A trace mineral deficiency can affect yield, disease protection, weed pressure, nodulation, reproduction or chlorophyll density and any of these will impact upon your profitability. Here are some guidelines that may help you in the management of trace mineral nutrition:
It is much more effective to apply trace minerals as foliar sprays, in comparison to soil applications. In fact, it is up to fifteen times more effective. The stomates on the underside of the leaf serve as direct entry points for foliar nutrition. Uptake efficiency can be further improved if the trace mineral is combined with fulvic acid. 300 grams of soluble fulvic acid powder per hectare is usually sufficient to sensitise the cells, increasing the permeability of the cell membrane to allow a 30% increase in nutrient uptake. Fulvic acid is also a chelating agent that is compatible with everything so it is an invaluable foliar additive. Fulvic acid provides inexpensive DIY chelation, based, like all chelating agents, upon neutralising positively charged cations to allow better uptake on the negatively charged leaf surface. However, there is another mineral delivery system that is not based upon uptake via the stomata. In fact, this unique system can deliver minerals through any part of the plant surface including stems and the top side of the leaf. The NTS Shuttle® system is the most effective way to address trace element shortages. Here the mineral ions are bound together in a nanocluster. A shuttle ligand removes individual ions from the cluster and delivers them to the plant surface to which it is magnetically attracted. A phenomenon called thermal vibration creates tiny openings into the plant. When the shuttle ligand has slotted its mineral lode into the plant it is drawn back to the nanocluster and the process is repeated until the mineral delivery is complete (hence, the “shuttle concept). The Shuttle trace minerals are considerably more effective than EDTA chelates and much less expensive.
Seed treatment is one of the most cost effective ways to provide some trace mineral nutrition, particularly if you have a tight budget. The mineral package should always include core trace minerals like zinc and copper but calcium should also be present as a carrier and to push the cell division that is part of early growth. Molybdenum and cobalt should also be present, as these minerals are so often deficient and are so important for nitrogen fixation (involving both leguminous or free living nitrogen fixing organisms). However, the most important trace mineral component of a good seed treatment is manganese. This mineral is a seed energiser and it is often called the element of life. It is more important to have manganese available at the onset of vegetative growth than at any other time of the season. Seed treatment usually involves mixing the concentrate with equal amounts of water and applying it to the seed before plant. Seed-Start™ from NTS, for example, is applied at 5 litres per tonne of seed. It is combined with 5 litres of water, placed in a backpack sprayer and sprayed onto the seed en route to the seeder.
During the past two decades, NTS Agronomists have analysed thousands of leaf tests from throughout the world and in over 95% of these tests we find that boron levels are less than optimum. This important trace mineral is most required immediately before flowering and there are very few crops that will not benefit from a foliar spray of boron at this time. Boron is critically important for pollination and many other reproductive functions. Avocados are a particularly good example because they are an extraordinarily boron-hungry crop. This crop is renowned for a massive show of flowers but a poor conversion to fruit. Boron can be a key player in this poor fruit to flower ratio. A pre-flowering foliar spray involving a couple of kilos of solubor and a kilo of NTS Soluble Humate Granules™ per hectare, can lengthen the male pollen tube and significantly improve pollination and subsequent fruiting. This inexpensive investment can prove to be one of the most productive strategies to lift profitability in an avocado orchard.
Molybdenum is another missing mineral in many of the soil tests we analyse. This is the mineral required for two hugely important functions, both of which are linked to nitrogen. Molybdenum is a keystone of nitrogenase, the enzyme which enables nitrogen-fixing organisms to convert nitrous oxide gas in the atmosphere into ammonium nitrogen in the soil. If you are one of the many growers lacking molybdenum in your soil, you are not receiving the free gift of nitrogen from the atmosphere and you will require more, increasing expensive nitrogen from a bag, as a result. Molybdenum is also required to manufacture the nitrate reductase enzyme. This is the enzyme needed to convert nitrate nitrogen, stored in the leaf, into proteins. Molybdenum-deficient pastures, for example, will produce protein-deficient livestock. Similarly, fruit and vegetables grown in soils lacking molybdenum will have higher nitrate levels and lower protein levels. Both of these imbalances are injurious to human health. The ideal correction of a molybdenum deficient soil involves application of two kilos of sodium molybdate per hectare. However, if this correction is not economically feasible, you can foliar spray 200 grams of sodium molybdate with 200 grams of NTS Fulvic Acid Powder™ per hectare and this usually will supply enough molybdenum to fix nitrogen and make protein for a season.
Is it more cost effective to supply trace minerals to livestock via a mineral supplement or through a mineralised pasture? The answer to this common question is an unequivocal “no”! The mineral supplement offers a short term fix that will be needed indefinitely. The mineralisation of the soil costs more up front but will deliver the minerals for years to come and those minerals are more easily assimilated. Plant-derived minerals are 98% bio-available while inorganic minerals have much lower bioavailability and they are more dependant upon the health of the digestive tract and the biology it contains. There is another less expensive way to supply trace minerals. Small amounts of sulfate-based trace elements can be combined with fulvic acid and foliar sprayed on your pasture each season. I have never seen any published research on the cost effectiveness of foliar trace mineral nutrition versus the stock supplements, but I suspect that it is the better option, particularly when considering the plant minerals versus inorganic minerals uptake advantage.
Selenium is a mineral that most livestock producers include in their animal supplements because a shortage is linked to white muscle disease and other ailments. Selenium has not previously been considered to be an essential mineral for crop nutrition, however, this looks set to change. Recent research has shown that selenium may protect crops just like it protects animals and humans. Have you ever wondered how a plant can stand in direct sunlight for 12 hours a day and not suffer UV damage like most other life forms. The pigments in plants are antioxidants that counter the oxidation and free radicals associated with UV. However, we now know that selenium also reduces that stress and that this stress reduction can help build yield. Researchers in Finland, working with potatoes, reported a 30% increase in mean tuber weight when selenium was applied to the crop. This substantial yield increase was linked to enhanced photo oxidative stress tolerance. Chinese researchers mirrored these findings when they recently found increases in rice yields following application of selenium. It doesn’t just stop at yield increases.
European researchers have shown that if leaf levels of selenium could be maintained above 10 ppm, there was an associated 50% reduction in aphid populations. Aside from these benefits, there is also the issue of the importance of selenium in human health. We are what we eat and what we eat comes from the soil and that soil is screamingly deficient in selenium. CSIRO research in South Australia monitoring selenium levels in vegetable crops was a stark reminder of the scale of this deficiency. These researchers were unable to find a single part per billion of selenium in vegetables tested over a six month period. Brazil nuts contain the highest level of selenium of any food. A single nut contains 25 mcgs of this mineral. NTS include substantial levels of selenium in our top-selling liquid fertiliser, Triple Ten™, because this foliar will deliver directly into the plant. The plant-derived form of this mineral is so much better than inorganic supplements.
It is really common where trace minerals are marginal (broadacre and pasture situations) for the application of one trace mineral to induce a deficiency of another. This is related to a phenomenon called antagonism, where every mineral can negatively impact the uptake of another, if the balance between them is altered. The trick to avoid induced deficiencies is to include a little of everything else when applying a trace mineral in marginal conditions. The popular NTS trace mineral mix, Nutri-Key Shuttle Seven™, has exceptional levels of all seven trace minerals. The inclusion of as little as half a litre of this blend with the main trace mineral you are applying can prevent induced deficiency. If, for example, you were wanting to address a copper deficiency in a wheat crop, you might mix 1 kg of copper sulfate with 200 grams of NTS Fulvic Acid Powder™ in 100 litres of water and include 500 mL of Nutri-Key Shuttle Seven™ (this mix is applied to one hectare).
Zinc can have more impact on yield than any other trace mineral because it is directly linked to leaf size. The leaf is the solar panel within which the whole process of photosynthesis occurs. The larger the solar panel, the higher the potential sugar production and the greater the yield. Auxins are the plant hormone that is most involved in determining leaf size and zinc governs auxin production. Little leaf disease in citrus, for example, is induced by a zinc deficiency. Zinc antagonises iron, copper and sulfur so a little of these minerals should be included as background nutrition when addressing a zinc shortage. Typical application rates of zinc include the following: 1 kg of zinc sulfate can be combined with 150 grams of NTS Fulvic Acid Powder™ in 100 litres of water as a per hectare broadacre rate. In established orchards, 5 kg of zinc sulfate combined with 500 grams of soluble fulvic acid can be applied per hectare with as much water as is required. When zinc is used as a seed treatment in zinc deficient soils it can offer the biggest bang for your buck of any mineral. Zinc-Life™ is a micronised liquid zinc featuring a massive 65% zinc along with kelp and humates. It can be applied at 5 litres per tonne of seed to great effect. This investment of around $2 per hectare can boost leaf size and lift yield. It might deliver the bare minimum of zinc for that single season, but it can prove to be an exceptional investment if you are lacking this mineral in your soil.
Silica is a cell strengthener and an immune elicitor of considerable import in proactive agriculture. If your goal is to reduce your dependence upon expensive farm chemicals then the first step is to strengthen up the cell walls with silica and calcium. Interestingly, boron is a synergist for the increased uptake of both of these minerals. Boron can be applied to the soil in late winter to encourage the release of silica from the clay component of the soil (clays are alumino silicates). The soluble silicic acid can then move freely into the plant where it improves the cell strength of zylem and phloem. These are the pathways for water and nutrient transfer within the plant. Calcium is the most sluggish of all minerals when it comes to translocation from the soil to the plant. However, the enhanced nutrient highways sponsored by soluble silica help facilitate easy uptake of calcium where it is so desperately needed for cell division during rapid spring growth. Silica can be applied as potassium silicate or as Dia-Life™, the latter being a liquid micronised form of diatomaceous earth. Diatoms are microscopic creatures with a silica based outer shell. When micronised, this organic silica is highly effective. It can considerably lift leaf levels of silica with fertigated applications of just 5 litres per hectare.
Micronutrients are as important for micro-organisms as they are for plant life. The free living nitrogen fixing organisms, Azotobacter, need zinc to thrive. All nitrogen fixing organisms need molybdenum and cobalt to perform their important role. Calcium and soluble silica are also required to promote cell strength and associated resilience in microbes. Manganese reducing organisms and iron reducing organisms (the creatures so harshly impacted by glyphosate) obviously require these two minerals. This is why it is always a good idea to add small amounts of trace minerals to microbial inoculums like compost tea. These minerals can serve as a support mechanism for organisms entering hostile territory (minerally deficient soils).