HOME AGLIBRARY CATALOG NEXT CHAPTER
KEYLINE Absorption-fertility cultivation techniques are so differentin their effects on the land cultivated from those generally employed that theirintroduction on farming land will be considered as a "conversion" of landto these new principles. The first year in which these new principles operate iscalled "Conversion Year".
The "conversion" cultivation has as its object the maximumpossible improvement in soil structure, soil fertility and increased soil depth whichcan be obtained from this conversion. For this reason the first application of thetechnique will be different in some respects from the continuous later process. Theconversion stage is to be profitable, much more so than extraction fertility methods.The continuous processes of progressive soil development are profitable both fromthe increase in quality and quantity of production and in the capital value of theimproving land.
Soil erosion is not considered as a problem in the process, simplybecause it is cured incidentally. There is no problem of erosion when its cure orsolution is made profitable to those directly concerned.
Ordinary crop land is discussed first.
The considerations of the last chapter indicate quite clearly someimportant details of the type of cultivation that is desired.
The first requirement is minimum surface cultivation, mixing whatevervegetation is available into the few top inches of the soil. Some subsoil or deepsoil is to be broken to provide capacity for rapid moisture absorption. With oxygenand the other vital elements absorbed, some of the subsoil is converted to live soil.This deeper soil is only broken, and none of it is brought to the surface. The deepercultivation is to leave an uneven bottom, not all cut out clean at the maximum depthof cultivation. The cultivation is to again unite the soil into a complete structure--nota topsoil divorced from the deep soil by a compacted layer.
The surface of this cultivation is rough, rather than fine, in orderto resist the sealing effect of heavy rain and to allow the rainfall to penetratequickly and deeply.
The finer materials of this surface cultivation lie below the levelof this rough surface. Surface wind velocity is thus reduced--moisture losses byevaporation are lowered.
The deeper cultivation conforms to the Keyline cultivation, whichholds excessive rain longer on the land and permits more complete absorption.
Rainfall is quickly absorbed into cultivated poor land, making itwet and heavy on the rough, uneven bottom of the cultivation. The heavy wet soilis effectively knitted to the land and resists substantial water flow if it occurs.
New Keyline Absorption-fertility cultivation is practically erosionProof; within a year or two of the resulting improvement to the soil, it is certainlyso.
The maximum depth of this conversion year cultivation requires someserious consideration.
In so-called shallow or thin soils, this cultivation is restrictedto a depth that can be converted successfully to an improved structure by the aidof the fertility in the top soil. Considering the top fertile soil as a yeast, itis likely that too deep a cultivation could restrict the rate of soil development.This happens if a large amount of vegetation is not available for stirring into thesurface cultivation. This type of soil rarely has a large amount of vegetation available.
The too deep cultivation of sticky clay subsoil is waste of time andmoney. It will seal immediately rain falls. There is generally little purpose andno profit in cultivating to depths that cannot be held by definite soil improvement.
A good general depth guide for conversion year cultivation is doublethe depth of previous ploughing for crop productions, that is, approximately eightinches deep and in the poorer soils seven inches deep.
The means and the implements available for conversion year cultivationare restricted greatly by two factors. The lines of Keyline cultivation cannot befollowed satisfactorily by mouldboards or disc plows, nor are these implements suitablefor the deeper cultivation that must keep the subsoil under the cultivated surfacesoil. They also produce the destructive even-bottom cultivation.
They can both be made to do the surface cultivation reasonably well,while another implement of the tine type, with wider spaced rows than the usual farmimplements, could complete the deeper cultivation immediately following. Some tineshapes will keep the subsoil down.
Mouldboard plows, with the boards removed, give a satisfactory cultivation,if the final deep run is done with some shears removed to keep these furrows widerapart.
Scarifiers or tillers both give a satisfactory surface cultivationto 4 inches, but the tine spacing and design render them unsatisfactory for the finalfull depth run.
Rippers will follow the lines of Keyline cultivation for the finalworking. It is unnecessary in surface cultivation to do this. The resulting cultivationis satisfactory but the cost with any rigid implement is much higher than it needbe.
The Graham Chisel-type Plow is the ideal implement for conversionyear cultivation. The following details of Keyline Absorption-fertility cultivationboth for conversion year and the cultivations in following years, are given for usewith this implement.
The standard shank row spacings of the Graham Plow are 12 inches apart,approximately double the spacing of other farm cultivating implements. The GrahamPlow is equipped with tines, spikes or chisels two inches wide, which are set at12-inch row spacings.
With a suitably power matched tractor and Graham, set the plow's depthto enable the tractor to operate without labouring at a good speed. Five miles perhour is recommended if the surface is suitable for this speed. When stumps are encountered,reduce the speed to 3 miles per hour. The "first working" should be 3 to4-1/2 inches deep. Large clods may result from a first cultivation which is too deepand could necessitate some special extra work to break them down. Plow three or fourparallel runs completely around the area, marking out the area for cultivation clearly.
The paddock area is then "cut out" on this first run byplowing backwards and forwards, turning in the series of parallel runs first madewithout necessarily reducing speed on the turns. The Graham will follow as fast asthe tractor can turn.
Plow a second complete run immediately at a long angle to the firstwith the plow now set deeper and travelling at the same speed. It is more economicalusually to regulate the increased depth to suit the speed and not the speed to suitthe depth.
This second plowing will sometimes give a suitable surface "break-out"and the necessary depth of seven to eight inches. If this is so, the second cultivationrun will follow the Keyline cultivation principle of Chapter 2.
Usually three fast cultivation runs using two-inch chisels at twelve-inchspacing are, necessary for perfect conversion year cultivation in poor compactedsoils. In this case the depth of the last run is set at seven or eight inches, asalready discussed.
This simple Keyline conversion year cultivation will commence a cycleof soil fertility that can be carried forward to greater soil improvement and willproduce a better than usual crop at the same time. It will also be effective in holdingthe soil against erosion.
This fast and low cost cultivation will start to improve soil immediatelyadequate rainfall is supplied. The natural processes of decay will, at once, go intoaction.
Poor heavy soil, that is soil low in humus content, should be watchedclosely after heavy rain against a possible surface sealing. If this is apparentthe area is given a one-run Keyline cultivation immediately the soil is sufficientlydry. The soil will improve only with adequate air. This first year is one of destinyfor this soil.
If a crop has already been sown, it is still often advisable to aeratethe sealed surface soil when it is dry enough by this one-run cultivation. The spikesshould be spaced at 24-inch intervals for this aeration cultivation.
The health of the soil, the progressive development of structure,fertility and soil depth, is of infinitely greater importance to the farmer thanany one crop. This outlook will, however, result in better crops all the time. Evena crop newly out of the ground and partly destroyed by a cultivation to aerate thesealed soil will usually yield better for this treatment.
Conversion year cultivation of poor soil is completed by not morethan three fast workings, each becoming progressively deeper. The last working, whichis seven or eight inches deep, is the only one which follows the Keyline cultivationprinciple. Spikes are two inches wide and the spacings between the rows are 12 inches.
The increased moisture of conversion cultivation will continue decayprocesses longer and thus obviate one of the difficulties of stubble mulch farmingwith disc implements, that of having too little moisture available for rapid andcontinuous stubble decomposition.
The changes which will take place in this soil which has been convertedto Keyline Absorption-fertility should be watched by the farmer. Only absence ofrain will restrict the working of the yeast-like process of soil development.
Examination of the underneath cultivation by removing a couple ofsquare feet of the plowed soil will disclose the deeper chisel final furrows thatknit the soil to the earth.
Make an examination a few weeks after the first good rain has fallen--seethe change--smell the soil.
Again when a crop is well grown--examine the deeper broken subsoil--noteits further changed condition. Fertility development in the surface inches will beapparent and the deeper broken subsoil will be changing into good soil.
When the crop is stripped, examine the condition of the subsoil againto get a cue to the depth of cultivation to be followed for the next crop.
If a change from the subsoil to a soil is definite, second year workshould be a little deeper. The increase should be an inch or two at most. This brokensubsoil is to be converted to soil, a little each year--progressively.
In subsequent years, following a successful Keyline conversion year,a single run on the Keyline cultivation will complete the plowing. Now spikes orchisels with weed knives attached are used. These weed knives operate three inchesbelow the surface, mixing growth and trash correctly into the soil for rapid decay.At the same time the chisels operate at the full cultivation depth, properly aeratingthe whole body of soil.
These weed knives, which are adjustable in relation to the 2-inchchisel depth, permit a progressively deeper year-by-year cultivation, with the knivesoperating at a fixed depth below the surface. The uneven furrowed type bottom andthe "completeness' of all the soil is preserved.
The rate at which beneficial decay will take place in the soil willvary with soils and climatic conditions. The rate of decay accelerates as a positivenew soil fertility develops. Decay of the incorporated vegetation of conversion yearcultivation will be rapid given sufficient moisture. Decay in subsequent years willbe much faster as the active life in the soil has been built up enormously as a resultof this conversion to absorption-fertility.
For a short time decay does tend to rob growth of some of its requirements.Both decay and growth require among other elements, moisture, air and nitrogen. Acrop sown immediately in conversion cultivated land may first grow weak and yellowedfrom the lack of nitrogen which has been absorbed temporarily in the processes ofdecay. With adequate moisture, air and heat, nitrogen will be available to the cropin a few weeks. The. crop will respond with a rapid growth of healthy green foliage.
A rapid fertility gain and almost weedless farming on this crop landcan be secured by cultivating immediately the crop has been stripped and again eachtime a growth of grass and weeds reaches its "full green" stage prior to.the weeds seeding. The use of the chisel and weed knives combination tends to germinateall seeds together, while "soil turning" methods of cultivation do not.The "soil turning" implements bury some seeds in a dry layer of vegetation,which prevents their germination until a later cultivation, thereby assisting thecontinuance of weed growth.
Weedless farming. may disclose that the present row spacing of seeders,which are close together to enable crops to partly choke weed growth, is too closefor best yields.
There is a growing well-informed body of opinion among practical Australianfarmers, that wider apart seeder row-spacings will give better grain yields whenweeds are not a factor.
The sowing of seed into conversion-year cultivation requires somelittle changes from the old orthodox habits.
it is of particular significance that sowing be done in such a waythat this new condition of the soil is preserved as much as possible. If an ordinarygrain combine is used, the cultivating tines, both the front and rear rows are removedpermanently, use being made only of the two planting rows. The soil will continueto be in a suitable condition for the rapid absorption of rainfall. The use of allthe tine rows on a combine may so "fine-up" the soil that it will causepuddling and washing. The use of the combine with all the cultivating tines removedwill permit rougher and trashier ground to be seeded.
Planting depth for grain will vary also, but generally seed shouldbe planted into the moisture zone and not shallow-sown with complete dependence onlater rain for germination.
Soils of good structure and fertility may be cultivated directly withthe chisel and weed knife combination. If surface cultivation ever appears to betoo fine, use the chisels only.
Cultivation of soil in very low rainfall areas should be accomplishedby a shallow surface cultivation followed by a final Keyline cultivation with thechisels two feet apart. An overall cultivation that is too deep on these soils willtend to lower the moisture zone too much for best yields. As the fertility of thesoil increases humus will protect the moisture and hold it at a more consistent level.
Once a normal rainfall season follows, or good rain out of seasonhas fallen on Keyline converted land, the moisture horizon will be more dependable.Continued year by year, Keyline Absorption-fertility cultivation will keep adequatecrop moisture available for longer and longer periods into dryer times. No doubtlater, on this "Keyland", one good season's rain will produce two yearsgood crops.
The low cost and fast operation of this method of cultivation is apparent.
Conversion-year cultivation will usually cost less in time and moneythan extraction-fertility methods. Following conversion -year, costs are about one-thirdonly of old cultivation habits.
Deep fertile soil, then, is built up for crop land first by conversionyear cultivation with an, increase in the depth of the chisel penetration each subsequentyear. The weed knives operate at approximately three inches below the surface. Infrom three to five years soil depth to the limit of the Graham's 16-inch is formed.
When this depth is reached, a further "wave of fertility"may be induced in this soil by reducing the penetration depth of the chisel backto approximately nine inches and adjusting the weed knives to operate deeper underthe surface.
Instead of three inches, as used in the first cycle of increasingdepths, they are used five or six inches below the surface. For the following twoto four years increase the operating depth of the chisels one to three inches eachyear, but adjust the weed knives to keep them five or six inches below the surface.
The effect of this second series of increasing depth cultivationsand increased weed knife depth is expected to add a greater depth of intensely fertilesoil. By incorporating or mixing vegetation into a greater depth of top soil thisshould be achieved. The soil should now be in a condition to "take" thissomewhat deeper mixing of vegetation, whereas in the first years it would have beenlargely lost as a fertility gain. At the end of this second cycle--originally poorsoils in reasonable rainfall areas may rival the most fertile soils left on the faceof the earth. I say "may"--I do not know--yet.