C-P-Ca v's N-P-K - The Fight for Soil Life

vineyardNutri-Tech Solutions P/L has emerged as a “front-runner” in the soil fertility stakes. Their refreshing approach involves the provision of education, constructive advice, soil test analysis and other essential tools for cost effective, sustainable agriculture. This information-sharing policy, backed up by an impressive high-tech product range, has won many converts. The exclusive NTS range, representing state of the art organic fertilisers, is surprisingly cost-effective – the price does not reflect the exclusivity. In fact, some of these products can provide considerable benefits for less than $10 per hectare. Many of the Nutri-Tech products have been designed as specific problem solvers and they are “high performers” in their own right, but it is together, as a system, that the sparks really begin to fly. In fact, synergism has contributed to a high-performance hybrid. In contrast to the N-P-K philosophy the Nutri-Tech system involves fertilising programs which increasingly improve the soil. Carbon, phosphorus and calcium (C-P-Ca) are seen as the key “fertility builders”. Nitrogen is still recognised as a primary energy source, but a balanced, productive soil is not considered possible without prior consideration of the big three. In the following article, Graeme Sait from NTS discusses these three elements and compares the C-P-Ca philosophy to the prevalent N-P-K approach.

C-P-Ca The Only Way

“The only way” – it may sound like a Christian catchphrase, but there really is no other choice available if you wish to revive your dying soil. The importance of carbon, phosphorus and calcium cannot be overemphasised. These three elements comprise the essence of the life support system for soil micro-organisms and they are the elements which determine soil structure.

Organic carbon is the structure within which these miraculous creatures survive and multiply and, as we shall see, humus plays a large part in developing a good soil structure.

Phosphorus is contained in every living cell. It is needed by microbes and plants alike and would not be available to either for long, in the absence of one of the partners in this symbiotic relationship. The phosphorus-microbe-plant link epitomises the nature of the microbe connection. This connection is even more apparent when we consider calcium.

Calcium, the king of nutrients, is the governor of soil structure. Microbial life flourishes in a porous soil opened up by calcium, allowing easy access for oxygen, nutrients and water. Calcium levels can also affect pH-levels and soil microbes are pH-sensitive. Many species can’t survive in soils with pH lower than 5.5 or higher than 7.5. If we accept the concept that microbial life is the essence of fertility, then we can see that carbon, phosphorus and calcium (C-P-Ca) are infinitely more important in this regard than N-P-K. Synthetic nitrogen, acid treated phosphate and muriate of potash provide very few benefits for soil health. For a while this combination can generate yield increases (although quality suffers considerably), but eventually this capacity will decrease, and the strip-mining exercise, which is what much of the contemporary agriculture has become, will be complete.

Humus: The Carbon Solution

Humus or organic carbon is probably first on the list when we are looking at increasing fertility or rejuvenating tired soils. The organic carbon percentage on your soil test should be monitored and worked upon whenever possible. The relative success of any growing operation should be gauged by the movement in organic carbon levels. If this reading reveals an ongoing decline, then productivity within that particular growing enterprise will be limited accordingly. Chasing yield increases is an obvious financial necessity, but “real” success is achieved when yield increases are tied to organic carbon increases. In this situation, we know we are building fertility and we can expect ever increasing rewards.

Humus is the key to both water-holding capacity and fertiliser retention in the soil. A soil with 3% organic carbon will hold at least twice as much moisture as a soil with 1.5% organic carbon. Below 2% organic carbon, nutrient elements easily leach out, because a low-humus soil cannot retain them. When humus levels drop below 2%, the microbial life is in trouble. When levels drop below 1%, the microbes are battling to survive.

Humus is a reservoir for nitrogen, phosphorus, sulphur, boron and zinc. Clay also has considerable storage capacity, but there is no comparison with organic carbon. When you take clay in one hand and organic carbon in the other and measure the nutrients, humus holds three times more of these nutrients than clay.

High-Carbon Nutri-Store 180® – The First Humus Based Fertiliser

Nutri-Store 180® High Carbon Fertiliser contains 30% carbon. A patented process releases the organic carbon potential of bituminous coal, enabling the development of a remarkable humus-based fertiliser. Soft rock phosphate, cow manure, fish protein and mineral additives are also involved in the formulation.

Nutri-Store 180® contributes to soil productivity in many ways, including the following:

  1. Nutrients are released from the humus gradually, over a full growing season, and are available as the plant requires them.

  2. Nutri-Store 180® improves the tilth and friability of soil.

  3. It dramatically increases the micro-nutrient plant-availability through chelation reactions introduced by increased microbial activity.

  4. The fertiliser helps break down insoluble minerals. In this context, it is a perfect companion for the rock mineral fertilisers or rock phosphate.

  5. Nutri-Store 180® can release ‘tied up’ or complexed elements in poorly balanced soils.

  6. It has an exchange capacity, or CEC, of 180 (approx). This is why it has three times the holding capacity of clay. This storage capacity can greatly enhance the effectiveness of nitrogen. Albrecht’s classical study of the holding capacity of humus, in relation to nitrogen, revealed that the strongest of man-made acids could not remove this element from the humus colloid, and yet the mild acid exuded by plant roots could easily unhinge the nitrogen.

  7. Nutri-Store 180® increases the soil’s buffering capacity. This refers to an inherent protection mechanism, whereby we are not forced to suffer the immediate consequences of our mistakes. For example, excessive nitrogen, applied to a light sandy soil, will ruin the soil system rapidly. By contrast, if that same application were made in the presence of good humus levels, that soil could still last for years. Nutri-Store 180® can also buffer against high sodium. We have seen excellent crops grown with ridiculously high sodium levels, due to this buffering effect when humus levels are good.

  8. The dark colour of Nutri-Store 180® favours heat absorption and permits early spring planting.

  9. Nutri-Store 180® will support a greater and more varied microbe population, increasing the likelihood of bio-control. This thriving microbe population will increase fertility in other ways, including more effective decomposition.

  10. Nutri-Store 180® reduces toxicity of certain substances, both natural and man-made, i.e. trace element excesses, which are disastrous in some circumstances, can be negated with high organic carbon.

The Carbon Savers

This fertiliser offers assistance toward the replenishment of depleted stores of organic carbon, but retaining existing levels is a priority, which should never be ignored. In this context, there are three important things to remember:

  1. Don’t work wet soils. This is one of least recognised contributors to humus depletion. It is not uncommon to see huge organic carbon losses associated with working a paddock too soon after rain.

  2. Always apply a carbon source with every nitrogen application. Nitrogen burns out organic carbon. This can be avoided by applying carbon with nitrogen.

  3. Don’t burn crop residues. In some cases, this is the only carbon source that is returned to the soil.

The Nutri-Tech Carbon Program

We have devised a simple, cost effective program designed to conserve and increase humus. This program involves a combination of the following ingredients per hectare:

Phosphorus Soil Food V’s Plant Food

Our C-P-Ca philosophy differs markedly from the N-P-K approach with regard to phosphorus. Within the N-P-K system, potassium is generally considered a more important element than phosphorus. Potassium levels are usually structured to be twice that of phosphorus. Phosphorus is generally applied in the acid-treated soluble form at pre-plant.

In contrast, sustainable pioneer Dr Carey Reams believed that phosphate was the element responsible for crop quality. He insisted that sugar and mineral levels are governed by this element. Dr Reams enjoyed spectacular successes in the field and conducted extensive research, which supported his “theory”. His preferred phosphate option was always colloidal phosphate. His reasons for this preference relate to the stability and ongoing performance of natural soft rock phosphate in comparison to the acid-treated forms.
Super, triple super, DAP and MAP are all originally derived from hard rock phosphate which is mined and treated with sulphuric or phosphoric acid to isolate the phosphate in a soluble form. The problems occur when the phosphate hits the ground. Phosphate has a triple-negative charge and calcium has a positive charge. They seek each other out, like dogs on heat, and become inseparably fused in a similar manner. The phosphate content in Triple Super, for example, has largely reverted to the insoluble tri-calcium phosphate form within 30 days of application. This means that, at the crucial time of seed or fruit formation, when available phosphate will determine fruit quality, there is actually very little of the element remaining to perform this function.

Colloidal phosphate does not have these problems. Renowned US agronomis,t Neal Kinsay, refers to ‘soil food’ and ‘plant food’ when discussing phosphate sources. The acid-treated phosphates are plant food (if only for a very limited time), and they can never be used to build phosphate levels in the soil cost-effectively. Hard rock phosphate and colloidal soft rock phosphate are seen as incomparable soil foods, the latter being far more available in a wider variety of soil conditions.

NTS Soft Rock™ – The One Shot Fertility Booster

Our colloidal phosphate NTS Soft Rock™ is the only Australian source of this form of phosphate. It contains 10% phosphorus, 24% calcium, 26% silicon and a rich lode of trace elements. In fact, every element except nitrogen is present in this natural material. This is the way to build phosphate levels in your soil and address trace element deficiencies in one application. The colloidal nature of the product ensures ongoing plant-availability in all conditions. There is still a six to eight week initial period before the elements begin releasing. A starter phosphate is usually recommended until NTS Soft Rock™ begins firing, but a good strategy is to apply the phosphate several weeks prior to planting.

Cane growers using the product make a single 500 kg per acre application every five to six years with new plantings. Soil tests, three or four years later, confirm that exceptional phosphorus levels are still maintained. Growers report that NTS Soft Rock™ is responsible for two extra CCS points and impressive gross tonnage increases.
In broadacre, applications of 100 to 300 kg per hectare in the root zone have proven very productive.

The price of this product compares very favourably with the acid-treated phosphates, but, in this case, you are building your fertility with every application instead of building your reserves of ‘tied up’ phosphorus (and calcium). NTS Soft Rock™ is also the only virtually cadmium-free source of phosphate in Australia. Cadmium has become a major problem in many growing enterprises. Increasing levels of this heavy metal are providing potential health hazards which may eventually prohibit food production on affected properties.

Calcium and Soil Structure

The ‘ideal’ soil has been described as comprising 45% minerals, 5% humus, 25% air and 25% water. The key to achieving these ratios lies in developing a mineral balance in the soil. When the minerals are in balance, the correct mix of air and water occurs naturally. An unbalanced soil produces poor soil structure and a consequent restriction in the amount of space between soil particles. Air or water penetration will suffer accordingly.

Soil structure can be influenced in three ways:

  1. Manures, compost, mulch, microbial promotants or humic acid can be added to increase microbe numbers and provide them with food.

  2. Deep tillage – rippers, ploughs and chisels can all be used to break up a ‘hardpan’, but this is only a temporary solution.

  3. Correct fertilisation of the soil, whereby nutrients are supplied in the right amount as determined by soil tests.

Free Analysis for Balanced Soils

Nutri-Tech Solutions offers a very popular soil test analysis, called Nutri-Tech Soil TherapyTM. The ideal levels of each element for your specific soil type are noted and compared to your existing levels in table form. A base saturation table is completed, which provides the most effective overview of cation balance.
Base saturation percentages represent the fraction that each of the cations occupies on the clay colloid. The balance between calcium, magnesium, potassium and sodium is the essence of soil-balancing. Calcium, for example, should comprise around 68% of base saturation.

King Calcium

Calcium is the most important of the cations. Contrary to popular opinion, soil pH does not necessarily have anything to do with calcium levels. Magnesium, for example, can raise the pH-level up to 1.4 times higher than calcium. A soil high in magnesium and low in calcium can test around 6.5 pH, but will be inadequate for many crops. The pH-level does not reflect soil balance. The base saturation must always be analysed to determine how much, and what type of calcium, should be applied.

Calcium has been called the king of nutrients. It is the essential element. If insufficient calcium is available, the soil will not contain the right amount of air and water. A lack of these two elements produces hostile living conditions for the microbe population. A vicious down-hill spiral begins which can only be broken by an application of the right kind of calcium. The choice of a specific calcium source is critical. For example, in high magnesium soils an application of finely ground calcium carbonate can actually lower the pH-level over a three- year period. Calcium controls the magnesium influence, and magnesium has more impact on pH than calcium.

Foliar fertilising has become a popular technique to increase crop production, but, even with this apparently unrelated procedure, calcium plays a significant role. If the calcium base saturation is below 60%, then the uptake of foliar fertilisers will be restricted.
Finally, the calcium / magnesium ratio is perhaps the single most important fertility index. The ‘ideal’ ratio varies from around 4 : 1, in lighter soils to 7 : 1 in heavier soils. We can often pick a grower’s best performing block using only this ratio as a guideline.

The Nutri-Tech Commitment

We are passionately committed to improving soil quality in this country. The first barrier in achieving this goal is often related to convincing you, the grower, that a change is even necessary. Many of you are already aware that something is amiss, but others are not so sure. The old cliche “Knowledge is Power” is relevant here. The “power” in agriculture relates to control over ones destiny. If you know what’s happening and why it is happening, then you are empowered to do something about it.