References
Every clip on the Soil science page makes a short claim. This page lists what each clip rests on: papers, textbooks, standards and lab guides, in Harvard style. We loaded each source before listing it. Where a point is our own working practice and not a published finding, the note under the clip says so.
Soil growing
Soil structure
Weil and Brady 2017; Six et al. 2004; Dontsova and Norton 2002
Seacliff practice, not a citation: 'Compaction is a symptom' and 'Feed the biology and the crumb builds itself' are Seacliff's view. The two columns and the infiltration bars are an illustration, not measured data.
Soil temperature is the clock
Sullivan et al. 2019; Hartz and Johnstone 2006; Agehara and Warncke 2005
Seacliff practice, not a citation: 'Apply early. Expect a lag' and 'Plan by the thermometer, not the date' are Seacliff working practice. The two release curves are drawn from the halving rule (Q10 of about 2), not from measured data; in trials, high nitrogen meals slowed far less than that.
Cover crops are a nitrogen bank
Seacliff practice, not a citation: 'The price is the land for twelve weeks' is a Seacliff rule of thumb (the New Zealand guide quotes two months of spring growth). The growing plants and the counter are an illustration; 4 t DM/ha at about 100 kg N/ha sits at the low end of the published range for vetch.
Water deep, water seldom
Seacliff practice, not a citation: This clip is about in-ground soil and beds, and 'soak the whole root zone, then let the top dry' is Seacliff working practice built on textbook soil water and aeration principles. Living soil in pots is different and is covered in the next clip. The two panels are an illustration.
Roots feel tension, not litres
Lena et al. 2021; Klopp and Bly 2024; Lieth and Oki 2008; Montesano et al. 2015
Dry topsoil seals the tank
Allen et al. 1998; Shokri and Or 2011; Or et al. 2013
Seacliff practice, not a citation: From 14 October 2026 the clip is framed as outdoor bare soil only; 'in pots and beds of living soil keep it evenly moist under mulch' is Seacliff working practice (see clip 19).
Soil testing
Sample your soil like the lab expects
Hill Laboratories 2023; Morton et al. 2024
Seacliff practice, not a citation: 'Beds and pots: 10 cores, mid-depth, across the whole area' is Seacliff working practice; the published guides cover paddocks, crops and orchards. The 15 numbered cores in the drawing follow the Fertiliser Association guide. From 14 October 2026 the clip also shows a compost pile sampled by 10 random grabs from the core and the edges; that is Seacliff working practice (the published guides cover soils).
Read your water test before the soil test
Ayers and Westcot 1985; Flynn 2009
Seacliff practice, not a citation: '1 mg/L becomes 1 kg/ha for each 100 mm applied' and the worked example (20 mg/L nitrate N over 500 mm is 100 kg N per hectare) are our arithmetic: 100 mm over one hectare is 1,000,000 litres. The bicarbonate bands (under 1.5, 1.5 to 2.5, over 2.5 me/L) are the NMSU scale and pH bands; the FAO band of 1.5 to 8.5 me/L is for leaf marking under overhead sprinklers. 'Gypsum in the water or on the soil pushes it back' is Seacliff practice built on the SAR arithmetic. The 'example bore' markers are an illustration.
Savings account, wallet
Hill Laboratories n.d.; Hill Laboratories n.d.; Hill Laboratories n.d.; Saha 2022; Logan Labs n.d.
CEC: how big is your pantry
Hill Laboratories n.d.; Hill Laboratories n.d.; Saha 2022; Mengel n.d.
Hydrogen holds the seats
Hill Laboratories n.d.; Hill Laboratories n.d.; Mengel n.d.
pH is not a calcium test
Hill Laboratories n.d.; Hill Laboratories n.d.; Horneck et al. 2011
Same soil, two phosphorus numbers
Hill Laboratories n.d.; Hill Laboratories n.d.; Sawyer and Mallarino 1999; Ketterings and Barney 2010; Mallarino 1995
Beds are volume, not area
Hill Laboratories n.d.; Hill Laboratories n.d.; Morton et al. 2024
Indoor living soil growing
Living soil media: keep it evenly moist
Raviv et al. 2019; Lieth and Oki 2008; Montesano et al. 2015; Michel 2009; Seacliff Organics n.d.
Seacliff practice, not a citation: The 70 to 120 mbar band is Seacliff's working target for Living Soil v2 on a Blumat tensiometer (Dan, 14 October 2026); the product page currently prints 80 to 100 mbar. A tensiometer reads suction: 0 is saturated and the number climbs as the medium dries (Montesano et al.; Lieth and Oki). For comparison, conventional soilless mixes are usually irrigated at far lower tensions (Lieth and Oki: 0 to 8 kPa, that is 0 to 80 mbar; easily available water is mostly gone by 5 to 7 kPa), so the living soil target is at the drier end of what the soilless literature describes. The 'over 200 mbar' label, the two panels and the moving marker are an illustration. Dry peat turning water-repellent is from Michel 2009.
Dry pockets: roots you never fed
Fields et al. 2014; Raviv et al. 2019
Seacliff practice, not a citation: Three small rounds ten minutes apart, the mulch, the probe test and 'water takes the easy path down the pot wall' are Seacliff working practice and observation. The published trial supports the principle (dry peat and coir do not rewet in one watering; repeated waterings and a wetting agent help), not the exact routine.
Never let it stall
Seacliff practice, not a citation: This clip is Seacliff grower experience: that a hard stress can cost about a week, that each stress stalls growth for days, the quiet way routine and the kelp and aminos advice are not published findings. The two growth curves are an illustration drawn from a formula, not data. The one reference covers only the point that heat above 30 C cuts photosynthesis in a leaf study.
Mycorrhizae go on the roots
Smith and Read 2008; Besserer et al. 2006
Seacliff practice, not a citation: Dusting the rootball at every up-pot, a pinch per plant, not watering it through, not tank mixing and not applying late in flower are Seacliff working practice. That spores watered on from the top stay near the surface is the reasoning behind the practice and was not confirmed from a source.
Defoliation: when, how much, why
Danziger and Bernstein 2021; Danziger and Bernstein 2021
Seacliff practice, not a citation: The schedule and amounts (twice, at the flip and at day 21; never more than a fifth; one fan per node; nothing after week four; a hard strip costs a week; lighter still in living soil) are Seacliff working practice, not published findings. The two papers support the reason for defoliating: opening the canopy lets light reach lower flowers, and removing the lower third at the flip did not cut yield.
Environmental control
Keep the air moving in one direction
Anderson 2026; Anderson 2026; Justice 2026; Kitaya et al. 2003; Dupont et al. 2025; Shapira et al. 2024; Peiro et al. 2020
Seacliff practice, not a citation: The one-way loop past the dehumidifier and 'leaves should flutter, not thrash' are Seacliff working practice. The medical cannabis numbers come from the Cannabis Research Center and Coalition airflow trials (Dr Allison Justice) as reported by Pipp Horticulture, the trial's industry partner: trial one (near zero, 100 and 200 ft/min) found no significant yield difference; trial two (0, about 200 and 400 ft/min) found that below about 200 ft/min airflow had limited measurable effect and above it plants were taller, with higher fresh and dry flower weight and a lower trim percentage. The trial two write-up covers one replicate, with a second under way, and no peer reviewed paper has been published yet. 200 ft/min is 1.02 m/s and 400 ft/min is 2.03 m/s; the conversions are ours. 'Too much airflow snaps stems' rests on the CannMed 2026 abstract: excessive airflow increased the risk of mechanical damage, particularly in lignified tissues.
Oscillating fans wreck your airflow
Kitaya et al. 2003; Dupont et al. 2025; Shapira et al. 2024
Seacliff practice, not a citation: Preferring fixed fans in a loop over oscillating fans is Seacliff working practice and opinion; no study comparing the two was found. The kPa readouts are generated by the animation to illustrate the idea and are not measurements.
Canopy wind speed: two sets of numbers
Anderson 2026; Anderson 2026; Justice 2026; Kitaya et al. 2003; Kitaya et al. 2004; Dupont et al. 2025; Shapira et al. 2024
Seacliff practice, not a citation: The one-way loop past the dehumidifier and 'leaves should flutter, not thrash' are Seacliff working practice. The medical cannabis numbers come from the Cannabis Research Center and Coalition airflow trials (Dr Allison Justice) as reported by Pipp Horticulture, the trial's industry partner: trial one (near zero, 100 and 200 ft/min) found no significant yield difference; trial two (0, about 200 and 400 ft/min) found that below about 200 ft/min airflow had limited measurable effect and above it plants were taller, with higher fresh and dry flower weight and a lower trim percentage. The trial two write-up covers one replicate, with a second under way, and no peer reviewed paper has been published yet. 200 ft/min is 1.02 m/s and 400 ft/min is 2.03 m/s; the conversions are ours. 'Too much airflow snaps stems' rests on the CannMed 2026 abstract: excessive airflow increased the risk of mechanical damage, particularly in lignified tissues. The 'other crops' band comes from Kitaya et al. (abstracts read on Europe PMC, 14 October 2026): in 2003, sweetpotato leaf photosynthesis and transpiration rose steeply from 0.01 to 0.2 m/s and net photosynthesis was almost constant from 0.5 to 1.0 m/s, while a tomato seedling canopy doubled its photosynthesis from 0.1 to 1.0 m/s above the canopy; in 2004, photosynthesis of tomato seedling canopies saturated at 0.2 m/s inside the canopy. Neither tested above 1 m/s. The boundary layer drawing follows Dupont et al. 'Clones: gentler' and the 'untested' band above 2 m/s are Seacliff working practice; no trial in these sources went above 400 ft/min.
VPD and temperature by stage
Allen et al. 1998; Nelson and Bugbee 2015; Grossiord et al. 2020
Seacliff practice, not a citation: The four stage targets (VPD, temperature and humidity for clone, veg, early flower and late flower), 'hold it within 0.2 kPa' and 'cooler and drier as the buds fill' are Seacliff working practice and common grower targets. No published study gives VPD targets by stage for medical cannabis.
VPD swings lower your yield
Grossiord et al. 2020; Allen et al. 1998; Lawson and Blatt 2014; McAusland et al. 2016
Seacliff practice, not a citation: 'Hold VPD within 0.2 kPa' and the list of causes are Seacliff working practice. The stomata animation and the two growth bars are an illustration driven by the animation's own formula, not measured data. The research on slow stomata was done with changing light, not changing VPD.
Measure VPD at the leaf
Allen et al. 1998; Resource Innovation Institute 2022; Nelson and Bugbee 2015; Grossiord et al. 2020
Seacliff practice, not a citation: The measuring routine (emissivity 0.95, lights on for an hour first, 15 cm, the same five top leaves every day) is Seacliff working practice. The 26 C, 60% and 24 C readings are a worked example, calculated with the FAO equation.
Calibrate your humidity meter
Seacliff practice, not a citation: The 12 hour sealed wait, repeating every three months and writing the date on the meter are Seacliff working practice, not a standard. The meter reading 71% and the +4 offset are a worked example.
Temperature sets the speed limit
Rodriguez-Morrison et al. 2021; Chandra et al. 2008; Llewellyn et al. 2022; Chandra et al. 2011
Seacliff practice, not a citation: The five dial ranges (PPFD 500 to 1400, CO₂ 420 to 1200 ppm, leaf temperature 22 to 27 °C, feed EC 1.2 to 2.2, VPD 0.9 to 1.4 kPa) and 'turn the dials together' are Seacliff working practice. The feed EC and VPD ranges and CO₂ above 750 ppm are not from the cited trials. The growth speed bar is an illustration.
Where the dehumidifier goes
Resource Innovation Institute 2022; ASHRAE 2021
Seacliff practice, not a citation: Where the unit sits (in the airstream, at canopy height, downstream of the plants, intake facing the flow, one unit in the loop rather than two in corners) is Seacliff working practice, not a published finding. The humidity readings in the animation and the 12-plant sizing example are illustrations.
Buds make their own weather
Buirs et al. 2025; Thomas et al. 1988; English et al. 1989; Mahmoud et al. 2023
Drying medical cannabis: set points
Justice 2025; Sandelman 2025; Cannatrol n.d.; ASTM International 2022; ASTM International 2022; Das et al. 2022
Seacliff practice, not a citation: Justice (CRC) trial: control room set to 60 F and 60% RH with air conditioning and a portable dehumidifier; the Cool Cure controls dew point; traditional room swung in dry bulb temperature; Cool Cure retained 16% more total terpenes (2.890 v 2.429% dry weight, p 0.0215) with less decarboxylation; 'it is recommended to bring a product below 0.65 water activity'; drying rate is set by vapour pressure. Cannatrol numbers: 14 millibars at 68 F (Sandelman) and a cure dew point of 54 to 52 F with 60% RH hold (setup guide). Conversions are ours: 60 F = 15.6 C, 68 F = 20 C, 54 F = 12.2 C, 52 F = 11.1 C; 14 mb at 20 C is 60% RH and a dew point of about 12 C. 'Common rooms run 18 to 21 C, 50 to 55% RH, 5 to 6 days' is Das et al. ASTM D8197's title gives the 0.55 to 0.65 range; D8196 is the measurement practice; both loaded as Crossref records only. The dials, the moisture curves and '0.60' are an illustration. Full Crop Sciences drying guidance was searched for and not found; the Justice interview with the 60/60 comment (MJBizDaily) could not be loaded.
Microbes
Soil biology
Bardgett and van der Putten 2014; Lynch and Whipps 1990; Bonkowski 2004; Sasse et al. 2018; Jakobsen et al. 1992
Seacliff practice, not a citation: 'Feed the crew, not just the crop' and 'living soil does the rest' are Seacliff's way of putting it, not published findings. The moving dots are an illustration of carbon going out and nutrients coming back.
How we make our inoculant
Seacliff practice, not a citation: Rewritten 15 October 2026 at Dan's request. Everything on screen is Seacliff's own process and record: the 2018 start, the local forest floor biology as the first inoculum, extract from Lex's long running compost pile (Lex taught Seacliff thermophilic composting), the Johnson-Su bioreactor (fungal compost, kept moist, never turned) and the passage of extract from each batch into the next. '50-plus Soil Food Web assays' is Dan's count of the microscope assays run while refining the Johnson-Su process. Johnson and DeSimio 2017 is cited for the bioreactor method only (static, never turned, kept above 70 percent moisture, fungal dominant). The earlier Ingham 2005 brewing reference was dropped because the inoculant is bioreactor compost and extract, not an aerated brew. The WHY IT MATTERS card no longer says Otago: the product is sold across New Zealand.
The root's bodyguards
Harman et al. 2004; Hashem et al. 2019; Chitarra et al. 2003; Ongena and Jacques 2008
Seacliff practice, not a citation: 'Inoculate at sowing, re-apply after a flush' is Seacliff working practice. 'A bare root is an open door. A colonised root is a closed one' is a slogan; the research shows these microbes reduce disease, not that they stop it every time. The animation is an illustration.
Chlorine stops at the surface
Colorado State University Extension n.d.; Water Services Authority - Taumata Arowai 2025
Seacliff practice, not a citation: Standing brew water overnight or adding a pinch of humic acid, and 'spend the money on compost', are Seacliff working practice. 'It is spent before the water sinks in' is the clip's reading of the two sources, which say chlorine binds to soil particles and reacts with organic material.
The poop loop
Ingham 2000; Ingham et al. 1985; Bonkowski 2004; Soil Food Web School n.d.; Werblow 2023
Seacliff practice, not a citation: 'Poop loop' is the name Dr Elaine Ingham uses in her teaching; the Soil Food Web School page says predators 'excrete their waste' as a nutrient dense liquid the root absorbs, and The Furrow profile has nematodes 'poop them out'. The carbon to nitrogen figures (protozoa 10:1 or much more, bacteria 3:1 to 10:1), the release as ammonium near the roots, and 'bacteria and other organisms rapidly take up most of the ammonium' are from the Primer, which Ingham wrote. The trial card is the 1985 Ecological Monographs abstract (blue grama with bacteria plus bacterial-feeding nematodes grew faster and took up more nitrogen; fungal-feeding nematodes did not add growth; the extra mineralisation matters when the microflora alone cannot meet the plant's needs). The amoeba, nematode and chips are an illustration; the bars are not to scale.
Rhizophagy: roots eat microbes
White et al. 2018; Paungfoo-Lonhienne et al. 2010
Seacliff practice, not a citation: Stages 1 to 3 follow the 2018 abstract and figure 1: microbes enter root tip meristem cells, sit between wall and membrane as wall-less protoplasts, are degraded by superoxide from NADPH oxidases on the membrane, and survivors exit at the tips of elongating root hairs. The 'about 30% more nitrogen' figure is White et al. 2018 reporting their earlier grass seedling experiment with 15N-labelled protein; the paper itself says it could not separate rhizophagy from uptake of microbe-mineralised nitrogen, and that 'how important this process is for nutrient acquisition is still unknown'. The 2010 paper used non-symbiotic E. coli and yeast in Arabidopsis and tomato. The root drawing and the 'N' chips are an illustration; nothing on screen is a Seacliff product claim.
Mycorrhizal fungi: ecto and endo
Ingham 2000; Brundrett and Tedersoo 2018; van der Heijden et al. 2015; Smith et al. 2011; Citterio et al. 2005
Seacliff practice, not a citation: The two drawings are schematic. The Primer: in exchange for carbon, mycorrhizal fungi bring phosphorus, nitrogen, micronutrients and perhaps water; ectomycorrhizae grow on the surface layers of the root as a sheath that penetrates between cells and does not invade them, commonly on trees; endomycorrhizae grow within root cells, commonly on grasses, row crops, vegetables and shrubs. Percentages are Brundrett and Tedersoo (72% of vascular plants arbuscular, 2.0% ectomycorrhizal). 'Up to 80% of plant N and P' is van der Heijden et al. The hemp figure is Citterio et al. (42% colonisation by Glomus mosseae in uncontaminated soil; growth was reduced in that pot trial). Pines, oaks and beech as ectomycorrhizal hosts is standard mycology, not taken from these sources. 'Feed the fungus and it feeds the plant' and 'not the fungus for your medical cannabis' are Seacliff wording.
The organic nitrogen cycle
Robertson and Groffman 2015; Stein and Klotz 2016
Seacliff practice, not a citation: The diagram is simplified: anammox, nitrifier N2O and ammonia volatilisation are left out. 'Feed organic N and let the microbes meter it out' is Seacliff's practice.
Rhizobia: pink means working
Ott et al. 2005; Meat and Livestock Australia n.d.
Seacliff practice, not a citation: The nodule drawing is schematic. 'Match the inoculant to the legume' is standard practice (rhizobia strains are host specific) rather than a claim from the two sources.
Free-living nitrogen fixers
Reed et al. 2011; Smercina et al. 2019; Ladha et al. 2016
Seacliff practice, not a citation: The kg per hectare figures are global budget averages, not field measurements. 'Hold back the soluble nitrogen' follows from the nitrogen-availability control in Smercina et al.
Composting
Just add compost
Jasim, S; Sullivan and Miller 2001; Hill Laboratories n.d.
Seacliff practice, not a citation: Rewritten 14 October 2026 at Dan's request to show mineral variation, not only C:N. The numbers are Jasim and Smith Table 6.1, year 1 (home composts from kitchen and garden waste, 64 households): total potassium 0.42 to 4.15% dry matter (median 1.88), total magnesium 166 to 626 mg/kg (median 336), pH 5.6 to 8.6 (median 6.8); the report says nutrient concentrations varied up to tenfold and did not correlate with the waste inputs. These are home composts, not commercial bags; the point is that one word covers a tenfold range. 'C:N, salts, sodium: ?' means those were not in that table. 'Too much potassium blocks magnesium' rests on Xie et al. 2021 (clip 86). Hill Laboratories: composition is set by the raw materials and the process. 'Every batch in a Seacliff bag is tested' is Seacliff's statement.
Compost for nitrogen overshoots phosphorus
Sullivan et al. 2018; Sullivan et al. 2019; DuPont and Granatstein 2020; Reid and Morton 2019
Manure overshoots phosphorus too
AHDB 2023; Bary et al. 2016; Griffiths 1998; Mahr n.d.; Reid and Morton 2019
Thermophilic compost: temps and turns
Seacliff Organics n.d.; Rittenhouse 2015
Seacliff practice, not a citation: The 10, 30, 60 recipe, the 50 % drip test, the three temperature targets, 'over 72 C the pile makes compounds that hurt roots', 'below 32 C the worms move in' and 'six to twelve months' are the Seacliff blog. The 25:1 to 40:1 band, 55 to 77 C for 15 days and the five turns are the USDA organic compost rule as reproduced by NCAT. The temperature curve is an illustration of five cycles, not logged data; 'weed seeds and pathogens are cooked through' is the purpose of the rule, not a figure from these sources.
A worm farm that is not too wet
Sherman 2017; University of Arizona Cooperative Extension 2021
Seacliff practice, not a citation: 'One bucket of scraps, one bucket of peat or coco, a sprinkle of ag lime' is Seacliff practice (Dan, 14 October 2026). Sherman's one pound of worms to two pounds of scraps a week is shown as the same ratio in kilograms, and 1 inch as 25 mm. The bin drawings are an illustration.
Johnson-Su: the no-turn compost
Johnson and DeSimio 2017; Seacliff Organics n.d.
Seacliff practice, not a citation: One foot is shown as 30 cm, 140 to 165 F as 60 to 74 C and 80 F as 27 C. The manual's design has six air columns; the Seacliff build in the blog uses four pipes. No fungal to bacterial ratio is given in the manual beyond 'fungal dominant', so none is shown; the BEAM product page figure (2:1) is not used here.
Biostimulants
What's in the bag
Seacliff Organics n.d.; Hill Laboratories 2022; Hill Laboratories n.d.
Seacliff practice, not a citation: The six ingredient groups are the product page list, shortened to fit: 'humic and fulvic' is Bio Ag Ful-Humix, 'BEAM microbes' is the Seacliff BEAM extract, 'two kelps' are Macrocystis pyrifera (Zelp) and Ascophyllum nodosum (Acadian), and wheat germ and the oyster shell chitin are not shown for space. The heavy metal figures are from the one certificate on the Lab tests page (sample 'Living Soil', 4 May 2022; the totals and metals on it are outside the lab's IANZ accreditation), compared with the NZS 4454:2005 and BioGro values printed on it; the Hill note lists the same limits (cadmium 1, arsenic 20, lead 250 to 300, mercury 1 mg/kg). 'Every batch is tested', 'balanced to targets', 'little or no extra feed in a 50 L pot' and the Blumat target are Seacliff's own statements. Note: the product page gives a Blumat target of 80 to 100 mbar; the clip uses Dan's 70 to 120 mbar instruction of 14 October 2026.
Foliars: fast fixes, then the soil
Seacliff practice, not a citation: Stopping foliar sprays three weeks into flower, spraying weekly until new growth is clean, and the choice of products to spray are Seacliff working practice, not published findings.
Yucca and quillaja: make water wet
Ulaganathan et al. 2019; Güçlü-Üstündağ and Mazza 2007; Fields et al. 2014; Fernández et al. 2013
Seacliff practice, not a citation: The doses (a few drops per litre; foliar 0.5 to 1 mL per litre; soil 1 to 2 mL per 10 L every second watering) are Seacliff working rates, not published findings. The published work covers quillaja saponin and synthetic wetting agents; using yucca extract the same way rests on saponins in general.
Kelp is not fertiliser
Organic Materials Review Institute 2026; Seacliff Organics 2026; Almeida et al. 2024; Reid and Morton 2019; Shukla et al. 2019
Humates: modest, not magic
Rose et al. 2014; Nardi et al. 2021; Lyons and Genc 2016; Olk et al. 2018; Li et al. 2022
Amino acids: fast nitrogen
Jones 1999; Jones and Kielland 2002; Näsholm et al. 2009; Ingham 2000; Seacliff Organics n.d.
Seacliff practice, not a citation: Jones 1999 (10 soils, 15 labelled amino acids at 5 mM): mean half-life 1.7 h in topsoil at 18 C, 12.2 h in subsoil; 34% of the carbon respired, 66% into microbial biomass; lower concentrations should turn over even faster. Jones and Kielland 2002: half-life about 5 h in taiga forest soils, the pool turning over about 20 times a day. Näsholm et al.: roots have amino acid transporters and field uptake is proven, but direct evidence that organic nitrogen contributes significantly to plant nutrition is still lacking. 'Nitrifiers turn ammonium into nitrate' is from the Primer; that nitrate leaches is common knowledge. The product figures are the Seacliff product page. The curve is drawn from the 1.7 h half-life; the chip positions are an illustration. 'Little and often beats one big drench' is Seacliff working practice.
Fulvic acid: the small chelator
Zanin et al. 2019; Seacliff Organics n.d.
Seacliff practice, not a citation: Zanin et al. 2019 (review): humic substances form stable complexes with metal micronutrients through oxygen, nitrogen and sulphur groups; soluble Fe-HS complexes can be used directly by plant iron uptake; treatments induce lateral roots and root hairs through auxin-related signalling, and the root plasma membrane H+-ATPase is a recognised target; effects vary with the source, molecular size and chemistry. 'The smallest, most soluble humic fraction' is the standard operational definition of fulvic acid (soluble at all pH). 'The same trick works on zinc, copper and manganese' rests on the review's general statement about metal micronutrients. The 10 to 30% reduction in other inputs and the rates are from the Seacliff and NTS product pages, not from a trial. The two panels are an illustration.
Aloe for cuttings
Yüksek et al. 2026; Seacliff Organics n.d.
Seacliff practice, not a citation: The only trial loaded: tea cuttings, seven IBA doses (perlite only), Aloe vera gel and untreated control in perlite and clay soil, 120 days, three replications. Abstract: aloe gel was associated with greater root length, particularly in soil based media; the highest rooting and survival rates came from 5000 ppm IBA in perlite; aloe 'may represent a promising alternative for soil-based rooting systems'. The three cuttings are an illustration of those findings, not measured lengths. The label's list of enzymes and plant hormones is the product page; the trial measured roots, not hormones. 'A gentle rooting aid, not a hormone' is the clip's reading of that one trial; other aloe rooting studies exist but were not loaded.
Kelp for cuttings
Gomes et al. 2018; Luna Rodríguez et al. 2024; Stirk and Van Staden 1996; Seacliff Organics 2026
Seacliff practice, not a citation: The two cuttings are an illustration of the two trials, not measured roots: 'about 10% more rooted' is the passionflower result at 40% extract, 'longer, heavier roots' the spearmint result at 10 mL per litre; 'fewer rooted, shorter roots' is the control in each. Neither trial used Tri-Kelp or a cannabis cutting. 'Dip the base at the foliar strength' is the clip's reading of the product page, which names rooting dips but gives no dip rate; 'a clean blade and warm, humid air still do most of the work' and 'pairs with the aloe soak' are Seacliff practice, not trial findings. 'Not a measured auxin dose' means the auxin-like activity in Stirk and Van Staden is a bioassay response, and no trial here measured hormone content in the product.
Auxins: the tip rules
Thimann and Skoog 1933; Caplan et al. 2018; Stirk and Van Staden 1996; Taiz et al. 2015
Seacliff practice, not a citation: The plant drawings are schematic. None of the hormone research except Caplan et al. 2018 was done on medical cannabis.
Gibberellins: stretch and wake
Peng et al. 1999; Paleg 1960; Mohan Ram and Jaiswal 1972; Taiz et al. 2015
Seacliff practice, not a citation: 'Kelp carries gibberellins' rests on the seaweed biostimulant literature cited in clip 68 (Shukla et al. 2019); the dose warning is Seacliff's. Later cannabis trials give mixed results for GA3 alone; the 1972 paper is the classic demonstration.
Cytokinins: the root's reply
Richmond and Lang 1957; Letham 1963; Yong et al. 2009; Stirk and Van Staden 1996; Taiz et al. 2015
Seacliff practice, not a citation: The 1957 experiment used kinetin, a synthetic cytokinin, on detached leaves; the link to kelp and coconut water late in a crop is grower practice, not a trial.
The rest of the signal kit
Yang and Hoffman 1984; Mittelheuser and Van Steveninck 1969; Grove et al. 1979; Malamy et al. 1990; Farmer and Ryan 1990; Gomez-Roldan et al. 2008; Ries et al. 1977
Seacliff practice, not a citation: Each tile gives one job per signal; all of them do more. 'Chitin leans on the jasmonate pathway' rests on Doares et al. 1995 (clip 21 references). 'One signal at a time' is Seacliff's advice.
Agronomy
Calcium, magnesium, and the one-off till
Kopittke and Menzies 2007; Chaganti et al. 2021; Chaganti and Culman 2017; Dontsova and Norton 2002; Hill Laboratories n.d.; Lefever et al. 2014; Lee et al. 2008; Roberts and Morton 2023
Seacliff practice, not a citation: Fixing a ratio that is well out with gypsum, ag lime or oyster grit, tilling once and then going no-till, and 'fungi and roots bind the new crumb; a second till breaks it again' are Seacliff working practice and Dan's position, not trial findings. The trials found no best ratio and, on two Ohio sites, no change in soil structure when gypsum shifted the ratio; the magnesium and tight clay effect comes from a laboratory study on four US soils.
Gypsum: calcium without the pH
Lefever et al. 2014; Beegle and Lingenfelter 2014; Lee et al. 2008
Too much of a good thing
Xie et al. 2021; Rietra et al. 2017; Ova et al. 2015; Deng et al. 2014; Dontsova and Norton 2002; Kopittke and Menzies 2007; Albrecht 1975
Seacliff practice, not a citation: The pie chart is an illustration of potassium crowding the exchange sites, not measured data. The symptom wording for excess potassium, 'calcium locks boron and phosphorus' and the gypsum line in THE FIX are grower rules of thumb that the listed papers do not test.
Particle size sets the clock
Scott et al. 1992; Kanabo and Gilkes 1988; Watkinson 1994
Seacliff practice, not a citation: The 'weeks, months, years' labels, the release curves and 'blend = steady supply' are an illustration of the principle, not measured timings. 'Micronised for this crop, chip for the bed' is Seacliff working practice.
Nitrogen for the whole crop
Sullivan et al. 2019; Hartz and Johnstone 2006; Lazicki et al. 2020; Gale et al. 2006; Di and Cameron 2002
Seacliff practice, not a citation: The demand curve, the slow hump and the fast spikes are a drawn illustration, not data. 'Front-load the slow, top up with the fast' and 'top up when the leaves ask' are Seacliff working practice.
Carbon decides when N shows up
Lazicki et al. 2020; Sullivan et al. 2019; Gale et al. 2006; Clark 2007; Ferretti 2023
Seacliff practice, not a citation: 'Pair carbon with nitrogen or wait it out' is Seacliff working practice. The exact break-even C:N ratio is debated: published thresholds run from about 15:1 to the mid 20s, depending on the material and the study.
Nitrate leaches, ammonium waits
Di and Cameron 2002; Weil and Brady 2017
Seacliff practice, not a citation: 'Feed in smaller splits', 'Watch the forecast' and 'Two small feeds beat one big one before rain' are Seacliff working practice, in line with the review's advice to match nitrogen supply to crop demand. The falling nitrate dots are an illustration.
Too much P turns mycorrhizae down
Breuillin et al. 2010; Deng et al. 2014; Gosling et al. 2013; Ova et al. 2015
Seacliff practice, not a citation: The shrinking network and the dial are an illustration. Research shows mycorrhizal colonisation is reduced as soil phosphorus rises, by an amount that depends on the crop; there is no published switch-off point. 'Test before you add' is Seacliff working practice.
Phosphate stays where it lands
Grant and Flaten 2019; Beegle and Durst 2017; Clark and Beegle 2025
Soil pH, water pH: how to move it
Weil and Brady 2017; McCauley et al. 2017
Seacliff practice, not a citation: The living soil range of 6.2 to 7.2 with a 6.6 target, water in at 6.0 to 6.5, the phosphoric acid and potassium silicate doses, and testing slurry or runoff every couple of weeks are Seacliff working practice for a peat based mix, not published findings. The moving 'your water' marker is an illustration.
Wood ash is lime in disguise
Griffin 2004; Saunders 2018; Browning 2019; Schoessow 2020; Environment Canterbury n.d.; Safa et al. 2020
Hard water limes every watering
Lopez et al. 2010; Cox 1995; Argo and Biernbaum 1996
Everything in, nothing screened
Environmental Protection Authority 2023; Stanway 2024; Hill Laboratories n.d.; Sullivan and Miller 2001; Seacliff Organics n.d.
Seacliff practice, not a citation: The two bags are an illustration. EPA: clopyralid persists in sprayed vegetation and in manure from animals that ate it, composting does not remove it, and beans, peas, tomatoes, lettuce, carrots and roses are affected. WasteMINZ: damaging at 1 to 3 parts per billion, residues can persist for more than 12 months. Hill Laboratories: sawdust from tanalised timber brings arsenic, copper and chromium; cadmium limit 1 mg/kg (Grade A biosolids and BioGro values printed in the note). Sullivan and Miller, Table 9: elevated salts are often associated with composted manure and grass clippings. The saturated paste list (sodium, chloride, bicarbonate, aluminium) is the Seacliff testing service page. 'Pesticide' is shown as a screen a buyer can ask for; no residue figure is given on screen.
More isn't better
Hill Laboratories n.d.; Ova et al. 2015; Nelson and Janke 2007; Environmental Protection Authority 2023; Hill Laboratories n.d.; Sullivan and Miller 2001
Seacliff practice, not a citation: The five climbing meters are an illustration, not data. The 2.5 mS/cm figure is the top of the highest potting media conductivity band (vegetables, M5: 1.0 to 2.5 mS/cm, 1:1.5 volume extract) in the Hill Laboratories note; 'salt stress' is the note's own term. The phosphorus and zinc link is Ova et al. (wheat in native soil); the phosphorus and mycorrhizal link is Nelson and Janke, both on field soils. Clopyralid in manure and compost is from the EPA advisory; treated timber metals and salts from manure and grass clippings from the Hill note and Sullivan and Miller. 'Measure, then add the least that works' is Seacliff working practice.
Rock dust: use it on purpose
Lewis et al. 2021; Beerling et al. 2024; Swoboda et al. 2022; Ramezanian et al. 2013; International Zinc Association n.d.; Kelland et al. 2020
Seacliff practice, not a citation: Reframed 14 October 2026 at Dan's request: the cards now read 'where it shows', 'where it does not' and 'measure it'. The published figures are unchanged. 'Soil test first, buy a dust with an analysis, re-test after a season' is Seacliff working practice.
What's blocking your minerals
Xie et al. 2021; Ova et al. 2015; Rietra et al. 2017; Kopittke and Menzies 2007
Seacliff practice, not a citation: 'Remove or dilute the excess, or bypass it with a foliar' is Seacliff working practice; the foliar bypass has rarely been studied. Of the three pairs shown, potassium against magnesium and phosphorus against zinc are backed by the listed papers; magnesium against potassium is only weakly supported.
Every amendment brings passengers
Ballance Agri-Nutrients 2026; Ballance Agri-Nutrients 2026; Ballance Agri-Nutrients 2026; Seacliff Organics 2026
Mulder's chart: what blocks what
NutriAg Academy 2020; Canna n.d.; LandWISE n.d.; Rietra et al. 2017; Xie et al. 2021; Ova et al. 2015
Seacliff practice, not a citation: Mulder's original 1953 publication was not loaded; the wheel follows the chart as printed on supplier handouts. Lines on that drawing whose direction could not be read with confidence (Cu and Mn, Fe and Cu, Zn and K, Fe and P, Mo and P, Zn and Mg) were left off rather than guessed. 'Check potassium and calcium on the test first' and 'fix the excess' are Seacliff working practice.
Microbes unlock the phosphate
Richardson and Simpson 2011; Alori et al. 2017
Seacliff practice, not a citation: 'Rock phosphate, bone meal and seed meals are not soluble' and 'moisture, carbon and warmth set the pace' are textbook and Seacliff practice; no figure is attached to them.
Foliar sprays: read the tissue test
Jones and Jacobsen 2009; Fernández et al. 2013; Rietra et al. 2017; Xie et al. 2021
Seacliff practice, not a citation: The tissue bar chart is an illustration, not a real report. 'Sample the same leaf at the same stage from 20 plants', 'spray Epsom salts now', 'test a few leaves first' and 're-test three weeks later' are Seacliff working practice; 20 plants is the common extension sampling figure. The 0.5 % zinc sulphate solution is the Montana State guideline (5 g per litre is the same figure in metric). That iron, manganese and molybdenum do not move to new leaves is textbook plant nutrition.
pH sets what the roots can take
Truog 1947; Hartemink and Barrow 2023; Barrow and Hartemink 2023; Criscione 2025
Seacliff practice, not a citation: The bands are redrawn from Truog's sketch and are not measurements; Hartemink and Barrow 2023 make exactly that point. 'Living soil runs 6.2 to 7.2, target 6.6' is Seacliff's own range (clip 30). The 14 second length was Dan's request.
Eh: the other dial next to pH
Pezeshki and DeLaune 2012; Husson et al. 2021; Husson 2013
Seacliff practice, not a citation: The mV figures are approximate thresholds at about pH 7 and shift with pH. The scale is drawn as a continuum; real soils vary over millimetres. 'Keep air in the mix' is Seacliff's practice.
Crops take different nitrogen, and when
Seacliff Organics 2026; Reid and Morton 2019; Cassity-Duffey et al. 2020
Seacliff practice, not a citation: The bar heights are the planner's editable defaults, not measured uptake for a given paddock. The demand curves are the planner's shapes (leafy ramps to a plateau, fruiting peaks mid-season, root and bulb peak late, legumes low) and are heuristics.
Minerals and what they do
Old leaves or new leaves?
McCauley et al. 2011; Cockson et al. 2019; Maillard et al. 2015
Nitrogen: what it does
Marschner 2012; McCauley et al. 2011
Seacliff practice, not a citation: The FEED IT WITH list is Seacliff's choice of nitrogen inputs, not a published ranking. 'Pests' as a result of too much nitrogen is general textbook teaching and was not confirmed in the source that could be read.
Phosphorus: what it does
Marschner 2012; McCauley et al. 2011; Ova et al. 2015
Seacliff practice, not a citation: 'Builds up; test before adding' and the FEED IT WITH list are Seacliff working practice.
Purple is not always phosphorus
Nielsen 2022; McCauley et al. 2011; Mackay and Barber 1984; Chalker-Scott 1999
Potassium: what it does
Marschner 2012; McCauley et al. 2011
Seacliff practice, not a citation: 'Bud density' and 'small loose flowers' are grower observation, not in either source. 'Luxury uptake wastes it' and the FEED IT WITH list are general teaching and Seacliff practice.
Calcium: what it does
Marschner 2012; White and Broadley 2003; McCauley et al. 2011; Dontsova and Norton 2002; Lefever et al. 2014
Seacliff practice, not a citation: The FEED IT WITH list (including calcium nitrate 'for a fast fix') is general practice, not a published ranking.
Magnesium: what it does
Marschner 2012; McCauley et al. 2011; Dontsova and Norton 2002
Seacliff practice, not a citation: The FEED IT WITH list is general practice. Checking the calcium to magnesium ratio follows Dan's position: act when a test shows it is well out; there is no single target number.
Sulphur: what it does
Marschner 2012; McCauley et al. 2011; McCauley et al. 2017
Seacliff practice, not a citation: 'Size it from the Hill report' is Seacliff working practice. 'Sulphate leaches like nitrate' is general textbook teaching and was not confirmed in the sources that could be read.
Iron: what it does
Marschner 2012; McCauley et al. 2011; Jones and Jacobsen 2009
Manganese: what it does
Marschner 2012; McCauley et al. 2011; McCauley et al. 2017
Zinc: what it does
Marschner 2012; McCauley et al. 2011; Jones and Jacobsen 2009
Copper: what it does
Marschner 2012; McCauley et al. 2011; Roberts and Morton 2023
Seacliff practice, not a citation: 'Copper sulphate in tiny doses' and the Biomin chelate as a source are Seacliff working practice.
Boron: what it does
Marschner 2012; McCauley et al. 2011; Brown et al. 2002; Jones and Jacobsen 2009
Seacliff practice, not a citation: 'Never guess the dose' and 'kelp carries a little' are Seacliff working advice. The boron rate is a Montana State guideline for soils that test low, not a rate for every soil.
Molybdenum: what it does
Marschner 2012; McCauley et al. 2011; Jones and Jacobsen 2009; Roberts and Morton 2023
Seacliff practice, not a citation: 'If a legume cover crop will not nodulate, think molybdenum before more seed' is Seacliff working advice built on molybdenum's role in nitrogen fixation.
Silicon: what it does
Seacliff practice, not a citation: Adding potassium silicate last and diluted, never mixing it neat, and 'build it in early' are Seacliff working practice and label advice. Diatomaceous earth, rice hulls and basalt dust are listed as general silicon sources without a reference; silicon from rock dust is slow and small.
The full citations are in the reference list.