Dale, where do you grow? Very interesting post.

I grow so many orchids outdoors in Florida and find certain plants seem to have nutritional deficiencies despite regular fertilization.

Would be interested in what you grow and where you grow.

Thanks,

Jane

Currently growing in So.Calif. Growing CA Native Plants, a Few Landscape Plants, and Vegetables. Starting Bonsai Hobby backup. Grew Pines, Manzanitas, Sage Brush, Ca Incense Cedars for restoration project in 2000-2002 Anza Ca elevation 4500ft.

In addition, correct Irrigation water from pH 7.5 to 6.0 before adding fertilizer to water. Sometimes add Diatomaceous Earth to Irrigation water about 1 tsp per gallon . This is for Silicon and pest control. Some Silicon should become available by microbial activity. Articles about the importance of silicon for plant health and disease resistance, especially squash, cucumbers.

Food grade diatomaceous earth is often used in the garden as a natural pest control substance. However, many studies have also been conducted to analyze the effect that diatomaceous earth has as a soil amendment.

These studies have shown promising results, suggesting that diatomaceous earth may significantly enhance nutrient retention and moisture retention in soil.

Southern Cross University

A study conducted at Southern Cross University in Australia tested soils amended with fertilizer and various rates of diatomaceous earth, with the fertilizer acting as a control substance.

The study found that with the addition of DE, the nutrient level of the soil was significantly improved and the leaching of any fertilizer was greatly reduced. The results of this study suggest that the addition of DE to soil amended with fertilizer may allow for more efficient use of fertilizer and reduce the impact that fertilizer has on the environment through leaching.

As a result of this study, it was also discovered that food grade diatomaceous earth improved the retention of moisture in potting mix, soil and sandy soil by holding a greater bulk quantity of water and drying at a slower rate. As well, it has been shown that the addition of DE to soil can increase drought resistance when added to the sand of golf putting greens.

Silica the Hidden Cost of Chemicals

Forgotten Element, Silicon

The benefits of silicon fertiliser for sustainably increasing crop productivity

Silicon: An Essential Plant Nutrient?

What an excellent post! Many of the regulars here argue that silicon is not available to plants from DE, and the one study you linked to actually says just the opposite! Once again they were completely wrong! I wanted to add that I use larger pieces of DE as a soil amendment instead of using perlite. You can obtain it from a number of sources Optisorb and Napa floor dry are 100% DE and it is what I use.

http://www.sciencedirect.com/science/article/pii/S0341816212001841

http://www.sciencedirect.com/science/article/pii/S0341816211001615

I haven't followed the Discussions very long,just recently started.When I posted weighting of containers for irrigation scheduling. It seems time consuming, but once you get a reference you can then go by feel or number of days. When you have a tray of 200 seedlings, you don't want test each container with your finger. So you go by a average value for the tray.

Why not add DE, it won't cause problems either way. It may be less available if the DE is Calcined. I think the article is referring to untreated natural DE.DE has other benefits in the mix. One is more Plant Available Water stored , than Calcined Clay (Turface, Oil Dri etc) . This is because of it's larger pore dimensions. ( Less Capillary Tension holding water). Its better to try something, to test your theories. Most discoveries have been made by accident through history. Organic acids slowly dissolve rock to release plant available nutrients. It was stated that plants take up Silicic acid. They are constantly discovering many things about mycorrhiza and other soil life helping plants take up nutrients. But they do add a more soluble form of silicon for Hydroponic solutions.

Maybe set up a test with Cucumbers or Squash. Plant a number of plants or seeds in containers each using different media. One without DE, With DE in mix, Watered with DE solution. Compare the results of plant growth, health, lack of moldery mildew problems etc. Another reason I started watering with DE food grade, the ants have been a problem this year. They are getting into the soil of some containers.

Dry Fertilizer Application Rates Calculation Methods

A general rule used in agriculture is the soil weight for 1
acre (43,560sqft) 6” depth weights approx 2 million Lbs. So when their soil test
recommends 100lbs Nitrogen per acre. The PPM Nitrogen content applied is 1/2
the value in lbs 100lb/2 = 50ppm.

A helpful correlation is that Ounces per cubic foot is equivalent
to Grams per Liter. A teaspoon is
defined as 5ml (5grams @sp=1) or 1/6 fluid ounce. For example: when a soil mix recipe calls for
5lbs of 5-10-10 per cuyd (27cuft). This
is equal to 5lb*16/27 or 2.96oz/cuft or
2.96 grams/liter. To convert to teaspoons divide grams by 5 or 2.96/5 = 0.6
tsp/liter about a heaping ½ tsp. If the fertilizer weight is less than water
sp=1, then divide the previous result by the fertilizer specific gravity usually
0.67 to 0.8. A #1 nursery container is about 3 liters in volume.

For PPM application methods , it usually based on the dry
weight of the soil. You can use the weight of water (sp=1)1 gram per cubic
centimeter (ml) or Loam Soil about 1.42 grams per cubic centimeter (sp=1.42). For example:
If you wanted 100ppm N in 1 liter (approx. quart) of mix using 5%N
fertilizer. Then use 100* 1000cc/1,000,000 = 0.1 grams N. This is (
0.1grams/.05) * 1 or 2 grams 5%
Fertilizer based on sp=1 or about ½ teaspoon/Liter.

Most recommendations are for about 1.2 grams N per liter per
year (0.1gram N/month). This is 100ppm N monthly at sp=1 . Example using Osmocote
15%N 6 month release period. For a liter
of soil mix add

( 0.1grams *6months )/.15 or 4 grams Osmocote about 1tsp per
liter ( 1 TBS per #1 Gallon Pot really 3Liters).

I use food grade for pest protection, so i don't really need the Calcined DE for silicon. I don't really care to run a comparison as I it would be such a small sample, results would be statistically insignificant. Observation tells me I have better results compared to the years I didn't use it. That's good enough for me. Any comparisons would be po-poed by the users here anyway. I don't really care what others do, i know it works for me. I suggest others try it and see for themselves.

Dale - did you ever use an EC meter for determining fertilizer concentration?

And what are you using to lower PH?

I received a new EC and pH pen about 3 weeks ago. Haven't used the EC yet. Wanted to start testing growing medium salinity more it the future. Wanted to use the Pour Thru Method. As far as concentration , just trusting the manufacturer's posted nutrient analysis and mathematics. Have you found errors in the calculated solution values? PH adjustment just use 5% acetic acid Vinegar. Just started using pH adjusted water a couple weeks ago. Started to notice some yellowing in the low pH plants( Birchleaf Mountain Mahogany , some Manzanita's). I have high alkalinity water, city water report states 200 to 300 ppm calcium carbonate, and only 20ppm Mg. They are perking up now :-) I just wanted to get more detailed in the propagation to see if the results are worth it. The scientist in me wants more accuracy, versus the engineer saying close enough. The biggest challenge is irrigation optimizing. I really like capillary mat methods of irrigation, also Net Pots or other Air Pruning Containers. Getting great results, less work .

Side note: Also it seems Palms get more leaf edge scorching not sure if Potassium Low , Salinity High, or other nutrient problem.

Just received new Sun Groer issue. Link to article

The Sun Gro Silicon Story

Dale, I appreciate your posts and knowledge. Please continue to post.

It is like a breath of fresh air.

Thank you,

Jane

Dale - I'm still waiting to get my liquid EC tester in the mail. Hopefully should arrive by next week! I've been calculating based on manufacturer recommendation as well.

My soil EC testers are usually reporting 0.1 to 0.2 ms/cm for my container plants. Out in the yard I tried to keep my flower bed around 2.5 ms/cm or so for the summer.

What I found is that rain water leeched my outdoor flower bed MUCH faster than expected, so it was pretty much worthless to follow the manufacturer's instructions. Instead I relied on my actual soil readings.

For my container plants, I expect EC concentrations to decrease even faster since I water so much more frequently (as opposed to relying on rain). I am also soaking my pots when growing indoors since it lets me water everything much faster.

Which is why I haven't been terribly shy/worried with fertilizing my plants, coupled with the fact that my growing media has a very low CEC.

My end goal is to water routinely with my desired EC amount and then flushing every couple waterings just in case. However, with my soil EC meters it's easy to check that I don't have detrimental salt build up.

Is there a reason you're using acetic acid/vinegar instead of phosphoric acid/ph down? I've been debating between the two, although many hydroponics growers discourage vinegar. That's an extreme case of container growing I suppose, but the same reasons apply.

I have obtained a copy of my local water quality reports with specifics on inorganic and organic parameters in mg/L or ug/L, just that I haven't quite spent the time to figure out how each amount relates to plant micronutrient requirements or toxicity.

Mycorrhiza and soil phosphorus levels

Mycorrhiza and soil phosphorus levels

A SIMPLE METHOD FOR MAKING YOUR OWN MYCORRHIZAL
INOCULUM

A SIMPLE METHOD FOR MAKING YOUR OWN MYCORRHIZAL INOCULUM

I wanted the EC meter mainly to periodically monitor the growing
medium for excessive salinity. The units are in mhos (ohm spelled backwards) or
siemens in metric system. I know they use EC more in Hydroponics for their
nutrient solutions. Plus include EC and TDS values to use for various crops. For
container gardening the EC would show all dissolved solids. I not sure how to
differentiate the individual nutrient amounts. I also thought EC would be
useful to test the CRF and Organic Fertilizer release rates over time. With
salinity I would have to look at charts to see the tolerances of various
plants. Plus its a new tool to experiment with. I was using Vinegar for convenience.Phospheric
acid is used by many growers, plus provides Phosphorus. It may to caustic for
me at home. On the Water Report mg/L is equivalent to ppm,and ug/l to
parts per billion. To me things
like pH ,Alkalinity ,Magnesium Calcium, Boron were important.There are some
good info on water quality metrics on the web and Nursery Manuals from

http://www.rngr.net/publications/nursery-manuals
.

Adding to the
Fertigation notes. I was using Constant Feeding for small container, maintaining medium fertility
at a specific PPM desired. Some use a Periodic Method , heavier doses at longer intervals(
every 1 to 2 weeks). Irrigated with
plain water between applications, for an averaging effect for PPM. Periodic Doses are usually printed on packages
such Miracle Gro. One can make their own
custom solutions based on various Hydroponic Formulas. I have many small containers with different
needs and small quantities of irrigation solution needed. Have been using travel bottles with drip tops
filled with 5 to 6% N solution to add to 500ml to 1 liters of water. Mixing 5 to 6% solutions by adding dry Soluble
Fertilizers to correct amount of water.

%N Solution= (grams fertilizer/ grams of water)* (%N/100)

1tsp =4.93grams at sp=1 approx. 5grams/tsp

Most salt based fertilizers such as Miracle Gro have a
sp=0.8, according MSDS sheet of product.
For
Dry Fertilizers, purchased 1/10 tsps for small quantity applications, 1/10 tsp
made for more accurate measurements.

Fertigation Notes for Tree Seedlings, Notes from Container Tree Nursery used for Conifers.

Notes From Native Plant Nursery for Fertigation and CRF Applications.

Fertigation Breakdown analysis example :

I will use Grow More Cactus Juice 1-7-6 , and Shultz Cactus Plus 2-7-7.

Apply at 1tsp/ Gallon
so the Nitrogen rate would be:

(1tsp/768tsp water)*1/100=
1.3e-5 or 13ppmN

(1tsp/768tsp water)*7/100=
9.1e-5 or 91ppm P2O5

(1tsp/768tsp water)*6/100=
7.8e-5 or 78ppm K2O

Shultz Cactus Plus 2-7-7

The dropper supplied might be larger than standard size.

How to Apply

Shake bottle well
before each use.

EVERY TIME YOU WATER:
Apply 7 drops (1/8 tsp.) per quart of water. Water from top to bottom, avoiding
wetting the leaves.

1 quart is approx 0.95 Liter, use 0.95 a proportionality
constant if wanted. Using the 7 drops per 500ml or ½ liter correlation . (7drops* 2%N)/2= 7ppm N constant feed.

If using 1/8tsp reference: 1 quart= 192tsp

(1/8tsp/192tsp)* (2%/100)= 13ppmN

ONCE OR TWICE A MONTH:
Use up to 14 drops (1/4 tsp.) per quart of water.

Drops per tsp on label listed as 56? Big dropper supplied? would be 25ppmN at 1/4 tsp/quart.

Using the 14drops per 500ml or ½ liter correlation . (14drops*2%N)/2= 14ppm N

When to Apply

Use every time you
water or once or twice a month.

Where to Apply

Can be used on all
cacti and succulent plants.

This is not the
product label. Always read the product label before use.

Coverage Area

7 drops (1/8 tsp.) per
quart

One full squeeze of
the dropper dispenses approximately 14 drops.

4 fl. oz. Container:
24 tsp., 192 quarts, 48 gallons

It seems that 13ppm N is recommended for constant feed rate on the packages for both products.

Some Fertigation Rates per Plant Type

Finally got my EC meter today! I wanted to share the readings for the fertilizers I had around the house.

Dale, hopefully you don't mind that the measurements are in µs/cm. I find this a bit more useful because it avoids conversion factors and my soil EC testers are in mS/cm.

Readings are EC @ Manf. Recommended Dilution (Manf. Recommended Usage):

• 4 µS/cm - Distilled Water
• 328 µS/cm - Tap Water
• 368 µS/cm - Miracle Grow 12-4-8 @ 5mL/4L (Houseplants)
• 498 µS/cm - DNF Gro A 2-0-2 & B 0-1-3 @ 2x1.25mL/1L (Container Plants)
• 453 µS/cm - Plant Prod 20-20-20 @ 6mL/5L (Houseplants)
• 642 µS/cm - Plant Prod 15-30-15 @ 6mL/5L (Houseplants)
• 136 µS/cm - Schultz Cactus Plus 2-7-7 @ 0.61mL/1L (Indoor Succulents)

Note that the fertilizer EC readings above exclude my tap water EC reading. Which means that if I used MG 12-4-8 at the recommended dilution with tap water, the resulting watering solution would be an EC of 695.5 µS/cm.

For reference, over the past many months I have been fertilizing every other watering with a ~560µS/cm solution.

Which I would say is pretty good news. These rates for fertilization are very reasonable (although the usefulness of their NPK ratios is debatable).

Next step for my own growing knowledge is to measure the EC of my watering leachate (Pour Thru Method or 2:1 Method) and confirm what my soil EC testers are reporting.

Hopefully I will be able to solve many other things I've been thinking about as well. =)

ewwmayo did you get info with the meter to correlate EC to PPM or TDS?

Dale - My EC meter gives TDS PPM with a 0.5 conversion factor. Different EC meters can use different conversion factors to PPM (0.5 to 0.7 typically), which is why I like µS/cm or mS/cm.

General Rule of thumb is to add 1lb Limestone/ cuyd of mix for each 10% of Sphagnum Peatmoss in Mix. May apply to Bark also.

When making 5-1-1, which is 5 parts pine park + 1 part peat moss + 1 part perlite, guidance (and what I do) is to use 1 Tablespoon of dolomitic lime per gallon (volume) of mix. I also use Dynamite All Purpose Select CRF which has favorable NPK ratio and most but not all micronutrients.

I have had good results, but never measured it in any way. This mix is meant to replaced annually but I sometimes leave a plant in it for 2 seasons.

85.7% Peat and Bark in mix, so about 13 grams limestone/ #1 container (3liters) is 2.6tsp close to 1 TBS (3tsp) 1 US Gal 3.785 liters 2.6* 1.26= 3.2tsp. Also depends on final pH, the previous post was to get about pH 6.5 target I think.

Where do get the Dynamite All Purpose, I cant find it locally. I would prefer this over Osmocote.

I wanted to ask what everyone was referring to as a Gallon of Mix. Was it a True US Gallon 231 cubic inches or #1 Nursery Container which they just call a 1 gallon container?

i use gallons measured with a bucket meant for mixing paint that is graduated in gallons and maybe also quarts. I am assuming it is a true us gallon.

I've been interested in mycorrhizal associates of plants for decades now. Very generally speaking, most studies I've reviewed where an attempt to "inoculate" soils or media with specific strains of known mycorrhizal species have been disappointing. Notable exceptions were in cases of extremely depleted soils, mine tailings, and other essentially "sterile" media. Now this is not at all intended to cast doubt on the importance of mycorrhyzae. Just the opposite, they are indeed being proven to be everywhere, in every type of plant community, and in virtually every geographic region. What I am saying, is that so far, man-made attempts to duplicate what nature does every day in this regard have been decidedly unspectacular. It seems that two effects are in play: One, if the soil and associated plants have been in association with one another for a good length of time, very likely such mycorrhizal associates are already present. Adding more, in the form of supposedly viable propagules will not effect the balance. The other aspect is, nobody really knows exactly what species is associated with a given landscape plant. True, there is such knowledge in silvicultural studies, usually associated with coniferous species, but to simply extrapolate what is know there to your average garden situation is extremely unlikely to work. Additionally, we do not know what is happening when a soil already colonized by such organisms is having another strain, or an altogether different fungal species, introduced to it. Are we accidentally ruining a good thing? Are we just wasting money and effort?

I find such matters of immense interest, and I don't think the book is closed, just that perhaps it needs to be set aside for a while and taken up again later when understanding has increased. This is complicated stuff, especially in a world where very large acreages of land are given over to just two plant species-corn and soybeans-where the parameters of nutrient requirements have been pinned down tightly. In other words, mankind's largest horticultural enterprises are vastly more simple than what is likely happening in that little wood lot that didn't get knocked down for more development near your home. We're rank beginners at this...may as well face it.

+oM

Edit: Correction The Limestone 1lb per cuyd (27cuft) (0.6g/Liter) (0.12tsp/Liter) for each 10% Peat or Bark was for 1 point pH increase. This is where the 1/10tsp comes in handy and for very small containers.

Tom- Finding Phorphurous levels affecting mycorrhizal activity , usually >50ppm. You should see the Ecto on Pine Roots in Containers, and Mushrooms on the container surfaces. Local strains are always better I think, trying to culture with trap plants. Using Dr. Earth Fertilizers to see if i helps. Using Mulch with high C/N ratios favors Fungi Environment. The Oaks need the fungi, sometimes summer watering or excessive fertilizers kill oaks. Due to Fungi disconnect protecting roots from diseases. I am trying to encourage the Mycorrchizal as much as possible with Lower fertility levels, mulches, etc.

I like the direction you are taking, Dale. I have a tree plantation in the "near north" area of NE Wisconsin. Sandy yet loamy soil, lots of rocks, used to be an alfalfa field which suggests at least some ag-soil tendencies, but very near the line where farming stops abruptly, and on into National Forest. The point of all that is, we have now planted just under ten thousand seedlings, nearly all pine-family members-white pine, red pine, Norway spruce, and hybrid larch. Planting on this scale means zero aftercare...the plants are literally on their own from the second they go into the ground onward. No supplemental water ever. No supplemental anything! The growth so far? We began in 2008 with the first few, then went nuts a couple years ago and pretty much finished covering the acreage. To say this has been successful so far would be an understatement. Now this isn't big, long Florida growing seasons here, but much shorter N. Wisconsin version, yet of the original plantings in 08, many trees are now 25 ft. tall. We are blessed in having numerous tracts of nearby forests, including some of our own, from which spores of beneficial fungi are able to travel freely in the wind. And while I've never done the study to be certain, I'd be willing to bet mycorhizzal associates have moved in, their being of the macro-fungi type that produce visible mushrooms, things like especially boletes. It is my understanding that each pine-family member is associated with its own fungal partner, that there is surprisingly little crossover from species to species. At least, that's where my knowledge stands today. Always open to revision as more data is captured.\Not much to do with this thread or indeed, this forum, but a fascinating aspect of plant growth, one which-I believe-will be of major importance in the world ahead.

+oM

I did reforestation projects on my property in the early 2000's. That started me in studying Propagation and Outplanting survival techniques. Now combining Forestry, Permaculture Techniques ( soil building, water harvesting, Chop and Drop Mulching, etc). I grow Alfalfa, Cowpeas, and other Nitrogen fixers( wildflowers like lupines) in my yard for soil building. Just use occasional clippings around yard. Alfalfa is one of best fertilizers I have found also, the roses go crazy. One great product is the Groasis Waterboxx by Pieter Hoff.

This is a quite different thing we're at on our site. No "permaculture" per se, though I know of and support much of that. This is reforestation plain and simple, in an area of the country very well-suited to such a venture. That said, all the farmers around me think I'm nuts for taking "good farmland" (no, not really, lol) out of production and back into trees. Everybody else around there is clearing land, which breaks my heart. More corn and soybeans, yeah!

Actually, in terms of getting itty-bitty tree seedlings to grow, the alfalfa was a real b*astard-easily one of the toughest competitors around. Then my farmer guy (he rented land from me) wanted to grow corn. Well, I didn't want my land plowed up but a forester who was working with me said corn is a good base to subsequently plant trees into because it leaves a "clean field". So I relented and in the corn went. Well, I wasn't thinking about it too much but this guy, like every other farmer in America, wanted to go with Roundup-Ready corn seed. I was OK with that since glyphosate leaves no residual effect. Heh, I was in for a surprise.

True enough-no residual effect whatsoever, and up came the annual weeds...weeds like I've never seen before. Try to imagine 20 acres solid ragweed, head-high, pollen just billowing out of that crap! This is what my field full of tree seedlings was after one year. Doing anything about it was out of the question, and that turned out to be exactly the right move-none. By the second year, every bit of that ragweed was gone, completely changed over to perennial meadow species, things like giant Canada goldenrod, asters, etc. All the while, the seedlings were making surprisingly good growth in that cover. I couldn't have formulated a better plan really. Now, most of those little trees are up and above the weed layer. In short, they are winning the battle for light. But again, I'm taking this way OT...but the main point is this is 100% no-input growing. Only the rain and snow that falls from the sky, zero other inputs....and it's working extremely well. What it has to do with container gardening eludes me. Oh, I suppose you could say that in this case, the container is planet Earth!

+oM

Matching Fertilizers to Water Quality

http://www.pthorticulture.com/en/training-center/matching-water-soluble-fertilizer-to-water-quality/

Potential Acidity/Basicity of various Fertilizers

24-8-16 potential acidity 667 pounds calcium
carbonate per ton (2000lb)

20-10-20
potential acidity 392 pounds calcium carbonate per ton

15-16-17 potential acidity 215 pounds calcium carbonate per ton

15-5-15
potential basicity 141 pounds calcium carbonate per ton

15-0-15
potential basicity 296 pounds calcium carbonate per ton

I came across another useful formula used by many growers to calculate oz/Gallon for a desired PPM concentration. They use the correlation that 1oz of substance per 100 gallons water is about 75ppm.

oz per Gal = PPM desired/(% nutrient *75)

Example: Using Foliage Pro 9%N for 100ppm N

oz/Gal= 100/(9*75)= 0.148 oz FP/Gal

You can approximate 2TBS and 6tsp per oz, or weight with a scale.

6tsp*0.148oz = 0.89tsp

If you want to adjust for FP density(Sp 1.33) 0.89tsp/1.33 =is 0.67tsp

Just round off to the nearest multiples of 1/4 or 1/8 tsps if desired.

Very interesting post, Dale, thanks! Regarding silicon supplementation w/ diatomaceous earth, what if I want to keep the ants in my garden? I'm using DynaGro ProTek (K2SiO3). The ants seem to do more good than harm, constantly aerating, tiling and redistributing nutrients in my hard adobe clay among other things (recently started a garden 6 months ago, so I need all the help I can get from ants and worms).