Super Cool Tools – Less Guesswork when Monitoring Plant and Soil Health

Imagine a reliable tool to check soil-life counts, monitor microbe brews and differentiate biological inputs. Imagine if you could do this with your mobile phone within ten minutes – it is now possible with the microBIOMETER®.

In-field monitoring is integral to successful Nutrition Farming®. You are all familiar with the importance of tools like the refractometer for checking plant health, yield potential, likely pest pressure and your skills as a chlorophyll manager. Perhaps you are also aware of the benefits of monitoring potassium or nitrogen with a hand-held Horiba meter. In this blog, we will discuss an exciting new addition to DIY microbe monitoring, and we will also review the benefits of monitoring sap pH and paramagnetism.

The microBIOMETER® – A breakthrough new tool for microbe management

Imagine a reliable tool to check soil-life counts, monitor microbe brews and differentiate biological inputs. Imagine if you could do this with your mobile phone within ten minutes. An American researcher, who is the holder of a series of unique blood test patents, has now turned her considerable expertise to the measuring of microbes. The microBIOMETER® involves an inexpensive, in-field testing kit, linked to a smartphone App, to enable the fast-tracking of microbe monitoring.


How Does It Work?

A powdered formula is added to a vial of premixed soil and water. Over a ten-minute period the fungi, bacteria, protozoa, Actinomycetes and nematodes are enveloped and isolated in the solution. A few drops of this living solution are collected from the vial with an eye dropper and dripped onto a card. A smartphone or iPad App is then utilised. The camera is activated by the App, and a beam of light illuminates the entrapped microbes on the card. A score representing microbial biomass soon appears on the screen and it is identified and stored on the App for future reference. Ideal levels vary between compost teas, compost and microbial inoculums. Here are the guidelines for soil microbial biomass;

Below 200 very poor
200 – 300 low
300 – 400 average
400 – 500 good
Above 500 excellent

Growers wishing to qualify for the new Nutrition Farming® Certification, just launched in India, will need to achieve scores above 400, along with 14 other certification requirements.

cocktail cover crop

The microBIOMETER® enables you to monitor the profound biological impact of cocktail cover crops.

Top Ten Benefits of this Exciting New Tool

  1. Microbial biomass is the best single indicator of soil health (Doran 2000) – poor fertility soils have very low microbial populations, while highly fertile, productive soils have high microbial populations.

  2. Soil microbes perform important functions such as nutrient solubilisation, root growth stimulation, atmospheric nitrogen fixation, disease suppression and soil humus building (carbon sequestration).

  3. The key goal of regenerative farming is to follow practices that create soil conditions ideal for proliferation of soil microbes, ultimately reducing dependence on chemical inputs.

  4. The ability to conveniently measure microbial biomass gives farmers the power to monitor and track the effects of farming practices, in particular to determine the value of different soil amendments and the efficacy of different cover crops.

  5. This tool also allows growers to determine the quality of DIY and commercial inoculums, and to differentiate the good from the bad.

  6. The results from the microBIOMETER® are extremely accurate and reproducible, while being considerably faster and less expensive than laboratory testing. This tool has the added benefit of allowing on-farm testing, eliminating the effect of transit time/conditions on microbial levels.

  7. A convenient, easy-to-use and accurate tool to accurately measure the microbial biomass in soil, compost or compost tea (or specialist inoculum brews), in just 10 minutes.

  8. This test costs a fraction of the price of conventional laboratory analysis. Test card refill kits are available (10 per pack).

  9. An essential tool for regenerative farmers to ensure their farming practices are positively affecting microbial activity.

  10. The kit involves a smartphone/iPad app to digitally analyse and store readings for tracking soil health. The base starter kit also involves ten testing cards.

microbiometer smartphone ipad app

The revolutionary new microBIOMETER® is now available from NTS, along with refill kits. Call +61 7 5472 9900 or email for details.

Sap pH Monitoring – Insights from the Plant

Over 17 years ago, I travelled to Spokane in Washington State to interview the brilliant American consultant, Bruce Tainio, for my first book. He shared several of his findings, but I found the most profound of these related to the use of sap pH as an indicator of plant health, productivity and pest resistance. In fact, I returned home and immediately tested the concept on my research farm. I found it to be an invaluable concept for monitoring key minerals and their impact on production and pest pressure. In fact, I have yet to find a diseased plant, anywhere in the world, with the ideal sap pH of 6.4.

Bruce Tainio

The late Bruce Tainio discovered the relevance of sap pH.

How Does It Work?

The pH of plant sap is governed by the same minerals that alkalise or acidify both the soil and our bodies. The ideal pH in all three systems is identical. Our urine and saliva should ideally be pH 6.4 upon awakening, just as the plant thrives at that pH. Interestingly, the soil delivers its mineral bounty most ably at that same pH point.

From a human perspective, if we are acidic, as many of us are, then the solution is to consume more alkalising minerals. What do they include? You guessed it, it is the same major cations that raise the pH of the soil – calcium, magnesium, potassium and sodium. In the soil, we might add lime or dolomite. In our bodies, we consume more fruit and vegetables, as they are the primary source of these alkalising cations.

Like the soil and our bodies, an acidic pH below 6.4 in the plant sap indicates a deficiency of calcium, magnesium, potassium, sodium, or a combination of these. Just as acidity is a precursor to disease in the human body, the same applies to plants. The lower the sap pH, the greater the likelihood of fungal disease. In fact, if the sap pH of your crop is 5.4, you are guaranteed to have pathogen pressure. How do you determine which mineral is missing? Generally, sodium is not a player, although it is vaguely possible. The culprit will typically be calcium, magnesium or potassium. Here’s how you can use a process of exclusion to isolate the destructive deficiency.

Let’s assume that you have squeezed some juice from the plant leaf and placed a few drops into the shallow well of the hand-held Horiba Sap pH Meter. Your sap pH is 5.4. You are lacking one of the aforementioned trio. The first step is to squeeze a few drops more from the same plant and place a few drops onto the screen of your refractometer. If you observe a fuzzy line on the refractometer, it may be an indication that calcium is not the missing mineral. Then, you squeeze a few more drops into the well of your Horiba Potassium Meter and check that mineral, according to the guidelines if available*. If potassium is adequate, there is only one candidate remaining. You have identified a magnesium deficiency. Foliar spray with a few kilograms of magnesium sulfate, combined with fulvic acid to chelate and magnify, and your sap pH will rise, while your disease stress will fall.

What does it mean if your sap pH is 8.4? An alkaline pH (above 6.4) reflects an excess of nitrate nitrogen, or a shortage of either sulfur or phosphorus, within the plant. Acid/alkaline balance is like a seesaw. If your plants are lacking the counterbalancing effect of the two most acid-forming minerals, sulfur (think sulphuric acid) and phosphorus (think phosphoric acid), then the alkaline end of the seesaw rises. A high sap pH is much more related to likely insect pressure. It makes perfect sense. Sulfur is an essential in the creation of the protein that drives plant immunity and associated insect resistance.

Phosphorus is also intimately involved in the creation of protective phytochemicals. It is a little more difficult to determine the key culprit here. If you are familiar with the sweet spot for nitrogen (determined with your Horiba Nitrate Meter), you can determine if excess nitrogen is the culprit. You can also easily check for N deficiency with that meter. You can compare the top leaf and bottom leaf of the plant, as you would for potassium. Nitrogen is second only to potassium in terms of mobility. You can assume that if the lower leaf reveals lower nitrogen levels than the top leaf, then you have a nitrogen shortage.

Sulfur deficiency presents as an overall paling of the leaf, on new growth, while a P shortage is evident on the lower leaves, often as a purple shade.

There is also a low-cost option for sap pH monitoring, where you can use a simple pH strip, with an attached color chart. Just squeeze a few drops of plant sap onto the strip with your garlic crusher, and determine pH from the colour chart provided. This technique can also be used to monitor potassium. Potassium is a super mobile, alkalising mineral. Using a single pH strip, you squeeze two drops onto one end of the strip from the top of the plant. Then, on the other end of the same pH strip, you squeeze two drops from lower leaves. Ideally, both ends should have the same color. Acidity is represented by a lighter shade of that color. When the lower leaf has a lower pH than the top leaf (i.e., it is a lighter shade), it is fairly safe to say that this reflects a potassium shortage.

horiba sap ph meter and ph test strips

Horiba pH Meters and booklets of pH strips are available from NTS. Call +61 7 5472 9900 or email for more information.

The PCSM Meter – Monitoring Light for the Roots and Soil Life

Those of you who have attended my courses around the world will have been briefed on the concept of paramagnetism. A valuable tool to measure this phenomenon, the PCSM meter, was developed by Professor Phil Callahan, in conjunction with talented, electronics engineer, Bob Pike. It is available for a little over $US500 from the manufacturers, at Pike Agri-Labs.

What is Paramagnetism?

This is a low level magnetic attraction that has always been part of physics, but no one ever knew it had a link to soil fertility, until Phil Callahan.

Phil had wondered about the superior fertility invariably related to volcanic soils. In fact, these soils are the most productive in the world. He found that you could mimic every aspect of soils with a volcanic origin. You could copy the mineral, humus, clay, sand, silt and microbial components, but the original would always outperform the copy. There was something else at play determining the superior productivity of these fertile soils.

It was during a visit to Easter Island that the penny dropped for Phil. He was visiting the famous carved rock figures adorning the foreshore, when the tour guide mentioned that local graziers have a ballot system for who can graze around the statues, and when. Phil wondered why on earth there would be such demand for unfertilised grasses, when the surrounding dairy pastures were all “improved”. He removed his refractometer from his carry bag to seek some answers. The pastures around the granite monoliths had far higher brix levels than the surrounding “fertilised” farms. The volcanic-based granite statues were obviously impacting surrounding soil fertility, and had done so for centuries.

easter island head statues

Soon after, Phil developed a theory that volcanic soils have an antennae-like quality that allows them to draw in a particular form of atmospheric energy and convert it into tiny light particles called biophotons. That energy comes from Extra Long Frequency (ELF) radio waves, which themselves are a byproduct of 6000 lightning bolts exploding in the planet’s atmosphere every minute. These one billion bolts of electricity per strike do not simply disappear – they are converted into another energy, called ELF waves.


Lightning bolts convert to ELF radio waves, which in turn become biophotons in the soil.

Eventually, armed with some volcanic basalt, Phil decided to visit the laboratories of Professor Fritz Popp, the scientist who discovered biophotons. At that time, Fritz had the only equipment in the world capable of measuring biophotons emissions. He was initially reluctant to test a random piece of rock with his expensive equipment, but Phil convinced him otherwise. The basalt revealed biophoton emissions exceeding 4000 tiny light particles per microsecond. Phil’s theory had been proven. Volcanic soils effectively provide light stimulation for the roots and the army of soil-life that surrounds them.

The exciting thing about this breakthrough is that those of us with non-volcanic soils now have an inexpensive way to boost fertility, through the introduction of volcanic rock. In Australia, we can source crusher dust from basalt quarries across the country. It is often available for as little as AU$15 per tonne and it can be a great investment in building fertility. Unfortunately, there is a big variation between the paramagnetic qualities of various crusher dust products. It has been determined that a crusher dust must read over 1600 cgs (centimetre-gram-second) to be of value.

The Benefits of Owning Your Own PCSM Meter

The PCSM meter allows you to monitor the relative fertility of any field, at any time. It simply involves collecting 50 grams of soil in a small plastic container and placing it in the machine. The machine is set up, prior to each use, by placing a pre-measured sample into the well and calibrating accordingly.

pcsm meter

The meter can also help you determine which crusher dust might be more effective. There are several visual benefits from this natural rock dust bio-stimulant. Earthworms love the stuff and other, less visible creatures are similarly stimulated. I vividly recall a producer of rock dust fertiliser at field days, putting a billboard outside his tent, advertising scheduled feeding times for his earthworms. He would uncover a large box of earthworms at “feeding time” and sprinkle his rock dust fertiliser over one end. Despite their hate of direct light, the earthworms would surface and writhe amongst the crusher dust in a frantic feeding frenzy. It must always be remembered that earthworms decompose organic matter and create all-important humus four times more rapidly than any other form of decomposition. They are immeasurably important in the brave new world of climate change farming.

You can source your own PCSM meter by visiting

If you have any queries regarding the NTS range of Monitoring Meters, or wish to place an order, please contact us on +61 7 5472 9900 or

*Note: Published crop specific data is limited as this is a relatively new research area. However, comparing data in your crop from season to season while noting yields and insect pressure, as well as making comparisons on sap nutrient status between healthy and suboptimal crops/plants, and comparing young and old leaves, can provide valuable information for fine tuning fertiliser inputs and correcting imbalances.

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