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Climate--The First Factor
CLIMATE, the first factor on the Keyline scale of permanence, governs our approach and guides all agricultural matters. Climate sets the pattern of farming and grazing. The traditionally independent man on the land is completely dependent on the weather.
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For the sake of clarity and brevity in the following discussions it will be assumed that we are dealing with the fairly general type of poor agricultural climate so typical of Australia's farm and grazing lands of the mid-temperate zone. This area is not snowbound for months in each year, but the temperatures are often high. The rainfall is insufficient and unreliable and droughts of a few months occur every year; flooding, destructive rains occur about as often as the severe longer drought. The position of excessive run-off followed by rain shortage for pasture and crops is a more or less constant feature. Generally, if all the water that runs to waste was conserved it could be utilised in practically every year.
Life cannot get down to living, let alone developing fully, until it is adjusted satisfactorily to its environment. This is the climate that set the course which our agriculture is only now seeking to follow.
The natural soil of this climate would not generally be of the deep, highly fertile type. Its development would have been continuously retarded or restricted by the shorter period of good soil climate and the longer and more frequent dry soil periods. It would have reached a natural development of a low to medium fertility and would not now be improving, Its fertility is constantly ebbing and rising a little, according to the season's changing climate.
Our climate cannot be altered, but as soil climate is the critical factor, what can be done to improve the effect of our general climate on soil climate? Varying degrees of beneficial control may be exercised on moisture, warmth and air.
First, water must be used more effectively and none must be allowed to run to waste.
If the period in which adequate or improved amounts of moisture remain in the soil is extended, even a little, the improved soil climate quickly affects the whole of soil-life development and with it the fertility of the soil.
Planning, then, is designed to retard moisture loss in hot weather after more moisture from rain has been induced to enter the soil's depth. All run-off rain, conserved in farm storages, is to be made available as irrigation water and applied to the special irrigation areas immediately it can be used. It may be needed as early as six or eight days after rain in summer and surely must represent a very powerful instance where soil climate can be tremendously improved. Air, too, is to be kept in the best association with moisture and warmth.
The correct association of these three influences--moisture, warmth and air--provides the best conditions for pasture and crop growth, and also the optimum conditions for the development of soil-life climaxes which rapidly change the whole soil, its colour, structure, feel and smell.
Since roots are dying and new ones are developing continuously while there is growth above ground, lack of air to the full depth of this dead root zone restricts and wastes the benefit in fertility to the soil of this important organic soil food. Therefore, air is to be provided to the full depth of this zone when the other factors are suitably present. It can be done by the right type of cultivation at the correct timing for soil life and at the appropriate depth. All items are to suit the particular soil and the condition of the soil at the time of cultivation.
Climate--the first factor on the Keyline scale of the relative permanence of things agricultural--sets the approach to everything.
Adequate air is provided by means other than cultivation in a soil that has been developed to a high state of fertility. The teeming soil-life populations provide air by the strong and continuous formation of the crumb structure of this soil and the burrows of the soil life itself, the dominating and obvious ones being the larger forms, the earthworms. The large roots which on dying and being absorbed into soil leave channels in the soil. Good aeration, a constant factor of fertile soil, waits for moisture and warmth. The earthworm population, large and vigorous, continuously moves in the section or horizon of the soil, where for the time being it finds the most suitable living conditions. When these influences extend to the surface of the soil, the earthworms will break through and cast all over the land. They delve deep into the subsoil, casting as they go into underground passages and cavities. The effect on the factor of aeration by an immense earthworm population in a highly fertile soil must surely approach perfection.
When the soil we are developing, by first of all improving the effect of general climate on soil climate, approaches this state of high fertility, it can look after itself. It will provide its own air requirements, absorbing its full share of rain and continuing to improve. When it does eventually lose its moisture and dries out, which it does more rarely as it improves, its response to small amounts of rain is dramatic. On the other hand, on such a soil, a week of flooding rain will cause no damage. It holds its air and does not drown nor asphyxiate.
When irrigation water is applied to land it critically affects the soil. Poor natural soil developed in poor climate cannot withstand this new condition. Water is an essential part of the soil fertility process, but it can, and does, drown and destroy as well as develop and preserve soil fertility. Whenever irrigation water is applied to soil, then that soil needs air. It may need to be provided more drastically for a time than in any other circumstances of the soil's water and air relationship. The great improvement in soil climate which increased quantities of water make possible can only become real, valuable and permanent when air also is suitably present.
Only soils of the highest fertility other than coarse dead sands are capable of maintaining a suitable relationship of moisture and air when greatly increased quantities of water are applied. When this optimum relationship is maintained, then the poor soil under irrigation will be transformed into highly fertile soil in an incredibly short time. A summer season of the new soil climate that irrigation with adequate air can maintain will produce a complete transformation of poor clayey soil. This has been a consistent result on our "Nevallan" and "Yobarnie" properties each time we have applied irrigation water and maintained, with adequate cultivation, good soil aeration.
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There is an almost infinite range in types of climate. There is great variety even in the general climatic condition that forms the background to these discussions. There is every type and variety relating to the one factor of precipitation--rain, snow, ice, dews and fogs. Then there is the wide variety of other climatic effects on the general pattern of precipitation, such as prevailing winds, seasonal winds and heat and cold.
A dominantly winter, but low annual rainfall area may still lose great quantities of water by run-off in the winter. Although generally a dry climate, the over-abundance of rain in the winter may be the most unpleasant and unmanageable aspect of the farming enterprise. An annual rainfall of 18 inches in this case would provide very significant run-off for valuable farm storages. Another climatic condition with the same rainfall but spread uniformly throughout the year may not provide any regular water for irrigation storages. This climate may produce no reliable annual run-off, but the condition is rare in a Keyline programme, where occasional run-off cannot be conserved profitably.
The dominantly summer rainfall region of north-eastern Australia often creates a problem of extreme water shortage in conditions where the annual rainfall is 50 and more inches. The greater part of the rain which falls in the three summer months goes and may leave the property in drought conditions a month later. In these circumstances, large farm storages could be constructed and would provide enough water for extensive irrigation. The impossible-to-grow grasses and clovers would immediately become highly valuable pasture. A wide variety of plant species prohibited by the natural incidence of rain would in the new circumstances quickly become part of the economy of the farm.
Cold and heat are powerful agricultural influences. However, the planning of tree belts and water supply can greatly improve the living conditions of soil life, crops, pastures and stock, where the conditions of heat are uncomfortable. Tree belts also retard the extreme influences of cold. The soil which improves and becomes darker is notably warmer than a light infertile earth. The darker soil will provide a better growth factor while at the same time improving and further darkening to add more warmth to the soil.
Two days of hot drying winds may draw much more moisture from the soil than a week of hot weather with no wind. Belts of trees, designed and located according to a Keyline appreciation of land form and climate, will reduce the wind velocity and the attendant loss of moisture to a very marked degree. The effect of trees on wind velocity is significant at a quarter of a mile from a good tree belt.
Very severe soil erosion by water is not a characteristic only of the medium to heavier rainfall lands. It is often a more dominating feature of our drier areas, both the flatter western slopes and gentle undulating country. It is just this type of country that lends itself to the construction of the largest farm water storages at the cheapest cost per water unit. While today water storage on such country is confined to stock tanks generally, tomorrow this country must be dotted with some of our most notable farm irrigation dams. All the advantageous means of managing irrigation water, which now apply to our large Government irrigation areas, will then apply in a more economical manner to these large farm irrigation dams.
Water conservation is rarely attempted on such land because the orthodox agricultural approach to farm dams for irrigation purposes is that they should be designed for real reliability against the minimum annual run-off. just why a cheaply constructed large farm irrigation dam is regarded as of no value because it only fills once in two, three or more years, I have never been able to determine.
Every single factor of climate can have both a beneficial effect, or a detrimental effect, according to its degree and relationship to the agricultural enterprise. The frost which wipes out a valuable crop can at the same time have a markedly beneficial effect on the soil of a recently plowed paddock. Snow, pleasant to play in, but not so pleasant to work in, can have almost a magical effect on soil at times.
The purpose of Keyline technique and the Keyline scale of permanence in relation to climate is to take complete advantage of all weather and climatic phases that will enhance soil climate through maintenance in the soil of improved relationships in the factors of moisture, warmth and air, and, by contrast, minimise to the full the disadvantages of those climatic elements that destroy, namely, flood rains, drought and fire.
In this regard, Keyline climatic technique is the surest form of control of the effects of weather now. in practice.