Development and Harvest Yields of Greenhouse Tomatoes in Six Orgnaic Growing Systems

[Dave Coulier]

Secondtry, Id like to hear your thoughts on something I read from Al, and Justaguy at gardenweb.

They both feel CEC is not at all important in container gardening. They didn't give any reasons, but I imagine some of them would be:

1.) We control how often they get fertilizer, so having a high cec to hold onto nutes isn't very important.

2.) We control the leaching of nutrients by how much run-off we allow. If we reduce our run-off we can eliminate the need for a high CEC in that regard.

Your thoughts?

 

[secondtry]

Hey Dave,

I like Justaguy, a nice person, I've had some contact with him years ago.

This is just off the top of my head and I may edit later, or correct, or clarify

1.) We control how often they get fertilizer, so having a high cec to hold onto nutes isn't very important.

If we used conventional horticulture (chemical fertilizers like Al and Justaguy) CEC is still important as it allows the plant to 'feed' between watering, this is important IMO.

2.) We control the leaching of nutrients by how much run-off we allow. If we reduce our run-off we can eliminate the need for a high CEC in that regard.

One quick point I am sure you know but others reading may not: negative CEC is for positive ions (cations) like N as ammonium, while N as nitrates are negative ions (anions), and they bind to positive AEC.

If lowering run-off one increases chances of nutrient lockout or imbalance especially as the media dries out between waterings over a series of waterings. CEC and AEC can hold ions throughout the media, while ions in solution (drench water) seems like they would tend to concentrat in the lower section of the media where pore sizes are smaller and water tensions higher. With lower water tension at higher areas of media the ions should more easily move downward within water, CEC helps mitiage this.

 

[Dave Coulier]

Hey Dave,

I like Justaguy, a nice person, I've had some contact with him years ago.

This is just off the top of my head and I may edit later, or correct, or clarify

If we used conventional horticulture (chemical fertilizers like Al and Justaguy) CEC is still important as it allows the plant to 'feed' between watering, this is important IMO.


One quick point I am sure you know but others reading may not: CEC is for negative ions (cations) like N as ammonium and P, while K and N as nitrates are positive ions (anions), and they bind to AEC.

If lowering run-off one increases chances of nutrient lockout or imbalance especially as the media dries out between waterings over a series of waterings. CEC and AEC can hold ions throughout the media, while ions in solution (drench water) seems like they would tend to concentration in the lower section of the media where pore sizes are smaller and water tensions higher. With lower water tension at higher areas of media the ions should more easily move downward within water, CEC helps mitiage this.

That paragraph is why Im glad you are here. I didn't even think about how drainage/water retention from top to bottom affects nutrient availability.

Since were on the subject of leaching. Here's a good one:

http://www.greenhousegrower.com/magazine/index.php?storyid=1691

PS. You've got your charges backwards for cations and anions

 

[secondtry]

Hey Dave,

Thanks, but I'm sure you would have thought about it sooner than later. And thanks for the link.

 

[secondtry]

And thanks for the correction of charges, doh! Opposites attract...


Fixed:

One quick point I am sure you know but others reading may not: negative CEC binds positive ions (cations) like N as ammonium and P, while K and N as nitrates are negative ions (anions), and they bind to positive AEC.

All the best

 

[Dave Coulier]

I was gonna buy some of those ewc, but I can't justify spending that amount of money on ewc. Bills come first sadly . Ill probably just buy 4.5lbs of wiggle worms for $5.

 

[secondtry]

Cool. I am ordering from Worm Power too. Let us know what you think.

 

[secondtry]

Hey,

Wiggle worm is good, no worries. I have used it before and liked it. It's a fine source of OM and bulk density.

All the best

 

[secondtry]

EDIT:


I wrote that the Worm Power vermicompost is composted vermicast but that is not correct. To remove human pathogen from cow manure feedstock that cow manure (and the corn silage?) is first composted (thermophillic) for 2-3 days to kill pathogen following USCC regs (or it could be a different gov body than USCC) then it's given to the worms.

From Worm Power blog:
http://wormpowerorganics.blogspot.com/

There has been much curiosity as to why we compost our feedstock material (dairy manure) prior to vermicomposting. On the surface, this may seem slightly redundant, but there are many key issues which the process addresses. The controlled thermophilic composting (natural high heat) process we utilize completes three things for us:

1. It removes some of the potential for the material to heat up (compost) after being fed to the worm population (removal of energy). The last thing we want is to have the feedstock material start actively composting in the worm beds; thus making the living conditions undesirable or uninhabitable for the worm population (higher temps);

2. PFRP = a path to further reduce pathogens;

3. Weed seed destruction. Finished products should be weed seed free;

4. Produces a richer feed for the worms.

 

[mad librettist]

I was wondering why they would want to break down all that valuable mucous and turn EWC to compost.

 

[secondtry]

Hey all,

Check out this study, I don't agree with all the statements but it's a good study for sure, the link is to the full text.

In the study the researchers listed the properties of SunGro soilless media, the makers of SunShine Organic Mix:

• BD = 0.3 g/cm^3 (that is a good level and mostly due to verm and perlite)
• pH = 5.7
• EC = 1.12 (that's kind of high)
• % Total N = 0.77
• Nitrate = 1242 mg/Kg
• Ammonium = 30 mg/Kg
• % OM = 63.6 (due mostly to peat)
• % Organic C = 34.3
• C:N = 44.7

Study:

Betsy Leonard and Anu Rangarajan. 2007.

Organic Transplant Media and Tomato Performance
Dept. of Horticulture, Cornell University, 2007
http://wormpower.net/pdf/Cornell_Organic _Transplant_Media_and_Tomato_Performance_2007.pdf​

Abstract:

Successful transplant production begins with good growing media. Healthy vigorous transplants will be less susceptible to insects, diseases and transplant shock leading to better crop performance. Formulating organic potting mixes is especially challenging. Organic sources of nitrogen such as compost can be inconsistent. Compost can change over time with storage and release nutrients unpredictably. Many organic potting mixes are supplemented with organic nitrogen sources such as alfalfa meal, soybean meal and blood meal. Another alternative N source is vermicompost, which often has more nitrate than the compost starting material. We compared dairy based thermogenic, dairy based vermicompost and hog based vermicompost along with plant based nitrogen sources for their impacts on tomato transplant growth.


When evaluating a potting mix for tomato transplant production, consider the following properties:

Physical Properties

• Particle size appropriate to container
• Density will hold up plants
• Good aeration and water holding capacity
• 10-20% air space, water (40-60% common)

Chemical Properties

• Nutrients levels low to moderate
• Salts and EC: 4-8 dS/m (saturated paste extraction)
• pH near 7

Biological Properties

• No plant pathogens
• Decomposition rate should be low

Need adequate supply of organic nutrients for growth

• Organic sources often inconsistent
• Compost based media-select a well-cured compost
• Some soluble fertilizer sources are available, such as fish meals

Release of nutrients from organic sources difficult to predict

• Some will result in ‘composting’
• Others increase salts

In 2007, we compared twenty one potting media including an industry standard SunGro and a peat, perlite, lime and vermiculite mix with no added nutrients (control). The control media was the base mix for other mixes. This mix was amended with thermogenically composted dairy manure, the same dairy manure feedstock but vermicomposted, hog based vermicompost, alfalfa meal (Eagle Mix 3-1-5 Alfalfa Meal, Bradfield, Inc, Springfield, Missouri and organic alfalfa meal, (Lakeview Organic, Penn Yan, NY), sesame meal (produced by the sesame oil industry), blood meal mixture and organic soybean meal (Lakeview Organic, Penn Yan, NY). In some cases, amendments were combined, to assess the additive effects to the media. The plant-based amendments were ground to a 2 mm mesh size prior to incorporating into the base mix. All mixing occurred one week prior to seeding.

Results and Discussion:

Most organic potting mixes tested supported good tomato transplant plant growth. All transplant mixes had similar physical structure, as indicated by bulk density values (Table 1). Compost amended mixes had much higher initial Nitrate-N content compared to plant amended mixes. Plants grown in Dairy Vermicompost with blood meal, Dairy Thermicompost with blood meal and Hog Vermicompost with blood meal were significantly larger than plants in other mixes (Table 2). Initial ammonium-N levels were 2-3 times higher in mixes with blood meal added. The addition of the blood meal mix increased fresh and dry weights of plants grown in these manure based composts (Table 2 and Figure 1). Although, blood meal did not enhance growth as dramatically when added to the peat base mix only compost based mixes. Adding blood meal seems to stimulate microbial activity in these mixes especially around March 9 (Figure 2). EC peaks higher in mixes with blood meal compared to the same mix without it. Bradfield alfalfa 5% produced a significantly larger plant than Alfalfa 5% which can be explained by Bradfield’s additional ingredients (meat meal, molasses and sulfate of potash). Alfalfa 5% mix started with 0.93 ds/M EC while Bradfield 5% mix was nearly triple (Table 1). Germination rates varied among the different treatments (p=0.0001) and were above 90% for all treatments except for Soybean meal 1 and 2.5%, which had final rates of 85 and 66% (Table 2). Both mixes had very low initial levels of nitrate-N and ammonium-N (Table 1).

Conclusion:

Compost based mixes enhanced with blood meal, rock phosphate and greensand produced stocky healthy tomato plants. Adding blood meal seems to accelerate nutrient release in compost based potting mixes. Alfalfa based mixes also produced smaller acceptable transplants. The commercial mix SunGro seemed to run out of nutrients more quickly than other mixes.

 

[Trichgnomes]

I have another source of microbe active compost passing SFI benchmarks.

Would you mind elaborating?

Sorry this is out of context, Second, I copied it and then kept reading the thread and got to a post in which you asked to not quote you out of context. I hope this does not misrepresent you,

 

[secondtry]

Haha. Damn you!

I was referring to CTGuy or the other online sources of compost for ACT.

All the best

 

[Cannalicious]

Dear secondtry,

I guess I don't know how to quote a small section of text, but on the first page of this thread, you mention how you use "drainless" containers. Can you be more specific with what this means and why you do it, or refer me to where you've answered this already?

Thanks,
-C

 

[secondtry]

Hey,

To quote a section of text you can copy/paste it and then put "[ quote]" before it and "[ /quote]" after it (without quotation marks and without space), or you can click the quote button at the bottom of the post and delete the text you are not interested in quoting.

RE: Drainless:
I don't use drainless containers, I am not sure what you are referring to. I know someone who did try to use drainless but it didn't work out too well for him. If you can quote me I can offer more info, sorry but I don't know what your referring to. FWIW, you don't have to use BB code (e.g., [ quote]) you could just enclose it in quotations marks.

Cheers

 

[Trichgnomes]

I don't use drainless containers, I am not sure what you are referring to.

IIRC, you use a air-pruning pot of some sort, no?

 

[secondtry]

Hey Cannalicious,

I think you mean "drainage layer", all that means is I don't suggest use a bottom layer of perlite (for example) which is claimed to increase drainage, but it does not. That's why I don't use a drainage layer, I use the same media all the way through the container, that counter-intuitively will increase drainage (verses using a drainage layer) while probably lowering the perched water table.

HTH

 

[secondtry]

Hey Trich,

Kind of, I used root girdling bags but the holes where too large to girdle cannabis roots other than the tap root (at least with LUI and Agent Orange in organic SunShine mix). I am ordering AirPots next week at the suggestion of CC.

A neat point is the morphology of roots is greatly effected by EC of media and the nutrient profile, along with moisture content.

All the best

 

[Trichgnomes]

I thought CC used smart pots (cloth), and my understanding is that he has had no experience with "air pots" (plastic).

 

[secondtry]

Hey Trich,

Thanks for the correction. I am not going to use Airpots, I meant the cloth kind, the SmartPots, oops.