Fertilisers and Fertility
N0 artist or artisan ever has such broad control of the mediumthrough which he expresses his own character and personality as does the farmer orgrazier in the control he can exercise over his land. The landman can create hisown landscape, but the artist gives only his impression of it, and few pictures canrival those scenes that are found on a farm which has been cared for by one familyfor generations. Age constantly improves the cultivated landscape; lakes, hills,and the flowing streams all gain in beauty and usefulness under the mellowing handof time. This beauty is forever changing as it is continuously being reflected inthe life of the streams, the ponds and the soil, as well as in grasses, crops andtrees. There is nothing still or dead in this scene in which the farmer lives andcontinues to live with the other life that is the moving enterprise of his farm.Everything that has life in this scene draws its life from the sun and water andfrom the soil and air. The scene is composed of these things and developed by time.
Farming as we know it in Australia should produce scenes likethese, but, unfortunately, there are very different landscapes which have been developedby man on which his hand has fallen as a destroying blight. There is a balance innature which can be easily upset and the "rape of the earth" and the "violationof the landscape" describe a scene where this balance has been disturbed andwhich we know only too well. The two landscape pictures, the one that is all goodand the other that is nearly all bad, may have started together on similar land andduring the first decade or two may have remained very much alike. The factors thatinfluenced them in the improvement of the one and the deterioration toward completedestruction of the other may have been very small or slight. Yet in the one casethese factors produced a change in the balance of things which caused a movementin the downhill direction of ruin, while in the other the changed conditions of theenvironment resulted in an improvement.
All types of life (including man) are concerned greatly withthe environment in which they live. No matter how small or apparently insignificantthis life, it still must adjust itself to its environment, and in so doing has itseffect on the environment and becomes part of it. Sometimes the introduction of anew life species into a stable environment may so completely upset the balance asto cause drastic and rapid changes, which in their turn affect other forms of lifein the environment.
Human beings have a greater power than other life over materialthings and so may quickly change or modify the conditions to suit themselves. Butthere are some factors of the environment over which man has little or no control,and so he must adjust his pursuits accordingly. In the handling of land, for example,he must consider the effect of these uncontrollable factors on the new environmentwhich he is trying to create. In agriculture, if the sum of all the factors thathe can control, and those which he cannot control, add up to an imbalance againstthe soil, then the effect toward deterioration, which at first may only be slight,will ultimately result in the great damage to landscape now familiar to us as soilerosion. The giant erosion gullies, the multitude of erosion gutters, or the scenewhich discloses a great slice of the landscape stripped of its top soil, are allevidence of the final result of only this first slight but progressive, and lateroften accelerating, imbalance of the soil environment.
However, all farms do not belong to one or the other categoryof these two opposite types. Most lie somewhere in between, and it is with thesethat we are now concerned. But, first, whatever examinations we may make of the broadfields agriculturally, our approach and conclusions, whether rightly or wrongly,pessimistic or optimistic, will be influenced mainly by just how we regard the soil.
The science of soil has progressed to the stage of classifyingand naming world soil groups. The structure of soil, its texture and chemical compositions,have become almost exact science and are of precise significance to those who sostudy them. The two great world soil groups are, first, the iron-aluminium soils--thepedalfers--and, secondly, the calcium soils--pedocals--and within these, all soils,varying with climatic effects, may be classified. On the other hand, and sometimeswith little interest in these physical properties of soil, there is the soil biologiststudying, identifying, classifying and naming the life species of the soil, whichalone interests him. But a document must be looked at as a whole, and so soil asa field entity, with all its aspects taken together, should be seen as the basicfactor in field agriculture.
Some of the wide classifications of soil science deal with materialswhich are suitable as the physical basis of soil, but which, owing to the climaticenvironment, are certainly not soil, and though they may not be varied much by theapplication of minute quantities of other material or agricultural chemicals, theseinitial soil materials may be so profoundly affected by the stimulation of the otherproperties of soil that the life properties may be affected in great degree.
So, always, the matters of greatest importance in the changeand improvement of soil are those factors of soil life which are very responsiveto the improvement or otherwise of soil climate. Therefore, the farmer, whether hisland is a real soil or whether he is developing an agricultural soil from a physicalmaterial capable of being so converted to fertile soil, must consider always theeffect on soil climate of all that he does on his land. In Australia, following eachnew development of chemical soil science, large areas of land constituting somethingwhich is less than soil are being transformed into agricultural soil which will supportprofitable farming and grazing businesses.
The application of chemical fertilisers to Australian soilshas grown greatly in recent years with mixed success. An inorganic fertiliser isa good servant but a bad master. Following the wide response of superphosphate inimproving some pastures, this fertiliser was tried out eventually on a wide and ever-wideningrange of soil and other material merely "earths". The scope of the useand usefulness of superphosphate was found to be limited, at least by itself. Theolder use of the various lime products had set a pattern, which in varying degreeswas followed in the use of superphosphate. Later the failure of superphosphate toproduce, on some land, its early success stories was found to be due to another factorwhich, when provided for, extended again the use of superphosphates on the pasturelands. The addition of lime with superphosphate to neutralise its acidity, whichhad prevented the early establishment of clover species on some lands, was a notableadvance. There was still more than one class of soil which produced no response inimproved pasture. On complete and fertile soils neither superphosphate nor any otherchemical fertiliser could show results. The lack of response to these chemicals onsuch soil was then a measure of proof of their fertility.
After further work and scientific investigation on yet othersoils, their lack of response to chemical treatment was said to indicate an absenceof another and new mineral element or chemical, and so "trace elements"came into agriculture. While the quantity of the applications of superphosphate,which had so often produced amazing results, were extremely low, with as little asa mere hundredweight to the acre compared with 1000 tons of soil in only the topsix inches of each acre, these new chemicals produced their also amazing resultswith minute applications of a few pounds down to an ounce to each acre of land. Andso another new and fascinating advance was made in the science of soil, and Australianscientists were again, as they often have been in the past, world leaders in thediscovery and successful use of trace elements. Following this basic chemical discovery,new scientific techniques were soon evolved for testing on all soils their responseto the various trace elements. The result was, as with the story of superphosphates,another quick surge in the development of large tracts of land which until recentlynobody wanted. Blocks of such land from a few thousand to over one million acreswere rushed into project type development and on the basis of a major clement like'super' and minor elements-the trace elements.
Always these new advances, which were the results of the discoveriesof farmers, agricultural officers and soil scientists, were paralleled by advancesin bigger, faster and better mechanical equipment with which to use and apply thenew knowledge to the land, and thus the development of new country became almostan accelerating process.
Words of glowing praise and graphic "before and after"pictures, which often showed the "before" as arid nothingness to the "afters"utopian lushness, told and retold the story, and still on and on it goes. Can itbe wondered at that the chemical science of soil has completely dominated agriculturalthinking for a decade or so, and that those who would hesitatingly mention that thereare as well other factors to this matter, are as a voice crying in a wilderness.But that there are very important other factors for consideration is proved and canbe seen, and even on those parts of Australia where the chemical fertilisers havebeen in use longest and where they are now considered the main core of grazing andcrop land management.
In passing, it may be as well to mention the use of artificialfertilisers for growing wheat. In the production of this and other cereals the artificialwas almost exclusively superphosphate, and there is no doubt that over very considerableareas in all States of Australia the application of this artificial fertiliser madethe whole difference between an unprofitable or a profitable crop. Along with theearly tendency of those farmers living in the wheat-growing areas to be solely wheatfarmers, marched a deterioration of their soils, which was at first seen in the changingand deteriorating structure of their soil and later in widespread soil erosion. Thereis no doubt in my mind that the increased prices of wool following the second worldwar and the conversion of much badly erosion-damaged wheat land to sheep pasture,and coupled with a succession of better rainfall seasons, has done more to checkthe accelerated rate of soil erosion than has the combined efforts of all Soil ConservationDepartments.
With the earlier increase in wheat production resulting fromthe use of superphosphate not only was there this loss of soil fertility as evidencedby deteriorating structure and soil erosion, but at the same time there was a notableand continuing drop in the quality and food value of the wheat. The grain was inmany cases just not fit for human consumption, and on this being gradually realised,but called by some other name such as "poor baking quality" or "goodbiscuit wheat", those areas which were still producing good-quality wheat becameof great importance to the whole wheat and flour industry simply because the poor-qualitywheat could be used satisfactorily when mixed with a sufficient quantity of goodgrain. But this now scarcer good-quality wheat came from those areas already mentionedas fertile and on which superphosphate had no effect.
In New South Wales the north-western wheat area was in thisgeneral category, so it may be as well to examine the effect of wheat cropping onthese soils where superphosphate was not in general use. Here again we find a generalbut less noticeable deterioration of the soil, which in its damaged condition stilldoes not show a worthwhile result from superphosphates. Therefore, the lack of responseis not a true indication of fertility on these north-western soils. The soils ofQueensland's Darling Downs, where good-quality wheat is grown, as indicated by itsrelatively high protein content, are similar, since here also there is evidence ofdeclining soil fertility in the march of soil erosion but no general lack of availablephosphate in the deteriorating soil.
From this brief glance at soil in relation to the use or otherwiseof superphosphate, there is no evidence that superphosphate has any material effecteither way in destroying or maintaining soil structure or causing or mitigating soilerosion. The evidence suggests that the effect of superphosphate is governed solelyby the condition of the natural phosphate in the soil. If the natural phosphate isreadily available there is no response to the artificial product, and if it is notreadily available then the response is very significant. It does not in any way indicatethe actual content of phosphate in either of these soils. So it is generally withall artificial fertilisers, whether they be of the trace variety or the major elements.The apparent result merely discloses whether or not the soil, in its condition whenthe application of the artificials was made, contains or does not contain the addedelements in a form or condition which is suitable and available for the nutritionof plants.
It is very important to realise the full implications of thesefactors, since there is no indication or otherwise that the results would be constantif other soil factors were changed. For instance, if these soils were improved asto their soil climate for two or three years only, would the results and responsesbe as before or would it be found that the apparent deficiency in the soil of allor some of the major or trace elements had disappeared?
As with the major elements, so the trace elements were foundto be effective not only in bringing large new areas into the class of agriculturalland, but in improving pasture production and enabling new and better grass and cloverspecies to be grown successfully on land now deteriorated and which was occupiedfirst in the earlier days of our history. Now some of these responsive soils hadbeen greatly changed from their original condition prior to the successful applicationof trace elements and in no small measure many detrimental alterations had takenplace during the use of the major elements. On large areas of old wheat land thesoil had been cultivated in the orthodox fashion which insisted that cultivationproduce a "fine seed bed" of often powder-like fineness, and causing eachyear an increasing tendency for the soil to surface puddle and seal in the rainsafter each cultivation. The entry of rainwater was thus increasingly retarded, andso one of the important three factors of soil climate, namely moisture, was restrictedin a climatic environment which was short of moisture in the first place. The widespreadbelief in and the use of summer fallow, which left the soil in this finely cultivatedcondition, so that it could absorb a complement of moisture from any rains for thegrowth of the following crop, only damaged the soil further. On occasions followingcultivation for summer fallow and prior to the first fall of rain but with some moisturepresent, the soil responds quickly to the better air conditions, and the organicmatter present, notably the roots of previous crops and grasses, quickly becomesincorporated into the soil. This occurs only if and to the extent that moisture ispresent. If rain occurs before the existing moisture is used by the soil in thisprocess or evaporated by the heat and winds of summer, then a stronger circle ofsoil improvement ensues. The result is two-fold--first, moisture is stored as wasintended to result from the summer fallow, and, secondly, the soil itself is improved.Despite the fact that the cultivation is of the wrong type for storing rainwaterin the soil, it still does usually allow more to enter than would be absorbed intothe soil if it were left uncultivated in its settled and compacted or scaled condition.There had to be a reason why grain farmers continued to use summer fallow, and obviouslythat reason was simply that summer fallow was found to work. As some soils continuedto deteriorate and by their sealed condition restrict further the absorption of rainfall,summer fallow became in many instances the measure of success of the following crop.Now, rain at the right time for the soil, and each time it needs it for only twoyears, will, without any effort on the part of the farmer, appreciably improve thesoil. So the summer fallow, as we have seen, even with the worst type of overfinecultivation, can produce a similar but transitory soil improvement. But as appearsto be the case in so many agricultural matters, few things are wholly good or whollybad, and so the summer fallow, which provides generally a temporary condition ofimproved soil aeration, promotes at the same time the rapid loss of moisture fromthe soil. If the balance of the good and bad of these matters is against the soileven slightly, then, by the very nature of the process of soil deterioration, theend point of destruction that will result from the continuance of these methods willbe the same as it would have been if the balance against the soil had been much greater.
Over the last few years many of those who earlier insisted onthe fine-seedbed type of cultivation now have realised that as well as promotingthe early germination and establishment of the grain or other crop, it also tippedthe balance against the soil, thereby promoting its deterioration. Also it came tobe realised that moisture in contact with the seed, and not the fine seed bed itself,is the critical factor in the germination of seed.
Without condemning either the use of superphosphate or the principleof the summer fallow (and, indeed, there is nothing in these discussions yet to condemneither), can the balance which is against the soil in these two techniques be influencedin favour of the soil? Obviously superphosphate, or something else, is still necessary,because without it on this soil there is little or no crop, be it cereals or grass.Superphosphate was in many cases the factor that first permitted profitable cropping,and while the soil remains as it was or continues to deteriorate and erode, superphosphatemust be needed. Therefore, it is necessary to go to the soil itself and determinefirst whether it can be changed, and, secondly, what methods may be used to improveit. There appears to be little point in further investigating various other chemicalfertilisers, for, if these have not already been tried, there is the direct evidencefrom long observation that these applications, while possibly not causing soil deterioration,certainly on their own have not prevented it. The first avenue of possible improvementlies in the field of cultivation, and the second may be through a pasture stage.
Inorganic fertilising of Australian soils may have helpedthe agricultural industries, but it is not their salvation. There are other avenuesto be taken of which one is a new approach to cultivation methods. The followingincident is illustrative:
One of my men in the course of his duties visited a client whohad been notably successful in growing wheat by using cultivation procedures suggestedby us with his Graham plow. Standing on the verandah of the farmer's home, they werelooking over two adjoining paddocks which had recently been plowed in preparationfor wheat crops. One paddock, the neighbour's, had been cultivated with a disk plowwhich had produced the fine seed bed thought necessary, and the other, the farmer's,had been cultivated with the Graham to our recommended depth, which, in this case,was about one inch deeper than the disk-cultivated land of the neighbour's adjoiningpaddock. Suddenly the farmer said, "Watch this". The "this" wasa whirlwind, or willy-willy, in Queensland parlance, where the incident occurred,which entered the neighbour's paddock, whirling a dark thick column of his fine seedbed high into the sky. As they watched, it increased in size and blackness and movedacross the neighbour's paddock and entered our farmer's paddock. Immediately it ceasedto pick up dust so that the lower part of the column was practically clean air withonly pieces of dry grass or stubble whirling about. These pieces indicated that thewilly-willy was still twisting at its full speed, probably upwards of 50 miles perhour. All was soon over and an immediate examination of our farmer's paddock, initiallyleft somewhat rough and cloddy, showed it contained considerable quantities of veryfine soil particles or dust with the clods. The fact that the dust (or fine clayparticles) did not rise indicates that the effective wind velocity of the willy-willyat the fine dust zone had been reduced by the special cultivation to less than tenmiles per hour.
Now the fact that our farmer friend did not lose any soil underhis method of cultivation and the neighbour did from his fine seed bed is not thereally significant point to the story What appears to me to be so very importantis the fact that a method of cultivation reduced wind velocity very drastically;wind which, on other occasions, may continue for days to draw critical quantitiesof moisture out of the soil and to its great detriment.
The results of soil cultivation depending on the methodsused can be beneficial or detrimental, especially in regard to increasing or decreasingsoil moisture content.
All farmers are familiar enough with this fine-seed-bed typeof cultivation, the continuous year-by-year pulverising of the soil, with its veryserious deteriorating effect. Similarly, this constant depth plowing method producesa compacted subsoil layer and a plow-sole.
These compacted horizons, plow-soles or hardpans, as they arevariously named, are produced by such cultivation methods in as short a time as threeyears to my knowledge. They always have the effect of restricting the activity ofthe many important movements in the soil such as moisture, air and soil life. Theactive or vital depth of a soil, formerly six inches deep, may be reduced to onlytwo inches, and, as always, when the practices that cause soil deterioration arecontinued, the process of destruction is progressive. So also is the process of soilimprovement. On these partly-destroyed soils, or on any soil for that matter, a periodduring which improved cultivation (as far as soil itself is concerned) is practised,may so swing the scales in favour of the soil as to promote and maintain for a considerablenumber of years an improved and improving soil. A cultivation such as that producedby our Graham plow and regulated as to a depth that penetrates an inch only intothe compacted layer will have a markedly beneficial effect immediately soil moisturerequirements are supplied by the first following rain. But always no one soil treatment,be it through the various chemicals that may be applied or a particularly beneficialcultivation or any other matter, will produce a fertile soil. The critical factorsare (1) improved soil climate and (2) the necessarily progressive nature of all soilimprovements. It seems to me, from my own experiences and experiments in these matters,that a truly beneficial influence, whatever it may be, needs to be maintained generallyfor three years in order to produce a condition of new fertility in the soil whichwill then enable the soil to continue its own improvement.
The problem is how to get the most benefit from cultivationand other practices, including the use of chemical fertilisers. If special typesof cultivation (embracing the correct control of depth according to the present conditionof the soil and, as far as may be, done at the appropriate time of the year in relationto the continuously important factors of moisture, warmth and air in the soil) willgreatly improve the fertility of soil, can this improvement then affect the questionas to the most beneficial function of both the major and the trace elements? Allmy work supplies a definite affirmative to this question.
Agricultural practices should be designed to acceleratenature's beneficial processes. I propose to put a number of questions and give whatI believe to be the answers and finally to give my opinion on what is the main basisof the production of healthy crops and pastures.
Superphosphate has assumed such a dominating influence in theagricultural views of some soil scientists and great numbers of farmers and graziersthat many apparently believe that the whole agricultural development of this continent,both past, present and future, was and is vitally tied up with the chance occurrenceof large phosphate supplies easily available on neighbouring islands. But it is extremelyunlikely that the actual overall phosphatic content of our soils has been increasedby one ton with all the countless tons of our imports of this still very importantartificial fertiliser. What, for instance, was the weight of phosphate, includingthe plant available and unavailable types, that was carried to sea in a period offive weeks when six major floods occurred in the Hawkesbury River of New South Wales.As I saw it then, the floods were not water, but soup, its ingredients the finestand most valuable constituents of soil. At the same time other rivers were likewisetransporting to the ocean not only phosphates but every other valuable soil element.While it is a mere matter of conjecture as to what our phosphatic profit and lossaccount does show, and while it is not perhaps of any real importance to know theanswer, it is vitally important to have the answer to the question as to what isthe correct inference to be drawn from the varying results of all artificials andwhat is their proper or most beneficial function in Australian agriculture generally.
The answer, I believe, is to be found in the reactions to theseartificials when they are applied on soils which are being improved by other means.I refer to the control and improvement of soil climate. Certain trace elements appliedto soil have certain very desirable results. What would be the results if at thesame time Keyline soil development techniques were applied, methods which are designedto improve the soil climate by means already discussed? Again, what would be theresults if the trace elements found to be of outstanding benefit to this soil wereapplied after the soil had undergone a Keyline programme of soil improvement forthe previous two or three years?
It is fairly certain that the successful application and satisfactoryresults from particular trace elements is directly related to the actual conditionof the soil at the time of the application. The results could be completely differentif a poor, sealed and compacted soil was first considerably changed by using methodsof cultivation or treatments that improved the soil by first improving the soil climate.
Again, if the soil is one that the artificial chemical has beensolely responsible for bringing into the category of agricultural land, would thesesoil climate control methods accomplish a similar improvement without the criticalelement?
I believe that the answer to these questions in at least themajority of cases is that the methods involving, firstly, a direct improvement insoil climate, would produce results on their own far superior to the results of thetrace elements on their own. If this were so, would the trace element be abandonedas a method of soil improvement? The answer to this question is simply no, and thereason is a direct one concerning time and money. The results from trace elementsare very rapid, and they would almost always have the great advantage of promotingquicker initial growth, when compared with root organic accumulation, the main basisof the high development of soil in Keyline. The releasing of trace elements thatare initially in the soil and not available in their present state to plants, ismuch slower than this almost immediate response of the applied trace elements. Thecontrols or influences of soil climate do not operate to release mineral elementsuntil the new cycle of improvement is well under way. From my own observation theperiod that must elapse before any effect is strongly evident is from twelve to fifteenmonths, but our experiments do not yet cover a sufficiently wide field for me tobe sure whether this time is relatively constant or otherwise. In climatic conditionssimilar to those on my own farms this time factor appears to be relatively constant,but reports on these matters from dryer areas are conflicting, some suggesting theapparent release of a trace element within a few months of the first rain on thenew cultivation, and others, that two years or a little more brings the desirablerelease. No doubt the actual chemical association of the element is a factor alsowith climate and weather conditions. The very important effect though to the landmanwho is developing a pasture and strictly following a Keyline programme, is that theapplication of the trace element saves valuable time, and therefore should be usedas a "trigger" element to quickly get a stronger fertility cycle underway. With the new soil programme I am now advocating it is my belief that it is generallyunlikely that there will ever be any need for a second application of trace elements.
In these discussions there is no indication of a case againstthe use of trace elements where they are at present recommended by our AgriculturalDepartments, but there is this new view as to just what these results mean.
The very small quantities involved in the application of traceelements against the weight of the soil which they so profoundly influence is a verystrong argument against those who maintain that all such soils are completely deficientin these chemical elements. Considering soil six inches deep, some of these effectiveapplications are in the proportion of one part in ten to twenty million. Surely thechemist, who with the finest laboratory at his disposal must still employ all hisskill to produce any metal or chemical in an absolutely pure state, should not creditnature with such freak accidental "purity" as would be involved if suchabsolute-deficiency theory were true. All these trace elements which have been foundto be so necessary on some soil or soil materials are quite evidently also widelyand in many places liberally distributed throughout all soil and soil materials thatdo not require their application. It is from the evidence of these latter soils,producing as they do much dust to the atmosphere, the dust which housewives generallyfind in sufficient quantities inside the house to warrant removal each day, thatof itself make such a general theory untenable and indicate that such absolute traceelement deficiencies are rare.
What is to be said for the major elements? Is there anythingrelevant as to their true province in agriculture indicated in these discussionson trace elements?
It was stated earlier that little changes in their present orthodoxuse could be contemplated unless soil was first considered in a changed and improvedcondition. As with the trace elements, it seems likely that the major elements aregenerally present in those soils also which show the best responses to their use.But on these soils the elements are again in an unavailable condition as far as plantsare concerned, or alternatively, the rate at which they naturally become availableis too slow.
So it may be asked again, is there anything wrong with thesechemical fertilisers in themselves, and then are they being used generally in thebest possible way? Before directly answering these questions, some materials notyet soil and described as soil materials are at present being improved into agriculturalsoils by many farmers and graziers and can be included in this survey.
The methods being employed in making this soil are either throughvarious procedures of cultivation in conjunction with the sowing of clovers and grassesand adding chemical fertiliser, or, alternatively, through the application of thesewithout any cultivation of the original material. This soil material is being convertedto something better than it was via a pasture stage, although seldom does the grazierthink directly about it in this way. But it should be the general approach to allsoil. Whatever the type of fertility of the soil with which the landman deals, heshould consider his main task one of improving his soil by the processes of farmingand grazing. And now for the question: Is there anything wrong with the chemicalfertilisers themselves? This is a controversial topic that has been going on fora long time. Unfortunately, no judges of the matter have been found and appointedwhose verdicts are acceptable to both sides, but in the final analysis the landmen,given the advantage of time, will determine the correct answer. There were originallytwo extreme schools of thought on the matter; one, the exponents of chemical fertilisersas almost the be all and end all of agriculture, and, two, the "organic school",which just as wholeheartedly condemned every artificial as injurious to the soil,to the health of plant and animal life, and, finally, to the health, well-being andlong life of the human population.
Now the chemical school could show wonderful results which neverlost in the before and after pictures with which they continuously supported theirclaims. Furthermore, because chemical fertilisers are very big business, and bigbusiness, very sensibly, always allocates appropriate moneys for special advertisingand public relations generally, the chemicals had the advantages of the big money.On the other hand, there is little or no money to be made in the advocacy of theorganics in farming. When organic fertilisers such as composts and farmyard manurewere claimed, and more often than not, in my opinion, proved to be superior and infact something more than superior in that they were right, logical and natural, itbecame a simple matter for the chemical adherent to analyse the organic fertilisersand show that on the chemical analysis they offered less in value of the basic chemicalknown to be plant foods than did the artificial fertilisers. Then the organic schoolbelieved in the "cycle of life" and that everything that came from thesoil should be returned to the soil to complete the cycle and continuously improvethe soil. The adherents of the chemicals then could show that in the modern world,with its various waste disposals, including water-borne sewage, the cycle of completereturn was impossible in a general way, even if possible in some instances by concentratingthe waste of other lands on to the organics farms. Therefore, they argued that thechemicals taken by the plant and animals from the land must still be returned byartificial fertilisers. It is my view that eventually all agricultural land shouldbe capable of supporting its own fertility without the additions of outside chemicalfertilisers or organic materials other than those produced by the land itself; butmore of this later.
There is no doubt that each school of thought not only had itseffect on the landmen, but on each other as well. Nowadays there is wide publicitygiven to the value of humus and organic matter in the soil by the actual makers ofartificial fertilisers. When artificials on their own completely failed to hold eventhe original fertility of the soil and widespread erosion marched always with theuse of these chemicals, then the artificial fertiliser people had to borrow fromthe organic adherents.
The organic school, by excluding the uses of artificial chemicalsfrom their agriculture were able to prove, again in my opinion, that the use of theseexclusively organic methods produces a fertile soil that reflects itself in the healthof plants and animals which were almost completely immune to the diseases and pestswhich were the curse of chemical farming methods. The adherent of the organic schooldid not encounter the erosion problems of the chemical school.
In organic farming various minerals in the natural form butsuitably crushed may be added to the soil, so that there are processes common toeach school. The addition of the natural lime products and various other rock productsare advocated by both.
Generally any of these materials that are in a more or lessnatural form may be applied to the soil and not disturb unduly the complex of thesoil life. If chemicals which could not naturally come into soil in its originalconditions are applied, then it is next to impossible to predict all the consequencesthat may follow. There is no doubt that the excess application of such chemical fertilisershas a very definite effect on the soil-life populations. One fertiliser will destroya certain species and accelerate the development of another, and the reverse couldbe true of yet other chemicals, and in the whole complex of soil life gradual changesmay take place with the repeated applications of specific chemicals. These changescould then affect plants, animals and people in a very positive and detrimental manner.There is not sufficient knowledge of their direct results on health, because theissues are always clouded by other factors. For instance, if it were proven thatcertain maladies of people were common to those areas using artificial fertilisers,it would also be found that those same countries so refine and denature their foodsthat this factor could cause their illnesses.
These, then, and very briefly are the considerations which haveexercised my own mind, and no doubt many other farmers, in the approach to soil improvementthrough the use or otherwise of artificial fertilisers.
It is my firm conviction that any system of farming andgrazing which will create conditions in soil which increase its organic life is creatingsimultaneously a sound and sure basis for healthy pastures and crops.
I have decided in my own case to assume that any chemical nota natural ingredient of soil should be considered as probably very harmful to soiland the general health of all life which comes from the soil. Artificial fertilisersthat can be observed to destroy the earthworm, for instance, could be a real danger,and for this reason would play little or no part in my own work. Again, fertilisersthat noticeably spoil the flavour of fruits and vegetables will probably be injuriousto the cattle or pasture so treated. While vegetables, produced in my own yard fromsoil treated by composts, were of excellent flavour, I have often noted both theunpleasant smell in cooking and the taste of vegetables raised on artificials. Ibelieve that some artificials are very harmful to soil and to everything that dependson soil and that their use should be very carefully controlled. But all artificialfertilisers do not have the same degree of harmful effects. While sulphate of ammoniaquickly affects the earthworm population, continuous applications of superphosphatehad no noticeable effects on these indicators of good soil until after the thirdyear. This last experiment was conducted on my own property, where two similar-sizedpaddocks were treated identically as to keyline cultivation and stocking control,except that one paddock had an initial dressing of one hundredweight of superphosphatewhile the other had three hundredweights applied each year. The stock reactions werewatched, but there was none until after the end of the third year, when it was foundthat the cattle concentrated unduly on the one hundredweight paddock. The two paddocksadjoined and with the common gate left open for free movement the stock at this timevery definitely favoured the one hundredweight paddock. After the third year theywere often driven back into the heavy -superphosphate dressed paddock but would noteat it down, so that the one paddock was nearly bare while the second carried plentyof grass which the stock refused. At the same time there were then fewer earthwormsin evidence in the second paddock. In 1956 number one paddock yielded a good cropof mushrooms and number two, with the heavy application of superphosphate, had nomushrooms.
On the other hand, an experiment to improve soil and developpasture without the use of superphosphate or any other fertiliser as compared withthe initial use of one hundredweight of the superphosphate showed two things veryclearly. One, that my own soil can be developed by Keyline methods without superphosphate,and two, that then it takes longer. The conclusion is that where superphosphate iseffective in an orthodox manner on certain soil, then Keyline methods are much fasterif an initial application of the artificial is used. Further, in good seasons soildevelopment in Keyline proceeds very satisfactorily with a one hundredweight initialapplication, but if the season is dry and no climax development takes place in thesoil after the first application, then a second application is an appreciable advantage.Many other experiments of our own tend to confirm the belief that superphosphateis much more valuable when used in Keyline methods to directly improve the soil byproviding the initial "kick" for the rapid development of the pasture rootsystem, which then is the real basis for soil and pasture development, than it iswhen used simply to stimulate pasture growth. There is quite a lot of evidence thenthat superphosphate is much more valuable to the poorer agricultural land than eventhe present methods of use indicate. While formerly it marched with soil erosionit should now be a powerful factor in excluding soil erosion by assisting in themost important work of soil development.
There are many other pointers to the use and results of thevarious methods of superphosphate applications, and I have for many years been veryinterested to hear farmers, with many more years of experience than myself, speakof their experiences. I have now met and talked at length with a group of farmersand graziers who have had approximately thirty years of experience with the use ofsuperphosphates. They all have a similar story to tell, a story of outstanding importancethat should be told again and again in every newspaper and periodical that catersfor the landman.
Each of them told me that he was considered a crank by otherfarmers when he started the use of superphosphate to develop improved pasture, but,on the other hand, was considered a progressive farmer by soil scientists and, ofcourse, by himself. They all applied superphosphate generally each year and saw theirpoor pasture develop a higher and higher carrying capacity. The top dressing, withvarious added pasture seeds, was spread by similar means by each of them. Then, aftersome years, the period varied with each farmer, something went wrong. With some thehigher carrying capacity was followed by higher and higher lamb mortality rates,more disease, and, as one put it, queer behaviours in the flock. There was more needto be a progressive farmer to keep up with the newest cures for the newest diseasesand troubles. Pastures that had been their pride and pleasure later collapsed andsome of the farmers faced disaster. Great efforts were made to determine the causeof the troubles with every help being given from the various sciences of agriculture.There was a consistent pattern to the various accounts, although the causes and cureswere not the same. The pasture which was developed with the aid of the superphosphateshad gradually become shallower rooted, and so the plant nutrients other than theapplied phosphate, were progressively extracted from a very shallow horizon of thesoil. Eventually one or other of these elements was gone, and the collapse of thepasture resulted. In some instances it required twelve months to determine what elementdeficiency had caused the trouble, but whatever it was or how it had happened, eachfarmer had had a very bad shock. With the application of the missing element somesort of recovery took place, and each was able to carry on again, some with the helpof bank finance. But while the pasture recovered, the health of stock and survivalrates were not good. Often the pasture was plowed up in some paddocks and a cropgrown. On this land the following pasture was better, with notably less health troubles.This is explained by the fact that a very considerable mass of old and dead pastureroots, aerated by the plowing, became more or less rapidly incorporated into thesoil by the quick development of the soil-life species and a new surge of biologicalfertility developed with an almost immediate if perhaps short-lived response in thehealthy pasture and stock. Always with these farmers was the fear of another collapseand they commenced to look for other means of safely holding their pastures. It seemedto me that the length of time their pasture lasted in apparently flourishing conditionswas very closely related to their climate. The better the climate the longer theperiod before the collapse. One farmer opined that the continuous dressing of superphosphatehad made the pasture lazy. It simply took the line of least resistance and grew onlyshallow roots in the very surface of the soil where the superphosphate was applied.
Another compared his pasture failure to feeding a jackass (Kookaburra)at the doorstep. Eventually, so he said, the bird becomes completely dependent andif not given the food he needs he forgets to hunt his own and will be found deadon the doorstep if the householder is away for any length of time. The pasture roots,when the deficiency becomes critical, cannot go down into the soil below, which hasprobably become dead because roots and the full soil life do not live there.
With the long experiences of these farmers in mind, I formedthe habit of looking for the answer, or rather the explanation of any wide successesbased solely on the applications of artificial fertilisers. Once it was claimed thata very famous stud bred all its stock on pasture dressed with a continuous yearlyapplication of superphosphate, it being inferred that the quality of the stud wasindeed dependant on this "improvement". Later a man who had worked there,on being asked somewhat casually on the running of the stud, disclosed the real facts.The stud animals were really pampered with the best food purchased from outside thearea and the farm pastures played a very minor part. Other famous sheep studs withthe finest of animals are fed almost entirely on the natural pasture, but slightlyimproved, and take their real breeding from the complete quality of the natural soil.
Then I had the rather wonderful experience of visiting, withtwo of my own men, an area of pasture which had received a yearly application ofthree to four hundredweights of superphosphate per acre for thirty years, and, wewere told, never been dry or even short of water. It was irrigated land. Under suchcircumstances it is difficult not to ask pointed questions which often, by the mereperversity of human nature, are countered in a manner to disguise the real truthswhich one wants to know. However, I signalled my men, whom I could see were anxiousto ask the questions, to wait for the story to unfold itself; and a very interestingand informative story it was.
On this area carrying capacity ranged from nine sheep per acrein the winter to thirty-three per acre in the summer, with an average of seventeensheep to the acre all the year round. Immediately lambs were born on the pastureboth the lambs and their ewes were moved to dry, undeveloped, unirrigated land, wherethey remained to rear them. Older sheep were then placed in the pasture paddock.But no lamb could be raised on this wonderful irrigated pasture; it seemed that theyjust died. Other sheep could not be kept too long on the pasture because they didnot do well. No lamb had ever been born and survived to a ewe born on the irrigatedpasture paddock.
In other words, this pasture was not capable of breeding anything.It was manifestly well supplied with some of the growth factors, but what about theothers? Would this pasture affect hereditary factors in the sheep that were fed therefor a time after they were raised to a suitable age on the completely undevelopedland?
We asked to be permitted to examine the soil of the pasturearea with a spade. This was readily assented to but caused a surprise. We dug downinto the soil for perhaps a foot, disclosing a near perfect moisture condition tothis depth. The bulk of the pasture roots were confined to the top two inches ofsoil, but there was more root growth, although little enough, below this depth thanI have ever found in a heavily superphosphate-dressed pasture without irrigation.The continuous but slow movement of water through the clayey soil probably carriedsuperphosphate with it, encouraging a few roots of cocksfoot to go down. The soilitself in the top inches had a pleasant smell, but below the top there was no smellwhatever. There were earthworms present in the soil of a size which to me indicatedan age of up to two months, but of this I cannot be sure. However, the largest wereabout two inches long and of a thickness near eight-gauge fencing wire.
The pasture itself appeared to be almost entirely composed ofcocksfoot and white clover, but the cocksfoot, although evidently a profuse growth,was so small and narrow of leaf that it was necessary to examine it near the crownto realise that it was really cocksfoot. The leaf of the white clover was extremelysmall, a leaf being of the size of the half of a little finger nail. The nodules(rhizobium) on the roots were very white and clustered tightly under the crown inperhaps half an inch of soil.
Apart from a very shallow "renovation" at infrequentintervals over the years our spade work was probably the only time the soil had beendisturbed.
One subdivision of the pasture area, which was without stockat the moment, appeared to have a good sward of grass ready for stock. We enquiredas to how long since it was eaten off and were told it was both eaten off and wateredfourteen days earlier. On our comment that the irrigation water had produced a veryquick growth we were told that the growth following irrigation had been very slowbut that a shower of rain only four days prior to our visit had produced the mainresult.
Here then was a soil never short of water and with all the advantagesof regular and adequate dressings of superphosphate producing evidently a great bulkof pasture to carry its heavy stocking rate yet incapable of providing the necessaryunknown factors or ingredients of health which would enable it to breed stock oreven carry the same sheep for any lengthy period. On similar adjacent soil but withno extra water on the 17-inch or 18-inch rainfall country and with no added artificials,sheep could live, maintain good health and propagate their species. Surely therecan be little doubt that the methods of irrigation and pasture management followedare very much at fault. The fact that the pasture is still high producing after somany years would be of little consequence if it was not supported by the naturalunirrigated unfertilised land available, which, after all, does supply the unknownhealth factors that enables the sheep to live.
A totally different but equally interesting area came undermy notice where exceptionally heavy cattle stocking rates had been carried on deepriver silts. No superphosphate dressings were employed earlier, but when carryingcapacity declined seriously superphosphate was applied without success. However,an examination with a spade disclosed the story. Although the rich black river siltsoil was many feet deep, the spade showed that only the top inch or two was beingused by the roots of the pasture species. Indeed, the main root of white clover hadpenetrated to two inches only and had then rotted off to an inch below the soil surfaceand produced laterals which grew out horizontally and just below the soil surface.
Here in this instance is soil deterioration on a soil formerlyof completely outstanding productiveness, that is unassociated with any artificialfertiliser and on which the later application of superphosphate and other additiveshad no effect in either improving or worsening the deteriorating condition of thesoil. It can be seen therefore that factors other than heavy dressings of artificialfertilisers can cause a soil to lose its fertility depth and restrict pasture rootsto the top inch or two of a formerly very deep and exceedingly fertile soil. Thedeep silts are generally good irrigation land, as they have good drainage and thereforesatisfactory aeration, but irrigation water applied without due consideration tothe maintenance of good aeration and coupled with the compacting effect on soil occasionedby the very heavy stocking rates can eventually have this effect. Our recommendationon the occasion of the black river silts was the simple and obvious one of Keyline.The soil was first cultivated to a depth of three inches with the chisel plow immediatelystock were moved off and before the land was again irrigated. Irrigation was appliedafter one day and produced a result in rapid growth better than anyone rememberedhaving noted before. This land was just about as flat as land can be, so it was furtherrecommended that a second cultivation at an angle to the first be undertaken duringthe same irrigation season and under the same conditions as the first cultivation.It was expected that this very simple procedure of Keyline would quickly restorethe soil to its former effective depth, and with the farmer watching his soil asmuch as he usually watches his pastures and stock he would know what it needed inthe future.
Also in relation to the flat land irrigation pastures, lastyear I spoke to a meeting of farmers and graziers in a Victorian irrigation districtand made comments on a similar strain in regard to the management of irrigated pasture.Following my talk, questions and discussions led to my, making a recommendation ofa definite procedure which I am sure was at first not in accordance with the ideasof all present. However, a few months later one of the farmers present at the meetingcalled at my Sydney office to inform me of his spectacular success which followedthis treatment on his irrigated pastures. In this instance again artificials hadnot played a part.
In another instance a notable and long-established pasture whichresulted from the yearly application of artificial fertilisers caused grave concernto the owner, as the lamb mortality rate gradually increased until it reached 40%of marked lambs. The pasture was not supplying a complete and healthy diet, but asingle cultivation which aerated the soil to the depth of the pasture root zone evidentlycaused the rapid change which at the next lambing produced a very satisfying resultin reduced mortality in his lambs. A further year of due consideration of the soilclimate which will promote the healthful change in the soil will largely solve thisproblem.
Similar stories come from other countries as well. A reportfrom the last Grasslands Conference in New Zealand recorded that it was now generallyimpossible to breed from year-old heifers in a certain New Zealand district. Thecourse of the district's pasture development had followed that of almost completereliance on heavy applications of superphosphates which produced very large returnsof butter fat. The conference seemed very concerned with the development of a propersystem for the reporting by farmers of these infertility records and then handedthe problem to the veterinary scientists. But it seems again a clear case for thesoil scientists with the condition of the animals clearly reflecting the unhealthysoil condition. Along with the dependance on artificials for the production of grassthere appears to march these conditions of animal ill heath, a condition which isgenerally a reflection of the soil's loss of balance. If it is accepted that a completelyfertile soil naturally produces healthy plants and animals then no other inferencecan be drawn in these cases.
In my opinion the answer to the question--is there anythingwrong with the artificials themselves?--is generally in the negative, but with notableinstances where there are some which could better be excluded altogether. The answerto the query is there anything wrong with the present and orthodox uses of artificialfertilisers must be a positive. I believe that there is something very wrong, andthat it is occasioned in the first place by a generally too narrow approach to allfactors of soil fertility. Certain growth factors of plants have been discovered,identified and manufactured and applied to soil as artificial fertilisers to directlyincrease the growth of plants. But not all growth factors in the soil are understood,and we certainly know very little of other factors at least as important. These unknownsoperating through the soil affect the plant, its health, and constitution, and itssusceptibility to disease and pests. Through the plant an effect is produced in animalslater, and in humans eventually. Artificial fertilisers are relied on too much andoversupplied in man cases. They can, however, be an extremely important factor inthe totality of soil fertility when they are properly considered in relationshipto the important factors of soil climate.
The intensive use of the year-by-year applications of artificialfertilisers (generally superphosphate) to pastures is, in my opinion, wasteful ofboth the superphosphates and the real potential fertility of the soil. Poor soilscan be turned into highly fertile soil and carry very productive pastures, and superphosphates,as an initial application at the start of a three-year programme of soil development,can be of great value in speeding up the soil's improvement. More superphosphatesthan is now used could be applied in this manner over a greatly widened area of Australia.But there is danger in the general overuse of artificial fertilisers. I believe itshould be used somewhat sparingly on the procedure suggested, and more in the mannerof a drug which will cure disease (the disease of infertility), and promote healthwhen good plant food produced by the improved soil itself, and not drugs become thenormal healthy cycle.