held good moisture all year round.

dirt is dirt around the world nothing exclusive to any country or county.

len

now that bit about swales and tree rubble berms I will absolutely agree with, Len.

sandy soil typically lets water in, but if the sand is fine enough it and the fine silt float like talcum powder. I have to deal with this stuff every day here in Los Angeles.

Now, it's entirely possible that the gypsum could help because of a Ca/Mg imbalance or a SAR issue but we don't know that because we haven't been given any soil test results. But to make our sandy soil wettable, his money is most likely better spent on a load of nitrohumus.

Dirt is not all the same. If I catch another friend putting wood ash on there soil out here because every garden book says it's awesome, I'm going to go crazy.

to give you an idea Len, my soil tested at 6400ppm Ca. Adding gypsum would be like pouring table salt into the ocean.

Thanks for all that. To clarify some points, my land is not rich agricultural land, that's two miles away in the valley floor. Mine is cut-and-fill from the post-glacial hillside of alluvial conglomerate and sand and silt. It is fertile only where I make it so. Calcium is not a deficiency, when it rains hard, I get flowers of gypsum efflorescing out of the block wall that supports the raised bed. I call the soil tests "normal" (they're home done do-it-yourself) because none of them shout Wow! That's the problem. The soil in general has little cohesiveness and capillarity, so water flows through it and doesn't come back up as surface water evaporates. I have hydrophobic soil all over the surface where there is no plant growth, the berms are dry and crumble. BUT, I am having trouble only with the lemon and the fig, other plants, orange, plum, apricot, sunflower, pumpkin, peppers, rosemary, potato flower bush, Indian firecracker, madonna lilies, are doing well in the same 6-foot by 30-foot bed, so I must think that I did not do as good a planting job with these two trees as the others. In fact, I moved the fig a few feet just last year and probably did not do anything for the new location. All that said, here is my plan to rescue those two trees (with follow on work for the yard in general):
1. a thin layer of leonardite (natural humate, fossilized compost from the end of the Pleistocene), covering the basin of each tree, with a paper cup protector for the trunks,
2. a 1-inch layer of composted manure
3. a 2-inch layer of nitrohumus or similar store-bought compost,
4. as much as I can get of fresh green clippings from my yard
5. a sprinkling of complete commercial fertilizer
6. a sprinkling of Ironite.
water gently and often, not much at a time.
keep adding green clippings as the layers compact and sink in.
punch holes 8 inches deep with a fork, near the dripline, inside the basin berm.

Does that sound OK?

Bob - some random thoughts, no particular order ...

Your observation of what you believe to be Ca efflorescence strikes me as cause for concern. Do you have a good determination of your soils pH, Ca and sodium levels?

It seems to me like you're making it more complicated than you need to. If it were me, I would focus on organic matter as near to humus as possible, topped with a decent hardwood mulch. I would choose compost, ~ 2", topped with 2-4" of hardwood mulch, avoiding the redwood, fir, cedar stuff and bark mulches for at least two years. Let the yard have the grass clippings.

Fertilizer - see if you can find a good palm tree fertilizer. The good ones have about everything, and don't run excessive in anything particular. In my experience they work really well on fruit tree plantings. If you get a decent one you won't need the Ironite.

If you have a cordless drill, see if you can find a "soil auger" like the one shown in the link below. They basically look like a wood auger bit on steroids, and typically have ~ 1.5 - 2" bore and ~ 18" length. I can get a decent one from a local hardware store for ~ $25. On a drill they make fast easy work of boring holes. I use them in our heavy, expansive TX gumbo clay for deep root feeding and adding OM around tree plantings I have 4 Meyer lemons growing in heavy, sticky, gooey TX Gulf coast clay. After 8 years, they seem mostly indestructible so long as the soil is moist. Haven't fed them anything in 6 years.

Most Figs are shallow rooted, and water, or lack of it, is one of the frequent reasons they fail.

Good luck!

Here is a link that might be useful: Garden Auger

don't use ironite that stuff is awful and won't be available in high pH soils. Use that auger that TX recommended and drill a few holes. Fill those holes with a mix of equal parts sulfur and ferrous sulfate. That will do a good job providing available iron.

And you should really send a soil sample to UMASS and get the basic test and Organic Matter and Salinity. It's only $20 for the 3 tests. The home test kits are crap and a waste of money.

I agree will nil13, with one minor exception - the lab to do the testing. U Mass is a very respected soil lab. But, soil testing is typically optimized by regional soil characteristics - there are many variations in methods because of common regional issues. UMass follows lab protocols that have been optimized for northeastern soils, not western soils, and specifically not CA. I would suggest a CA lab. I believe CA is without a "state lab", but the UC Coop Extension Service for Sonoma County published a fairly comprehensive listing of soil labs in CA (link below). I know A & L Western Agricultural Labs (first in the list) comes well recommended, and their basic soil test charge is pretty much in line with common state lab fees ... URL for A&L Soil test packages:
http://www.al-labs-west.com/sections/anservices/soil/fees

Here is a link that might be useful: Plant and Soil Laboratories in Northern and Central California

The reason I recommend UMASS is because most of the people I talk to won't spend $50 per test. For some reason, it's hard enough to get them to spend $20.

But you're right TX, the recommendations will be better from local labs.

Yeah - private labs tend to be expensive. But A & L Western Agricultural Labs seems to be a bargain for a private lab ($12-$14 for a basic soil test with reasonable add ons), and they're in Modesto, CA.

g'day again nil,

you said:
"to give you an idea Len, my soil tested at 6400ppm Ca. Adding gypsum would be like pouring table salt into the ocean."

ok, so now what does that reading mean? and how does that level of CA manifest itself when you try to grow things? i my slef don't waste time paying for or having soil tests done, i simply get out there and do the planting, if plants show some distress eg.,. to high acid, then i apply some dolomite.

as you say it may very well be so that adding gypsum to your own particular soil may be likened to pouring salt into teh ocean, but we all would know you would need a mountain of salt and still make no difference to the ocean.

now i may be wrong but what CA is in gypsum is in soluable form, the CA by test may not be, in which case it will not be available to plants?

anyhow again for the poster nothing ventured nothing gained as yet i have not seen ongoing complaints from users of gypsum, i have been in these forums for around a decade now.

would getting more moisture into the soil leach the CA out over time?

anyway maybe bob could update us?

len

just searched this link:

adding gypsum might still help condition the soil especially in a program of say rip swaling and incorporating mulch(organic matter)

len

Here is a link that might be useful: about CA in soil

Gypsum is quite useful in a couple of situations. One is to increase Ca when pH is already in the desired range. Another is to correct high sodium levels in the soil via calcium replacement for sodium (which really needs aqueous leaching). Beyond that, it brings no special benefit.

Adding gypsum to soils that are already adequate in Ca or aren't sodic is not a good idea. It's use should be guided by soil analysis using methods appropriate for the soil type, as should the use of the various forms of lime. Acidic soils common in the eastern U.S. and alkaline soils common in the western U.S. are best analyzed by different extraction methods. Unfortunately, most of the DIY home tests kits are based upon methods best suited for eastern alkaline soils and are highly prone to error if used with naturally alkaline soils.

Before you go putting stuff into your soil to correct a suspected problem it is a good idea to get an appropriate soil test.

This post was edited by TXEB on Sat, Jun 22, 13 at 6:28

we use gypsum as a clay breaker conditioner, we don't waste time, effort or money acquiring wasted tests, our plants are all healthy, dolomite/lime is used to deacidify soil and alter PH so it has an application rate to be adhered to, where our plants show acid stress we apply some dolomite, but gypsum is used always and oodles of it.

so far in 12 months we have been here around 200kg of it and all plants are looking great, as when the soil has been conditioned nutrients are release, clay is full of locked up nutrients, so get a balance going then you already CA issue may go away.

that CA though there by test may not be available to the plants.

happy gardening keep it simple

len

len, keeping it simple is using the right tool for the job.

From your description your soils are acidic, and probably were low in native Ca as a result. I would also suspect that they are sodic if gypsum is effective at breaking up clay. Gypsum is great for adding Ca where it is needed, and it is the preferred Ca treatment for sodic soils. It works for you because of those reasons, and the lime also adds Ca while correcting for acidic soil.

Where I live the soils are alkaline, and they are loaded with Ca. Adding gypsum does nothing to break up the clay in our situation, it just adds more Ca that isn't need or wanted. All we have to do is get the pH down and plants get all the Ca they need from the natural levels. But the sturdy clay remains.

What works for you would be a waste for me, and would probably create problems from excessive Ca levels as well. Gypsum is the wrong tool for my situation. It is that simple.

BTW -- CA is California; calcium is Ca.

This post was edited by TXEB on Fri, Jun 21, 13 at 16:32

Update, what I've done.
Friday, 6/21/13, 10:00am PDT
Adjusted the basin berms around both trees (lemon and fig), hard to do with talcum powder dirt. Scattered some leonardite (John and Bob's "Soil Optimizer") in the basins, then a 1-inch layer of composted steer manure, then 2-inches of Kellogg N'Rich compost, then a good layer of fresh green clippings, a sprinkling of Hyponex complete 16-16-16, then some Ironite (it seems to work well for me, here, mostly iron sulfate and sulfur), watered down gently with some Grow-Vite liquid (in water) 16-4-2, with some chelated iron and zinc, and some Superthrive, and some Actinovate. I recognize that's more complicated than simple, but I don't know the cause so I can't hit it with the one thing that's right. This is an unusual problem, 2 plants going bad after doing well, alongside 80 plants still doing well. I'll let you know how this turns out. Thanks to all of you for your interest and help.

Bob,

Consider what you've spent based upon best-guessing, and then consider what you would know if you spent $35 for a pretty complete soil analysis.

This post was edited by TXEB on Fri, Jun 21, 13 at 21:43

TXEB

I agree with you about the cost, in principle. But a soil test is a spot sample, or an average that becomes vague. The vertical stratification of the soil at the lemon tree might require 3 samples/tests, so the test cost goes up. And even so, the tests might not identify a sure cure. The main expense in my shotgun cure appoach was the leonardite ($30) and I still have most of the bag left, a little goes a long way. All told, I'm out about $60, with considerable leftovers of stuff I use regularly. It's close, maybe yes, maybe no. Whatever the outcome, and I may end up digging it all up, I think I'll have better soil when it's done.

I just recalled what may have been a precursor to my problems with the lemon and the fig. Years ago, I had a lavender bush that was growing well. Abruptly, one branch withered and died. Then another. One branch at a time, the plant died. I took it out and forgot about it. A year later, I planted the lemon in nearly the same place.

The symptoms are different, the lemon is in total and uniform trouble, the fig is overall gone. But could there be something in the soil, very localized, that eats roots, one at a time for the lavender, more nearly all for the lemon and the fig? I have had a similar problem (to the lavender, with progressive loss) with snapdragons. There are no gophers, moles, or ground squirrels, or other critters that show.

Nematodes? See link to FL reference below.

Also from UC Davis see:
http://www.ipm.ucdavis.edu/PMG/r881200111.html

Here is a link that might be useful: Nematodes of Backyard Deciduous Fruit Crops in Florida

g'day bob,

your remedial sounds fine you just need to give it time, what is your earth worm population, also i may have missed it but when you plant dig at least 2 gallon sized hole or a hole twice the size of the root ball of the tree you are planting the removed soil can become berm(dampen it if need be to help with digging0 then back fill hole as you plant with something like that humusy stuff from the recycler of rubbish.

i'm still going with try gypsum, too much application of soil science will befuddle the scenario.

it was mentioned earlier that adding gypsum will be like pouring salt into the ocean, guess it will be hey the salt you pour into the ocean will not make one iota of difference.

once you plant a tree mulch around it well

in simple form it matters not what your native soil contains none of it may be in a solvable form and available to plants.

before plants can take anything from the soil it needs to be converted by worms and mycorzoria and various bacteria's, presented in simple usage terms for those very very fine hair roots that all plants have.

do rip swaling and all sorts of berms across your block water running through the soil will leach running over the surface will only make things worse.

pee in a bucket and add that the hand wash dish water or shower water that helps, and makes good water management.

i see others are still locked into gypsum only being good to add CA, and forgetting about its soil amending abilities. add some composting worms if you don't have natural worms.

keeping it simple is not getting locked in by some suggestions think broadly and laterally. are there other successful gardeners near by? what do they do?

if land around there is so bad why do people buy it?

what ever txeb, you are locked in that's fine, think outside the box and your comfort zone. like you said you have no idea what adding gypsum may do.

like that web site says if the soil is acid it will make the CA issue worse, so PH might be the key, and keep in mind the CA in the soil may not be in a soluble form.

does anything grow on your land bob? we pick land by the quality of grass it grows by sight.

len

len,

Previously above you cited a reference from Spectrum Analytic on Ca in soil. A more pertinent reference from the very same source on the benefits and misconceptions of using gypsum as a soil amendment is available from the link below. Quoting from that reference (same source as the one you provided on Ca in general):

"Many growers will see promotions for gypsum use that emphasize the many beneficial roles that Ca plays in both plants and soils. Most of them are probably true, to one degree or another. However, the fact that these claims may be true does not mean that a grower needs gypsum or any other Ca source. The vast majority of soils contain abundant Ca and applying more will gain nothing for the crop or the grower. Before spending scarce money on inputs based on nothing more that claims, the grower must accurately evaluate his crops needs. This requires the proper use of soil tests, plant analysis, and some time spent evaluating research results and/or on-farm field trials. Scarce input dollars must be spent where there are the greatest chances for the largest returns on investments. In most cases, the best returns will be from the proper use of more conventional, such as lime, fertilizer, seed, etc. "

So len, please tell us gain - what problem do you believe gypsum will solve for Bob on his high silt/sand soil?

Here is a link that might be useful: Gypsum - Benefits and Misconceptions

Duplicate post error

This post was edited by TXEB on Sat, Jun 22, 13 at 17:04

bob probably doesn't have many worms and that is completely natural and not concerning given our soil.

The whole dig the hole twice as wide is a recipe for a tiny root system. Ideally, the tree would be planted bareroot in native soil so as not to have soil interface problems.

"it matters not what your native soil contains..."
This is probably the most misguided statement I have read in along time. The amounts of inputs necessary to reduce the native soil contents to an insignificant fraction are enormous and cost prohibitive. Absolutely ludicrous.

Some comments responding to some comments:

Most everything here grows well, with a lot of work to change the graded home-site into garden soil. It started out as a hillside, cut and filled to give a level pad for a house. We buy land here because a house was built on it, not for the purpose of growing anything. This area is part of the Los Angeles suburban sprawl, the really good land is still rich agricultural land on the flood plain, for tomatoes, strawberries, and all sorts of similar stuff. We all have obligatory grass lawns, mine is pretty good. None of the nearby neighbors are active, intensive gardeners, hire lawn-mowers to cut the grass, most lawns look pretty good. My problem is local, mostly limited to these two trees, I have had some trouble with a strawberry bed, trying to solarize it now. But one foot away from the strawberry bed, squash and zucchini are thriving, with good carrots, beets, and garlic in between. (I grow garlic really well.) Where soil dries out, it turns hydrophobic, and I have trouble (no success) in recovering it. We live in a desert, had 4 inches of rain this years (normal is 17), and my water company asked (a few years ago, and that might have been the start of the hydrophobia) that I cut my water usage by one-third. The land is cut-and-fill hillside, scraped down to 6-10 feet below the original surface, so there was no native soil when I moved in 23 years ago, I just had to make it myself, out of sand, silt, and alluvial conglomerate resembling sidewalk concrete, equally impermeable to water but not quite so hard. Keep in mind that nearly everything is growing well, except for these two trees, occassional troubles that I think may be fairly common, and the hydrophobic, non-cohesive soil. I might as well be gardening in a bucket of glass marbles. It was not soil that I started with, everything fertile has been added. I hear that humus, mulch, will help with that, but it hasn't yet. Right now, I am on a rescue mission to save the trees, but except for my personal commitment, there is little lost, we won't starve because the crop doesn't come in.

The soil is slightly alkaline, pH=about 8, as all soil out here is. It may be getting lower in pH, locally, after 23 years of gardening. There is plenty of gypsum already naturally in the soil, by observation of efflorescense, not lab tests. I don't think adding any would be of any benefit.

I can't get a bareroot lemon tree, but I do dig a large hole, roughen the sides, and blend the backfill. I may have run short of soil amendment when I planted the lemon, and I'm pretty sure I didn't do a good job when I moved the fig, so I'm paying for past sins.

Earthworm population varies with location. When my compost is just right for them, I think they call their friends in. Some, but not many, in the garden dirt.

Could be nematodes? That's scary. Any fix? Marigolds? UC Davis site was interesting, but I'm not an industrial grower.

The garden is just a sideline, and I can't become as expert as you all are, my major focus is on continuing a published book on natural nuclear reactors (you really should read it if you have an interest in science, or kids in school, or grandkids, or pay income taxes. Or have Paget's Disease of Bone.) So this multi-layered shotgun cure everything (except nematodes) approach has to be my best shot. Otherwise, we'll buy lemons at the store.

Thanks to all, Robert J. Tuttle
rjtuttle@earthlink.net

Good stuff, Bob.

I just spent some time looking at the soils series for Ventura County. Your situation is interesting because your topsoil is apparently, as a result of the development construction, what would be the deeper subsoil for your area. In nearly all of the series I read through they are all described as calcerous. That would fit with your observation of efflorescence.

Your arid climate coupled with how you describe the base soil you were left with sounds a lot like what is common in a number of western U.S. arid regions. Those soils often are sodic because of the very low rainfall. The standard recommendation when that is found (via soil testing) is leaching with good, clean, low-sodium water. Of course, first you need to get the soil wetted before the leaching can begin. I still encourage a soil test, but focused on the basic soil that came with your site so that you will know what you're working with.

Yeah, nematodes are scary - at least to me. Today, home gardeners have very few options to control them. I've been blessed in never having had to deal with them, so I can't offer any help. But, again, the issue is first diagnosis before treatment.

yeah, we had a rough rain season this year. just brutal.

You might want to consider getting an MP rotator irrigation head and rig up a movable hose end irrigation setup. I use them on rebar stakes for spot irrigation of newly planted stock. They are low precipitation rate rotors that were designed for hillside irrigation without runoff. They are actually pretty astonishing.

Also, the whole water well thibg is more like a crescent on hills and they don't really hold a ton of water. Because of this, I like to make a mini-swale or furrow on contour ABOVE the plant as well, much wider than the planting hole. That way I can flood that and the water will flow down through the root zone.

I don't buy bareroot either. I bareroot the container plants before planting and correct root deformities caused by container culture. I only dothat for myself though, not clients, as the plants take a serious beating and drop tons of leaves looking horrible. In the long run, they will be stronger plants. For clients we can only get away with butterflying the root ball and spreading that out.

Have you thouht about rigging up some temporary shade cloth over the ones not doing so well to reduce the evapotranspiration rate a bit? Just drive some steel pipe or conduit in the ground and slide long pieces of rebar to which the shade cloth is attached and slip the rebar into the pipe. Or t stakes.

nil - are either drip or soaker hose useful at all in those soils?

i talk of using gypsum with mulching and berms the CA in gypsum is no issue as i see it even in your area, the plant will only take whatever CA it needs, if the mulching as well helps the gypsum condition the soil so worms and other bacteria can populate then the soil issues will be fixed.

but water not soaking in won't help, so swales of sorts and berms to change that.

nothing ventured nothing gained if i believed all the thrust of nay sayers i'd be sitting here watching grass grow, our last address was on 1 meter of clay fill with all sorts of industrial waste mixed in, that is how they do it. but our bale raised beds did well including citrus trees with oodles of gypsum. the authority rated our fill as as acid sulphate (man made)

try things don't get locked into what comes from science, so one tree died after transplanting, does not mean a catastrophe.

you get a few threads like this where seemingly those with vested interest really plus the no case, no balance is gained.

len

"the CA in gypsum is no issue as i see it even in your area, the plant will only take whatever CA it needs"

The issue of adding gypsum when Ca levels are already are sufficient or high is what happens with other plant nutirents as a result of excessive levels of Ca in the soil. From the Spectrum Analytic reference previously supplied by len:

•Phosphorus(P): As the soil pH is increased above pH 7.0, free or un-combined Ca begins to accumulate in the soil. This Ca is available to interact with other nutrients. Soluble P is an anion, meaning it has a negative charge. Any free Ca reacts with P to form insoluble (or very slowly soluble) Ca-P compounds that are not readily available to plants. Since there is typically much more available Ca in the soil than P, this interactions nearly always results in less P availability.

•Iron(Fe++) and Aluminum(Al+++): As the pH of a soil decreases, more of these elements become soluble and combine with Ca to for essentially insoluble compounds.

•Boron(B-): High soil or plant Calcium levels can inhibit B uptake and utilization. Calcium sprays and soil applications have been effectively used to help detoxify B over-applications.

There are well known perils in adding gypsum to soils that are already high in Ca.

TX, drip and soakers seem to be most useful on level and low slope areas. The drippers only soak a small area with the lower precipitation rates and the higher precipitation rates have a tendency to runoff on serious slopes. Soaker hoses work somewhat on slopes, but they throw off a lot more water than people realize and you have to cycle them with short bursts of water to prevent runoff. Also, both have the problem that they have to be laid carefully on contour or the water runs down the tube and concentrates potentially causing erosion. The MP rotators are really amazing for slopes. the first time I installed them on a 100% slope, I let them run until I got significant runoff. They were running for 45 minutes. Granted, that was on like 16 feet of fast draining DG.

ok that last sentence is a little unclear, I'll blame it on an insufficient quantity of coffee. lol. That soil was 16 feet deep DG fill so it was fast draining. The water was also being laid on bare ground, no mulch.

nil - thanks for the explanation. My area is extremely flat Gulf Coast terrain (a 1% grade here is a hill). We have drain commissioners who struggle to create runoff (which is really appreciated when we get coastal T-storms and tropical systems). When I built a new 12" raised bed veg garden bed this year I put in a drip system using drip tape. The problem I have with it is the soil drains so fast that I don't get much spread, so I have to supplement with about 2X weekly surface irrigation done by hand.

My drip system is laid on top of the soil. I know a lot of market growers bury theirs a few inches below the surface, even in very large fields. My thinking, obviously flawed, was that if drip tape/tube were buried 4-6" below the surface in Bob's soil it might help with getting moisture into the soil at depth in his fruit tree bed without appreciable runoff.

So much for flat-lander thinking :-/

that's assuming(all one can do) is if the natural CA is in a soluble form and is made available to the plants through the worms and mycozoria etc.,

like living near a highway lots of pollutants from exhausts and tyre wear to say the lest but unless that fall out is in a soluble for plants won't take it up, all you would then do is wash produce before cooking/eating.

still (unless i missed it) no mention of how high CA affects plants? what do you see?

again adding a splash of CA in like throwing salt in teh sea make no difference.

anyhow might be vested interests here, me i use common sense and KISS, keep it simple stupid.

len

len,

A soil analysis is designed to reflect the nutrient levels available to plants. A lot of work has been done over the decades to develop extraction methods that will mirror what plants can extract. Further, a similar amount of extensive research has been done to correlate the levels of low- moderate -high-excessive with plant response. The levels determined by a sound soil analysis reflect what's available to plants, and that doesn't require worms, etc.

The principle determinant of the amount of soil bound Ca available to plants is pH.

There are ill effects, as noted previously, from excessive Ca levels in soil. The problem is once you add Ca to western alkaline soils, it will probably be there for a long, long time. Well draining acidic soils are a bit more forgiving in that they enable leaching.

And BTW, the only possible sign of any "vested interest" I've seen in this thread is your continued insistence on the use of gypsum in the absence of anything that remotely suggests a need for added Ca, and in a region that typically not only doesn't need added Ca but one for which adding gypsum is ill-advised barring testing that indicates a need. What's your interest in gypsum sales and use?

This post was edited by TXEB on Mon, Jun 24, 13 at 20:36

TX, the bigger problem out here with burying the drip tape is that the gophers chew through it to get the water. And when it's on the surface, the coyotes like to chew through it.

Figures. We have coyotes, but not gophers. However, while they've run down my street they're kept out of the backyard by fencing. Think I'll stick to my gumbo clay. As miserable as it is, it sure seems better than what you deal with.

Gee, if you could train the coyotes to eat the gophers, maybe they'd both leave the water lines alone.

ok txeb,

that is man trying to determine by his parameters what might be in the soil, science unless dramatically serious leave them alone, they don't sue natural unchanging parameters they create their own based on speculation and ongoing theory.

so we have determined that the bit of CA in gypsum is like a drop in the ocean,

now if CA is at the level science says and is soluble then how does it then manifest it self so when you plant anything you see the plant is not thriving, in bob's case he has stuff growing but this lemon tree seems not to have liked the move.

why would a gardener get an expensive theoretical soil test done, before trying less expensive way?

gypsum still breaks up clay, helps water permeate through it flushing the soil as it goes.

we sue oodles of the stuff gypsum that is at least 1/4 gallon dish full for each planting and good layer over the beds first up, we don't see any problems fact not theory, every thing grows well even native bushes with growth to 1 meter in 12 months that is not common from tube stock they usually grow slow.

clay is sedimentary soil and has lots of nutrients locked up in it, release those nutrients using gypsum or other if acid ph use dolomite at recommended rate.

anyhow we garden happily and simply on and forward.

bob sounds like he needs oodles of mulch and berms, put any run under ground. had a couple ph tests done over the years free, never tried to do other that cost valuable money.

when we buy property we look to soil quality the health of the grass it grows can indicate that. a house is for living in teh soil is for growing in so a house would be second consideration.

len

len,

That you don't understand, comprehend or like the science is fine. I'm not trying to convert you into a believer. But, your notion of using gypsum without established good reason is, in western U.S. soils, just plain reckless. It can, in a number of areas, result in excessive soil Ca levels, with very negative effects for plants. It has been well tried, tested, studied and proven. That's a point you just don't seem to get - the soils in the Western U.S. are not like yours, and the same treatments will not have the same effects.

Try this from the Colorado Extension Service:

Gypsum is a mineral found in large quantities in most Colorado soils. The belief persists that adding gypsum can "break up" the compact clay soils so typical of the Front Range area. This is not true and here is why.

Calcium sulfate or gypsum when added to our clay soils only increases the already high calcium content. Since plants growing in our soils already have all the calcium they need, the added gypsum does nothing to improve plant growth. Spending money and time to add gypsum to a soil that is already high in calcium is a waste of money and effort.

As far as relieving soil compaction, gypsum has no effect. Loosening soils is a physical process, not a chemical one. The way to break up tight, clay soils is through adding and mixing in organic amendments. The amendment holds the clay particles apart creating more space for the air so critical to plant root growth.

Improve the aeration and drainage of your clay soils with organic amendments such as compost, peat and manure. Add a two inch layer of the organic amendment on the surface of the soil and till or spade in to a four to six inch depth. When purchasing organic soil amendments, buy four cubic yards for every thousand square feet of area.

It's easy for gardeners frustrated by hard, clay soils to grasp at anything that sounds like it might work. With gypsum, the expression "If it sounds too good to be true, it is too good to be true" applies. Decades of research has proven gypsum is not the answer for us. The secret to developing a good soil for gardening in our area is one organic gardeners have known for years - organic amendments

Here is a link that might be useful: Colorado - What About Gypsum?