Thus in developing the method of grain analysis, I compared its accuracy against soil analysis and leaf analysis, which are the current methods used by agronomists for providing fertiliser advice. The accuracy of a fertiliser recommendation is firstly only as good as the sample chosen and analysed, and in this context, grain samples are proving to be exceptionally better samples than soil or leaf samples.
A grain sample is conveniently taken at harvest, in a clean, dry, uniform state suitable for immediate posting to a laboratory. Compared to a grain sample, a soil sample is highly heterogeneous, and might also be contaminated by sheep and cattle droppings and urine. For a wheat and sheep farm, it is difficult if not impossible to avoid a urine patch, which is high in nitrogen and potassium. The soil sample may also contain a significant level of fertiliser residue from the previous crop, as fertilisers are usually applied to furrow depth with the seed. Leaf samples are taken relatively late in the growing season, and represents changing levels of nutrients in contrast to a grain sample. Accurate leaf sampling depends on sampling at a specific growth stage, which might be missed; and the sample, if not dried immediately may deteriorate affecting nitrogen nutrient levels. Later sampling and analysis for leaf tissue also means valuable time could be lost in purchasing the needed fertilisers.
A grain sample taken at harvest represents nutrient availability from a very high soil mass (hundreds or thousands of tons), as the plant's roots has grown to depth and removed nutrients from it over several months. A soil sample, in total weight, may be two to three kilograms sampled from the whole paddock. A leaf sample represents the amounts of nutrients taken up by the plant in the first month or two, and not during its whole growth stage.
This property of grain analysis, which allows the sample to represent nutrient supply from a huge mass of soil over a longer period of time, makes the results highly accurate and representative for advisory purposes.
Soil analysis on the other hand represents nutrients in a small mass of soil after harvesting a crop. Leaf analysis represents nutrient supply from a smaller (than grain) mass of soil over a shorter period of time.
By selecting the seed for analysis, a measure of nutrients is obtained which represents the first fertiliser package for the young plant. In this respect, the analysis of grain is forward- looking and gives a good indication of fertilisers needed. This is because nutrients in grain fall between quite specific and narrow margins depending on the type of seed. We use this information to determine whether a particular nutrient falls in the low, medium, or high range. The data is drawn from a large number of samples that have been collected over a long period of time from soils with varied fertility and fertiliser treatments. The nutrient ranges obtained are therefore extremely useful for interpretation.
For example, if an analysis of wheat grain falls in the low range for phosphorus (0.18% - 0.27%) and zinc (7ppm - 19ppm), the farmer would benefit by using extra phosphorus and zinc fertiliser. If the analysis falls in the high range for phosphorus (0.34% - 0.45%) and zinc (30ppm - 41ppm), phosphorus and zinc fertiliser might be reduced or not even used. A table for nutrient ranges for wheat grain is given below. The values were compiled from wheat grain samples collected from a wide area of the wheat-belt over a period of time of 20 years, while working as a chemist and research officer at the Chemistry Centre of WA.
| Wheat Grain (dry basis) | Low range | Medium range | High range |
| % Nitrogen % Phosphorus % Potassium % Calcium % Magnesium % Sulphur ppm Copper ppm Manganese ppm Zinc ppm Iron ppm Boron ppm Molybdenum ppm Cobalt |
1.30 - 1.67 0.18 - 0.27 0.28 - 0.49 0.015 - 0.036 0.080 - 0.123 0.073 - 0.117 1.1 - 2.6 10 - 36 7 - 19 14 - 22 0.6 - 3.0 0.02 - 0.34 0.010 - 0.030 |
1.67 - 2.04 0.27 - 0.34 0.49 - 0.60 0.036 - 0.053 0.123 - 0.146 0.117 - 0.144 2.6 - 3.9 36 - 62 19 - 30 22 - 31 3.0 - 5.5 0.34 - 0.66 0.030 - 0.060 |
2.04 - 2.41 0.34 - 0.45 0.60 - 0.73 0.053 - 0.072 0.146 - 0.175 0.144 - 0.183 3.9 - 5.5 62 - 89 30 - 41 31 - 43 5.5 - 8.0 0.66 - 0.98 0.060 - 0.090 |
With the close cooperation of the Chemistry Centre of WA and its huge data bank built up over several decades, the analytical ranges for canola , barley and lupin grains have also been obtained. Together with wheat, the data will no doubt go a long way towards increasing the productivity of these crops in WA.
The grain analysis data for wheat is still useful when the next crop following a wheat crop might be rotated to, for example, canola or lupin. This is because the wheat crop is being used as an indicator of nutrient levels and supply from the soil. In planning fertiliser applications for canola or lupin after wheat, or vice versa, added attention is then given to nutrients which present in the low ranges.
Another benefit of obtaining nutrient levels for grains, other than in interpretation of fertiliser requirements, is in assessing the quality of a grain. Protein, amino acids, vitamins, carbohydrates, moisture, grain weight and grain size can also be analysed in addition to the mineral nutrients. Together, they determine to quite an extent the quality of the grain, and reveals a lot of information about the soil in which the crop is grown. Quality will improve the vitality of the seed at germination, and help it to resist fungal and viral diseases. D. Davidescu (Fertilisers, Crop Quality and Economy, April 1972, p 1102, Edit. Elsevier, Amsterdam), has estimated from trials that 15 per cent of potential yield is due to the quality of seed the farmer uses, the balance of potential yield is due to the quality of fertiliser, cultivation method, seed-bed preparation and crop rotation. Grain quality analysis data would assist in improving management. Also, customers of grain crops are now increasingly demanding quality as competition between grain exporting nations increase.
The above discussion recommending the adoption of grain analysis recognises that soil analysis is still needed for certain analyses. Examples are soil pH for lime recommendations, EC for estimation of soil salinity, together with soil phosphate, soil potash, organic carbon, particle-size analysis, etc, when these tests are used to assess the status or value of a soil.
In considering the overall ease of sampling procedure, posting, sample preparation, analytical method, analysis, reporting, accuracy of interpretation and fertiliser recommendation, the method of grain analysis should be considerably cheaper and attractive. Used together with soil and leaf analysis to fine-tune fertiliser recommendations and crop management, grain nutrient analysis will play an increasing role in improving profitability for farmers.
This map is a transparent record of the existence of thousands of rivers, which formed a network feeding the main rivers, which conveyed excess rainwater to the ocean.
Many of these rivers have disappeared.
Superimposing present day maps of the road and rail network of country and metropolitan WA on this old map should spot the exact locations where these rivers came to an abrupt end.
For many years past, people blamed clearing and the removal of trees solely for the rise of stored salt to the surface. The obvious conclusion, that most of the rainfall occurs during the cold, winter months, when trees transpire little water, and that the shallow, sandy gravelly soils have little capacity to soak up water, were not made.
The real blame, of course, lies with the wide-scale economic development of WA during the last Century, where it was found to be cheaper to fill in the rivers than to wisely build a bridge over them for roads and rail.
Except for the invincible larger rivers like the Black-wood, Avon, Murray and Warren, many of the smaller rivers and tributaries, including countless streams, were culled off one by one, leaving WA without sufficient natural drainage to the sea.
Recent flooding and salt encroachment of buildings in Moora, after two successive floods, should convince the most hardened sceptics of the value of drainage.
To prevent the situation from deteriorating further, in case of another flood, the Moora Shire Council could identify old river-beds and where they have been blocked by roads or rail, and approach the Government for funds to clear and build bridges over them.
The mean annual and maximum flows (in cubic metres per second) of WA rivers versus annual rainfall (in millimetres or billions of litres) have also been faithfully recorded by our public servants. That these annual flows removed a major part of the rainfall, which prevented salinisation of WA before settlement and development, cannot be disputed.
Other factors assisting removal of excess rainwater were the natural vegetation, evaporation and recharge to groundwater. The excision and passing of the network of rivers removed their vital contribution, and put us on the path to salinisation.
Logic should indicate that time is fast running out with the recent dramatic rise of groundwater in South-West WA. If the contribution to drainage by rivers is not restored quickly, an irreversible situation will be reached for many areas.
This will occur when all efforts to remove water (by localised drainage, pumping, cropping and trees) cannot stem the rise due to sudden storms or increased rainfall.
With more and more farmers in dire financial straits, a cause of real worry for everyone, their contribution to the removal of water by cropping and planting trees could be greatly reduced.
Our potable water supplies, infrastructure and land values, in both country and Perth are all at risk.
A whole-of-catchment integrated approach to river reclamation and maintenance has been suggested (Countryman, February 8, 2001, p8). The cost to the people of WA could be $500 million a year for 20 years- a small sum of money indeed, compared to what is at stake.
Restoring the flow of smaller tributaries and streams that feed ocean-flowing rivers, fencing and re-establishing vegetation along degraded stream and river courses, and deep drainage of farms to contribute rainwater to the rivers are the keys to save a large portion of our State.
Drainage of land is now widely accepted as being the key solution to the salt crisis.
If we reasonably estimate the total cost of natural drainage by river reclamation to be $10 billion spread over 20 years, we will need to raise $500 million each year from revenue to spend on earthworks to clear blocked rivers and their tributaries, and on building bridges.
This will enable the salt to quickly flush out to sea with rainfall, as nature intended.
Positive benefits will flow in the way of increased confidence in the future of a large portion of our State, which includes Perth and its water supply; increased productivity of pastures and crops; improved value of real estate and employment opportunities.
A "Restore WA" plan should be both equitable and workable to be quickly accepted.
The area of land initially chosen for drainage should be land situated along the whole length of three main rivers that drain the catchment areas of the Dandaragan, Yilgarn and Black-wood plateau areas of South-West WA.
During year one, a budget of $500 million will enable $16 million to be spent on the earthworks and bridges along each of 10 smaller rivers which confluence with the three main rivers, leaving about $20 million each year for planning, administration and maintenance.
This plan is repeated every five years for the remaining main rivers, until within 20 years most of South-West WA would be effectively drained.
The people of WA will enthusiastically support a Government which will spend a part of their hard-earned money wisely on drainage to remove the invading salt from their land, and restore it to its former health.
This method of recording of pH may be convenient for industrial purposes as it provides a simple indicative value. For example, a change of one pH unit from pH 7 to pH 6 indicates that there has been a 10-fold increase in acidity of a solution.
When applied to agricultural soils, however, the significance of this scale may go unnoticed over time, with terrible consequences worldwide. For example, farmers may not be aware that a change of 3 pH units (eg from pH 6.8 at clearing to the present pH 3.8) represents a 1000-fold increase in soil acidity and not a 30-fold increase as some might think.
Farmers who are undecided about lime please note that this is now a major problem. It is scientifically well known that in acid conditions the plant uptake of all the major elements comprising N, P, K, calcium, magnesium, and sulphur become a problem which is further complicated by the loss of valuable trace elements through acidic leaching.
Better farming methods, which include liming, and fertilisers containing trace elements are now crucial for sustainability.
It is time we developed a new scale for recording soil acidity which more clearly reflects the awful increase of soil acids, and consequent fall in productivity worldwide.
Although overshadowed by its companions, principally N, P, K, magnesium is accepted as a crucial member of this group as it is the central atom of the chlorophyll molecule or the green plant pigment which is responsible for the process of photosynthesis.
Photosynthesis occurs in leaves where the energy from the sun is harnessed to chemically combine water and carbon dioxide from the air to form glucose, the basic building block of all plant matter and foods. Glucose is further converted within plants to form starch, proteins and oil.
Besides magnesium's function in harnessing energy, it has a close interaction with phosphorus in many plant and animal enzymes responsible for growth, reproduction and respiration.
Increasing recognition of its importance as a companion to phosphorus is seen in the production of fertilisers containing magnesium.
However, in a similar way to urea, magnesium reacts with phosphorus to form a sticky compound, which makes granulation very difficult and expensive to achieve. This problem is not apparent in liquid fertilisers.
Salts of magnesium (eg. magnesium sulphate and magnesium chloride) are highly hydrated and carry up to seven molecules of water. This has led agronomists to suspect that magnesium occupies an important function in water economy of plants, revealing its potential importance in dry-land farming.
The highest concentration of magnesium in plants is found in seeds, and a 2.7-tonne crop of wheat removes about 7 kg of magnesium element (or the equivalent of 12 kg of magnesium oxide) per hectare.
The urine of sheep and cattle also causes acidic leaching of magnesium from the soil. Being an important member of the alkali minerals which include calcium, the removal of magnesium increases the acidity of soils, and decreases productivity.
As it is a powerful anti-acid, the increasing use of dolomite (calcium-magnesium carbonate) and magnesium oxide (E-Mag and Caus-Mag) by WA farmers is a good sign for the agricultural industry.
The child holds a flower, which a honeybee is claiming as its own. All the elements of life are present, carefully nurtured by the powerful environmental forces of heat, light, air, water, nutrients and microbes.
Spiritually, mankind has always recognised the profound influence of these environmental forces on life, although science has not yet united their relative magnitudes and relationship to life in a grand integrated scheme. Greater understanding is needed as we struggle to survive in an ever-changing world subject to the laws of these forces.
Chromosomes made up of DNA and residing in the nucleus of the cell are the keepers of the genetic blueprint, and repositories of information for the present and the future survival of the organism.
The cell and its genetic codes are constantly under the influence of the environmental forces, and its integrity is affected by them; its position in space can be considered to be at the origin of the three dimensional Cartesian coordinates x, y and z, which locate the six forces. An eight-sided crystal of influence (an octahedron) around the cell is formed, with the forces at each apex forming a bi-pyramid model. This model shows the interactions between the environmental forces themselves, and the cell.
Scholars in ancient Egypt, China and Korea have long recognised the influence of the environmental forces fire, air, water, earth; life is visualised as a constant battle between good and bad. The Korean national flag depicts this concept. A modern, scientific explanation could be that, under the influence of the combinations of forces with certain optimal values, the cell's immunity would be at a maximum, and disease at a minimum.
The forces act both externally (our environment) and internally (our health). Light is represented in the cell as bioluminescence (light without heat), by deep-sea angler-fish and the fire-fly.
We could use this model to make useful observations, predictions and measurements. For example, one can predict that, in the future, perhaps in 100 or 200 years, we should be able to improve our external environment and our internal environment to such an extent that disease is a thing of the past and life expectancies are greatly increased.
Hopefully this model can be used to explain the likely outcomes of things that concern us today. Such worrisome events as the effects of global warming on coral reefs; the hole in the ozone layer and the effect of increasing ultra-violet radiation on life; the depletion of vital nutrient elements in the soil and our foods; the pollution of the air we breathe and the water we drink; dieback in forests and soil degradation; the effects of overpopulation on resources, and the increasing incidence of powerful pathogenic microbes.
Within the living cells of the young plant, its nucleus carries the long thread-like chromosomes which holds the genes on which are encoded all the information it needs for its continued survival, its germination and growth, development and reproduction.
The young plant waits for the environmental signals of moisture, warmth, light, and air composition, and when these are just right, the enzymes, proteins, hormones, trace elements, mineral salts and carbohydrates are activated to begin the process of germination.
By means of a light absorbing protein called phytochrome, the young plant can detect how deeply the farmer has buried it in the soil. This information will determine whether or not the seed will germinate, and if it does, to emerge triumphant from the soil with a single leaf if it is a wheat plant, or a pair of leaves if it is a dandelion.
The various types of proteins, carbohydrates, minerals, trace elements and the moisture it carries, its "quality", determines to quite an extent its future yield. This quality, if optimal will cocoon the germinating plant in an ideal environment and strengthen its immune system against ever present fungal and viral diseases.
D. Davidescu (Fertilisers, Crop Quality and Economy, April 1972, p 1102, Edit. Elsevier, Amsterdam), has estimated from trials that 15 per cent of potential yield is due to the quality of seed the farmer uses, the balance of potential yield being due to the quality of fertiliser, cultivation method, seed-bed preparation and crop rotation.
This points to the importance of ensuring that crops are grown in soils which are not too acid and deficient in minerals and trace elements; plants being deficient in certain elements being more likely to produce lower quality seed and affect future yield.
The seed acts as the first fertiliser package for the young developing plant. Analyses reveal that the mineral nutrients fall between quite specific narrow margins depending on the type of seed.
For a wheat crop yielding 2.7 tons per hectare, we can calculate the actual uptake of each nutrient (in grams or micrograms) per square metre by multiplying the yield per square metre (270 grams) with the analysed value of the nutrient.
I propose that a grain analysis recommendation system for grain-growers would be beneficial, by comparing the nutrient uptake patterns of high performing crops against poor performing crops.
The soil conditions favourable to the developing seed are also the same conditions favourable to soil microbes and earthworms. These conditions are soil pH, moisture and temperature, organic matter, soil tilth and aeration. In acid or saline soils where the availability of trace elements and nitrogen, phosphate, potash, magnesium, calcium and sulphur are low, the microbes and earthworms will be poorly represented.
As a result animal manure and crop residues will decompose only slowly. This has led to the emergence of "organic farming". The organic farmers react to the fertility problems by applying liquid bio-fertilisers produced from composted manures containing microbes, while some breed earthworms for release.
The important thing to remember here is that the use of lime as E-Mag, dolomite, limestone or hydrated lime, and phosphate fertilisers containing trace elements, potash and sulphur will encourage naturally present microbes and earthworms to multiply and flourish, the soil thereby becoming "organic" and productive.
The "sustainable package" approach promoted by Western Fertiliser Technology Pty Ltd, based on Super Energy and the Tank-mix system, is gaining widespread acceptance from leading farmers. The package aims for a combination of scientifically planned nutrition and soil management, highly efficient seeds and varieties, better cultivation methods and effective weed and pest control for a highly rewarding, productive system.
Present understanding of the problem is that the phytophthora fungus in the soil attacks the roots and causes dieback, which is partly alleviated by phosphonate injections to the trunks of affected trees.
However, my interpretation of the problem is that it is dieback itself, which predisposes the roots of trees to parasitic attack.
What causes dieback?
I considered the source of nutrients to the trees after they settled down to grow new leaves after a fire.
Nitrogen is a key nutrient in all living beings, and its main source to forest trees (other than a small amount in rain) comes from legume plants living in close proximity to the trees.
With regular systematic burning, the numbers of these nitrogen fixing plants would decline, and further, their health would weaken from the loss of organically-bound nutrients released by the fire as soluble ash.
The resulting shortage of nitrogen supply to the trees would result in reduced chlorophyll (the green pigment of leaves), diminish carbohydrate and protein production in leaves and restrict the assimilatory power of the roots.
Thus the roots will be less able to absorb potassium and boron from the predominantly light soils which are poor in potassium and boron.
It is often observed that the classical dieback symptoms (death of terminal buds and leaves) in plants and trees is due to a severe deficiency of potash and boron.
Moreover, deficiency in potassium will render the roots of plants and trees susceptible to various fungal diseases such as mildew, rust and the dreaded phytophthora, as the cell wall thickness and firmness of the root cells are reduced, thus allowing the fungus to penetrate into the roots.
Injections of phosphorus will alleviate dieback as it will help the growth of roots, but it cannot prevent potassium or boron deficiency altogether, and the tree will succumb eventually to the combined effects of deficiency and attack from phytophthora.
The next step, I suppose, is for those having an interest in dieback to test the hypothesis through chemical analysis of affected and healthy leaves, treatment and observation.
In such an event, there will be a progression in understanding of this most pressing problem, and finally we may obtain the means of stopping dieback.