Well. Figured I would share some interesting results in my first ever no-till all organic grow. Guess it's not no-till yet technically but it's organic so "it's all about the microbes, man." Interesting experiment/results Intro: Chef Derek B. talks about plants balancing their pH when the soil is in balance. I have an interesting experiment from my recent grow notes demonstrating this process's successes and also some progressing results, in an all organic approach similar to Chef B's. This study holds promise for future study's basis on plants' genetics' preferences for initial soil acidity. One clone (Purple Punch) balanced a pH from an initial 5.0-5.5 pH to a perfect 6.0-6.4 pH at the end of a 13 day period without watering/feeding. One clone (Wedding Cake) had a soil pH change from 5.0-5.5 to 6.5-7.0 pH at the end of a 13 day period without watering/feeding. Last but not least one clone (Pie Face) did not have a change in soil pH, staying at 5.0-5.5 pH at the end of a 13 day period without watering. The interesting trend being, the healthier the plant, the healthier the pH change that occurred (Purple Punch being the healthiest). My hypothesis would be that the plant caused the healthy pH by working with the microbes in the rich medium, even though this is a well known theory. This research shows plants may or may not need/want a perfect pH medium to begin with, depending on the genetics. Methods: Started out with amended 420 Emerald Triangle Soil in 7-gallon fabric pots under 300W ViparSpectar light, with 3 clones in rockwool (pie face, purple punch, and wedding cake) in a 3x3x6' tent with a squirrel fan hooked to carbon filter pulling air through carbon filtered vent holes. My environment has averaged 78-80F during the day and has had 100% humidity at nights (outside, foggy). I use an AC to regulate temperature during hot periods and kept the inside of the grow tent below 85 degrees at all times. rH just outside grow tent averaged 50-60%. The amendments I added to the soils: worm castings (2" on top of soil mix), fish meal (1/4 cup, buried in the center), humic acids granules (2-3 tsp), insect frass (1/4 cup), and "Plant Success Tabs" (mycorrhizae) from Host Defense. I inoculated the plants when watering with Host Defense's soluble MycoGrow mix and also NPK Industries soluble kelp, Full Up (fulvic acids), OminA (amino acids), Silica (Extracted Diatamaceous Earth), and Yucca extract. Water used was PUR filtered and had a pH of 7.0. My water has 125 ppm of soluble calcium and magnesium from the tap. pH was pretty acidic in all soils (5.0-5.5 pH) when I first started the grow.
Results: All plants started with a 5.0-5.5 soil pH, even with a 7.0 pH hard-water watering, fulvic/humic acids, and 2" of worm castings. Purple punch, being the healthiest plant visibly and also the healthiest plant pH wise (6.0-6.4) at the end of the 13 day period, was over 1 foot tall, from an initial 4-5 inches, and looked perkiest/happiest. Wedding cake, being the second healthiest plant with the second healthiest pH (6.5-6.9 pH, a little high) at the end of the 13 day cycle, gained only a little bit of height (probably because of its parent of GSC), but still bushed out nicely in its own way. Pie face had the same pH at the end of a 13 day period without water, 5.0-5.5 pH, and was also the very last plant to start growing and also the slowest growing overall. She barely grew a couple inches and had only small leaves and stems form. The plants' individual pot pH represented the health of the plant well. The healthier the plant, the more in balance the pH (Purple Punch being the healthiest with the best pH of 6.0-6.4). Discussion/conclusion: The plants actually balanced their own soil's pH. At least 2 plants (Purple Punch and Wedding Cake) had significant changes in their soils' pH (5.0.-5.5 pH to 6.0-6.4 and 6.5-6.9 pH respectively). The fastest growing plant, Purple Punch, had the best pH (6.0-6.4 pH) at the end of the 13 day period and was also very healthy looking. Wedding cake, with its pH of 6.5-6.9, looked well adjusted at the end of the 13 day period and was starting to bush out nicely. Pie Face retained the same pH (5.0-5.5 pH) and also grew only about 25-30% compared to the other plants at the end of the 13 day period. This study indicates plants may prefer different starting acidity of soil depending on genetics, and confirms that plants work with microbes to balance soils. Pie face, having two parents with moderate to hard difficulty grow ratings (Leafly), probably was much more sensitive to the fertilizers I gave it compared to the other plants. For instance, although all plants exhibited slight salt toxicity (dark green foliage, brown crisping on lower leaves, epinasty, immobile element deficiencies in new foliage) at the beginning of the grow, Purple Punch nonetheless started growing almost immediately, and also is rated as an easy to moderate difficulty strain to grow. Genetics was the likely cause to the acclimation to the soils.
The pots retained moisture down to 2 inches for 13 days, and were visibly moist from above for about 11-12 days, so the soil mix was very good for retaining moisture, but anyone else trying this should reduce nitrogen containing amendments to reduce initial (N) related salt stress. Nitrogen is taken up whenever it is present for plants, so the plants were hitting hot (N) pockets whenever its roots grew and inevitably getting too much nitrogen for their small size. All plants exhibited salt toxicities. My water has over 120 ppm soluble calcium and magnesium, which is the standard recommended dose for cal/mag products. Crazy hard water. This should have buffered the pH of the acidic soil, but it did not. Only the plants working with the soil could buffer the pH is my conclusion. I also wanted to add rock phosphate to the initial soil mixes, but did not have them when I started my grow. Perhaps this would have made for better growing climate for my more sensitive strains, Wedding Cake and Pie Face, by adjusting the pH to be higher. Perlite also would have been an excellent amendment to add, as the 420 soil mix is fairly compacted typically. It's like an enriched redwood forest river-side type soil. Future study could either do this or test out whether plants prefer acidic or more basic starting soils. The unavailability of immobile elements, particularly (P) phosphorus, would indicate problems with starting in acidic soils. However, this experiment would indicate that it depends on the genetics. Purple punch enjoyed its acidic redwood forest river-side type soil, but the other two plants struggled for much longer and overall seem less established when compared, particularly Pie Face. A possible confound would be the worm castings I added in while watering at the end of the 13 day period in order to test the pH, as I tested the pH via water runoff from the smart-pots during the watering. I also watered with biostimulants, but they do not affect pH. With the wormcastings though, they affect pH. All plants recieved the same amount of worm castings (assumed 6.0-6.8 pH) but only the healthiest plants had significant pH changes, with Purple Punch and Wedding Cake (5.0-5.5 pH to 6.0-6.4 and 6.5-6.9 respectively). Further study should have larger sample sizes to verify these results with more power. Chef B is a good candidate. More genetics should be worked with to see what more plants prefer, and their origins should be taken into consideration to try to find trends. Further study should also test different amendments being added to soil, to see if plants prefer slightly acidic soils (5.0-5.5) when amendments. Further studies should also have control plants (same genetics) to compare all strains tested with.