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  KEYLINE discussions so far have been concerned with the land areas that contain valleys. The prime purpose of the lines of cultivation on the Keyline principle is to counteract the natural rapid concentration of rainfall into the valleys by an induced drift out of the valleys. At the same time the particular type of cultivation discussed in Chapter 4 enormously increases the absorption of rainfall into the soil and effectively uses this rainfall for progressive soil development.

  It is a practical impossibility to plow accurately on the contour unless every travel line of the plow is level pegged as a true contour line. This would require hundreds of lines of instrument levelling in every small paddock. When contour cultivation is attempted it must drift mainly off the contour. Contour lines are rarely parallel to each other. They are never parallel in undulating country.

  Keyline cultivation, although it may start on the contour, is soon "off the contour" by this parallel working. It is this off-the-contour effect that is controlled in Keyline in order to counteract the natural concentration of rain water in valleys.

  This controlled, and completely effective, drift-off-the-contour of Keyline cultivation is as fully applicable to areas of land which contain no valleys or depressions.

  A paddock area with an even slope in one general direction is best developed from a Guideline located as high in the paddock as possible, and one that still gives a line of sufficient length to serve effectively as a guide for Keyline cultivation. Cultivation parallels this Guideline down the slope. The small areas left above this Guideline are cut out in any convenient manner. If such an area contained small erosion gutters they would be cured by this cultivation method.

  Another paddock without a valley may have one side of the paddock steeper than the other. It may be necessary to drift the moisture in one direction while under different circumstances the opposite may be advisable. This can be done by Keyline cultivation, as illustrated in Maps 7 and 8.

  Map 7 illustrates a paddock area containing a steeper side, "a" and a flatter side "b". Assume that the area "a" is partly eroded and the whole paddock is to be Keyline improved. It will be necessary to counteract the fast run-off to the south-west from this area by an opposing drift in cultivation furrows away from this direction. A Guideline is located, the lowest suitable in this instance, and Keyline cultivation parallels this line up the slope of the land, as illustrated by the parallel lines of Map 7. These lines have a drift away from the natural run-off direction. Protection and development are thus secured.

  We can now assume an opposite problem on the same area. "B" in this case is wet or swampy and "a" is very dry. A drift towards "a" of the surplus moisture of "b" is desired.

  A Guideline is located in the highest, suitable position and Keyline cultivation parallels this Guideline down the slope of the land, as in Map 8. The surplus moisture of "b" now has a "drift" to the dry area "a", with the effect that both areas are immediately improved. The small areas left out of this parallel cultivation are worked out in any convenient manner. They will not affect the effectiveness of the work.

  The sour wet area "b" is properly aerated for rapid improvement and surplus moisture drifts to the area "a" to improve it. Surplus moisture in these circumstances may drift along the tine furrows underground away from "b" until this area is left nicely moist, as distinct from wet. Moist soil-not wet soil-produces healthy pasture growth.

  With an appreciation of the astounding effectiveness of Keyline cultivation and some experience of its use, it will be found that relative moisture content of problem land can be adjusted at will by the astute use of Keyline's off-the-contour type of cultivation.