Exciting News for the New Broadacre Planting Season

A seed treatment, liquid injection and a little granulated starter blend in the root zone, can together comprise the very best start for your crop. However, it is important to understand the dynamics and interplay of these strategies to ensure that you get it right. Let’s look at each of these practices separately, before considering how and why they best work together.

Seed Treatment

The seed represents a complete plant, encapsulated in a casing, containing all that is required to begin afresh. The idea of applying large amounts of unstable starter fertiliser at this time is a little like giving a 10-year-old pocket money of $500 a week, and hoping for a good outcome. The new plant is not equipped for the fertiliser flood, just as the child is ill-equipped for money management. However, small amounts of key minerals, microbes and humates can set up your crop for the rest of the crop cycle, much like mother’s milk for an infant.

Seed treatment offers the chance for some subtle support. This can make a major difference to germination and establishment and is super cost-effective. In fact, a good seed treatment can offer the best cost-to-benefit of any input. The question here is, what is a “good” treatment?

Ideally, a seed treatment should comprise key microbes, minerals, biostimulants and plant growth promoters (PGPs).

Seed Treatment Microbes

Mycorrhizal fungi should always be considered as a microbial priority. These creatures have been decimated in most farming soils (90% depleted). The colony forming units (cfu) of this inoculum germinate upon contact with the emerging root. They burrow into that root and begin growing into a massive network of fine filaments that eventually amounts to a tenfold (1000%) increase in root surface area. Products like Nutri-Life Platform®, from NTS, are in a powdered form that should be liquified and combined with the other nutrients that comprise the seed treatment.

The mycorrhizal root extension can scavenge for immobile minerals, like phosphorus and zinc, while pumping the plant with immune-enhancing biochemicals. The acid exudates can serve to break the bond between locked-up calcium and phosphorus in the soil, effectively freeing up these two essential minerals. The root extensions are better able to seek out moisture, and they can also mine potassium trapped within clay platelets. Mycorrhizal fungi offer profound protection against root knot nematodes and they are responsible for a sticky exudate called glomalin, which is now known to be a triggering mechanism for the creation of up to 30% of all soil humus.

That’s a pretty impressive package! Platform® is typically included in a seed treatment at lower than optimal rates due to budgetary restrictions. An investment of around $7/ha for example, (depending on sowing rate), will typically provide enough spores to initially colonise around 25% of your crop, but the aim is for the colonisation to continue, from plant to plant, throughout the crop cycle. The goal is to eventually develop a matrix of hyphae across the field, which will serve to effectively inoculate subsequent crops.

Trichoderma inoculums, like Nutri-Life Tricho-Shield™, can be another productive biological inclusion for seed treatment. Trichoderma species have been known to offer better protection against early damping-off diseases, like Pythium, than fungicide-treated seed. In addition, that protection persists for the full crop cycle rather than the typical 6-week protection offered by the chemical treatment. Trichoderma species protect via a combination of predation on pathogens, and the elicitation of an immune response. The enhanced immunity boosts both disease and insect protection and it also increases yield (a feature of all immune elicitors). Trichoderma are phosphate-solubilisers, they boost root development, and they digest cellulose to produce humus.

Seed Treatment Nutrition

Kelp is the number one seed treatment inclusion, as it offers three distinct benefits:

1) Seaweed contains all 74 minerals found in the ocean, many of which have long since been exhausted in our soils. All of these minerals are naturally chelated with a long chain carbohydrate called mannitol. There is sufficient mannitol in kelp to also provide chelation of other minerals that might be included in the seed treatment.

2) The complex carbohydrates in kelp are also a favoured food source for the beneficial fungi, so often sadly lacking in broadacre soils. This stimulation extends to the mycorrhizae and Trichoderma inoculums that might also be supplied in your seed treatment.

3) Most importantly, the application of seaweed to the seed provides a supplement of the four natural hormones that drive every plant process, from germination to seed sizing. Cytokinins, gibberellins, auxins and betaines are commonly deficient in many crops, because they are made from a broad spectrum of minerals that are simply no longer present in heavily farmed soils. Kelp seed treatment can counter this shortage and provide a pronounced improvement in germination and early establishment.

The minerals most required for seed treatment include calcium, phosphorus, manganese and zinc. There can also be great benefit in supplying some boron around this time, but I favour a different strategy for optimum boron nutrition, and I will discuss this option later in this article.

Manganese is of particular importance here, particularly if you have been using glyphosate. This herbicide kills the manganese reducing organisms responsible for converting manganese to a plant-available form. Manganese is often called the “seed energiser”, because it is so critical for a good start.

Zinc is so often missing in broadacre soils and a seed treatment of this mineral can provide a cost-effective boost to assist early crop establishment. Zinc is required for the production of auxins, which, in turn, govern leaf size. A zinc deficiency will always mean a smaller leaf, and this sub-standard solar panel will always cost yield.

Calcium and phosphorus are best supplied as micronised powders. We have seen tremendous response, in terms of root growth stimulation, with the inclusion of inputs such as micronised lime, gypsum or guano on the seed. These are far more effective than chelated calcium, or simple calcium nitrate. Seed-Start™ from NTS, is formulated with these in mind, (plus biostimulants), and costs less than $2 per hectare, (depending on sowing rate).

Liquid Injection

The concept of squirting a little liquid nutrition in the seed zone during planting is a relatively recent innovation and it has several distinct benefits. The liquid can sponsor inbibition, the process where the seed takes in a little moisture, which in turn, triggers earlier and more vigorous germination. This strategy also offers the opportunity to provide a more substantial microbial inoculation to kickstart and protect the emerging crop. My favourite inclusion here involves beneficial anaerobes. These inoculums include multiple strains of Lactobacillus along with fermenting fungi, Actinomycetes, nitrogen-fixers and purple non-sulphur bacteria (PNSB). A product like Nutri-Life BAM™ (Beneficial Anaerobic Bacteria) can provide multiple benefits at this time. BAM™ can be brewed so that the ideal liquid injection rates of 10 litres per hectare can cost just $3 or $4/ha. The lactic acid found in this inoculum has a pH of just 3.5, and this acidity can help sponsor fungal proliferation in the root zone, while also helping with solubilisation of both locked-up phosphate and citrate soluble phosphate fertilisers like guano.

A highly productive liquid inject formula might involve 6-8 L/ha (depending on row spacing), of Springboard™, which contains a full suite of N-P-K, trace elements, (including molybdenum), as well as biostimulants like kelp and fulvic acid. This can be combined with 10 litres of brewed BAM™ and a further 30-40 litres of water.

Buffering and Boosting the Planting Blend

Most broadacre crops need some plant-available phosphorus to trigger early root growth and good establishment. This is generally supplied with either DAP or MAP (depending on the soil pH). There are some downsides to this practice and the most significant of these relates to the burning of beneficials. Both of these inputs involve alkaline ammonium nitrogen tagged to phosphoric acid. Unfortunately, the combination ionises in the root zone, releasing the full acid burn of the phosphate.

This often impacts new roots, but it also sizzles the fragile mycorrhizal network, like applying a blowtorch to human hair. It has been suggested that the dramatic decline in mycorrhizal fungi in our farming soils may be largely linked to this acid burn phenomenon. The other DAP/MAP problem relates to the inherent instability of water soluble P. Research has consistently demonstrated that almost 75% of this input becomes insoluble and locked-up within 6 weeks, (depending on soil type). It then becomes part of the estimated ten billion dollar lode of frozen phosphate found in Australian farming soils.

Mycorrhizal Fungi on Roots

There is a better option, and that involves buffering the burn, stabilising the soluble P and magnifying the availability of the P, via the use of NTS Soluble Humate Granules™ at planting. There is also a very strong argument for introducing a combination of granular guano with the DAP/MAP and humic acid granules, to generate a combination of soluble and slow release P. This will help ensure full-season phosphorus availability.

It can be a great strategy to provide full season P, as there is much more P required during seed-fill than germination, and DAP/MAP are typically locked up by this time.

Ideally a planting blend might include 50 kg of guano granules, 50 kg of DAP/MAP and 5 kg of NTS Soluble Humate Granules™ per hectare. However, there is another consideration here, and that relates to the importance of boron at this time.

Yield Boosting with Boron

Boron is notoriously lacking in broadacre soils and this is a deficiency that needs addressing. Boron is essential for optimum growth, development, yield and quality, and the minimum requirement is 1 ppm on a soil test. Most broadacre soils struggle to make 0.5 ppm of boron, and there is a price to pay for this neglect. Let’s look at the critically important roles of boron in broadacre:

1) Boron deficiency dramatically inhibits root elongation, due to impaired cell division. Boron is typically thought of as a mineral for improved pollination and seed set, but it is just as important at the start of the season.

2) Boron increases uptake and availability of other plant nutrients, including N, P, K, zinc, iron, copper and calcium.

3) Boron ensures less empty grains and markedly less sterility of wheat seed.

4) In legume crops, boron is an essential requirement for nitrogen fixation in Rhizobium and Actinomycetes symbiosis. The lack of a pinkish-red interior in legume nodules is a classic sign of boron deficiency, and it is a signpost of poor nitrogen fixation.

5) Boron also plays a pivotal role in nitrogen metabolism, as it is required (along with molybdenum) for the nitrate reductase enzyme that converts nitrates through to protein.

6) Boron deficiency can also negatively impact the most important of all plant processes, photosynthesis. This occurs due to disruption of chloroplast (the sugar factory) membranes and messing with the stomatal openings required to capture CO2 for photosynthesis.

7) Low boron also means lower levels of vitamin C and glutathione within the plant, due to a drain on both of these antioxidants through constantly neutralising the excess free radicals created by this deficiency. This creates a less resilient plant with a greater need for chemical intervention. It also significantly diminishes the nutritional (and medicinal) value of your produce.

Hopefully, it is now apparent that you always need boron at planting, along with a foliar spray of boron directly before flowering. I have found the best option to be the inclusion of NTS Stabilised Boron Granules™ with the starter blend, (the best responses have been at around 8 kg/ha). Boron is the most leachable of trace minerals and the inclusion of boron humates will ensure this unstable mineral is there for the full season.

In Conclusion

A combination of seed treatment, liquid inject and a stabilised boron-enriched planting blend is the key to a kickstart that will invariably deliver better establishment, greater crop resilience and improved yield.

Please feel free to contact me on graeme@nutri-tech.com.au, or phone NTS on +61 7 5472 9900 if you have any queries.