Interesting topic.

Off the bat I will say this is an issue as well with biennial or perennial crops such as homesteaders or permaculturalists commonly use. A familiar example would be asparagus, less common these days are rhubarb, walking onion, sun choke, etc, as well as situations where naturalized annuals or biennials are established and thusly self-sowing and germinating in many cases spring and fall. I have many of these situations, so the typical annual tilling and easy incorporation of fertilizer and amendments is absent or desultory. I have to rely on soil drenches, which are labor-intensive (basically lugging five-gallon buckets of manure tea) and mulches.

The belief that more organics = good has been overplayed...especially by those that believe anything organic is automatically awesome.

A lot of people I've seen online and advised in person (usually after the fact) build their garden beds with huge amounts of organic "soil" leading to huge compaction or disappearing soils. We get a lot of warm/acid/moisture/fungal/microbe action in our specific climate and organic amendments can be degraded in a year or two quite easily.

People building beds can easily see inches of their soil line disappear quite quickly and the only real benefit is it is improving soil structure many inches below the soil surface where what portion that hasn't been complexed off has gone to settle.

For some reason it's a hard sell to some that, at most, you only need 10-20% compost and 80-90% topsoil for your beds (and some would argue 20% compost is too much, and I'd only advise it if you're intensively producing on the bed and don't want to amend too much every year). They seem to think that topsoil is useless trash and organic amendments are absolute gold. The thing that really drives me crazy is the people that dump perlite/vermiculite into their outdoor beds...it's effect on structure is overrated, especially around here where it rarely gets mixed in beyond the first few inches of soil and tends to "float" or hold it's position near the top few inches of the soil profile rather than working it's way deeper.

The mineral component of a soil cannot be ignored unless you want to constantly keep applying organic amendments...sometimes to the detriment of both structure and nutrition of the soil.

A little bit of organic goes a long way, even in an intensively cropped area, and having a good mineral portion of the soil can help plants use it better/longer with less applied.

This post was edited by nc-crn on Mon, May 13, 13 at 22:15

I like Steve Solomon's take. Makes sense to me without going too far over my head.

Lloyd

Soil is soil is soil is an indication that the person making that statement knows not what they are talking about. There is little difference between "agricultural soil" and "horticultural soil" although there is a difference in the soils that will grow Rhododenrons and that will grow Sweet Corn. Most all plants will grow quite well in a soil well endowed with organic matter (about 6 to 8 percent) that is evenly moist and well drained.
One great misunderstanding about organic matter is that it is not a one time thing and OM needs to be added continuously since that is what the Soil Food Web feeds on it "disappears" over time and needs to be replenished. Another misunderstanding about organic matter is what it is and OM is any, and all, vegetative waste, and could even be Poison Ivy. Without organic matter in the soil the Soil Food Web has nothing to live on so they either go dormant (until the conditions they need to live are met): or die.
If one looks they will find that a rose needs the same soil as does sweet corn.

Kimm, I disagree.

Annual crops have much heavier fertility demands than either perennial crops or ornamentals, with exception of annual flowers that are harvested like crops. Those latter effectively are annual crops.

It is quite obvious that annual crops have been bred to bear very heavily in a very short time. This is an extremely useful and valuable quality but it requires serious feeding.

kimm - the labels agricultural and horticultural are used solely for distinguishing the comparative demands on the soils and the ability of the grower to amend the soil. They are used for convenience of discussion.

Using those labels, as you well know there are significant differences in what a grower can practically do to amend and maintain agricultural soils vs. horticultural soil, unless you want to dig up the perennial and permanent plantings every year. As you also well know there are also different demands for soil-borne nutrients between annual and perennial plants. So, what's you point?

At least it's good to see that you and the good professor referenced above are in agreement on proper levels of soil OM in general. The question is then how to get it and maintain it over the long term, given the practical limits on how those soils in those different applications can be managed?

BTW - where was it said "Soil is soil is soil"?

I am directly experiencing the issue of way to much OM in one of my gardens now. For many years I piled wood shavings and dust from my shop in a shady area; later after removing a large tree that area became sunny and I started growing stuff there. The soil is extremely rich and very fungal, and will be taken over by brambles in about a week during the growing season if I don't constantly pull them.

Despite this no crop has done spectacularly well. Potatoes have done pretty good; last year tomatoes got early blight there; this year peas germinate poorly and won't hardly grow, I think because the top layer of ground is so fluffy and organic it just dries out in a few days of sunshine. Perennial onions do well because they have the cool season to get deep roots established - past the overly organic layer.

I think it needs a heavy dose of lime and a good spading to get the old OM on top more incorporated into the mineral portion.

Stop and think about this. The people who produce peat moss for a living, and want to sell as much of it as possible, tell gardeners/landscapers to apply 1-2 inches of it on your soil. Unlike the organic-obsessives who watch a few Youtube videos and suddenly become 'experts,' they don't advise you to use as much organic matter (that they sell) as possible.

Who would you trust - the people who are giving you advice that actually goes against their own profit-making interests, or Youtube Guy?

"Use as much compost as possible" is a good recommendation for most gardeners, who can't possibly make enough compost to fill their needs - like me. The problem is with people who take the advice literally, and have money to burn.

I dunno. I'm obsessed with mulching - grass clippings, leaves, bark, compost, anything organic, and only truly happy if I have 6 inches of mulch around everything.

That never happens. The mulch keeps getting incorporated into the soil. So I add some more. Never ends.

When people ask me how much of my compost to buy for their garden I always ask how the garden produced in the past and how much materials they have added and what kind. If the garden produces relatively good, I recommend no more than 1/2 an inch worked in. If it doesn't produce so well I recommend an inch. I see no reason to put excessive amounts of OM into the soil.

Lloyd

Lloyd, I am sure that's great counsel for your climate and soils. In our sub-tropical climate down here on the Gulf coast, where we grow year round and true freezes are a rarity, any OM in soil disappears with amazing rapidity.

Ya, sorry. My point was, is that not everyone recommends more than what a person needs.

Lloyd

It's a good and valid point. Most of the folks selling stuff will typically recommend more than you need.

pnbrown - that last exchange with Lloyd made me wonder ... is possibly part of your challenge a result of adjusting to the differences in soil and conditions from FL?

No, I have done most of my gardening in MA, and concurrently with FL.

Nor would I say I have only one challenge....though the problems I described earlier are strange and confined to the one small plot. The common thread is that the plot is new and I had introduced huge amounts of wood shavings over many years previously. This thread refreshed my memory about all that wood.

Anyway it's possible that is not the problem, the peas seem to be getting savaged by birds - just bitten to bits by them. Big increase in bird populations around here in the last couple years. Overwintered peas did very well last spring on the same plot.

So who the heck knows.

brown - I apologize if my question seemed insulting - looking back it looks rude to me; it wasn't meant that way.

I was probably projecting from my own experience after moving from MI to TX. The first two years I was trying to figure out what was growing and what to do with it. Everything was radically different - plants, trees, soils, pests, diseases. After 18 years I am still trying to figure a lot of it out.

I'm having my own challenges with a new raised bed veg garden that I built over winter. Bought a soil blend that I've used with great success for annual planting beds and is the one highly recommended around here for veg gardens - a lot of organic matter in it. But I never used it in any depth over 4". The new bed is 12" deep and was filled in February. Seeds of all kinds germinate great, provided you keep it moist on top (it drains almost too well), growth starts strong, but then both root crops and the leafy greens (lettuce, spinach, etc.) come to a screeching halt at about the halfway stage of their full development, and just sit there. It's like they go into suspended animation. Carrots, beets, turnips just stop growing at about half their normal size, where they will sit for weeks before I get frustrated and pull them up. They're good, but small. They have lots of long, fine roots hanging from them, so I know penetration isn't an issue. I have Danvers and Nantes half-long carrots in the ground, about half-size, after 90 days.

Peas did okay, but were slow to mature. All the solanaceae are growing strong and are fruited like crazy - never seen so many tomatoes set per plant, but rather than ripen them, they just keep blooming and fruiting. I have early girls over 5' tall with more than 20 tomatoes set, all green, the plants are still flowering and setting new fruit like mad, and they've been in the ground for 69 days from 10" tall very healthy plants.

There's something going on down deep in that soil, but as of yet I don't know what it is. Hope to figure it out during the summer doldrums.

Again, my apologies.

This post was edited by TXEB on Wed, May 15, 13 at 8:36

No sweat. I figured you had gotten the impression I was recently relocated from FL.

Yes, the issue of crops doing well initially and then reaching a point of suspended animation is also something I encounter now and then. This business with the peas is a complete novelty, though. In my other plot a couple miles away the peas are doing just fine.

I think the birds are actually eating the leaves off so fast that the plants cannot gather enough energy to grow. Last year they waited until the plants were well up and flowering, doing very well and then just started ravishing the plants so they made few pods. Again I had to rely on the other plot. When the birds get over there I'll be in trouble when it comes to peas. Knock on wood they stay away.

Tex, I don't know if you've had a soil test on the slow to mature crops, but a sufficient phosphorus to potassium ratio helps to mature the crop. Too much potassium tends to delay maturity.

wayne - I like your thinking. The bed, irrigation, etc. all came together in February, the soil went in, and I started planting a couple of weeks later. I didn't test it before, and gritted my teeth a bit, but went with rec's and comments from other gardeners in the area. Since planting it's been too full of stuff for me to grab a good composite sample, so I am waiting for the summer turnover.

With that I am going to do 4 different sets of samples -- deep from the 7-10", top 0-3", middle 3-7", and total composite. The reason for the profiling is the soil went down on top of a high calcium gumbo clay that had about a 1" layer of OM on top from turf, then just the heavy clay. While I'm grabbing samples I want to see if there's any discernible effect from the clay subsoil and/or the deep soil OM. The total composite will get a routine + micro + Boron + OM; the three profile cuts will get just the routine (pH, NO3-N,conductivity, P, K, Ca, Mg, Na, & S).

This post was edited by TXEB on Wed, May 15, 13 at 18:03

That's interesting about excess K, I didn't know that. In the normal course of things, it's hard to imagine how that would occur.

I've spent more than half my life as a research chemist. I've dealt with some vey complex, multi-phase equilibria over the years. But the most complex of all for me, beyond even human physiology, is soil-plant systems. I get all the basic plant nutrition 101 and soil relationships. But as soon as you get to the second order interactions, I find it mostly incomprehensible -- too much of A in the soil leads to a deficiency of B,C, and D in the plant, or a an apparent deficiency of X is best resolved by adding Y. It's an incredibly tangled web where every plant nutrient seems to affect many of the others in some way. Every time I try get my head around it, I end up mumbling to myself in a great state of confusion. That alone is the reason why I like soil testing when things seems funny, and when trying to establish stability for new gardens. There are people out there who actually understand this convoluted mess, so I will rely on them because I surely don't.

what you just said TXEB is why I get a little dumbfounded when people cavalierly discount soil testing. Why wouldn't someone want a better picture of what is going on? oh well. I know the feeling of moving to a more southern latitude. I moved from OH to CA 20 years ago and still have problems timing everything.

pnbrown, I am sharing your pea pain. I am convinced I need to cage the whole veg garden in with chicken wire the birds are so bad at my new house.

kimmsr, I disagree. Agriculture plants and horticulture plants can definitely need different soils and not just because of pH issues like rhodies and corn. Australian plants can't tolerate Phosphorus. Most of our western natives resent high OM and would rot out in soil that makes corn happy. And let's not even talk about the deserts. Maybe in MI most plants like soils like agriculture plants do but that doesn't hold true everywhere.

I think the distinction between agricultural and horticultural soils is a good one. Agricultural plants generally have similar soil requirements and the goal is production so it makes sense to modify the soil in such a way as to maximize that production. the area devoted to agricultural plants is also more limited making modification more feasible. When you get into perennial plantings, the scale is typically larger making modification less feasible. Also, the goal isn't production. who cares if your tree only attains a height of 30 feet as opposed to 50? However 30# of tomatoes versus 50# is a significant difference. I feel that when it comes to perennial plantings you should just work with what you've got and mulch it (deserts withstanding on the mulch). You will certainly be able to find plants that will grow in your native soil that will function as needed.

TX, I agree the second-order functions are mind-numbing. I don't attempt to understand them.

Have you yet tried amending the gumbo clay and see what crops will grow in it?

Nil, I agree with your points. A rose bush and a corn plant have different purposes and certainly different requirements.

pbrown - yeah, tried doctoring the gumbo clay a bunch of years ago, and did a complete rehab landscape project in the stuff about 12 years ago. For permanent landscapes it is actually quite good provided that you can manage both irrigation and drainage, and choose the right plants, trees, etc.. But working it is a learned art. Thankfully, I had a highly experienced nursery owner and landscaper who was willing to teach and guide me in exchange for all the materials I bought from him.

For annual veggies and the like, it is near hopeless - way to dense for rapidly growing things, and near impossible to break up fine enough. The only crops they grow down here in my area are rice, cotton and sorghum, and some forage grasses for cattle. It's great for rice - plow the filed, form the dikes/spillways, plant and later flood. The stuff expands enough to be self-sealing, so the only water loss is evaporation. The predominant land use for agriculture is either cattle pasture (beef) or rice.

TAMU has been trying to figure out ways of working with it for annual horticultural plantings for years. These days their recommended method is: apply 3" of expanded shale on top (we have a lot of shale in TX), then spade it in to a depth of 6" to evenly distribute it (by hand recommended over machine tilling). After that add 3" of finished compost on top, and spade that in to a depth of 6" on the previously shale amended clay. The result is a 6" raised bed with 50% OM, 25% expanded shale in the top 6", the a 3" layer of 50% shale below that. Mulch heavily and re-amend with compost at least biannually.

I rented and tried a rototiller once - pretty useless. I don't know anyone who owns or uses one. A rice shovel is the preferred tool for working the stuff.

Oh and birds, got lots of those where I am. The two biggest pests to gardens around here are mocking birds(unfortunately, the State bird of TX) and blackbirds (a major crop pest for the rice farmers). Between the two, they will take your entire garden.

Tex, I am curious to how large an area in Texas you are talking about and what are the dominant soil types in the gumbo area.

Wayne - see the link below for some insight (once there, click on the map for a larger, clearer view).

There are over 1200 different soil classifications in TX. The state is divided into 21 major land resource areas where the soils are similar. The soils broadly referred to as "gumbo clay" by locals occur as the predominant soil in 4 of the areas totaling about 50 million acres, or about 29% of the states land area.

I am in the Coast Prairie region. Going north and slightly west from where I am (12 miles inland) towards Dallas / Fort Worth, very similar soils dominate in the Claypan Area and Blackland Prarie. Those three total about 27 million acres.

From where I am if you head WNW toward El Paso you eventually get to the Edwards Plateau, which is a very large area (23 million acres). It has similar clay soils, but they tend to overlay limestone deposits in upland areas.

Other areas have segments of similar clays, but the four I noted above are the major ones where everyone calls them "gumbo". Officially, the soil in my immediate area is classified as Pledger clay.

Here is a link that might be useful: Soils of Texas

This post was edited by TXEB on Fri, May 17, 13 at 3:56

I didn't realize Texas has so much clay. I know there is a big onion-growing region there, I guess it must not be in the gumbo.

Tex, Thank you for the information. My sister and her husband have been wintering in McAllen.

I am linking the Purdue Crop Map where you can clink on any county in Texas to see what they raise.

Here is a link that might be useful: Crop Map

This post was edited by wayne_5 on Thu, May 16, 13 at 17:34

Here is a crop map for all the country.

Here is a link that might be useful: Crop Map for the country

yeah - onions are a bid deal in TX. The Granex onion was developed by TAMU - they have an onion research group - and it's the base for most of the US sweet onion varieties, except for the Wala Wala. The famed Vidalia onion are truly Texas bred onions grown in GA . Vidalia had better marketing and a better location for marketing in the early days. In TX the big onion crops are grown in and around the Rio Grande Valley and Laredo, Trans-Pecos land area where the issue is getting enough water (no, they don't like clay). TX also has a modest citrus industry, grapefruit is big. Again, along the Rio Grande Valley near the border.

One of the reasons TX clay soils are so notorious is because they encompass the Houston and Dallas Metroplexes, and Austin, which is where most of the people live. Building on the stuff is a bit of a trick, and no basements allowed, but pools are popular. The rule for pools in these expansive clay is once they are built, you fill them as soon as possible and then keep them filled. If they are empty and a wet spell occurs the pool shell can be lifted and raised right up out of the ground.

Over the years I've learned that farmers are mostly a very smart group - they work with what they have. That certainly shows in what is grown where in TX. They adapt and use the land resources as nature deems most appropriate. Those who don't aren't farmers for very long. The move to broaden land use focuses heavily on things like hoop houses and high tunnels. A lot of that throughout TX.

wayne - McAllen is really nice area, on the north side of Dallas. Have a friend who lives up there, and yes, he is in the clay stuff. He just went through the pains of building a swimming pool in his backyard.

Those maps are very cool!

Texas vertisols are interesting stuff...there's a streak of them in the eastern/middle part of the state from north to south and a huge chunk of them in the northern part of the state. Vertisols are kinda vague because they can be (and in Texas are) different from black to red in color/materials, but the common bond are a lot of very fine clays that heave and shrink depending on moisture/dryness.

They're extremely unstable shrink/swell soils, but some of these properties make for good cotton/wheat/rice production as long as the soil crusts don't get too thick early in crop growth (especially emergence)...or go without irrigation/rain for extreme periods of time.

nc - I live at the southern end of the N-S belt.

They are incredibly interesting - uderts and usterts. When we built in my little neighborhood, we got a good look at the soil profile. Because we are the extreme edge, and we live in an area that is prone to extreme rainfall rates and have a very flat terrain, the city required that a containment basin be added for the neighborhood of 34 homes. The soil that came out of that was used to lift the back (N) part of the neighborhood to create a N to S drain flow. I live on the N edge, right in the middle. My spot has the max of that fill. So, my profile is a bit inverted - red stuff on top of black stuff (for about 10"), then a layer of black stuff for a couple of feet, then back to the red stuff. All calcerous, and if you dig down in the black stuff very far when it's moist, it quickly becomes clear that it is anaerobic.

I'm starting to feel better about glacial till.

I'm used to seeing most all land under tillage or have some kind of obvious use. I have noticed that starting 20 miles east of Columbus, Ohio and eastward , more than halfway up in Michigan or Wisconsin or Minnesota or south of the Ohio River. land tends to be hilly, and have less intensive uses.

I'm glad for till too.

Wayne, not sure if you were making a play on words, but if not by glacial "till" I was referring to my soil type: sandy loam over very gravelly sub-soils.

This is very deep detritus left by the glacial terminus. Farther inland one can easily find bedrock scraped clean by the glaciers (and surrounding soils made of decomposed granite), here the bedrock is very deep, buried by the till. In some areas there are very large erratic boulders on the landscape - they are quite interesting. One nearby is called "pulpit" rock, supposedly sermons were given from it in Colonial times.

Anyway, point being it is about as different from gumbo clay as could be. This thread is making me aware that while glacial till has a lot of drawbacks as cropland it also has advantages.

Around here, its sandstone bedrock with shallow, loess soils.

I've been thinking about the role of adding organic matter - the hay/alfalfa growers will, every few years, plow everything under and start over. The alfalfa guys will do 5-6 years alfalfa, then grow a crop of oats and plow that under, then replant alfalfa. Orchards grow grass, many have sheep/goats grazing, or at least they mow stuff.

On my property, when it comes to the long-term plantings, I heavily mulch my fruit and ornamental trees, berries, all the flower beds. The reasons are are many - cuts way down on weeding, feeds the plants, and above all in this desert environment, helps keep the soil temps and moisture more even.

These last few days, I'm getting the vegetable garden ready for planting. The process involves mixing up last years' mulch with fresh grass clippings, then watering the whole garden - which dries out considerably over the winter and gets very difficult to work - to soften and moisten the soil so the worms can get to work. In a few days, if I pull back the mulch, I'm going to find a worm every inch chewing way on the mulch. In a week - 10 days, the ground will be soft enough and loose enough from the worm activity that I can easily do all the planting.

So to me, the secret to success here is continually adding organic matter in the form of mulch - and now that I think about it, I let the worms figure out the rate of incorporation into the soil.

Pat I am on the Eastern Corn Belt plain [Tipton Till Plain]...glacial for 100 more miles south where it ends. This area is east a bit of where the prairie began. It is silty/clay/loam with limestone bedrock.

Here is a link that might be useful: My area.

Dave, I guess it's all fine so long as there is mulch to be gotten, right?. As you point out, the guys actually growing the mulch can't be mulching. So they have to do some fallowing and putting gains from photosynthesis directly to the soil.

Wayne, that's an interesting map. I'll have to read up more on the different glacial eras. I know many landscapes contain elements from different glaciations and thus can be very different ages, as alluded to in the description for your region. I'm not sure if my area is that way as well; I believe not.

Here is a link to the ecoregions of the country. If you go back to the link 'Crop Map for the country',... May 16, you can do a lot with it.

Here is a link that might be useful: US ecoregions.

Wayne - used the crop map posted last Thursday, and found some interesting tidbits. I never would have thought of the county I live in as a corn growing region, but in 2007 there were 18 farms growing maize and they produced nearly 800,000 bushels from 10,450 acres - at ~76 bushels per acre. Not great from a corn production perspective but unexpected for me.

What is really interesting is to see some changing patterns between '97 and 2007. Comparing 2007 to 1997 as baseline:

Corn 8X (on 3X as many farms)
Rice 0.5X (on 0.4X as many farms)
Cotton 0.6X (on 0.3X as many farms)
Soybeans 0.1X (on 0.1X as many farms)

Over that 10 years a significant portion of the northern part of the county ag area has been lost to urbanization. That may explain some of it (57 former rice farms reduced to 24; 35 former soybean farms reduced to 4, etc.). But the growth of corn, both farms and amount, I find surprising given our soils.