How to adjust the major nutrients during the plant lifecycle?

[Azimuth]

Can someone point me to a chart or something showing when the plant needs what during its cycle?

I know higher P, for example, is needed for flower, but I also see it needed for root growth. And N should be dialed back during flower.

What about K? When does need for it increase/decrease?

Also interested in Ca, Mg, Fe, Si, and S, etc.

I've searched some and most of what I see are adjustments for using the major nute lines, but I'm more interested in learning the basics behind adjusting the ratios.

I'm kind of looking for ppm's.

 

[mgom21519]

Here's a chat for the main and secondary nutrients. The main 3 nutrients that matter are N.P.K
During seedling stage there is really no need to add nutrients to the plants for the fact their babies, the roots can't handle the uptake of the nutrients. Depending on the soil you use it contains the NPK already so the soil itself can feed your plant up to 2-4 weeks its first life. About week 4 is when you want to start actually feeding the plants nutrients and the main nutrients that matter most till flowering is Nitrogen which makes it grow leaves and produces sugars (chlorophyll = photosynthesis) for the plant to grow. Depending on what brand of nutrients you'll will use depends on the amount you will give it, usually the the company will send a chart on how much to use during each stages of life. Depends on how long you want to let your girls stay in veg. stage (the longer in veg stage the bigger you'll plant will get: a weed plant can be kept in veg. stage for a long time) usually its good to keep the plant in veg stay for about 6 weeks before switching to flowering. But, a lot of elements matter, when to switch to flowering such the size of tent which matters most because when you switch from veg stage to flowering your plants can grow anywhere from 2-3 times its size at the end of veg stage so pay attention to grow space. Once flowering stage starts take away the Nitrogen (still give it some but little amounts) and give your plants PK they both plant part for roots growth (better roots = strong plant better yield). The other nutrients matter on the chart but in little amounts look at the chart and is the basic chart to show what weed plants need to grow and the Ph level as well. If you have an question don't hesitate to ask!!!


PS
The ppm depends and defer on the brand of nutrients you are planning on using

 

[Azimuth]

Here's a chat for the main and secondary nutrients.

Thanks, Mg! That helps a lot. I'm planning on using organic inputs from other plants and they each have a different combination so I'm just trying to find the right approximate mix for the different stages.

 

[mgom21519]

No problem!!! You can check out my Grow Journal I'm doing organic but natural grow right now...another person you can check on is Nutty Professor on here

 

[Azimuth]

Thanks, will do. Nutty's been using the water based extractions of Jadam. I'm more likely going the KNF route, but all part of the same neighborhood.

 

[bruno12345]

Well, many questions science has still to answer.

And with all considerations regarding PPM, we got to know that there is a giant variation on Cannabis plants.
This means that different genetics may perform better than other, and even have different nutritional needs.

Veg NPK is already studied, ive posted it in the scientific part of this forum.

Around 160PPM for nitrogen.
Around 30PPM for Phosphorus.
and Around 100 to 160PPM for Potassium.

I agree that Phosphorus could have a part in the early root development (of seedlings and clones?), and maybe at initial flowering stretching burst, as its the "energy" atom.

Regarding P action in plants during flowering, an scientific paper named "Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes"

"C. sativa plants are to be grown for the florescence and/or cannabinoids or terpenes either for the fresh flower market or a distillate market, a P concentration above 11.25 mg·L −1 is preferred. While a P concentration of 22.5 mg·L −1 resulted in the greatest bud fresh weight when compared to the lowest two concentrations, it did not result in any greater increase in the active or acid cannabinoid pools. Additionally, higher P rates above 22.5 mg·L −1 did result in greater lateral production and consequently more nodes to produce the economic portion (floral material). Thus, a follow-up study should be completed to see if the increase in lateral nodes and floral material would result in a greater whole plant yield in floral material, despite the higher concentration of P resources not resulting in greater cannabinoid production in said flowers. Thus, for production in a cannabinoid or distillate market, a P fertility concentration of 11.25 mg·L −1 would be adequate, while for fresh market production, a P fertility concentration may be greater (22.5 mg·L −1 ) to account for more visually appealing floral material."


We know that Plants do have a mechanism for internal regulation of P, avoiding problems with excess.
So if i could choose, i would go for like 50 to 80PPM during flowering, looking for that greater lateral growth, and good energy supplying, also trying to reach the plateau on leaves.

Nitrogen in flowering has a negative relation with cannabinoids concentration.
So you could basically sacrifice yield by not using Nitrogen (or using small amounts), and producing very concentrated buds.
Or, you could go around 160ppm of Nitrogen, to have a good balance of cannabinoids and the greatest yield (i prefer this one).

Potassium has to be studied. A single article i found, testing 15, 75, 113 and 150 PPM of K, found the 75 and 113 concentrations to have produced the biggest dry flower biomass. But some genetics may increase production until 150... 170ppm of K.

Micronutrients the basic is, if you dont have a deficiency, youre fine. and there are deficiencies that dont even impact yield. Just be sure you dont have it, and be good at identifying the most notable ones.

 

[bruno12345]

Well Ca, and Mg i lack specific MJ articles.

But i guess you could use K:Ca:Mg ratios.
There is some people that stand for 41

Example:
100PPM of K
50PPM of Ca
25PPM of Mg.

Balancing these ones, you can avoid deficiencies.

 

[Azimuth]

Thanks, @bruno12345. I've been looking at various plant components from things like dandelion, comfrey, s.nettle, etc. and trying to see which might be better for different stages of growth, or even which combinations might work.

For example, comfrey is relatively high in both P and K, while nettle is relatively low in both. Both plants are widely touted as good ones to use for their nutrients, but comfrey might be better used in flower and maybe nettle in veg.

Also, nettle is relatively high in Ca and Mg, while comfrey is low in both.

So, maybe starting off with a nettle base, combining them in the middle and finishing off with comfrey might be a viable strategy. Not sure what the N component in comfrey is, but suspect it is also high which might not be a great thing for late in flower.