Keyline Concepts for Subsoiling

Keyline planning is based on the natural topography of the land and its rainfall. It uses the form and shape of the land to determine a farm ’s total layout. The topography of the land, when viewed in the light of Keyline concepts, clearly delineates the logical position of on-farm dams, irrigation areas,roads,fences and farm buildings. It also determines the location of tree belts to provide shade and give wind protection. Keyline concepts also include processes for rapid soil enrichment. The shape of a landscape is produced by the weathering of geological formations over millennia. The processes are always the same. And so the topography of agricultural land has a basic fundamental consistency. It is the inevitable nature of land shape that river valleys collect water from smaller creek valleys. They in turn are fed their water from still smaller valleys, until finally the water derives from the very first, or primary valleys of the catchment area. In any country,anywhere,when rain shapes the land over long periods of time, it inevitably creates and determines the topography of that land. Ultimately, at the extreme upstream of any river system there always exists thousands of primary valleys. The only variation to consistent topographical shapes occurs where geological features, such as hard rock outcrops modify normal surface weathering.

A contour is a line meandering over the ground, always at the same height above sea level.The name Keyline was given to a single, very unique contour that occurs in all primary valleys. As you walk up the watercourse in a primary valley, the slope of the valley floor will suddenly increase. That point of sudden steepening is the “Keypoint ” of the valley. A contour line surveyed to run through this Keypoint becomes the Keyline contour for that valley. Because of the consistency in water-formed topographical land shapes there is always a Keyline. The Keyline is always the primary contour and guideline that tells us which way to cultivate when attempting contour cultivation. It is also a logical starting point for any farm layout planning,and supplies a fundamental principle on which modifications to existing layouts can be based. In planning the layout of a farm or ranch it is often the case that no other contour lines on the property need be surveyed and pegged, just the Keylines for each primary valley. Keyline contour surveying expenses therefore are always minimal. Normally when any conventional contour ploughing is undertaken,a contour line is first pegged or otherwise marked on the ground, then ploughing commenced. Cultivation runs are made somewhere between the valley centre line and the adjacent ridge. The first furrow is ploughed adjacent to, and parallel to the marked contour line. The second run is of course adjacent to the first and so on. Let ’s say, for illustration that each run is ploughed below the previous run, as in the diagram on page 134. Because of the natural topography of rain formed land shapes,cultivation runs soon and inevitably depart from the original and accurately marked contour. This always happens and usually after only a few parallel runs.

In conventional contour cultivation this effect is never appreciated and, more often than not, is seen as an apparently unexplainable irritation. Or it ’s ignored and invariably to the detriment of the land. Because of this off-contour drift, water flow can be directed the wrong way and contour cultivation then creates the very erosion problems it is supposed to solve. Keyline cultivation centres on the planned and logical use of this “off-contour ” cultivation and water drift phenomenon. In the illustration the length of the guide contour shown might be a few hundred yards long and the picture represents an area on the side of a primary valley. The slope of the land surface is always a little steeper at one end of this line than at the other end. This difference is important in understanding Keyline cultivation. In the illustration, when ploughing by paralleling the guide contour and then progressively progressing down the slope, each successive cultivation run will be slightly lower at the steeper end of the paddock. This follows as each pass with the cultivator will always have the same width, but across each width the vertical height will be slightly different. Inevitably, after just a few passes, the ploughed furrows will no longer be on a true contour. They will now have a de finite fall one-way or the other, in this case to the left. Rain run-off will therefore tend to have a positive flow, or drift along the now slightly descending furrows. Now, if on the other hand the ploughing starts parallel to the true contour but this time ploughing progresses up the slope, then each successive cultivation run will be slightly higher at the steeper end of the cultivation area. Again the individual cultivation runs will no longer be true contours. The drift of rain or irrigation water run-off will be reversed. The water will move to the right. It ’s logical to delay the concentration and velocity of rainwater wherever possible so it makes sense to give water a bias to move out form the valley centre and not into it. Such drifts dramatically minimize the all too common rapid concentration of rainwater in valleys. The hundreds of furrows in Keyline pattern cultivation spread the water and inhibit concentrations. In total contrast the contour banks or drains advocated by standard soil conservation practices are designed to rapidly concentrate water into a valley, which naturally increases its eroding action. Understanding this fundamental concept gives us control of rainwater drift and flow over the land surface. Of course if an area, for some extraneous reason is always too wet, reversing the sequence of cultivation will dry it out. The Keyline contour is extremely important in contour cultivation. Above this unique contour the valley is steeper than the adjoining ridge. Below

the Keyline the valley is flatter than the adjacent ridge. Thus cultivating parallel to the Keyline contour and moving up the slope drifts water out of the valley and cultivating parallel to the Keyline contour and moving down the slope also drifts water out of the valley. If this phenomenon is not recognized, what is supposedly contour cultivation can manufacture the erosion that contour cultivation is traditionally believed to prevent. This subtle but critical feature occurring in all natural landforms determines surface water movement and this must be appreciated before attempting contour ploughing. The Keyline contour is thus the “transition ” contour. Above the Keyline, contour cultivation runs must progress up the slope. Below the Keyline, contour cultivation runs must progress down the slope. The result of such Keyline Pattern cultivation is that the overall drift of surface run- off water tends to always drift run-off away from the wet valley floor and out onto the dryer ridge. Erosion caused by rainwater flow is effectively eliminated. Normally most water erosion occurs down the centre line of a valley and results from

the excess concentration in water volume and water speed that normally occur there. Keyline pattern cultivation spreads the flow out over a wide area, rendering it harmless. It also markedly increases the time of contact between the rainwater and the soil. Water has more time to be absorbed. Keyline pattern cultivation has the effect of allowing heavy storm rains to be absorbed more easily into the earth. Generally such absorption only ever happens with steady soaking rain. Keylines in adjacent primary valleys are always slightly lower as you proceed down the main valley or watercourse linking the primary valleys. The location of farm dams or ponds are decided by using that valley ’s Keyline to determine the highest water level for the proposed dam. A Keyline contour drain can then collect any run-off and help fill the dam. Because of the drop in height of successive Keylines, an outlet pipe through a dam wall will generally approximate the level of the Keyline in the next valley downstream. Generally, with very minor adjustments in levels, dam sites can be logically linked so each Keyline dam can feed, via a contour channel, to the next lower dam. These contour drains are can be the same as conventional soil conservation drains but must be almost flat to prevent the erosion soil conservation drains can cause. A fall of 1 in 500 or even 1 in 1, 000 is usually plenty. Installing a big outlet pipe is wise when constructing a farm dam as this gives absolute control of the system and pumping becomes unnecessary. Everything is done by gravity. The design of farm dams, constructed with large irrigation pipes a foot or more in diameter, buried under the dam wall and fitted with valves, and farm dams that can be filled or emptied by contour drains, is a Keyline concept. It is a concept my father borrowed from his experience in gold mining and gold washing in Australia and New Guinea. In gold mining, water often has to be transported for miles, usually through dif ficult country and it must be done cheaply. In gold mining, even more so than in farming, water itself is gold. Water ’s collection, storage and cost are of critical importance. The placement of dams with their feeder and delivery channels

determined by the relevant Keyline contour is the logical adaptation of old mining water handling techniques to agriculture. I once found an old contour earth drain, miles long, in the hills near the town of San Andreas in California. It must have been hand built by some of the “forty-niners ”to wash gold from their claim. To me it looked exactly like a Keyline drain on my father ’s farms. As sometimes can happen, storm rains occur when farm dams are already full. But that ’s O. K. as the Keyline cultivation patterns in the valleys effectively spread the width of the moving floodwater and so decrease its velocity. The valleys become covered with a wide sheet of slowly moving water. Even in steep country the land won ’t erode. Keyline ’s cheap ef ficient dam construction and water transport systems mean that increasing grass and crop production by irrigating from the on-farm water storage ponds can vastly accelerate soil fertility development. To irrigate using the Keyline systems the pipe through the dam wall is turned on, flooding the Keyline channel to the next dam. This channel can then be blocked with a pegged down sheet of canvas (called a “flag ”)forcing the water to over flow the channel and flood down the slope.

The patterned cultivation spreads the water with ample consistency. The canvas wall is then moved further along the feeder channel to a new location and the process is repeated. Each move takes just a few minutes. In very flat land a slightly different system is used. Either way a person can comfortably irrigate and control water flow rates easily exceeding one acre-foot per hour (one mega litre per hour). The per-acre cost of irrigation equates to simply interest cost on the capital to create the dams and the contour channels, plus the few minutes required for each move. There is no cheaper form of irrigation. Keyline principles are totally against the concept of concentrating run-off water into manufactured disposal drains that are speci fically designed to remove rainwater off the farm as rapidly as possible. Yet the supposedly safe rapid removal of water off a farm is the basis of all current soil conservation principles. In Australia, the driest of the world ’s continents, such advocacy is almost criminal. Using Keyline design principals either land is cleared, or on cleared land trees are planted, to form both windbreaks and shaded areas for livestock. Trees are ultimately harvested and the tree belts replanted. The other major facet of the Keyline system involves the soil itself. Keyline uses concepts of rapid and economical soil fertility enhancement. As Keyline developed it became obvious that rapid increases in soil fertility from the substantial increase in soil biological activity, could and should be an underlying fundamental of all farming endeavours. The soil in Keyline philosophy is never cultivated by turning the earth upside down. Cultivation is only undertaken using modern versions of the forked stick of ancient agricultural practices. The Graham Chisel Plow was used for years for Keyline soil development until we developed, in the 1970s an ef ficient and practical implement, capable of effective subsoiling as well as ful filling the role of a chisel plow. This implement reached deeper into the soil than a chisel plough but with considerable less soil pro file disturbance. The resulting improvement in soil fertility, with either implement not only increases crop yields and food production, but also simultaneously reduces costs. Additionally, less water is required if irrigation. For more on subsoiling see EXTRA:THE FORKED STICK AND THE SUBSOIL PLOUGH in PRIORITY ONE Chapter 8. Soil is never homogeneous even if it appears so. In any soil, individual bits randomly clump together and form crumbs or aggregates. The better the soil, the greater the quantity and mass of aggregates within the soil. The bits in the aggregates tend to hold together much more tightly than the assembled aggregates hold to each other. The degree of aggregation de fines “soil structure ”. Soil aggregates however, can easily be broken up and destroyed by tumbling in a cement mixer. Either wet or dry, the aggregates break up. Excessive soil cultivation has the same effect. Land is sometimes cultivated several times to produce a “fine seed bed ”in which to sow. This is a mistake. It is a harmful practice and is being abandoned. Edible crop seeds germinate within soils when humidity levels are high and air is available, not in water saturated soil. However, in any crop preparation prior to planting, at least one cultivation is required, both to loosen compacted soil and act as a weed killing operation. The much-publicized arguments promoting the concept of “minimum tillage ”is primarily an argument that the weed killing cultivation should be abandoned and herbicides be used to control weeds. In the so-called “zero tillage ”concept, crops are supposedly to be grown using only seed and chemicals. Many farmers have tried zero tillage but found (as one might expect)it doesn ’t work. The shape and the size of the aggregates in soil vary considerably. They are typically the size of very small pebbles. The spaces between the aggregates (called pores)can fill up with air and water. If the aggregates hold together well and resist crushing, and have a good general shape so that the pores form nice little connecting channels, then the soil is said to have a good “structure ”. The tiny fibrous roots of plants and grasses love to meander down through the maze of passages in a well-structured soil, hunting for nutrients. All those little pores and channels have the ability to hold water. The volume held is termed the “field capacity ”. Field capacity is de fined as the measure of a soil ’s capacity to retain water for plant use. Retention is a critical factor so field capacity is usually considered as the volume of water retained in the soil a couple of days after heavy soaking rain. It is what is retained after excess water has had time to drain away. Field capacity determines how long soil life can function and operate ef ficiently before another rain shower becomes essential. Rich, humus-laden soil has excellent field capacity. Poor soil has very little. Sand has almost none. Organic farming and Keyline farming practices massively increase field capacity, thereby decreasing rainfall and irrigation requirements. To initiate the soil building process in Keyline (and in any natural fertility enhancing process), it is first necessary to grow a “crop ”of almost any form of vegetation. That crop dies, drops litter, or sheds root matter, which in turn decomposes to become soil organic matter and ultimately stable humic acid. The crop need not necessarily have accepted commercial value. It only needs to be voluminous and readily decomposable. The use of limited quantities of chemical fertilizers, such as lime or superphosphate, to stimulate the volume or mass of that initial crop is, unlike strict organic farming mandates, perfectly acceptable in Keyline development, but only in the first year. After that, chemical fertilizers must be avoided to ensure a rapid increase in active soil life. It is acknowledged that ef ficient biological soil development processes are impossible with continuing high chemical use. If not constituting the first crop, then grasses and legumes should be utilized in the second growth phase. This second crop has de finite commercial value. It can be eaten off periodically, or it can be regularly forage harvested. Keyline concepts beginning in the early 1950s have consistently advocated the overstocking of con fined grazing areas for short periods such as a few days, then moving the stock animals onto a new area to produce a constantly decomposing mass of root matter. This procedure is discussed in Chapter 8:HOW WE CREATE FERTILE SOIL TO STOP GLOBAL WARMING. This same procedure has just recently been adopted and promoted as “cell grazing ” or “rotational grazing ”by the new “holistic ” agricultural consultants. Cell grazing concepts however, form only part of the broader concepts of soil fertility enhancement. The development and enrichment of fertile soil are processes that have been known for centuries. Keyline soil enrichment systems merely streamline the process. Organic farmers are usually familiar with the general techniques. In Keyline the soil building process is accelerated by subsoiling with an implement that guarantees minimum soil layer disturbance. This is then coupled with rotational grazing and, ideally, with low cost irrigation. The objective in Keyline is to always make the creation of healthy fertile soil a pro fitable endeavour for the farmer. There are several facets of Keyline. Over the years since its inception many have been adopted singularly and have proved pro fitable even in isolation. Farmers have adopted Keyline layouts for rainwater collection, storage, and irrigation,

especially following the successful trials on Keyline techniques by Sydney University at their McGarvie Smith Animal Husbandry experimental farm at Badgery ’s Creek NSW in the 1960s. The University very successfully promoted the Keyline concepts as a form of “water harvesting ”. Although Badgery ’s Creek is in the same county as Yobarnie and Nevallan, the soil types are not absolutely identical, but the University found the bene fits indeed were. Here in Australia I am often asked, “Have Keyline concepts been taken up by many farmers?”. Yes they have. Over the last fifty years I have seen Australian agriculture change dramatically. Many of the facets of Keyline have now become “conventional ”agriculture in this country. We see Keyline concepts and philosophies adopted everywhere. We see it in the establishment of tree belts, the design and location of farm dams, the general use of contour drains, not to supposedly prevent erosion, but to convey water to and from farm dams and to flood irrigate from these drains. We see it in the widespread adoption of non- inversion tillage practices with the widespread use of chisel ploughs and the heaver subsoiling ploughs developed from them. We also see farmers minimizing or often eliminating their use and reliance on agricultural chemicals. This change has come despite considerable resistance by the Australian soil conservation establishment to most of the concepts of Keyline thinking. It is a marketing reality that big money talks. In consequence, and by a variety of means, government agencies everywhere are coerced by the agrochemical companies into listening to and accepting almost as gospel, the promotional material the companies produce. Most governments now accept the fabricated concept that bene ficial agriculture totally relies on and is dependent on, high chemical inputs. Such indoctrination unfortunately prevents both the enrichment of the world ’s soils and the entrapment of carbon dioxide into them. In addition to their use in agriculture, Keyline topographical concepts have been included in several university architectural and town planning courses in Australia, the concept being that the layout of large-scale subdivisions and even whole towns could be planned based on the concepts. Keyline concepts and designs are becoming increasingly widespread as time goes by. Professor Stuart B. Hill, Ph. D. , who holds the Foundation Chair of Social Ecology at the University of Western Sydney, and Martin Mulligan, a lecturer in that faculty, and who is also editor of the journa