The concept of increased sustainability in agriculture has traditionally evoked images of ‘sacrifice’. In this paradigm, recent converts to organics supposedly give up all their tools and the battle begins. Productivity drops dramatically but eventually you crawl back out of the hole, through lower inputs and higher organic premiums. This ‘sacrifice’ concept may seem absurd to any grower well-versed in the advanced agronomy involved in the biological approach, however, huge numbers of farmers around the globe still subscribe to this belief (albeit with billions of dollars of propaganda support from the chemical corporates). They genuinely believe that maximum productivity and profitability can only be achieved with an NPK punch, backed by chemical protection.
I often speak about the importance of passion in your chosen profession. It’s such a short life, if you can’t feel passion about an enterprise which will occupy most of your waking hours on the planet, then don’t waste your allotted time – find another profession that ‘sparks’ you. There is no passion in poisons. It’s not possible to be enthusiastic about donning your sweat-soaked spacesuit to poison your entire working environment and the food you’re striving to produce. The whole process is anti-passion! It is marketed as a ‘necessary evil’ because there is no viable alternative. If we were to use the health of our children as the benchmark for the performance of conventional agriculture, then the word ‘evil’ seems deadly accurate. Recent US research involved testing for the presence of the thirteen most commonly used farm chemicals in 400 school children from throughout the country. Researchers couldn’t find a single child who didn’t have unacceptable levels of all thirteen chemicals. Childhood cancer is now the largest killer of our kids and diseases like childhood leukaemia have been directly linked to these chemicals. There is an alternative to this travesty and in this two part article I will outline some key strategies to achieve maximum productivity and profitability without petrochemicals.
The Nutrition Nexus
Plant production and protection are based upon nutrition and nutrient density is a function of balance. Whether we speak of the ratio between calcium and magnesium, of fungi to bacteria or the ratio of pest to predator, the importance of this equilibrium is paramount. Disease and pest pressure are symptoms of an imbalance and the grower’s role is to determine the nature of that imbalance and to address the root cause of the problem. Conventional agriculture has been about treating symptoms and it has been a gravy train for those supplying the ‘leak pluggers’ because when we never solve the problem, there is no end to our need for their products. Achieving the desirable balance and associated plant protection involves both soil and plant nutrition.
Oxygen for the Dying – The Albrecht Anomaly
Dr William Albrecht highlighted the chemical, physical and biological links to soil fertility. Over 50 years ago, he showed that if the chemistry (the mineral balance in the soil) is corrected, then the physical structure changes. The ratio between calcium and magnesium, for example, determines the flocculating capacity of the soil and when calcium is at optimal levels in relation to magnesium, the soil opens and breathes. The physical structure changes and the soil-life flourishes with the unrestricted flow of oxygen into the root zone (in this context, oxygen is arguably the most important of all elements). However, things have changed with the addition of millions of tonnes of chemicals to our soils during the past five or six decades. The simple equation, where the balancing of the elemental components leads to promotion of a desirable physical structure, which then generates a powerful biological response, is not always applicable in 21st century agriculture. In many soils, we can no longer assume that the biology will ‘kick-in’ following the balancing of soil chemistry. An oxygen boost for the near-dead doesn’t cut it anymore. This doesn’t detract from the validity of Albrecht’s work, it simply heralds the need for a change of tack. Every farmer needs microbe brewing equipment to allow inexpensive regeneration of compromised soil biology. Many official trials of the Albrecht approach around the world have failed because of sick, unresponsive biology. When this situation is corrected with inoculums and soil-life stimulants the Albrecht balancing philosophy is fully validated.
In my travels around the world, I often encounter soil scientists, academics and government officials who are so incensed with perceived ‘faults’ in the Albrecht approach that they no longer seem capable of appreciating all of the other things I have to share with them. I find that if I can put their minds to rest on this issue from the outset then they become much more receptive to other aspects of our comprehensive holistic system.
There are two key issues which seem to raise the hackles of so many soil professionals. The first of these relates to their understanding of Albrecht’s ‘ideals’ for calcium to magnesium ratios in different soils. The idea that the Ca:Mg ratio for a specific soil is ‘set in stone’ and therefore essential for success, has been widely dispersed around the globe. This concept has alienated more scientists than it has inspired because it is simply not correct. In some soils the Albrecht ideals will definitely prove most productive, particularly in soils with a CEC between 8 and 28. However, the rules change in heavier clay soils. Farmers and consultants argue that if their soils already contain 10,000 ppm of calcium, but that only represents 55% of calcium base saturation, then surely they should not be expected to invest in 10 tonnes of limestone per hectare to achieve the desired 65% – “Surely 10,000 ppm of calcium is enough to supply the plant’s requirements!”, they implore. On many occasions, consultants and farmers may have worked with their particular soils for decades and they know for a fact that there is no gain in adding 10 tonnes of lime and so the Albrecht approach is discredited in their region and all of the other potential benefits of this approach are now ignored. The fact is that 10,000ppm is plenty in some soils. The difference between soils depends upon the dominant clay type in any given soil. Some soils give up their calcium easily and others hold tight, like beggars to a scrap of food.
How do you determine your specific requirement for calcium if you farm heavier soils? How do you know if you’re wasting your money playing the numbers game? It’s simple, you just use conventional leaf analysis. If the plant has good levels of calcium and you only have 55% calcium base saturation then this is all you need. As soon as I highlight the fact that these ratios are not “written in stone” and suggest the simple solution of using leaf analysis data to determine calcium requirements, the disgruntled soil scientists relax and become more receptive. This concept of verification with leaf analysis applies to all of the key ratios – if your iron to manganese ratio is 10:1 in favour of iron, for example, when the preferred ratio is close to 1:1 then some Albrecht consultants may recommend several hundred kilograms of Manganese sulphate to correct the ratio. This is usually not necessary. We find that calcium is actually the key player in manganese availability. If your calcium levels are good then a simple inexpensive foliar spray of manganese sulphate (chelated with fulvic acid) will often be sufficient without investing hundreds of dollars in a soil application. Let leaf analysis be your guideline. It often verifies the importance of Albrecht ratios but just as often you will find that a particular ratio is not so critical in your specific soil and conditions.
Nutri-Tech Solutions (NTS) work in thirty different countries with thousands of farmers. We focus upon Albrecht-style balancing with a much-needed biological emphasis. Our four day Certificate in Sustainable Agriculture Course has been internationally acclaimed and we have developed over 300 products during the past twelve years, sixty of which are organically certified. NTS offers the largest number of organic options in the world because we were determined to make every tool available. We wanted to facilitate a painless conversion to organics, if that was the chosen path. However, the vast majority of our clients are conventional growers who are seeking to increase efficiency, reduce chemicals and build profitability. We have been disillusioned with conventional organics in many countries because the emphasis is all about what you are not allowed to do. There are whole manuals of restrictions with barely a word about what you should be doing to produce nutrient-dense, disease resistant plants. We feel that the higher cost of organic produce can only be fully justified if that chemical free food tastes better and has more medicinal qualities. The absence of chemical residues is of immense value in preventing the ongoing assault of our immune systems but the second half of this equation is often ignored. Where are the minerals that are a critical requirement for immune support? In light of this concern, we have increasingly promoted an alternative to organics we call Nutrition Farming®. Here the emphasis is upon the production of protective, nutrient-dense food with forgotten flavours and extended shelf-life. In South Africa, we have recently achieved a major breakthrough. We conducted two of our four day certificate courses in that country in mid 2006. These courses were attended by a good mix of farmers, consultants, soil scientists, academics and three representatives from each of the major supermarket chains in that country.
Subsequent to those courses, Woolworths, a large, progressive, privately owned supermarket chain, have decided to pioneer the marketing of nutrient-dense food in South Africa. They commissioned NTS to return for another four day certificate course, specifically for Woolworths’ growers, in late 2006. When the widespread adoption of food produced with Nutrition Farming® proves successful in South Africa we then have a model to expand the concept elsewhere. The conversion of a national supermarket chain all at once will help achieve the much-needed improvement in food quality far more rapidly than one farmer at a time.
A key strategy in Nutrition Farming® is to reduce chemicals by understanding why chemical intervention was required and how to avoid it in the future. The starting point in plant protection is cell strength and resilience. A strengthened cell wall can act as a physical barrier to protect from insect and disease attack. Two minerals govern cell strength – calcium and silicon.
Tooth enamel, for example, the hardest material found in the human body, is based upon the combination of these two minerals. In plants, the fungal pathogen must use its hyphae to drill through the cell wall before feasting on the inner contents. The pathogen will not reproduce until it has successfully established this food supply. A cell, which has been strengthened with luxury levels of calcium and silicon, can provide a physical barrier which buckles the hyphae and encourages the pathogen to look elsewhere. Similarly, an insect will not chew on leather when he can source cake down the road. The recent International Silicon Conference in Brazil, featured photos of insects with their entire eating apparatus worn away through attempting to eat silicon-strengthened plants.
Several years ago, when I read some of the research papers on silica, I was sceptical about the need for a mineral which was so abundant. Silica is the second most prolific mineral on the planet. Sand is silica-based and clays are alumino-silicates so it is not a mineral which is easily leached or mined from our soils. However, when we began to include silicon in our soil testing, my opinion changed. The plant-available form of silicon is orthosilicic acid and this is what the soil test measures. The ideal level of silicon (as silicic acid) in the soil is 100 ppm but we found that virtually every soil test revealed a serious deficiency – most soils didn’t make it to half of the required minimum.
Silicon the Essential Non-Essential
Silicon is officially considered a non-essential mineral but this status may change as the research world discovers the potential of this neglected element. The presence of silicon in the plant confers an inherent pest and disease protection but when a pathogen has gained a foothold, it is also possible to neutralise the disease with foliar sprays of soluble silicon. The plant will mobilise all available silicon to strengthen the cells bordering the infection site and this can prove a very effective technique to prevent the spread of the disease.
Silicon is an important player in the most important of all plant processes – photosynthesis. Silicon-strengthened stems support the solar panels (leaves) in ideal positions to access optimum sunlight from above and CO2 emanating from the roots and soil organisms. The strong stems are also much less likely to lodge. Improved photosynthesis means more sugar delivered by the plant to the rootzone organisms, who in turn deliver more minerals to the plant. In this context, silicon has also been linked to improved nutrient uptake. Silicon is also involved in the formation and strengthening of phloem and xylem, the nutrient highways within the plant. When these structures are enhanced there is improved nutrient delivery and mineral translocation.
Silica-treated plants exhibit greater stress tolerance due to increased cell strength and new research also suggests an increased tolerance of salinity and heavy metals.
There is also research showing that silicon promotes Induced Systemic Resistance (ISR) in plants, where the plant’s immune system is activated and the plant is stimulated to produce a range of protective biochemicals. The ISR response enables the plant to fight its own battles.
Obviously we are looking at a nutrient that deserves ‘essential mineral’ status, particularly in terms of proactive protection and the associated reduction in chemical usage.
The Calcium/Boron/Silicon Connection
Calcium and silicon are the all-important cell strengtheners but how do we mobilise a ‘sluggish’ mineral, like calcium, to move it into the plant? Author/Consultant, Gary Zimmer has accurately stated that “calcium is the trucker of all minerals and boron is the steering wheel”, and there is no doubt about the validity of this statement. There is no point investing in tonnes of limestone if your boron levels are low because calcium needs a boron synergist. How does silicon fit into this equation? The problem with silicon is that although the soil is jam-packed with this mineral it is no longer present in plant-available form. The Japanese government has acknowledged the problem. They have recognised the role of silicon in the beautiful hair, skin and nails of their people and they’ve realised that their staple food, rice (containing 16% silicon), needs to be supplemented. Japanese rice farmers are now legally required to apply soluble silicon to their crops.
So something in the way we farm has shut down silica solubility. In all likelihood, there will prove to be a biological link to the shut down but we have also found a link to boron. Boron seems to serve as a silicon synergist just as it serves as a calcium synergist.
We find that an application of boron in late winter can free-up silicon to build better pathways into the plant which, in turn, improves the uptake of calcium in spring (when it is critical for cell division). In fact, calcium uptake seems to be improved at any time when boron and silicon are combined with this mineral. In recent Dutch research involving a consultanting company, called Lucel Horticulture, the research team were evaluating techniques to improve calcium uptake in leeks. These agronomists work with the Nutrition Farming® approach and they were familiar with the calcium/boron/silicon connection. The researchers tested a wide range of combinations including a liquid blend of these three minerals. Not only did this trio deliver the most calcium into the leaf but a host of other minerals were better represented in the leaves of plants from the calcium/boron/silicon treated plot. I guess that when the trucker, the steering wheel and the road builder are all involved, increased nutrient uptake, across the board, is inevitable.
Nitrogen and Nutrient Density
Most NTS growers use a refractometer as a standard tool to determine how well their crop is photosynthesising. This user-friendly, pocket tool offers instant feedback about the nutrient-density of your crop and the associated potential for pest and disease pressure. The most common cause of low brix levels, in our experience, is an oversupply of nitrate nitrogen. Nitrate nitrogen invariably enters the plant with water, so there is always a nutrient dilution factor involved in watery, nitrate-packed plants. Insects are attracted to nutrient deficient plants and nothing calls in insects as efficiently as a weak plant that has been ‘pumped up’ with nitrates. The consumer purchasing that plant receives a double whammy! Not only can they be assured of receiving a plant that has required a considerable level of chemical intervention but the nitrates are carcinogens in their own right. In this context, nitrate management becomes a key tool in the production of high quality, chemical-free food. The catch phrase I often use in relation to nitrate nitrogen is “how low can you go?” Nitrogen is the most abundant nutrient required for plant growth, so we must ensure adequate nitrogen is supplied. The question becomes how much nitrogen, what form is most suitable and when is this nitrogen best applied? This usually involves your own research work involving your specific crop in your unique conditions.
A plant sap nitrate meter, is an invaluable tool when monitoring the levels in the leaf. Lucel agronomists in Holland have found that the ‘ideal’ level for nitrates in their major crop, strawberries, is in fact much lower than what was generally recognised in the industry. They looked closely at “how low they could go?” and found that it was just one-third of the commonly recommended levels for that crop. Once this new ‘ideal’ was determined, it was often necessary to fast-track the lowering of nitrate levels to maintain crop quality and pest resistance.
Here they showed wonderful initiative by piecing together information I had delivered in my regular seminars in Holland over the past three or four years. They have developed a formula which can reduce nitrate levels in the leaf by 1000 ppm in just three days. The recipe involves sulphate sulphur (which is needed for the conversion of nitrates to proteins in the leaf), molybdenum, which is part of the reductase enzyme (also essential for the conversion of nitrates into proteins), magnesium (which is the core of the chlorophyll molecule and is required for hundreds of enzymic reactions including nitrate conversion) and fulvic acid to increase membrane permeability, thereby increasing the uptake and efficiency of the three nitrate-reducing minerals involved in the recipe.
This recipe is as follows:
The Recipe for Nitrate Reduction
Dissolve 5 kg of Magnesium sulphate in 250 litres of water (2%).
Add 500 mL of Nutri-Key Molybdenum ShuttleTM (a complexed molybdenum product from NTS) alternatively you might you use 100 grams of Sodium Molybdate.
Then include 150 grams of soluble fulvic acid powder (available from NTS).
This formula is applied to a hectare, whenever nitrate levels need to be lowered in the leaf.
Accessing the Free Gift
An essential part of managing nitrogen for increased crop quality is to ensure that a large part of your nitrogen requirements are sourced from the atmosphere, rather than a bag. The most productive soils on the planet have produced massive amounts of biomass for thousands of years and most of their nitrogen was sourced from the atmosphere. 74,000 tonnes of atmospheric nitrogen hovers over every hectare and this is where we’re supposed to get our nitrogen. This was the free gift that we somehow forgot to open. Not only does this gift from God come free of charge but it is the form of nitrogen most closely linked to crop quality, disease protection, flavour and shelf-life. It was nature’s intention that we harness both the Rhizobium organisms housed in the nodules of legumes and the free-living, nitrogen-fixing organisms like Azotobacter. These creatures deliver the perfect form of nitrogen to enhance plant health and that nitrogen is supplied as it is required by the plant, rather than the common practice of force feeding. It is no accident that the most abundant gas in the atmosphere is also the most abundant nutrient required for plant growth. It’s there for each and every one of us, but how do we access the gift?
The Recipe for Free Nitrogen
The key to accessing a virtual sea of free nitrogen involves five factors:
The Calcium to Magnesium Ratio must be acceptable. This ratio defines all beneficial soil-life activity because of it’s link to oxygen supply in the soil. However, it is particularly important in nitrogen fixation. Azotobacter, for example, the most prolific and important of the free-living nitrogen- fixing organisms, are the most aerobic organisms on the planet. A high magnesium soil struggles to breathe, like an animal nearing death. Improving the Ca:Mg Ratio (if necessary) is the first step in any biological program.
Soluble phosphate must be present as an energy source for the enzymatic conversion of atmospheric nitrogen (NO2) into the plant-available ammonium form (NH4). Adenosine-tri-phosphate (ATP) is required for enzymatic reactions. In the natural scheme of things, soluble phosphate is supplied by mychorrizal fungi. These creatures exude acids from their massive pipelike network of hyphae which constantly solubilise phosphate from the ‘frozen’ reserves of insoluble tri-calcium phosphate in the soil. However, these are also the creatures most decimated by chemical agriculture, so we can no longer rely upon their contribution to the recipe. If your soil life has been compromised, then soluble phosphate (preferably complexed with humates) will be necessary for the 5 part recipe. 100 kg per hectare of MAP with 5 kg per hectare of soluble humate granules is sufficient.
Molybdenum is one of two minerals that form part of the nitrogenase enzyme responsible for conversion of atmospheric nitrogen to ammonium nitrogen. Sodium molybdate can be dissolved and applied via irrigation or boom spray. Just 2 oz per acre is sufficient.
Iron is the second mineral which forms part of the nitrogenase enzyme. Iron is the most abundant mineral in the universe but it is often termed “the reluctant mineral’ because it is not always present in a soluble form. We find that humic acid has a tremendous affinity for iron. The simple and inexpensive addition of a few kilos of soluble humates per hectare should release enough iron for nitrogen fixation.
Cobalt is the final ingredient in the recipe. Cobalt is like mother’s milk to nitrogen-fixing organisms. Their health and productivity is strongly influenced by this trace mineral and yet it is seriously deficient in many of the soils we analyse. Like molybdenum, you will only require two or 100 g of cobalt sulphate per hectare.
In this, the first part of a three part article, I’ve suggested that if the struggling soil biology is kicked along with stimulants and inoculums then the rewards from balancing the mineral component become much more profound. I questioned the tunnel-visioned emphasis upon ensuring chemical-free status in organics while often ignoring the issue of food quality and I highlighted the links between nutrient-density and our immune and detoxification systems. I also focused upon silicon and its synergists when addressing the issue of proactive protection and I detailed the nuances of nitrogen in relation to crop quality. In the second part of this three part article I’ll cover monitoring techniques and nutrition strategies that reduce the requirement for chemicals while increasing crop quality and profitability.
Profitability without Petrochemicals
In Part One of this article I argued that nutrient density is the key to plant protection, crop quality, production and profitability. Building nutrient density in food is also a major priority from a human health perspective. Here we have a classic win/win situation – if we lift the nutritional quality of plants then we reduce our requirement for petrochemical-based fertilisers and pesticides while increasing our potential to survive the plague of degenerative illnesses currently afflicting the developed nations.
How do we prevent ourselves from becoming a grim statistic in a world when one in every two of us will suffer a degenerative disease during our lifespan? It is immune function and detox capacity that provides the plague protection and both of these critical systems are fuelled by the minerals that are missing in our food. Over 80% of us are zinc deficient, for example, yet zinc is essential for the production of killer T cells in the immune system and protection from prostate and breast cancer (our largest killers outside of heart disease).
Magnesium deficiency is almost as common as the shortage of zinc and both of these minerals are key players in Phase 1 and Phase 2 detoxification. Molybdenum, manganese and sulphur are also essential for both phases of detoxification and selenium is another, often neglected, powerhouse protector. The paradigm shift needed in food production is the recognition that we were supposed to derive our minerals from plants rather than bottles. Why else would plant-available minerals be 98% bio-available? So, what’s best for us as growers is also best for the consumers of the food we produce. This particular win/win situation is very similar to the multiple benefits associated with building humus levels in our soil.
The Humus Parallel
There is a striking parallel between the loss of nutrition in our food and the impending crisis associated with the build-up of greenhouse gases in the upper atmosphere which is now so obviously impacting upon climate. Here we have another win/win situation for farmers. Agriculture has a crucial role to play in reversing this build-up. In fact, agriculture can account for over 50% of the required reduction in CO2 (the worst greenhouse gas offender).
If we can increase organic matter by 1.6% in the 8.5% of the earth’s surface that is farmed then we have successfully sequested the extra 100 ppm of CO2 in the upper atmosphere that man has created (i.e. we are currently at 380 ppm CO2 when it is now understood that during the past 600 000 years the previous high point was 280 ppm). It is important to recognise that a large percentage of this offending 100 ppm of CO2 was derived from the loss of humus (organic matter) in our soils. A loss of 1% organic matter per hectare represents around 20 tonnes of CO2 released into the atmosphere. It’s mind boggling to contemplate the contribution of faulty farming practices to the current crisis. The loss of organic matter on The Great Plains alone has produced more atmospheric CO2 than all of the American motor vehicles ever produced.
In this win/win situation there is also no sacrifice required. What’s best for the environment turns out to be best for us (on all levels). When we increase carbon levels in our soils we not only solve global warming but our productivity increases, we boost water efficiency, we reduce pest and disease pressure and we produce a more nutrient-dense product for the health of everyone. It doesn’t get much better!
The efficient production of nutrient-packed plants involves a series of monitoring tools and techniques combined with strategies to increase nutrient uptake. At NTS we use the term ‘Plant Management’ to describe this approach and we refer to Plant TherapyTM in relation to crop monitoring and correction strategies.
The tools we use include refractometers, sap pH meters, sap conductivity meters, ion meters for nitrogen and potassium, and a crop specific data analysis technique when reviewing leaf test data.
Our strategies to improve nutrient uptake include the use of humic and fulvic acid to magnify mineral absorption, microbial inoculums to improve nutrient delivery, micronisation, various forms of chelation and plant growth promoters.
The Beauty of Brix
The refractometer is a six inch pocket tool which has become essential equipment for tens of thousands of biological farmers throughout the world. This tool measures dissolved solids in the plant and it is a direct measure of how well your crop is photosynthesising. Photosynthesis is the most important process on the planet as we are all dependant upon green plants for food. 95% of plant production is directly related to this process. If we burn 100 kg of plant matter, 5 kg will remain as ash and this represents the mineral component. The balance of the plant structure (95%) comes from the miraculous process where sunlight, CO2 and water are combined to produce the basic glucose building blocks of life.
The refractometer measures how well the grower has managed chlorophyll, the green pigment that facilitates photosynthesis. If you have succeeded as a chlorophyll manager then the brix levels of your crop will reflect that success.
Brix levels indicate levels of sugars, amino acids and minerals within the plant. The higher the brix the greater the production potential and the lower the pest pressure. High brix produce is sweeter tasting and more minerally nutritious, with a lower nitrate and water content and better storage characteristics. This produce will have higher true protein and greater specific gravity or density. These high quality crops will also have a lower freezing point with inherent frost protection.
Seven Secrets of Brix
There are several factors influencing brix levels including the following:
Storms or impending weather changes will lower readings, i.e. the plant translocates sugars to the roots when anticipating periods of stress.
Droughts can raise the reading since the water content of the plant is low and plant juices are more concentrated.
Several consecutive cloudy days will lower brix levels as photosynthesis falters in the absence of sunlight.
The lower the humus content of the soil the faster the brix levels will drop following a prolonged lack of sunshine.
Fulvic acid has been termed ‘the second sun’ because it can be foliar sprayed during long cloudy periods to compensate for the missing sunlight.
Brix levels should remain uniform throughout the plant. If there is a marked variation from the top to the bottom of the plant then this indicates a soil imbalance.
There should always be a variation in brix levels during different times of the day. Plants translocate 60% of their photosynthates to the roots at night. In early morning, brix levels should always be lower than afternoon readings when the photosynthates are back in the leaf. If the levels don’t differ then the chief suspect is a boron deficiency because boron opens the trapdoor to allow movement of sugars from the chloroplast.
In Pursuit of Perfect Plant pH
There are strong parallels between person, plant and soil when it comes to the significance of pH. A pH of 6.4 is considered ideal in the soil as this is the pH where almost all minerals are most plant available. Your saliva pH should ideally be 6.4 upon arising (although it should gradually rise to 7.4 by nightfall) and the perfect pH of plant sap should also be 6.4. Disease is more prevalent in both acidic soils and acidic humans. US consultant, Bruce Tainio, has shown that acidic plant sap pH is also a precursor to problems. We have confirmed Bruce’s findings in Australia and around the world on many occasions.
Low plant sap pH suggests greater disease pressure. In fact, at a pH of 5.4 it is virtually impossible for a plant to remain disease-free throughout the crop cycle. Conversely a high sap pH indicates the likelihood of higher insect pressure. If the sap is acidic (below 6.4) then this suggests a lack of alkalising minerals. These comprise the most abundant cations within the plant including calcium, magnesium, potassium and to a lesser extent sodium. If the plant sap is alkaline (above 6.4) then there is an anion imbalance.
The trick is to determine which of the cations is deficient to be able to address the problem and reduce disease potential. This diagnosis can often be achieved by using a combination of monitoring tools. A refractometer, for example, offers some insight into calcium levels in the soil. When looking through the eyepiece of this device, the brix level is determined by where the dividing line falls on a scale of 1º to 30º brix. There are two indicators of a calcium deficiency – low brix can mean poor mineralisation because calcium (the trucker of all minerals) is lacking. The second indicator is a sharp, clear delineation between the two colours visible through the eyepiece. In general, the sharper the delineation the more pronounced the calcium deficiency. Conversely, a fuzzy delineation usually spells sufficient calcium.
Let’s look at an example; our sap pH is just 5.4 and we are seeking to determine the missing mineral that may be responsible. Our refractometer reads 10º brix with a very fuzzy line so we can assume that calcium is not the culprit. We check the crop with our potassium meter and no shortage is revealed. Then, through a process of elimination, we can assume that the missing mineral must be magnesium. If this is indeed the case then a foliar spray of 2% magnesium sulphate (1:50 dilution) combined with 1 litre of fulvic acid per acre should sponsor a rise in sap pH (and probably brix) and your crop’s potential for increased disease pressure is immediately reduced.
Reduced reliance upon petrochemicals requires a proactive approach where you seek solutions rather than treat symptoms. These monitoring tools significantly boost your ability to be proactive.
Managing Energy Flow
Energy farming pioneer, Dr Carey Reams, saw soil conductivity as an indication of the availability of energy for plant growth. That energy is released from the mineral salts of which soil conductivity is a measure. In a situation comparable to an athlete’s need for electrolytes to maintain performance, the plant requires an optimum level of these salts to sustain productivity. Reams referred to ‘ergs’ as a measurement of conductivity. In his system the soil required minimum ergs (energy) at planting and energy demand increases to peak during the reproductive phase. This is, of course, a much different approach to many contemporary growers who load their crop with fertiliser from the outset and then begin the ludicrous chemical war against insects and disease that they themselves have initiated with mineral mismanagement.
The plant sap conductivity meter manufactured by Japanese company, Horiba, measures sap conductivity with just a few drops of juice squeezed from the leaf or petiole. Plant sap conductivity indicates the level of simple ion uptake. Low EC is an indication that elements are not being made available to the plant. There is usually a direct link to soil conductivity and it means that your soil lacks the energy to promote optimum plant performance.
In the soil a crop should ideally be started with an EC reading of around 300 µS/cm (0.3 mS/cm) and the soil conductivity should be increased to around 700 µS/cm (0.7 mS/cm) during the energy drawdown period of fruiting or seeding.
In the plant sap these figures are higher. The young seedling should ideally measure 2 000 µS/cm and conductivity should gradually increase during the crop cycle, peaking at 10 000 to 12 000 µS/cm during fruit fill. If sap EC is too high, during any stage of the crop cycle, then mineral ions will not be complexed correctly. The most common cause of this problem is the over-supply of nitrate nitrogen and this can be determined with the use of a nitrate meter.
It has been determined that a healthy plant requires 75% of its nitrogen in the ammonium form and 25% in the nitrate form. This balance is important because the conversion of nitrates to amino acids and proteins is a very energy-intensive process involving the molybdenum-based reductase enzyme and sunlight. If nitrates are over-supplied then yield-building potential can suffer due to this misspent energy.
Unfortunately, much of the produce purchased at your local supermarket contains 75% nitrate nitrogen and 25% ammonium nitrogen. This inverted ratio spells major problems for both plant health and human health. Nitrates are proven carcinogens. There are hundreds of published papers on the nitrate-sponsored reduction in the oxygen-carrying potential of blood (in animals and humans) and the cancer-causing potential of nitrosamines (formed during digestion when nitrates combine with amines).
In Part 1 of this article I covered the potent nitrate connection to low brix levels and I stated that high nitrates are a calling card for insects. Why on earth would we pump our plants full of this energy-sapping form of nitrogen which guarantees increased chemical intervention and poisons consumers of our food (with a combination of nitrates and additional pesticide residues)? The reason, of course, is that growers are often paid so little for their produce that they feel compelled to ‘pump it up’ as fast as possible to ensure profitability! In reality there is an optimum amount of nitrate nitrogen for every crop and every soil situation and the best way to discover this amount is to discover ‘how low you can go’ with the use of an Horiba nitrate meter. These devices are not quite as user-friendly as the other tools I have mentioned as they require calibration on a daily basis, but they are accurate within 5% of a conventional leaf analysis and they offer finger-tip control of nitrates to maximise crop quality.
As a rule of thumb, nitrate levels (as measured by this meter) should not exceed 5000 ppm during the vegetative stage and should not rise above 3000 ppm during fruiting or seed fill. However, the aim is to discover the lowest amount of nitrates for your crop before it becomes yield limiting (and this is often much less than 5000 ppm). Then we start to produce mineral dense food packed with phyto-nutrients for the benefit of us all.
The Potash Powerhouse
US biological consultants often highlight the dangers of excess potassium including the inhibitory effect of this excess upon calcium, magnesium and boron. The Reams-influenced consultants also focus upon the potassium to phosphate ratio and associated problems with phosphate availability when potassium is over-supplied. While heavy-handed potassium fertilising or naturally high potassium soils can definitely create these problems, and others, it is not something very common in Australia or in other countries in which we work. It is actually more common to see an oversupply of nitrogen negatively affecting potassium levels in the plant.
Bruce Tainio has made an important observation in recognising that a yield limiting, nitrogen-fuelled potash shortage in the plant can often go unnoticed if we solely depend upon conventional leaf analysis to monitor this important mineral. Potassium is incredibly mobile within the plant and it rapidly moves to where it is needed. Potassium is actually the only mineral that doesn’t become an integral part of the plant structure. In fact, if it rains on cut hay, the potassium can flow straight from the hay into the soil. Potassium is needed to convert nitrogen into protein, it regulates stomatal opening for improved photosynthesis and most importantly it facilitates the movement of sugar and starches that are needed to size up fruit and grain. It rushes about catalysing thousands of chemical reactions by regulating around 50 enzymes. In short this mineral can have a major impact upon yield. The standard procedure for leaf testing potassium (and other minerals) involves sampling the last fully developed leaves on the plant. The problem here is that this highly mobile mineral may have vacated the lower leaves to satisfy the potassium hunger in new shoots and developing fruit and we are actually measuring the region to which it has moved, i.e. we are missing the early stages of potassium deficiency which is found in the lower leaves. When this alkalising mineral becomes deficient in the lower leaves their pH levels drop and they become candidates for disease. Think about potassium-hungry tomatoes – where does the disease usually begin? It begins in the lower leaves where the potassium has vacated and when we test the upper leaves we don’t detect this serious yield limiting deficiency.
An Horiba Potassium Meter is a solution to this problem. Readings from the lower leaves should be equivalent to those from above. It is suggested that the whole plant should read around 3500 ppm during the vegetative phase but should increase to 5000 ppm during the reproductive and fruit filling phase. This rough guideline will vary between crops but the key factor is to understand the need for improved monitoring of this critical nutrient in a nitrogen-obsessed world where potassium availability is so easily compromised.
The Big Four
During the past 13 years, as we have developed the NTS holistic approach, we have trialled numerous concepts and fused those that worked best for us into a functional hybrid we call Nutrition Farming®.
Several years ago Gary Zimmer, Jerry Brunetti and I embarked upon an action-packed whistlestop tour of Australia and New Zealand called ‘The Three-Up Tour’. The 100 page seminar manual from that tour, called ‘The Three-Up Tour – Nutrition Farming® Explained’, remains one of the most popular texts on biological agriculture in many countries. We learnt from each other during this intense time together. Gary and Jerry came to understand the potential of humates as NTS has been a leader in this field. Jerry Brunetti triggered my desire to understand more about human health issues and I now find myself writing and speaking on human health as often as soil and plant health. Gary Zimmer redefined the concept of ‘passion’ for me as I watched him ‘spark’ growers across the country. During that time Gary shared a finding, in relation to interpretation of leaf analyses that was to become an integral part of the NTS approach. In his work as a dairy nutritionist Gary was intent upon raising the nutrient density of pasture to reduce the requirement for cereal grains in the animals’ diet. Birds are the only creatures designed to eat grain and this acid forming, enzyme inhibiting stockfeed has a negative impact on animal health. Conjugated Linoleic Acid (CLA), a powerful cancer fighting compound found only in grass fed ruminants, is largely absent in grain-fed animals and the whole fatty acid and mineral profile in the meat is similarly compromised. While researching high protein pasture production Gary used hundreds of tissue tests to monitor his progress. In the process he discovered that if four specific minerals were at luxury levels on the leaf test then that crop would exhibit all the desirable characteristics he was seeking. This finding intrigued me and I set about checking years of our previous leaf tests to find examples of luxury levels of these four minerals. Then I contacted the growers involved and asked if that specific crop had been anything special. In every instance the growers reported bumper crops of high quality produce. It soon became obvious that Gary Zimmer had made a major discovery that applied equally to all crops. The Big Four, as I call them, includes calcium, phosphorus, magnesium and boron.
The Sugar Synergists
When we analyse the respective roles of these four minerals it becomes obvious why they are so important. Each of these minerals plays a major role in the production and transport of plant sugars. They are, in effect, photosynthesis facilitaters and when we consider that photosynthesis accounts for 95% of plant production, The Big Four truly deserve their elevated status.
Calcium, the trucker of all minerals, affects the uptake of the trace minerals that determine chlorophyll density. Blotches, stripes and pale colours in the leaf are symptoms of poor chlorophyll management. Calcium should always be first priority when addressing mineral balance.
Phosphorus is the energy mineral. It is the basis of ATP (Adenosine Tri- Phosphate) which is the energy currency for every enzymatic reaction in microbes, plants, animals and humans. In the miniature sugar factory inside every chloroplast, a series of phosphorus compounds fuel the entire process. In fact, it is not possible to build a high brix plant in the absence of phosphates. DAP and MAP became the world’s largest selling fertilisers because of this sugar connection. The problem here, however, is that this soluble phosphate doesn’t remain soluble for the full crop cycle and growers have not been informed of this problem. In fact, you get just 23% of your phosphate from DAP/MAP before it locks up and becomes part of a massive ‘frozen’ reserve in the soil.
Magnesium is the centrepiece of the chlorophyll molecule and in this context it becomes a key player in photosynthesis. 70% of all the leaf tests we analyse at NTS reveal a magnesium deficiency which is compromising photosynthesis. Magnesium is also a phosphate synergist. It is sometimes possible to see a greater increase in phosphate in the leaf following a foliar spray of magnesium sulphate (with fulvic acid) than following an actual application of phosphorus.
Boron is a calcium synergist. Calcium can not deliver its grand suite of benefits in the absence of boron. In fact, all calcium applications should include boron for maximum effect. Boron is also involved in the transfer of sugars from the chloroplasts on a daily basis. Boron activates the trapdoor that allows the chloroplasts to ship out their daily production. If there is no change in brix levels from morning to evening, then a boron deficit is the chief suspect. Suddenly this single trace element becomes incredibly important. If the daily sugar production is not shipped out then the roots miss out and more importantly the army of micro-organisms, that normally receive 30% of daily sugar production, get to starve. As a result we see less nitrogen fixation, reduced nutrient delivery and recycling, diminished protection from pathogens and a lower production of plant-promoting exudates from the ill-fed workforce. All for the sake of 1 kg of soluble boron per hectare and 2 litres of humic acid to boost uptake.
So, The Big Four is about the minerals most involved in photosynthesis and their synergistic relationships. Gary Zimmer has made a genuine breakthrough in plant nutrition but now the question becomes ‘how do we achieve luxury levels of these four minerals in the plant?’ and herein lies some major problems.
Micronised Minerals – When Small is Better
The NTS Plant TherapyTM service involves an in-depth analysis and programing service based upon leaf analysis data. It has been estimated that over 30% of the many thousands of leaf tests that have crossed our agronomists’ desks have been deficient in all of the minerals that comprise The Big Four. Calcium is the most common shortage with 80% of all leaf tests revealing a shortage of this critically important mineral. The problem here is that many of these tests also reveal a nitrate excess (the mineral most often in excess). How do you rapidly address a calcium deficiency when the major source of soluble calcium is calcium nitrate? Similarly, a correction strategy for a magnesium deficit might include either magnesium sulphate or magnesium nitrate. Sulphur is often in excess, according to leaf test data in intensive horticulture, due to the use of sulphate-based fertilisers and trace minerals. What was clearly needed here was a mineral source that did not involve the unwanted ‘tag-ons’. This is why we developed the concept of Micronised Mineral SuspensionsTM (MMS).
When high quality limestone is ground down to an average particle size of 5 microns it can be held in a liquid suspension with the use of natural gums. We have found that we can get more than a kg per litre into solution which delivers a very high analysis end-product containing ‘fast food’ calcium with no unwanted extras. We can achieve an analysis of 44% calcium with this technology compared to 17% calcium in calcium nitrate. Magnesium carbonate can be similarly treated to produce a liquid magnesium fertiliser with over 20% magnesium compared to the 10% magnesium found in either magnesium sulphate or magnesium nitrate. Dolomite can be micronised to deliver both calcium and magnesium or micronised gypsum can supply calcium and sulphur. The concept is about dramatically increasing the surface area of these mineral fertilisers to increase their rate of biological breakdown. We can monitor with leaf analyses and find impressive plant availability within days of application.
The most successful MMS product in Australia is a liquid fertiliser based upon micronised guano (called Phos-LifeTM) with an end product analysis of 26% calcium and 10.4% phosphorus. Calcium and phosphate are usually incompatible in soluble form but in this ‘almost soluble’ form they deliver the same synergistic energy kick that we would expect in a fully soluble equivalent. So, if a leaf test revealed low levels of The Big Four then we might choose micronised guano to address the calcium and phosphate shortage and micronised magnesium carbonate for magnesium. These would be combined with soluble boron to address all four shortages.
Written by Graeme Sait