In the fall of '07, I dug gypsum into my garden soil to improve drainage. Prior to digging in the gypsum I had the soil tested and it came back at mid range in calcium content. So this should not cause an excess problem. I will be planting some sort of fruit tree either apple/pear in this section of my garden. This soil was a mix of clay, loam & manure. Will this make a difference in the success of the fruit tree? I hear fruit trees need good drainage to prevent root rot. _____________________________________________________ The reason I dug in the gypsum to this problem spot was because I planted an apple tree last year and it appeared to have heavy soil that did not drain quickly. It was over watered by lack of knowledge and the tree began showing a decline in health. it did not recover, so I removed it. The spot next to this "gypsum treated area" does not support any fruit tree. I planted 2 apple trees in the past, and the roots would not even open up to grab the soil after a good long year of being planted...the apple tree died! I used transplant fertilizer but it helped very little. Soil test says everything is good and it is a full sun spot. What is wrong?
Gypsum flocculates a clay soil only if that soil is high in sodium. If a soil has a high water table, gypsum is not enough to change that whether the soil is alkaline or not. There are a variety of things that might be tested for. If the problem spot has something limiting present that is one of the things a particular test will show, then you might be able to get a clue from that. However, if the test being used doesn't test for what the source of difficulty happens to be, that test will be of no use in discovering it. And maybe it's something that no soil test would test for, like a pest or pathogen. Pretty much impossible for anyone who does not have access to the soil there to determine, unless you happened to discover and report here something that was a significant clue, like honey fungus mushrooms popping up around the dying trees or rodent gnawing marks on the trunks.
Thanks for the reply Ron! How can one change the water table of the soil or atleast mildly improve it? Ph is 6.6
Like other organic amendments, after it decomposes you eventually end up where you were. Vegetable gardens and annual flower beds can have additional amendments dug in to maintain organic content, plantings of permanent subjects like trees and shrubs cannot. Planting in existing soil, in wide shallow holes and mulching afterward, maintaining a mulch is the way to go with these.
Plant in same soil that came out of hole unless you are going to make hugely wide excavations that will place new trees in same (new) soil for many years. You don't want to plant in a small area of one soil surrounded by a bigger area of another, ESPECIALLY where there may be a problem with too much water in the soil.
I first saw how Gypsum / Lime (Calcium) improve drainage, at one of Oregon's country clubs, years ago. First learned about how it worked, in college. Tried it in business first in the 80s on a lawn. The homeowner has me skip a small patch, and did not explain why. Found out later it was his test to see if it made a difference. He called me many months later to ask what I applied, because all the areas improved except the section he had me skip, and that he wanted to apply in that area too. Basically, it chemically aggregates soil in a similar fashion to how organic matter chemically aggregates soil. Except that with decayed compost, it's a complex sugar and glomalin that do the job.
"When gypsum is added to a soil containing substantial sodium, the calcium and sulfate separate. Calcium has two electrical charges and is a stronger element than sodium with only one electrical charge and will replace the sodium on the clay particles of the soil. The sodium is then free to react with the sulfate to form sodium sulfate which is very water soluble. The sodium sulfate then leaches downward in the soil and out of the root zone. Since the sodium has only one electrical charge and the calcium that replaced it has two, the calcium has the capacity to attach several clay particles together, thereby creating soil aggregates. These soil aggregates make the soil more friable and granular with an increased water infiltration and percolation rate" "Gypsum will not improve soil tilth, structure and permeability unless excess sodium is present. In most areas of heavy clay soils, sodium is not the problem. Consequently adding gypsum simply adds additional calcium and sulfur to the soil. In many cases, the soils contain more than enough calcium so adding the gypsum makes the overall nutrient availability less favorable" "If heavy clay soils are the problem, and they do not contain excess sodium, the only practical solution is the addition of some structural material to improve soil tilth and structure. Adding organic matter will improve soil tilth, texture and permeability, but only for relatively short periods of time. For example, adding peat moss will aid the structure of a heavy clay in Oklahoma for little more than one year before the organic matter is decomposed by microorganisms. Adding sand, calcined clay, pea gravel or other non-organic structurally stable material, will help only if enough is added to reach the threshold point. The threshold point is that amount of sand required to hold all of the clay particles apart" --Whitcomb, Establishment and Maintenance of Landscape Plants (1987, Lacebark Inc., Stillwater, Oklahoma) http://www.lacebarkinc.com/establish.htm http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Horticultural Myths_files/Myths/Gypsum.pdf
I have very high levels of sodium in my soil....and the ph is 6.6. It is not really clay...it is loamy in texture also. Maybe the gypsum I applied will help.
It might make for a fun home soil experiment sometime. Trying different mixtures in a bunch of coffee cans or wooden squares and see how each one drains and changes over a year. Nothing is more certain than actually putting an idea to the test. It would be handy to know what Whitcolm means by excess sodium. Maybe it's less than we might expect.
