There are no cures, but there is a better way

Brett Petersen | 0800 549 442 |

If you want to avoid pests and diseases, produce superior pasture, animals and crops with minimal chemical sprays, then read on.

To get disease, there must be three factors present. They are a susceptible host, a viable inoculum and suitable conditions. It does not matter what crop or type of pasture we are talking about; the rules are the same. Break the rules and diseases and pests will follow. Collective wisdom will tell us all plants of one species are susceptible to their specific diseases and pests; some more so than others, but susceptible all the same. I do not accept that diseases or pests are compulsory. When man makes poor fertiliser choices, regularly pugs paddocks, uses toxic chemical weed sprays and other poor management practices, the chances of getting diseases and pests increase as plants are stressed. Rust, PSA, facial eczema and other fungal ills, grass grubs, clover root weevils or any other diseases are the result of poor and imbalanced nutrition. In nature, no one plant, animal, insect, bacterium, fungus or disease can dominate, as everything is in balance. If one undesirable customer rears its ugly head, the forces of nature deal to it. The damage is minimal and temporary.

That scene is not played out on most farms where the natural order of things is seriously disrupted. Dr. Linus Pauling (1901-1994, Biochemist), winner of two Nobel Prizes, stated: “In my opinion, one can trace every sickness, every disease and every ailment to mineral deficiency.” You will be well on your way to disease proofing your farm when you accept that opinion. Not only will you have a healthy farm, your pasture yields will be superior; your stock will be healthier, and your job of being a farmer or grower will be a pleasure. Delivering superior nutrition to those that consume your produce will be the ultimate payback.

Most researchers will tell us the causal organism of a disease is the fungus or bacterium (the viable inoculum). But being the causal organism does not make it the cause. It is merely a symptom. The cause is a mineral deficiency, or deficiencies. It is far better to prevent diseases than to catch them.

I don’t believe we are on the right track by treating symptoms. If we were, the number of diseases would diminish. However, the list of diseases is added to year after year, while the list of chemicals available to treat the diseases also expands at an alarming rate. There are almost 30,000 registered chemicals. Are they really working? Something is definitely wrong with this system.

Attacking bacteria or viruses with a chemical spray may win you time, but not the war. To do that, we must look at the soil. The soil is the plants stomach. The ultimate aim must be to balance the nutrients in the soil. Once that is achieved, the plant or crops immune system will be able to cope with almost anything that attacks it.

Most fertiliser programmes are based on NPK. In nature, most soil nitrogen is in the ammonium form. In agriculture, most soil nitrogen is in the nitrate form. Furthermore, in nature it does not come at a price from a factory or a fertiliser company. It comes free from the air which is 78% nitrogen. There are 74,000 tonnes of nitrogen above every hectare. To get free nitrogen, you must have a correct calcium-magnesium quantum, available phosphorus, available iron, molybdenum and cobalt. You need to earn the right to free nitrogen. It doesn’t happen overnight, but it does happen.

On average, the majority of applied superphosphate complexes with aluminium, iron, calcium and other cations, within 6 weeks of application. In some cases, it is only a matter of hours. When tying up, the phosphorus becomes less available than the phosphorus in the reactive phosphate rock used to manufacture the superphosphate in the first place. Soluble phosphorus products kill vesicular-arbuscular mycorrhiza fungi (VAM). VAM can increase the roots effectiveness to extract phosphorus and other nutrients, by up to1000 times. Plants grown with VAM have superior health. Depending on the soil, phosphate levels need to be 365-550 kg/ha, sometimes higher. Use a mixture of alkaline phosphorus products.

Potassium chloride (KCI) can kill microbes good and bad alike; just 2ppm (4kg/ha) of chloride is enough to cause harm and the net effect of this is a rock-hard soil. KCI also encourages certain weed growth. Potassium chloride has a salt index of 116 – potassium sulphate has a salt index of 46. Insist on applying only potassium sulphate when correcting soil potassium deficiencies and to provide potassium for the crop. Large amounts of potassium are required to satisfy plants’ needs. The soil for pastures must have 3.5-5.0% base saturation potassium. (For trees and woody plants including berries, potassium needs to be 7.0-7.5%) Sulphur from sulphate is far more useful than chloride from muriate. The sulphate form of potassium enhances palatability while the chloride form does the opposite by making produce taste bitter. The soil requires greater amounts of calcium than any other nutrient.

Calcium is king. Get it to 60-70% of base saturation. Fungi are responsible for retaining calcium in the soil. Calcium and magnesium govern oxygen and water in the soil, by setting the amount of pore space. Calcium can increase the uptake of many nutrients, so when the calcium supply is inadequate, other nutrients may also be inadequate.

Magnesium needs to be 10.1-12% of base saturation. Any more or less and a deficiency will exist in the plant. Yes, too much in the soil will cause a deficiency in the plant. Not only a deficiency, but the amount of nitrogen required to support the crop will increase by up to 50%. That same situation also ties up potassium. Magnesium forms the centre of the chloroplast and is vital for photosynthesis. It drives the solar panels. Magnesium in deficit means phosphorus cannot get into the plant efficiently.

Sodium needs to be 0.5-2.0% of base saturation. In some cases, sodium is higher than potassium, causing dehydration problems in summer.

Minimum sulphur levels in the soil are 20 ppm. 50 ppm is even better, but 100-150ppm is excellent. Similar amounts of sulphur and phosphorus is required but seldom applied. Sulphur leaches easily on free draining soils; the ideal soil for most crops. Spraying glyphosate and other chemicals decreases organic matter increasing sulphur losses.

Iron has to be a minimum of 200 ppm. It can be a lot higher and often is. Some parts of NZ lack iron, but it may be in the subsoil. Check your iron status. In some circumstances it can take huge amounts to correct, if deficient. A major limitation to plant growth in most agricultural soils is an inadequate supply of plant nutrients, regardless of the supply in the soil. Iron crystals have a large surface area and are highly charged. As a result, nutrients such as phosphate, sulphate and trace elements are tightly bound to the crystals and unavailable to plants. If anaerobic micro-sites are able to develop, the crystals break down, releasing the nutrients for plant uptake. Ferrous iron is released into the soil. Other nutrients including calcium, magnesium, potassium and ammonium, are held on the surface of clay and organic matter. The release of ferrous iron displaces these nutrients into the soil solution where they are available for uptake by plants.

Manganese must not be higher than iron. Make sure it is at least 5 ppm less. The minimum is 40 ppm, but 125-250ppm provided iron is higher, is excellent. An inverse iron-manganese ratio limits root growth, followed by the consequences of that. Silicon is abundant in the soil, but not necessarily available. Available silicon in plants can thwart penetration by fungal hyphae and can cause dehydration and death of insects.

Boron is a calcium synergist. Minimum soil level is 0.8 ppm; 1.5-2.0 ppm is better. Boron allows the chloroplast to dump 60% of the sugar into the roots. From there, 50% of that sugar is exuded to the soil to feed the microbes. In return, the microbes make minerals available to the plants.

Copper needs to be a minimum of 2 ppm in the soil, but 5 are better and 10-15 are excellent.

Copper and sulphur influence flavour. Collectively, calcium, silicon, manganese, potassium, copper and boron are involved in plant strength. To stop pastures and crops getting pests and diseases they need to be in the correct proportions.

Zinc should be in the 7-20 ppm range, but zinc is linked to phosphorus and must be correct for the level of phosphorus in the soil. I.e. at phosphorus levels of 240 kg/ha, zinc needs to be 12 ppm; at 365 ppm phosphorus, zinc needs to be 20 ppm. 

Molybdenum needs to be 1-2 ppm and cobalt 1-2 ppm. Selenium hardly ever gets a mention. Add selenium (10%) at 1 kg/ha  of product as selenium confers insect resistance. It is the cheapest trace element you can buy.

pH is the result of your soil’s chemical composition. It will be the result of your fertiliser programme; it should never be the cause of your fertiliser programme. If you follow the rules above, your pH will fall into the region of a healthy 6.4. However, having a pH of 6.4 without having a balanced soil is meaningless.

The above guidelines not only confer pest and disease resistance, through an enhanced defence system for plants and an ehanced immune system for animals, but also results in superior yields of any crops, year after year. If you want to follow up on this, please contact the author.

Superior yields of pasture are in the range of 20,000 kg/ha and higher. The rewards are substantial. Specific numbers have been mentioned; ppm, %, or kg/ha. These figures are relevant only to Perry Agricultural Laboratory and Kinsey Agricultural Services and cannot and must not be applied to or from any other source or soil test. They are not interchangeable with another test. I.e. I have noted an NZ lab’s molybdenum figure of 5 ppm, but 1.6 ppm from Kinsey Agricultural Services in USA. The calcium figure from NZ was 38%, but over 78% from KAS. It doesn’t matter what the figures are. What matters is how to interpret them, how to overcome deficiencies and how to avoid or reduce excesses through applying the correct amount and type of fertiliser. Every credable lab will have its own rules. It's not a guessing game.


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