Advancing Eco Agriculture, Product Science

[orechron]

I'm also on the fence on how to properly use cover crops. This indoor round was the first time I've sown clover or anything for that matter in my soil along with starts. My goal was to have the clover grow with the clones then chop and mulch so the N contained in the nodules would be released in the first week of bloom for an extra boost. One thing I noticed is that there were no nodules on the clover roots. Maybe they weren't developed enough but I'm suspecting it has more to do with the soil C:N being around 10:1 and the clover has all the N it need and doesn't recruit the microbes to fix it.

Milky, where do you think silicate falls in the balance scheme? I've got some soil at 25ppm, some at 100ppm, and one other batch at 200ppm. I'll be messing with all of it in a month or so. Just wondering if you've found any research that suggests a target ppm? AEA guys say 50ppm right?

 

[milkyjoe]

you gotta tell me..I am thinking 100. But I have not actually been there so I don't know. I would love to know what the 200 ppm does. I think Jerry Brunetti did the best work on this subject, along with a lot of others.

I gotta say I really like the 1/3 peat, oly and pumice mix. Plant went into it and is just kicking ass so far. I will try to get a pic in the next night or two. it drains nice and fast but it also retains water very well.

And yes AEA says 50 ppm. But they don't know any more than we do.

 

[plantingplants]

Orechron, I thought most of a cover crop's N comes from its above ground parts anyway? Re:nodules, your seed was inoculated, right?

 

[orechron]

The nodules are where the N is fixed. It was an assumption that there were significant amounts within but yes, protein in the above ground plant matter might be a bigger source. Either way I mulched all of it and the microbial products I use have N fixers so the bacteria are present. I just don't think with such a low C:N ratio that the plants need to recruit N fixers. My same thoughts on plants not recruiting mycorrhizal fungi in high P soils.

 

[milkyjoe]

I don't know for a fact but it appears my winter grass has dreadlocks indicating it may well have mycorrhizal fung infectioni. My weed plants did not show that. I pretty much don't know what is going on different.

 

[FoothillFarming]

I thought most of those N fixing bacteria were mostly present at soils above 7 ph? Are they really present/active in soil with a ph of 6.4?

BTW, never fixed the problem with Rejuvenate. Just ordered 30 gallons and had issues.

 

[plantingplants]

Orechron, Google says legumes need specific bacteria. Ie, clover needs rhizobium trifolii. While reading that I came across other info: if N is present in soil then plants will just get it there since N fixing is costly (carbs and sugar are used to break the atmospheric N down). Also, the majority of N is in the above ground biomass.

 

[oct]

I don't usually trip when I see cucumber beetles and know they're gonna do a little damage here and there. But They're on a whole different level this year. 6-8 of them are on every plant and doing some serious damage.

Google wasn't very helpful.

Solutions?

 

[maxmurder]

i ordered a 5 which is actually 2-2.5's. both had blown thru the screw cap and leaked a little during shipping i cleaned em up, burped em and i put one in storage and took one home. the one i took home i burped and resealed to shake up, took the lid off and set it down to get measuring up , i looked up to see a flow of rejuv spewing out like lava from a volcano, lost a bunch. went to storage 2 weeks after dropping off the 2.5 and it had swolen to point of tipping over and falling off the box it was sitting on and spilled all over the floor making a huge mess. they need to use that tape they put on the gallons. i thought i was being smart buying in bulk hahahah.
speaking of smart, my dog some how managed to chew and unscrew the lid of a 2.5 of special blend a and remove the cap without spilling or knocking over the bottle all over the floor.
does anyone know what is in the special blend a and b?
is it just mixtures of all the bottles?
just wanna know if i'm being redundant adding sea shield, rejuv etc when feeding with sb a and b.

 

[maxmurder]

I don't usually trip when I see cucumber beetles and know they're gonna do a little damage here and there. But They're on a whole different level this year. 6-8 of them are on every plant and doing some serious damage.

Google wasn't very helpful.

Solutions?

yeah they seem a little early here too, started seeing a couple in my greenhouse last week.
i was told that most sprays or bt's won't do shit. these guys had it really bad and tried everything and finally took a shopvac and sucked em all up then put em in a little blender and made a slurry, then smeared the slurry all over the gh, i guess they put off a pheromone or something that keep new ones from coming in.
i was told their whole purpose is to get into your soil to come back next year and to use preditor nematodes in soil once a month to kill any larva.

 

[plantingplants]

Oct, no experience myself but Google says beneficial nematodes offer control of cucumber beetles, as well as certain braconid wasps. There are also lures you can use to trap them. Apparently they're very attracted to cucumber plants, so I would put some out and let them leave on their own.

This is pretty comprehensive: http://www.agrisk.umn.edu/cache/arl02957.htm

 

[orechron]

Plantingplants, is that species needed for all clover varieties? I was just banking that one of the few azotobacter or rhizobium would mingle. I don't think I'll bother with it anymore because there is plenty of N present. Maybe switch to a grass for a deeper root system.

Foothillfarming, I'd bet there are many N fixers present in low pH soils. You can see vetch going in the native clay soils around here (5.0-5.8 pH) and lupine growing in the cascades (5.0-6.1 pH). There is little N in these soils so they probably have to call in N fixers.

Oct, did you get your micro sulfates drenched in? The only time I had cucumber beetles was when my plants started putting roots below my amended topsoil and into infertile clay below. Sap pH was high (7.0-7.2) because the top foot of soil had plenty of Ca and Mg but was way overloaded with all K (10-14% base saturation). I didn't have enough anions in general and my micros were low. If I remember right your base cations are good. Sea shield has helped me with insect pressure on a few occasions. I'd probably spray micros and kelp as well.

 

[oct]

Great advice. It would suck to spray a deterrent because all my ladybugs would vanish as well. I did get all my micros in. I've been laying low on foliars because I was out of town for a bit and didn't want my guys to mess anything up. Now I'm back and gonna start hitting them. Nutri-live and kelp will be sprayed very soon.

I'm gonna try the blender method and get some cucumber plants today, hopefully they jump ship.

Thanks bros

 

[milkyjoe]

oct...AEA's flea bettle rescue...

FleaBeatle Pressure
FOLIAR
Product
rate per
1,000 sq. ft. unit
Micro 5000 1/4 tsp. by volume
Pepzyme C 2 ml.
. Sea Stim 24 oz.
Sea Crop 12 oz.
Sea Shield 12 oz.
MicroPak 3 oz.
Salute/Rebound Mn 6 oz.
PHT Ca 6 oz.
Water 60 oz.

Ignore the acre shit but do use the 1000 sq ft stuff. Micro 5000 and Pepzyme are real keys to small insects.


edit...let me clear that mess up some


The water is the minimum amount you should use...more is easier. Also you can replace the PHT Ca with Albion...better response on the meter.

 

[plantingplants]

Milky, why does Albion ca metalosate smell so terrible?

Orechron, yea all true clover. Sweetclover needs a different one and is part of cross-inoculation group A which includes alfalfa. I finally found numbers on N in legume cover crops-- 75-90% of N is in the topgrowth. N is 3-4% of the topgrowth mass. (18-24% protein)

 

[milkyjoe]

I think it smells like whey protein...I would not call it terrible

 

[Dab Strudel]

I went ammonium sulfate because S was 17 ppm and I do not want to add elemental sulfer until after the growing season...I do not want to kill microbes right now.

You need to study cation exchange some...all of those cations do not = a constant. You are leaving out H+, it makes a huge difference.

You need a balance of anions just like you need a balance of cations. So sulfate needs to be in balance with phosphate, nitrate, silicate, molybdate, B, Cl and other anions.

Even Monsanto understands the infrared dinner sign. Every element has a different mass, mass = energy, every element has an energy that gives off a specific infrared signal...the right ones combined puts off a specific signal that draws insects. The work was done at Florida U or State...Tom Dykstra.

Cover crops should live off the exact same elements your plant does. If you do not have enough minerals to support an additional crop you have cut it to close and need more dirt or to fill that cec better.

A decent cover crop is going to fix somewhere around 100 lbs of N per yr. If you go to your local university extension they can be more specific.

Your biggest problem will be keeping the cover crop alive when your plant shades it out.

See... now I am diving into molecular learnings. Got me learning the periodic table and associated items of information (all the while kicking my 6th grade ass for blatantly ignoring this 'needless' information.) Can you please add or subtract the elements that we have to manage, I have not a clue what comes from rock dusts so Ive got 21 (not sure if the 'rest' of the 82 elements are something that we have to consider in TCEC or how to go about measuring them when making a new soil.)
H, B, C, N, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Mo.

Late summer is one of the best opportunities for vegetable growers to establish a legume cover crop to supply the following year’s nitrogen needs. Planting in late summer allows time for the legume to establish in the fall. Enough fall growth is needed for the plants to develop a strong root system and enough shoot growth to provide valuable winter cover. Most of the nitrogen is fixed during growth in May... Legume winter cover crops provide a great deal of nitrogen. If well-managed, they can provide as much nitrogen for the next crop as fertilizer containing 100 to 150 lb/ac of nitrogen.

If the N fixes around 100 lbs a year, what happens to it all? Does it become available on the exchange sites or does it stay in the heterocysts? If it hits the exchange sites, wouldnt we want it to die off around the time the plant shades it in order to not fix 'too much' N for the sake of the ratios, availability of other nutrients, and the insects that feed off of too much N?

Legumes (alfalfa, peas, beans, clovers, vetch, lupine) have a symbiotic relationship with soil bacteria; bacteria provide legumes with access to the nitrogen in the air, while the roots provide nutrition to the bacteria. The nitrogen is stored in nodules on the roots and remains in the soil for other crops to use. In tests, hairy vetch sown in fall and turned under before planting tomatoes increased yields 45% over those using black plastic mulch. It also enabled the plants to produce longer into the season. Hairy vetch not only fixes nitrogen but smothers weeds and improves the soils ability to retain water. It is also more drought tolerant than other vetches.

I think that answers that... So IF it does stay on the nodules how will it effect CEC..? regardless if the cover crop stops fixing at a certain point (which I do not think happens) how would you end up managing the amount of N? On one hand, if you have to keep the N levels down in the soil to fix the N in the air, how would that fare to the ratios of the exchange sites? On the other hand, if N does fix from the air despite the amount of N in the soil, how would we manage to keep the plant from using more N than we want during flower? My presumed answer to the latter theory is that (atleast in the case of the folks who are close to peaking photosynthesis) the plant will just take what it needs, but not over indulge, coming from John Kempf's talks. I could be way off base, rebuttals?

There are easter eggs in these articles

 

[milkyjoe]

This is Humphrey Davy's explanation of cec:


From a soil perspective.....

CEC refers to the number of negative sites, expressed in meq/100g, or how many cations it will hold per 100 grams of soil.

say your soil has a CEC of 10. It holds 10 meq/100 g of soil. So if all the sites were taken by Ca, that would means that 100 grams of soil could hold 200 mg of Ca. My point is, meq weight of calcium is constant.

Also when they refer to lb/acre, just view the "acre" term as 2 million lbs (the assumed density of field soil, 1 acre 6" deep weighs 2 millions lbs)

So into the wormhole even deeper...

Labs test a specific volume of the soil and assume it's density.

Labs take a set volume of your soil, they assume they're dealing with say 100 grams, when really they have say 25 grams. So if they say your CEC is 15, that means it can hold 15 meq/100 grams of soil. However, it's actually 15 meq/25 grams of soil, which in CEC would mean 60 meq/100 grams of soil.


Bottom line, the ratios they give you in your reports are correct, it's just that they assume your soil per weight hold less of everything than what it does. However in C:N tests they actually do take your density into consideration".

So it is the negative sites that determine a soil's cec. Nothing to do with what elements are present. Now some cations, like Ca in excess give a false reading for tcec just because of the nature of the test. But true cec is fixed based on the soil itself.

Nitrogen is tricky because it can exist in different states...it can be an anion NO3 and that is the one plants will take up more than they need. It can exist as NH4, a cation which can be stored on cec sites or as a neutral, protein, where it is used in microbiology.

Our concern is to get enough for yield. But to limit NO3 particularly in the plant NO3 always brings water into the plant with it so it "waters down" the sap resulting in more water, therefore less cations. It is also the thing that will most attract insects

Mo is key to controlling this. It is part of the nitrate reductase enzyme. That enzyme allows NO3 to be converted to protein.

 

[Dab Strudel]

That is about how much I understood. What I didnt understand I just read about. Later I will get more into what else is not coming together for me and go from their. I am stoked so much science is involved in 'growing pot'. Since my final in Microbiology I am so fascinated with microscopic beings. I didnt take the whole class, but when you have to do a final on Aliivibrio Fischeri you cant exactly wing it. Good stuff..

Clay particles generally have a negative (-) charge, so they attract and hold positively (+) charged nutrients and non-nutrients. Soil organic matter (SOM or just OM) has both positive and negative charges, so it can hold on to both cations and anions.

http://www.soilminerals.com/Cation_Exchange_Simplified.htm

 

[milkyjoe]

http://buildasoil.com/collections/composts

Orech...check out the test results for the pinto bean compost. A tcec of 79 and it is filled. Is probably as heavy as top soil but holy moly there is some stuff in it. I got to meet the guy that makes it, he uses it to feed peach orchards. Nice dude. But no surprise, high in P and K.

I made a batch with SS 4 (2 bales), 2 cf of stutzman chicken shit and 2 cf of pinto bean compost. We will see what we see.

Just a hint for anyone...do not drive around in the hot sun with stutzman's in your trunk. Holy shit my car stinks.