Regularities are characteristic of any technical facilities and processes. TRIZ states that considering long time periods will help to trace the so-called “Expansion-Trimming” pattern in the field of technology (Fig. 1).
The “Expansion-Trimming” pattern describes the life cycle of a technical system starting from its appearance to its replacement with a new system which performs a similar function.

The following steps can be identified within this pattern:

1. Formation of a functional core of a system or process
2. Introduction of one additional object or operation into a system or process
3. Introduction of several additional objects and operations
4. Formation of a full expanded composition of a system or process and providing their satisfactory working ability
5. Removal of one object or operation from a system or process
6. Removal of several objects or operations from a system or process
7. Transition to a maximally trimmed system or process

At the expansion stage, the number of elements, parts, and subsystems of a technical device (or, correspondingly, the number of process operations) grows. It is the complication stage. At the convolution stage, they combine into an integral construction or a set of process operations is reduced to a single operation, the machine or process becomes simpler.

The “Expansion-Trimming” pattern can be traced in all fields of technology. Let us illustrate it by the example of the car body evolution. 

First cars were ordinary carts equipped with an engine and control system. In terms of TRIZ, it was the functional core of a car. Such cars practically had no cabin, the function of which was performed by separate elements: a frame, seats surrounded by a low side (Fig. 2).

The design of first cars was expanded by introducing new elements – carries of additional functions. The necessity to move in the dark led to the appearance of head lights. The roof and windshield appeared as a protection against weather effects. By the thirties of the last century, the car design had acquired practically all elements of the modern car. 
Since that time, designers’ efforts have been mainly directed at trimming the car design elements (of course, the process of increasing the number of functions has not stopped but this trend has lost its leading role). The roof and the cabin were combined into a single unit. The headlights lost their own housing and its function was also taken by the car body. Then the cabin was combined with the fame and there appeared an integral body – the main part of the modern car.

A similar regularity can also be traced in the evolution of soil cultivation processes.

1. Hole sowing

When people started growing crop plants, there was no question of tilling implements. Seeds were thrown into holes made by piercing soil with a pointed stick. Soil disturbance was minimal. As a matter of fact, it was zero till at a low, primitive level. Weed control and fertilization were realized by the simplest method – by burning the wood to free space for a future field. Weeds burnt down and wood ash was an excellent fertilizer.

 

2. Plowing without soil furrow slice inversion

The population of the Earth was growing so the need for food was also growing. The next step in agriculture was invention of a wooden plow drawn by people or animals. Using the wooden plow increased soil cultivation productivity but the grain growing technique itself underwent minor changes.  Instead of holes, seed were sown into a narrow furrow made by the plow edge. The furrow was closed manually or by pulling a snaggy branch on the field – the prototype of the modern harrow (Fig. 3). Weed control and fertilization did not suffer any changes – fortunately forests were still in abundance.

 

3. Plowing

The plow was an effective implement as long as it was possible to burn forests for clearing and fertilizing new fields. That, however, could not be endless… The soil fertility on long-used fields was degrading. A new method of increasing land productivity was found – soil loosening and weed control.  Already in Ancient Greece, they used a moldboard plow which plowed under weeds to a depth from which they could not come up. The classical technique of that time which included plowing with a moldboard plow, manual sowing and harrowing for closing seeds was much more advanced than swidden farming.

4. A maximally expanded soil cultivation technique

Productivity increase remained the most urgent demand and the extensive way of farming evolution seemed to be the only one acceptable.  More and more operations were being added to plowing in accordance with the “Expansion-Trimming” trend. The most expanded technique used in the middle of the 20th century included plowing, several cultivation cycles, harrowing and pre-sowing leveling. They were followed by sowing and additional compacting of soil.  Tractor power, plowing depth and plow coverage were permanently growing. Plows themselves were permanently improved, there appeared plows for smooth plowing which did not form a backfurrow. Tilling implements were combined into hybrid devices similar to cars in complexity and cost. It seemed that a signal victory over nature had been secured.
Yet it was a Pyrrhic victory. Huge resources were spent, first of all oil; labor input in soil cultivation exceeded all conceivable limits. As a result, the upper layer of soil became fluffy while the layer below the plough-pan was strongly over-compacted (Fig. 4). In flatland regions, wind often came and the fertile soil layer was carried away from fields remaining a desert behind itself. Dust storms became the whip of farmers, soil erosion spread on tens of millions of hectares. The content of humus in the best black earth fell from 10-12% to 5-6%. Farming agriculture came to the deadlock.

The damage caused by plowing became obvious and advanced-minded people sounded the alarm. As far back as the beginning of the century, Ivan Evgenievich Ovsinsky, a man of intellect, said: “The famous Krupp with his shells did not cause so much damage to mankind as one factory for the manufacture of deep plows did.”
What is harmful about the plow?
First of all, the fact that the shellboard turns over soil yet soil is not just earth but a complicated living organism. Its upper layer is inhabited with bacteria which breathe oxygen; they are called aerobic bacteria. Bacteria living deeper in soil die in the presence of oxygen, they are called anaerobic. When a soil layer is turned over, bacteria which can only live in the upper layer find themselves deep in soil and die because of oxygen deficit while bacteria living deep in soil are moved to the surface and also die. And the life activity of these bacteria ensures soil fertility and accumulation of humus in soil.
Another problem associated with the plow use is the formation of a plow-pan, that is, a layer of overcompacted soil formed at the depth of 20-25 cm. In normal conditions, soil breathes: moisture permanently moves in capillaries. At a reduced atmospheric pressure, it is supplied from the soil depth to the upper layers; a growing pressure causes moisture to move deep into soil. When the plow-pan blocks soil capillaries, moisture circulation in soil ceases and yield drops.

 

5. Boardless cultivation

It was the American researcher Edward Faulkner who declared to the whole world about the problems related to the plow use (“Plowman’s Folly”). The book immediately became a bestseller.
A persistent struggle for the introduction of boardless cultivation started. The new soil cultivation method excluded the use of a moldboard plow. Soil was cultivated to the depth of 10 to 15 cm with subsurface cultivators having wide horizontal undercutting blades or chisel plow having pillars provided with narrow end pieces (Fig. 5).

From the viewpoint of the soil cultivation process, convolution started. The key, extremely power-consuming operation – soil layer overturn – was excluded. Adherents of the new method worked in different countries of the world. In the Soviet Union, this struggle was particularly difficult because science and ideology were intertangled. Many supporters of the new method did their best to introduce non-plow tillage. The leader of this movement was the know agriculturist Terenty Maltsev. A titanic work on the introduction of non-plow tillage was done by the secretary of the Poltava Regional Committee Fedor Morgun. There were also other enthusiasts. They used to forge agricultural implements in their rural blacksmith shops, bring them to the fields in secret, get high yields and be punished.
The technology was gradually perfected and its “childhood” diseases (the main of which was the necessity to remove weeds without plowing in) were gradually overcome. This problem was solved by inventing “smart” herbicides which decomposed into harmless components some time after application. 

In the second half of the 20th century, a rapid development of boardless plowing started in many countries of the world, first of all in the USA and Mexico. It resulted in better plant growing and development conditions in fields, fuel saving, and soil preservation. All this led to a strong growth in yields, reduced labor consumption and product cost. What is presently called a “green revolution” took place, and that revolution was successfully missed by our country.

 

6. Minimum tillage
The next step on the way toward the soil tillage convolution was the transition to the minimum tillage when the soil tillage depth is equal to the seed covering depth, that is, the soil tillage depth is much smaller than that obtained by moldboard plowing.  The main theses of this technology were developed by the Ukranian agriculturist Ivan Ovsinsky in the middle of the 19th century. His ideas were strongly criticized. Nevertheless, Ovsinsky created special implements for shallow tillage of a soil layer and successfully used this method on his own farm. Harrows of a special design could mill the upper layer of soil together with vegetation. A kind of blanket was formed which reliably protected soil from the sun and frost, retained moisture and formed a comfortable bed for seeds. 
The new technology solved an entire complex of problems: it preserved the black earth fertility, helped to cope with droughts and remove pests and weeds. In addition, it abruptly reduced energy consumption.

 

7. No-till

The minimum tillage was naturally replaced with zero tillage (no-till).
The no-till concept has much in common with the TRIZ definition of an ideal system. Ideally, zero tillage does not imply any action on soil but, at the same time, soil is in an optimal state for plant growth and development. Due to the equilibrium between grasses, crop plants and microorganisms included in the biocenosis, the required human work is reduced to minimum. Today, zero tillage is the absence of tillage except for the action produced by the sowing-machine (Fig. 6).

The zero tillage of soil is not tillage in the common sense of the word. It is rather the provision of conditions for obtaining the optimal structure of soil. That is, tillage is absent but its function is delivered.
Thus, we have arrived at the point we started from, the evolution pattern is not finished at this stage (Fig. 7). Further, it is necessary to expect some new expansion principles of soil cultivation technologies. What it is going to be – tank-farming, biomass growing and processing into foodstuffs – will become clear with time.

Meanwhile, we have a classical spiral coil. The soil cultivation technology has passed the maximum expansion stage, people have seen that it was not as good as they wished. Now soil cultivation is living through a period which, in a certain sense, is similar to the first human experience on first primitive beds… This experience, however, is comprehended on a new level.
And one more thing. Looking at the evolution pattern on page 11, one can notice an interesting though disputable regularity.
Considering the soil cultivation technology evolution, one can notice that labor input is obviously decreasing. Is it really so? Perhaps, reducing the load on a worker, tractors, sowing-machines and soil itself is only possible by one method – by replacing physical labor with intellectual work.  And the total amount of work seems to be constant, just its main portion is moved to the virtual space, to the supersystem. For example, to provide non-plow weed control, it is necessary to invent and manufacture special substance for eliminating weeds which would be harmless to crop plants and man. In this case, hands are of no use, it is head that can help.
Most probably, the evolution of machines and technologies is based on a kind of labor conservation law and the cumulative labor input remains constant.

It would be interesting to calculate more precisely…

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You may find more information about technical system evolution, patterns and evolution trees in the book “TRIZ. Analysis of Technical Information and Generation of New Ideas” by N.A. Shpakovsky published by the Moscow publishing house “Forum” (www.mdk-arbat.ru/?book_id=647809). The book is dedicated to the use of evolution patterns for technical system transformation when solving inventive problems, circumventing competing patents and forecasting product evolution.