Available Nutrients:

• All nutrients
• Soil Test for  TOTAL + Soluble levels
• Plant-available form
• Placement / Timing
• Crop Uptake & Removal

Strong Root System:

• Avoid Salts
• Growth stimulants eg Kelp
• Add energy eg Humates
• Encourage biology
• Liquid Inject primarily for root growth

Constraints:

•  Sodicity – Sodium
•  Salinity – Chloride
•  Alkalinity – High pH
•  Poor Ca:Mg
•  Chemical Residues
•  Compaction

 F.A.R.M. will work with growers to develop a customised nutrition plan for a fee less than the cost of 1T of Urea. (If required, F.A.R.M. can also assist in sourcing products.)

Farm resources, constraints, history, farming system, experiences and other needs are all discussed and used to make field-specific recommendations.

Often the first step is organising some soil tests or reviewing past tests – please contact Ian Moss to discuss further.

ian.farm@bigpond.com    0428 910 073

In February of 1994 at the Austin, Texas Eco Fair I lunched with Neal Kinsey, one of America’s top soil consultants. Neal was lecturing about the key importance of calcium in the early stages of fruit development where cell division occurs, and his metaphor was an apple not much bigger than a prune had virtually all the calcium it would get by harvest. He tested soils for calcium and applied it as needed, but unfortunately this did not guarantee that sufficient calcium got into the apple.

When I asked him what he did in regard to boron, which was responsible for sap pressure, he responded, “Of course, boron is necessary for calcium uptake, and we test for boron. If it is needed we put it there, but we still can’t guarantee that calcium gets in the apple.”

Humm. So I asked what he did about silicon. My biodynamic experience showed silicon was the basis of transport in both plants and animals. Neal’s response was classic, “We don’t test for silicon. It’s in all soils, whether sand or clay.”

Until then it hadn’t sunk home with me that I was used to looking for the visual signs of silicon in plants and I hadn’t actually seen any soil or leaf tests that included it. This got me wondering, and as I investigated I found, almost uniformly, soil and leaf testing labs did not test for silicon unless it was specifically requested.

As a biodynamic grower, I was annoyed. Biodynamic fore-runner, Rudolf Steiner, with his doctorate in math, chemistry and biology, identified the oxides of calcium and silicon (lime and silica) as the opposite poles of life chemistry. I’d used this concept for years and years, along with Jochen Bockemühl’s leaf studies from his book, In Partnership with Nature and Johann W. von Goethe’s treatise, The Metamorphosis of Plants as guides. Neal’s comment that he didn’t test for silicon caught me by surprise. But on the other hand, my university curriculum was biochemistry rather than agricultural chemistry, so I hadn’t realized how 19^th Century agricultural chemistry was. Looking further, I found that in the early days of agricultural chemistry Justus von Liebig tested both soils and plants for silicon, found it in all cases, was unable to prove it was an essential nutrient by excluding it from plant media, and thereafter dropped it from his tests. This became the norm for agricultural testing.

Neal Kinsey, with his riddle of getting calcium into early fruit development, got me thinking. Gradually I realized there was an obvious hierarchy of how elements worked in living organisms. One thing had to occur before the next thing could happen, and on down the line in a sequence. In 2004 I put together a PowerPoint slide show for Graeme Sait’s agronomy team at Nutri-Tech in Yandina, QLD, and in it I summarized this hierarchy of elements, calling it the Biochemical Sequence.

I told the Nutri-Tech agronomists that boron kicks off this sequence by activating silicon, making it an amorphous fluid and providing sap pressure. I knew that boron was used in making glass, which is amorphous fluid silica; and I’d found this relationship also held true for plant chemistry.

Of course, sap pressure would be no use without a transport system to contain it, and silicon provides the actual transport of nutrients. Interestingly, applying too much boron too early in a crop cycle is notable for burning seedlings and young transplants-such as sprouting squash, beans or tomatoes-because too much sap pressure in such a tiny plant drives sodium out the leaf margins. Nevertheless, in plants where leaf veins are highly branched, like flowering beans, squash and tomatoes, boron is important in later growth to maintain strong enough sap pressure to make such a complex system work.

On the other hand, highly siliceous plants, such as grasses, need less boron to give them sap pressure since their transport vessels all run parallel without branching. That’s like irrigation lines that only feed one sprinkler head-it doesn’t take much pressure. An exception is bananas, which have a huge transport system with lots of fluid flow. They need plenty of boron to send calcium and amino acids all the way to the top of the bell stalk for cell division to occur in the bunch.

Obviously without robust transport, nowhere near as much nutrient reaches the leaves or is stored in the fruits. Chemical agriculture gets around this to some extent, since-even with a weak transport system-anything that is highly soluble, such as potassium nitrate, is simply taken up along with water. Though this dilutes the sap, it flows quite easily due to low sap density. This is why chemically grown foods commonly have coarse, watery cell structure, as well as lower nutrition and poorer keeping quality. However, without a robust transport system, heavier nutrients such as calcium, magnesium, complex carbohydrates and amino acids can easily be left behind.

Third in the biochemical sequence is calcium. This is the last thing you want to leave behind because of its role in nitrogen fixation and amino acid chemistry. Calcium balances charge in proteins and is particularly important in cell division, which is the first thing that happens in fruit or seed formation after pollination. Without it there would be no fruit or seed.

For example, in maize calcium leaf test targets are between 0.3 and 1.0 %, increasing as the maize approaches tasselling with the higher target range more desirable during kernel formation. If calcium does not reach the ear in sufficient quantities, the kernels near the end of the ear simply do not fill out. With a crop like soybeans, double or even triple the calcium values of maize are needed for full pod set without shedding pods-a common problem in soybeans. Wouldn’t you like to see every kernel on your maize fill out to the end of the ear and every soybean blossom produce a pod of beans? This only happens when boron, silicon and calcium work together optimally.

As just mentioned, wherever calcium goes, there also goes nitrogen, which is the basis of amino acid formation, protein chemistry and DNA replication. Once nitrogen enters the picture all sorts of proteins, enzymes and hormones are produced, and very complex things are set in motion involving trace elements such as iron, zinc, copper, manganese, cobalt, molybdenum and so on.

Above all there must be energy harvest or plants would never grow. Though all parts of a plant’s protein chemistry require amino acid nitrogen, large amounts of amino acids go into the formation of chlorophyll where energy is gathered. Since photosynthesis requires magnesium, it is fifth in the biochemical sequence, ahead of all the more minor trace elements. Of course, photosynthesis is not simply a matter of chlorophyll catching energy. The energy has to be transferred into producing sugars out of carbon dioxide and water, which requires phosphorous for energy transfer. Otherwise the chlorophyll burns up, and the leaves turn a wine red colour.

However, as long as there is enough phosphorous, carbon is pried loose from carbon dioxide so it can combine with water to make sugar and release oxygen. Then the sugars pass into the plant’s sap where potassium, the electrolyte, conducts them to wherever they most need to go.

Understandably, this sequence is oversimplified. For example, sulphur is the classic catalyst in carbon (organic) chemistry. Without it, nothing-not even the boron-would work. Also, potassium has a very close relationship with silicon, so when silicon carries calcium and amino acids to the cell division sites in the plant, potassium plays the role of an electronic doorway that lets the calcium and amino acids enter the cells that are preparing to divide. If cold weather slows potassium down, or if it is in short supply, then calcium and amino acids cannot reach the cell nuclei, the DNA cannot divide, cell division fails and the fruit falls off the plant.  Sometimes entire fruit crops are lost to a couple degrees of frost when a light spray of kelp with potassium silicate would save the day.

However, the most important thing to understand is the role of boron, silicon and calcium in the hierarchy of plant chemistry. Growers who simply feed plants nitrogen, phosphorous and potassium (NPK) tend to short circuit the biological processes where strong sap pressure (boron) leads to good nutrient transport (silicon), following which optimal cell division and photosynthesis occur (calcium, nitrogen, magnesium and phosphorous). Then with high plant energy (carbon, potassium) plants are able to shed enough of their sap as root exudates to feed abundant microbial mineral release, nitrogen fixation and protozoal digestion around crop roots so crops enjoy rich nutrition and are truly healthy. This only works where boron, silicon, calcium and amino acid nitrogen (from steady microbial fixation and digestion) are all high. If calcium and amino acids are watered down with nitrate and potassium salts, sap pressure is impaired, cell division is hampered, photosynthesis is weakened, magnesium and phosphorous are diluted, and we’re where NPK growers are today.

Comprehensive testing (the subject of another article) reveals that without taking the biochemical sequence into account it is common for plants-even in organic situations where soluble nitrogen and potassium are high-to luxury feed on nitrogen and potassium to the exclusion of calcium, magnesium, phosphorous and trace elements, particularly zinc and molybdenum. In sum, if we fail to solve Neal Kinsey’s riddle, we can be caught in this situation and suffer from the conventional NPK growers’ problems of pests, diseases, poor flavour and poor keeping quality.

• Not to be confused with reactive applications based on monitoring feedback (to be covered in a future newsletter).  Often we have modified fertiliser programs to reduce pre and at-plant nutrient input and expenditure with expectation of monitoring in-crop and applying extra’s only if and when needed.
• Foremost, any expenditure should be part of a budgeted plan, including the possible need for ‘corrective’ use of foliars for specific situations – water-logging (we wish…), nutrient deficiency, salt overload, etc
• At the risk of generalising, the following options should be considered where justified:
  • In cooler conditions and/or high pH soils consider early (banded) application of zinc + kelp
    • Products like BNS ZincPac use a chelated zinc form with carbon that is more easily absorbed and translocated within the plant. 
    • It includes amino acids as a protein form of N to stimulate plant growth. 
    • The carbon and metabolites give energy and the microbial enzymes boost plant nutrient utilisation and efficiency
  • If Zinc, N, P & Ca are fine then consider a kelp product
    • NTS Liquid Kelp Foliar or KFF are good options amongst many others.
    • Comprehensive research supports a smorgasbord of stand-alone or synergistic benefits associated with seaweed application. There are numerous individual and interrelated benefits, including:
  • If N / P / Ca is needed to kick things along then consider products like BNS Stimul8
    • A higher nutrient analysis product with biological stimulants specifically designed to stimulate vegetative growth.
    • Suited to crops with minimal or nil fertiliser applied or where plant monitoring indicate need for N, P and/or Ca.
  • If sodium and/or chloride salts are a significant constraint then consider 2 – 3 applications of soluble calcium such as BNS CalPac.
    • BioNutrient Solutions have written an excellent article on the role calcium can play – please let me know if you would like a copy of that article.

Further in-crop foliar options will be covered in future newsletters

Calcium from CalPac provides plants: • Structural stem strength.

• Improved Nitrogen use efficiency.

• Enhanced water use in saline or sodic soil environments.

• Disease resistance through increased Pectin production.

• Greater frost resistance via carbohydrate supply.

CalPac and Calcium

Calcium deficiency symptoms include:

• Abnormally dark foliage.

• Death in the tips of new growth.

• Weakened stems.

• Premature shedding of fruiting parts.

Calcium gives plants strength

Humans need Calcium for strong bones, so too plants need Calcium for strong cell walls and plant rigidity. In plants, low Calcium means poor cell wall strength and leaky cell membranes resulting in a loss of integrity and production efficiency.

Increased Calcium in plants results in increased pectin production. Pectins combine with polysaccharides (sugars) to bind plant cells together within cell tissue, giving cells them structural rigidity and strength. Plenty of Calcium means strong stems and reduced potential of lodging.

Calcium and Boron are the slowest nutrients to be translocated from the roots through sap to new tissue. Once deposited Calcium is immobile rendering it unavailable to further new growth. Hence, in rapidly growing crops supply of Calcium to new cell tissue can often be the limiting factor, resulting in reduced structural integrity.

Calcium is the first line of defence against disease

There is a strong relationship between Calcium deficiency and disease in crops. How so? Disease organisms break into plant tissue by producing enzymes (variations of pectinase) which dissolve pectin. Higher Calcium levels increase pectin concentrations and hence resistance to these destructive enzymes. It is not just a case of whether the disease, (e.g., net blotch, rust,

Research confirms that good plant Calcium levels reduce disease susceptibility both during the growing season and post-harvest storage.

Ascochyta) is present or absent, it is the level to which the enzymes they produce are able to dissolve their way into plants, breakdown tissue and spread. 7 CalPac can increase Calcium concentration and pectin levels; a valuable management tool to reduce plant susceptibility to disease. Calcium is the link between pectin levels and plant resistance to disease.

Calcium is king

In agronomic terms, Calcium is so much more than just a nutrient. Calcium dictates plant strength, disease resistance and nutrient regulation in the plant.

Calcium is known as ‘the Trucker of all minerals’

Calcium is critical to overall crop nutrition, cell function and development and hence influences overall efficiency of plant production. A shortfall in Calcium creates costly flow-on effects, such as increased Nitrogen input

“Calcium, assisted by Molybdenum, is the basis of Nitrogen fixation and amino acid chemistry. Nitrogen, allied with Calcium in the form of amino acids, reacts with every other nutrient element, the most important being Magnesium, which is the basis for chlorophyll and photosynthesis. Chlorophyll traps energy and shunts it via Phosphorous into Carbon structures, which go where Potassium, the main electrolyte, carries them.

Thus the biochemical sequence for plants is B, Si, Ca, N, Mg, P, C, K.”

Source -

1 into the plant. It is critical to plant production because of its influence over the uptake and distribution of other nutrients and carbohydrate stores through plant parts2. 3, greater susceptibility to disease4, increased lodging tendency in cereals, greater shedding in cotton5 and greater sensitivity to moisture stress6. Hugh Lovell. “After regular applications of CalPac, our irrigated lucerne has significantly improved, stems are solid, yield has increased 15% and we have noticed superior recovery following cuts in the heat of January. We are seeing big improvements in the crops ability to take in water and withstand heat stress, better than ever before. We calculate a $5 return per dollar spent, excluding lower insect pressure.”

Angela Druery, ‘Santa Lea’, Moree, NSW. February, 2009.

Calcium in soil

Why have people in agriculture applied Calcium for over 2000 years, well ahead of the green revolution? The answer is not for soil pH alone nor mineral replacement. It is about ‘efficiency’.

In soil, when Calcium as a proportion of the mineral cations exceeds approximately 60%, there are improvements in the soils physical properties. Flocculation, the process of binding peds together, is increased and structure and friability improved. Magnesium and Sodium (which make soils hard and dispersive) are displaced and the water holding and infiltration capacity increased.

Plant growth responds to these soil improvements, crops have reduced Nitrogen requirements, are less moisture sensitive and show improved overall strength because the efficiency of the soil:plant dynamic is better than where Calcium is low. Throughout history agriculture has thrived where Calcium in soil is plentiful, and struggled or failed where it is deficient.

Calcium is a plant regulator

As it is for soil, so too in plants, Calcium is more than a simple component part – it can be managed to affect plant efficiency by being a regulator of plant response to changes in environmental conditions. For example, in sodic or saline root-zones (which impede moisture flow into plant roots due to osmotic gradient), Calcium actually regulates the selectivity of nutrient uptake to reduce the impact the salts have on photosynthesis and productivity

This can occur because a large proportion of plant Calcium sits within the cell wall structure, whilst another portion remains exchangeable (in plasma membrane and within the vacuole) from where it is able to regulate cell function by selectivity in nutrient uptake.

4. As shown below, Calcium will positively reduce plant Sodium uptake. Figure 1: Relationship between plant sap Calcium levels and Sodium. (BioNutrient Solutions SAP test data, all crops, 2008).

Soluble Calcium facilitates crop selectivity in nutrient uptake, reducing the impact of excess salts.

What can limit Calcium supply to crops?

1.

Low soil Boron. 2.

Elevated Sodium, Chloride or Aluminium soil levels, which increase deeper in the soil profile. 3.

Excess soil Potassium. 4.

Soil applied ammonium (MAP/DAP or anhydrous ammonia) resulting in Calcium loss to precipitation (conversion into unavailable forms). Plant and biological processes then need to re-release the Calcium. 5.

• In cereals during rapid tillering, stem elongation and booting.

• In cotton 30-50 days after emergence during peak squaring.

Unlike other nutrients, Calcium stands in reserve, ready to activate a response when there is a stress associated with moisture, salinity, nutrition or heat.

Repeated pulses or spikes in the Calcium concentration allow plants to maintain cell elongation, cell division and cell pH during critical growth stages. Calcium will exchange with K

Solubility is essential. Soil Calcium is very slow to move into new plant tissue. Foliar applications of soluble Calcium such as CalPac can significantly increase plant responses compared to soil applied Calcium.

Quick Facts:

• Foliar applied soluble Calcium has been found to increase plant absorption of ammonium by as much as 100%, improve soil nitrate extraction and increase photosynthesis

• A greater Calcium to ammonium ratio in tissue increases plant deposits into harvestable parts. For example, Calcium concentration increases at ear emergence result in greater transfer of flag leaf energy production into grain yield

• Calcium is responsible for regulating the flow of carbohydrates from structural (stems) to fruiting parts thus improving the weight of grain, lint or fruit at harvest.

Periods of rapid plant growth that dilute and restrict the movement of Calcium through the plant to new cell tissue. +, Na+ or H+ to help maintain optimal plant function. 8; 2. References

1.

Gary Zimmer – The Biological Farmer: A Complete Guide to the Sustainable & Profitable Biological System of Farming. 2.

Hirschi, Kendal D., 2004. The Calcium Conundrum. Both versatile nutrient and specific signal; Plant Physiology, Sept, 136 (1): 2438-2442. 3.

Fenn, LB. Hasanein, B & CM Burks. 1995. Calcium-Ammonium effects on growth and yield of small grains. Agronomic Journal, 87:1041:1046, American Society of Agronomy. 4.

Carafoli, E., Klee. Claude B., Calcium as a Cellular Regulator. Amazon.com. 5.

Joham. H.E., 1955. Calcium and Potassium nutrition as influenced by Sodium. Plant Physiology. 30:4-10. 6.

Trochoulias, T., 2003. Increased Calcium in the soil and leaf tissue improved yield, kernel recovery and heat tolerance in Macadamia. Proceedings of 2nd International Macadamia Symposium, Tweed Heads, NSW. 7.

Lamb, C and Richard A. Dixon, 1997. The Oxidative Burst in Plant Disease Resistance. Annual Review of Plant Physiology & Plant Molecular Biology. Vol. 48: 251-275. 8.

Fenn, LB. & Sam E Feagley, 1998. Using Soluble Calcium to Stimulate Plant Growth. Texas Agricultural Extension Service. Putting it all together

• Greater plant Calcium levels positively influence the efficiency of plant production. It regulates the uptake and movement of other nutrients from roots throughout the plant cells, particularly Nitrogen.

•

Soil Calcium is essential, but very slow to translocate through plants, particularly during periods of rapid growth and cell division. Hence foliar applied soluble Calcium can overcome a shortfall quickly and cost-effectively compared to soil applications. •

Appropriate foliar or fertigation of soluble Calcium will reduce Nitrogen fertiliser needs, decrease disease susceptibility and increase mineral density in harvestable plant parts. Calcium is more than a nutrient, it improves soil and plant resilience to stress.

Figure 3: Liquid inject Calcium enhanced root growth.

CalPac application

CalPac is soluble Calcium bound within carbohydrate to provide plant available Calcium and energy, for plant and microbial needs.

• CalPac is less likely to burn plant leaves than nitrate forms.

• Provides Sulphur, Potash and trace elements.

• Is approximately 300 times more plant available than lime.

When to use CalPac

•

• In fertigation water to improve water quality (high Sodium or Magnesium) and provide crop nutrition.

• Foliar applications to improve Nitrogen utilisation during periods of rapid growth, e.g., tillering or stem extension in Cereals. Apply with Nitrogen (e.g., UAN) to increase ammonium absorption, nitrate uptake and to buffer against burn potential.

• Foliar applications to regulate nutrient flow in situations where soil or sap Chloride, Sodium, Aluminium or Potassium levels are elevated.

• As part of a structured disease management program, to build leaf cell wall strength and resistance to pathogens.

Liquid injection at planting into soils with elevated Sodium or Aluminium.

Rates and timing of CalPac applications Root Zone	Liquid injection		10-12L/ha in dry land broad acre. Higher rates are required in sodic or high Aluminium soils.
Fertigation		7-15L per irrigation depending of production goals and soil type.
Foliar	Early season (during rapid growth)		5-6L/ha.
Booting and pre-flowering		7-10L/ha.
With Nitrogen application		1:5 ratio with UAN or urea solutions.
Within disease management program		10L/ha. CalPac is not compatible with fungicides or insecticides. It is recommended to supplement, not replace, any specific disease management practices.

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Thanks again to all who attended the recent Crop Tour of the Downs. We enjoyed it and the feedback is you guys did too, and as much as anything else there is real value in simply allowing growers to learn from growers with help from people like us for the structure and technical detail.

The day confirmed that biological farming is about systems management, not just product inputs. It is about nutrition (the what, where and when), minimising disease pressure and maximising beneficial biology in a variety of soil types.

Many thanks must go to our hosts on the day – Robert Smith, Denis Wooldridge and Bill Hoare  and to those who were able to attend and contribute to the discussions, it was extremely valuable to have innovators and agronomists represented, the Beesley Boyce fellows, Raffs team and GoFarm from the north. A particular thankyou to Ian Moss from Farm Agronomy & Resource Management for being the primary organiser and his intrinsic involvement in agronomy at each of the farms visited over the last couple of years.

Key principles covered on the day

• We have to assume that moisture will become limiting at some stage during the season, so it is essential to build crops with larger root to leaf ratio’s to sustain them through dry spells.
  • This can be achieved using nutrients and biology through liquid injection at planting. Not just Phosphorus and Zinc, but soluble Calcium, all trace elements and triggers for root growth.
• When there is excess Nitrogen in the system, it will push vegetative growth, which creates a need for more Calcium and Potassium during rapid growth. Our soils tend to be able to supply Potassium but SAP testing shows that Calcium does not keep up to the requirement of rapid cell division in leaves.
• .
• Inadequate Calcium leads to weaker stem strength and susceptibility to lodging.
  • Lower pectin levels in the leaf, creates plants with weaker cell wall strength and hence lower resistance to disease. Leaf disease produces an enzyme called pectinase which dissolves pectin in the leaf to produce an entry point. Calcium is essential to increased pectin for defence.

 SAP testing can provide information before the end of each stage, thus allowing better management.

 Key sap testing results;

There are three stages to the winter cereal cycle;

• • Sap pH is an indicator of plant health. Low pH indicates disease susceptibility and high nitrates increases insect susceptibility. This is our experience in the field and simply reflects the nutrient balance in plant sap flow.
  • Nitrogen is overdone early in the crop and under done in latter stages for yield and protein.
  • Phosphorous and Zinc have not been a limiting factor in the majority of samples this year, trace elements Boron and Copper have been.
  • Sodium and Chloride accumulation in the crop increases with moisture stress and inhibits optimal plant performance. Recognizing and managing for this is essential. CalPac liquid injected at planting or as a foliar has reduced the impact of Sodium in the crop.
  •  

Overall, the crops visited have been grown on very little in crop rain and lower than conventional Nitrogen. The common denominator to all was;

Liquid injection of nutrition at planting, including Nitrogen, Phosphorus, Zinc, Calcium and trace elements, ie CerealRS. Remember, for Summer crop we use a specific formulation called Ignition®.

Inclusion of biology in the liquid injection at planting where required;

Eco-N Azotobactor for nitrogen fixation at planting for the cereals,

Rhizobium inoculant for the legumes, ie EasyRhiz

Remidi (Trichoderma) for crown-rot susceptible country.

Use of CalPac as a foliar during periods of rapid growth to consume excess nitrate in the crops and convert to protein. Eg Denis’ wheat and Bill Hoare explained last summers sorghum kicking up more than 1t/ac where CalPac was included in the flowering foliar – as a means of increasing grain weight during fill.

BNSEasyflo – Liquid injection distribution kits

We looked at the planter set-up with Robert Smith and Denis. Each was very different but achieved the goal intended, of no-fuss injection of suspensions. Getting the total water rate lower requires either a finer orifice plate – which is then prone to buildup and blockage – or switching to a gravity system like the Easyflo heads with one large restriction versus a small one per row.

Discussion on water rates concluded that less water in the total mix is better to avoid product settling. Dry sowing cereals with liquids is fine, legumes are more sensitive and we could see the result of high/low rates at Denis’ chickpeas.

Compost

Denis briefly discussed use of compost SolidStart to build soil mineral requirement whilst also adding biology and additional Calcium for higher sodium areas. We are looking to be able to produce bulk compost closer to the Downs in future, with a site at Inglewood coming on-line shortly.

 Stubble Digestion

Nothing like challenging the status quo to generate some healthy discussion, and so it was when we suggested looking for opportunities to put the stubble in contact with the soil.  Whilst not advocating a return to full tillage or any tillage necessarily, if you can meet your zero-till or erosion and infiltration objectives AND capture the opportunity to convert the energy and nutrients in stubble to plant-available compounds, then a significant benefit results.

Tools like Kelly Discs can be used to aid stubble digestion – so too can the addition of small quantities of nitrogen and/or appropriate biology and food source to increase the efficiency and effectiveness of this process.

Summer Crop Forecast:

Being a manufacturer of products which are more complex than dissolving nutrient in water has its up sides and down. The positives are that we, and hence you, achieve better crop response and soil performance than from dissolved synthetics. The downsides are that we don’t always have the luxury of un-forecast finished stock on demand without notice… it goes with the territory of innovation. So please help us help you by taking the time to fill out the Indication of Needs following and fax or email back to Helen so you get better outcomes.

Do not think this means you are committed, we don’t, it just allows us to avoid the strain of saying no, when with a bit of planning and forecast we can say yes, easy done! Thanks again.

In the soil, the Electrical Conductivity (EC) reading shows the level of ability the soil water has to carry an electrical current. The EC levels of the soil water is a good indication of the amount of nutrients available for your crops to absorb.

Think of it like this, all the major and minor nutrients important for plant growth take the form of either Cations (positively charged ions) or Anions (negatively charged ions). These ions that are dissolved in the soil water carry electrical charge and thus determine the EC level of your soil and how many nutrients are available for your crops to take in. Knowing your soils EC can allow you to make more educated farming decisions.

To support these claims, Researchers at Clemson University documented the correlations between EC and different crop inputs, documenting these at multiple sites over multiple years. They found unmistakable evidence showing that yield data have consistently supported the EC correlations with water, fertilizer, and pesticide use.

Using EC data to develop zones, in six on-farm tests, they overlaid yield maps developed after the crops had been harvested over EC maps developed before the crops were planted and found that the two maps match perfectly.

They also found that where EC levels were high (More available nutrients) less fertilizer is needed but more weed control in places where they had a morning glory problem. For example on sandier soils with low EC ratings, it took only a quarter-pound of active ingredient in the herbicide to get 80 percent control morning glory. On heavier soils with higher EC ratings, it took up to five times that amount to achieve the same level of control.

Other factors also contribute to soil EC variability include the connectivity of the soil water through soil density, soil structure, water potential, precipitation, timing of measurement, soil aggregation, electrolytes in soil water (e.g. salinity, exchangeable ions, soil water content, soil temperature). Also the conductivity of the mineral phase affects the EC reading for example  the types and quantity of minerals, degree of isomorphic substitution, and exchangeable ions. Regardless of what these multiple causes of EC variability are, what still remains is that EC measurements are consistently correlated to soil properties that affect crop productivity, including soil texture, Cation Exchange Capacity (CEC), drainage conditions, organic matter level and salinity, so knowing your soils EC level is a great predictor of your plants health.

For example if the soil EC is too high, it can be indicative of excess nitrogen based fertilizer or a high level of exchangeable sodium. Soils with an accumulation of exchangeable sodium are often characterized by poor tilth and low permeability making them unfavorable for plant growth. Soil EC is also related to specific soil properties that affect crop yield, such as topsoil depth, pH, salt concentrations and water-holding capacity. Thus EC is a great tool for explaining what your yields could be and taking action to get better yields.

Testing the EC of your soils

The way that Electrical conductivity can be measured is using an EC meter. The probe or sensor consists of two metal electrodes and a constant voltage is applied across the electrodes resulting in an electrical current flowing through the sample. Since the current flowing through the water is proportional to the concentration of dissolved ions in the water, the electrical conductivity can be measured. The higher the dissolved salt/ion concentration, the more conductive the sample and hence the higher the conductivity reading.

The unit of measurement for Electrical Conductivity is microSiemens per centimeter (µS/cm). Up until about the late 1970′s the units of EC were micromhos per centimeter (µmhos/cm) after which they were changed to microSiemens/cm (1µS/cm = 1 µmho/cm). Also a 1000 microsiemans is equal to 1 millisieman (1MS/cm)

Interestingly, the unit “mhos” derives from the standard name for electrical resistance reflecting the inverse relationship between resistance and conductivity – the higher the resistance of the water, the lower its conductivity. This also follows from Ohm’s Law, V = I x R where R is the resistance of the centimeter of water. Since the electrical current flow (I) increases with increasing temperature, the EC values are automatically corrected to a standard value of 25°C and the values are then technically referred to as specific electrical conductivity. A good EC meter will have ATC (automatic temperature compensation) so you can get accurate results regardless of sample temperature.

To get a soil extract we recommend a similar method as we do for testing pH so that both EC and pH measurements can be taken at the same time.

• Gather a fresh soil sample in a plastic zip-loc bag. Try to get a profile from the top 6” of soil that the plants will grow in and take care not to contaminate the sample by touching with anything.
• Open the bag and let it air-dry for a few hours until it is mostly dried.
• Mix the soil in the bag to ensure a homogeneous sample and then use a sieve with approximate 2mm spacing to remove any large soil clumps.
• Measure out ½ of a cup of the dried soil and put into a glass beaker.
• Measure out ½ of a cup of distilled water and put this into the glass beaker with the soil.
• Stir the mixture gently for 30 seconds. Do not mix to harshly as you may destroy the humus structure and the soil may give up elements that it otherwise would not do in nature.
• Let the soil-water suspension stand for 30 minutes.
• Stir water gently again before taking the EC measurement.
• Insert the EC meter into the beaker and swirl it gently around in the soil-water extract.
• After approximately 30-60 seconds or after the EC reading has stabilized, read the digital display on your meter.

Ideal EC Levels.

It is difficult to say what your ideal EC levels will be because there are so many variables affecting the EC level that it almost depends on your individual conditions which if you analyze over time, will give you a meaningful set of data based on the performance of your crops and the changes you have made to your fertility program.

As a general guideline however, a good soil EC level will be somewhere above 200 µS/cm and 1200 µS/cm (1.2 MS/cm). Any soils below 200 means there is not enough nutrients available to the plant and could perhaps show a sterile soil with little microbial activity. An EC above 1200 µS/cm may indicate too much high salt fertilizer or perhaps a salinity problem from lack of drainage so keeping your EC within this range. Also watch to see how EC changes over the growing season, you may see it increase as microbes are releasing more nutrients from the soil or you may see a decrease as your crops use up all the available nutrients. Either way you can fertilize accordingly.

Other uses of an EC meter.

Water purity testing: Water purity testers are nearly always conductivity meters. Pure distilled water as very very low EC as it has no contaminants in it. Generally good distilled water is < 20 μS whereas good tap water is < 200 μS. If you find your drinking water above these levels then it is not a good water source.

Compost: You can also use your EC meter to monitor your compost pile and analyze how well your pile is doing. Compost in early stages may have an E.C. number of 10,000 μS as the pile becomes active and At the peak of breakdown it can even reach >100,000 μS.  High quality finished compost should have an E.C. number of approximately 1,500 – 2,000 μS.

Foliar Fertilizers: You can use the EC meter to ensure your mixture is not to potent and to also ensure you get a consistent foliar spray potency each time. The potency of your spray should depend on what is in your spray, but as a rule of thumb, 15,000 – 35,000 is good for a normal spray mixture that you use only occasionally.

Leaf sap testing: Measure the leaf sap to find out how many ions are being processed into sugars. As the EC level goes down you can expect Brix levels (sugars being produced by photosynthesis) to go up before being transported around the plant. Expect leaf sap to be between 2,000 – 12,000 µS.

To check out our expanding range of Electrical Conductivity meters, click here.

Agriculture Solutions LLC

After quite a few requests, FARM have added a standard consultation option to the agronomy services offered. This service would include a farm visit to develop a field or crop-specific nutrition program and a second visit  in-crop to assess crop progress.  A small fee applies, dependent on the level of work involved.  Please contact Ian to discuss options.

Winter Crop

Oh, but for a little bit of rain at the right time….  Despite the promising start, minimal in-crop rain has again left so many crops struggling to finish.  Most exceptions seem to be the crops that had zero or reduced pre-plant N and had some simple root stimulants down the slot at planting – one of the things I love about what I do is that many of the choices that lead to better outcomes are often cheaper also.

What’s your plan for fields after harvest? If chickpeas or other crops are leaving things a little bare for your liking then give some consideration to a millet cover crop – even dry sown can be an option depending on weed expectations. Green plants photosynthesize and create the liquid carbon pathway for building soil organic carbon.

• Ground Cover Issue 67 – March – April 2007, Cover crops – Millet shows its worth as a cover crop
• Short term cover crops increase wheat yields in southern Queensland.

o   Cover crops help lift the rain harvest – Trials in the northern region are showing that planting a crop purely for cover delivers valuable benefits

Stubble digestion – lets cover this in more detail next time but keep in mind the opportunity to add and/or feed the saprophytic fungi that can capture the nutrients and energy in your stubble without compromising erosion control and infiltration objectives.

Summer Crop:

Some seed going in for those with irrigation or fortunate enough to have adequate planting moisture.  As always at this time of the season, it’s more important to be picking the start of a warm spell rather than watching the calendar.

For those of you on more sodic soils, please try to get some calcium down the slot – ideally as liquid but if that’s not possible then consider Guano if you can handle the lower quality granule.

Liquid Inject

• gives so many more options for fertiliser efficiencies and root stimulants. 
• Easier to set up than you first think and 12 row unit less than $1000 if you supply the tank and pump.. More info…

Interesting Stuff:

• FARMERS can expect a period of low fertiliser prices—but then they’ll need to be thinking on their feet as the price rollercoaster starts again
• Almost by definition, increases in soil carbon increase yield and profitability

·         Incitec dumps agronomists in bid to win back farmers

·         Perennial wheat on the drawing board

·         Carbon from the exhaust to the soil

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Most Popular Links

Another requested addition to the newsletter is to keep a few of the most popular links on each newsletter.  As some of you are explaining concepts or results to neighbours and friends it is useful to have easy access to this information:

Why synthetic nitrogen is bad for soil carbon 

Heavy use of synthetic nitrogen fertiliser not only burns away soil carbon, but reduces organic nitrogen levels in the soil and thus increases farmers’ reliance on bought-in fertiliser,. …  when NPK fertilisers began to be applied on the plots in the mid-1950s, yields leaped by 140 per cent. … there was an expectation that fertilisation would help the soil build a large reservoir of organic nitrogen, and carbon levels would rise because of massively increased residue incorporation. …Neither of these forecasts proved true, the researchers say. …  after half a century of synthetic fertilization that exceeded grain nitrogen removal by 60 to 190 per cent, soil carbon levels … declined substantially under heavy fertiliser applications.

USING ROTATION CROPS TO IMPROVE SOIL QUALITY

There has been no single soil characteristic that we have measured that can explain the cotton yield benefits of growing rotation crops, particularly with legumes. We have observed improved soil structure, nutrient availability and uptake, a more active and larger soil microbial biomass which combine to improve soil health, and enable future crops to be more productive and use inputs more efficiently.

The Importance of Soil Carbon – Ray O’Grady

A review of the decline in soil carbon and its effect on crop yields, soil health and the health and wellbeing of the farming family over the last thirty years, suggests that many have been worshiping the wrong sacred cow and need to change the focus to achieve a more sustainable triple bottom line. … reviews the historic loss of 50-60% of soil carbon and its effects on the physical, chemical and biological aspects of soil health. …. The importance of root exudates in maintaining a balanced soil food web, nutrient cycling, soil health and disease suppression are illustrated. The newly discovered soil ‘super glue’ glomalin maintains up to one third of the carbon in the soil for between 7-40 years. This provides evidence of the benefits of mycorrhizae.

Popular Websites

BioNutrient Solutions

BioNutrient Solutions design, manufacture and supply a comprehensive range of high quality Biological Fertilisers for agricultural production. Our fertilisers are manufactured locally to maximize your farming potential. Our Carbon Farming Systems® promote soil health and have been developed to support the principle of profitable, sustainable production, maximizing your return on investment (ROI) potential.

Enviroganics

Enviroganics® has been manufacturing and marketing premium quality organic fertilisers and soil conditioners since 2001. Our products utilise organic by-products from intensive agricultural facilities to create environmentally sustainable, fully composted, pathogen-free and odourless products for use in a wide range of circumstances.

 GRDC – Grains Research & Development Corporation

Soil Health Knowledge Bank

Are there other limiting factors or other nutrients needed?

Are you replacing crop nutrient removal or replenishing the soil?

Never has it been more important to get your fertiliser decisions right. Get it wrong and you not only waste your money but can cause more problems and costs than the right option. eg Too much up-front nitrogen will often lead to a mass of shoots without the root infrastructure to support it when moisture becomes limiting – at worst the crop just doesn’t make it, at best you have screenings issues.

So what is the right option? I wish I could trot out a one-size-fits-all solution but the truth is that every field is different – different soil properties, cropping history, fertiliser history, farming practises – the list goes on. The only way to get it even close to ‘right’ is to assess the current situation and apply experience, knowledge and science to come up with several options to address the key nutritional and other agronomic factors. Further in-crop monitoring & plant analysis combined with post-harvest economic comparative analysis will fine-tune what works for your particular situation and which option provides the best economic return.

The opportunity for improved nutrition efficiencies usually justifies the cost of having an independent agronomist working for you to measure, analyse and provide advice for your fertiliser choices and programs. With urea at approx $500/T, very little improvement in nitrogen efficiency is required to cover the cost of an advisor to help you develop a smarter fertiliser program. Further to those cost savings are the additional benefits of capturing yield potential opportunities , longer-term soil health improvements and getting a head-start on dealing with carbon issues.

Working alone or with existing agronomic advisors provides the opportunity to form farm and field specific solutions that are designed to meet your unique needs. Many agronomists welcome working with someone specialising in this area.

Farm Agronomy & Resource Management (F.A.R.M) nutritional agronomy is based on a blend of existing industry practices with personal experience and knowledge gained from field experience since 1989. With summer-crop fertiliser decisions upon us, now is the time to engage a professional, innovative & independent agronomic consultant to help with those decisions.