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13. Weedless Farming
I AM fully aware that it seems fantastically improbable to say that we should ever be able to farm land without trouble from weeds. Weeds have been keeping farmers busy for so many generations that they are taken for granted. In all of our farm planning, we have regarded weeds as a necessary evil; and moralists may even consider that weeds are a blessing, for the work necessary to check their growth keeps farmers out of mischief.
Thus unthinkingly we have accepted weeds as inevitable. But perhaps they are not inevitable. Perhaps they may be more vulnerable than we think. Like every other living thing, each individual weed must die at some time. None is everlasting, although there are some species which survive several years when undisturbed. In order to perpetuate itself, every species must have the opportunity to reproduce. If reproduction is prevented, the species can be eliminated.
It so happens that the majority of weeds that give trouble on farms are annuals; that is, they must originate each year from seeds produced by a previous generation. Since these annual weeds must propagate each season from seeds, it is obvious that the surest method of eliminating them from farm land is to prevent them from reaching maturity. The next season there can be no successors to those that were disposed of before they had borne mature seeds. Nobody will disagree with that statement, but everybody knows that the problem is not as simple as that, regardless of how logical it may seem. We all know how faithfully farmers work year after year to keep their land free of weeds; and yet weeds are perpetuated on the land of the most careful farmers.
Even this situation, however, is not as mysterious as it has always seemed. Without realizing what we were doing, we have buried weed seeds for future recovery every time we have ploughed the land. This statement may reveal the secret of weed perpetuation. We can cultivate a corn field as long as the cultivator can pass over the corn without damage, but we must stop as soon as use of the cultivator would break off the stalks. After the cessation of cultivation, there is a period of several weeks during which any weeds that have been missed in the cultivation can mature. All such weeds bear seeds. In addition, there are apt to be seeds -- brought by that final cultivation into a position suitable for germination -- that will germinate, and produce more seeds in the half-light of the shaded cornfield. There should be less mystery about how weeds manage to perpetuate themselves when we realize that they do their most effective work in a field after we have stopped trying to fight them.
If the land is ploughed after the corn has been harvested, millions of weed seeds per acre may be buried by the plough; but seeds that were buried by a previous ploughing will be brought to the surface. Perhaps the weed seeds brought back to the surface this time will be those that were ploughed under three years before after the last hay crop was cut. Although the land lay "idle" after the hay was harvested, it was producing ragweed, pigweed, smartweed, foxtail -- a dozen different kinds of annual pests of cultivated fields. The seeds, after three years of burial, are now ready to germinate; and the plants they produce will create the necessity for cultivating the corn that is to be planted.
Thus, every time we plough the land, we create a new reserve of buried weed seeds which, at the next ploughing. we resurrect. A vicious circle results. As long as we continue our present system of ploughing the land, unless we adopt drastically different weed-control methods, we are continually undoing, at each ploughing, whatever good work we started after the previous ploughing. Again it may be said that we are the victims of our own system of handling the land.
Such conditions need not continue. Indeed, we can arrest rather abruptly the propagation of annual weeds in our fields if we do not alternate the base of operations every few years. By refusing to disturb the seeds which we buried at the last ploughing, we will avoid creating the conditions favourable to their germination. Those seeds, on the other hand, which are placed in favourable position for germination by the act of discing in a green manure crop may be controlled with reasonable ease.
It must not be assumed, however, that a single field, properly handled with reference to weed control, will eliminate the possibility of weed growth, for seeds and fruits are wind borne in many instances. Success thus presupposes the application of controls by farmers generally over a considerable area. For the same reason, school lots, public lands, and all other similar holdings must not be left out of account. Weed control on a single plot will show very positive results, but as long as surrounding plots are contaminated to any considerable extent the labour of eradication must be continuous.
Here are my suggestions for eliminating weeds:
Seed the land to a green manure crop: rye in the autumn or a suitable summer crop in the spring. Let the green manure crop grow until it has reached the proper height to be worked into the soil with the available equipment. If weeds growing in the green manure crop begin to bloom, it is important that the crop be put into the land immediately. However, few weeds mature quickly enough to rush the incorporation of the green manure. Under almost all ordinary farm conditions in the humid section of the country, it will be possible to grow a winter crop and a summer crop, put each into the soil with its accompanying immature weeds, and in a short time bring about fertility of the soil and at the same time help rid the land of the weeds that create the necessity for cultivating farm crops.
In this discussion rye has been mentioned prominently and often -- not because rye is the only crop for green manure, but because it is more suitable for a larger area of the country than any other winter-growing crop. Many other crops may be used with equal success. In sections where other crops are as good as, or better than, rye, such crops should be used. Summer crops. too, can be varied to suit the climate or the farmer's pocketbook. If a farmer has millet seed, it would be poor policy for him to trade it for soy beans for use as a summer green manure crop. It should be remembered that when these green manure crops are disced into the land instead of being ploughed in, they are able to use air nitrogen just as well as the legumes do; therefore, there is no reason to prefer a legume for green manure. If the farmer has no seeds of any kind and the land is covered with weeds he can disc them in before they are mature and thus have adequate organic material. Anything that will rot will be advantageous when disced in and will improve the soil for the production of the next green manure crop.
It is impossible to determine in advance how many crops will have to be put into the soil before the land will begin to look black again; but discing ought to be continued until that point is reached. A rapid succession of summer and winter green manure crops should be used until the soil becomes highly granular and absorbent. It is difficult, also, to predict how many crops of immature weeds will have to be put into the land before the green manure crops will be free of weed growth, but the desired condition will be realized eventually. Inasmuch as the same few inches of soil are affected by each successive discing, every weed seed native to the soil zone chosen will finally have sprouted. Thereafter weeds will be produced only by those seeds which are wind borne or transported by other means to the area under treatment.
The eventual elimination of much farm work can be predicted on the assumption that weeds can be controlled. If weeds can be so controlled that the farmer's crops are not forced to compete with them for the plant food in the soil, then it goes without saying that no cultivation should be undertaken. There are important reasons for this, the most obvious one being that, since plant roots tend always to develop very near the surface of the soil, cultivation cannot be accomplished without cutting these roots. Destruction of plant roots is definitely not beneficial to the plant itself; therefore, if the plants are free from weed competition, to stop cultivating farm crops will be mandatory.
Crop rows are customarily spaced three to six feet apart, partly to permit the destruction of weeds that spring up between the rows. If few weeds are going to spring up, then it is obvious that the rows in which crops are planted may be spaced as close together as the supply of available food in the soil will permit. Ordinarily plants are placed closer together in the row than the rows are placed to each other. Potato plants are usually placed twelve to eighteen inches apart in the row, but the rows themselves are three to four feet apart. Without weeds to interfere, potatoes may just as sensibly be spaced eighteen inches apart each way. The ideal arrangement would be to space the plants close enough to each other that their roots would completely occupy the intervals. This would prevent the loss of nutrients which otherwise would be released by decay into soil unoccupied by roots.
One important fact deserves consideration at this point. Living plants require in their growth, and their dead bodies contain in their substance, only about one-tenth as much material by weight from the soil as they do from air and water. The contribution of the soil, then, to 100 bushels of corn weighing 5,600 pounds would be only about 560 pounds. Even if the entire 100 bushels were produced on one acre, the grain itself would take from that acre only 560 pounds of material. If 100 bushels of corn should be burned, the resulting ashes would weigh about 560 pounds. Therefore, it is evident that the growing of crops cannot be unduly wearing on the land. If, as indicated in Chapter 11, we can use soil acids formed in the decomposition of organic matter to obtain minerals, and the native bacteria of the soil to pull in nitrogen from the air, the production of crops several times as abundant as we have grown is just a matter of sensible technique. Properly handled, farm land can be just as self-sufficient as the soil of the natural landscape has always been, because, when properly handled, farm land will be maintained in approximately the same physical condition as soil always is in Nature.
The theories presented in this chapter have not been fully demonstrated, but experiments are under way at the present time to test the truth of the statements. No prediction can be made now as to when the experiments will be completed, since there is no basis for knowing positively just how long a time it will take to empty the upper few inches of soil of its stock of weed seeds, or when the soil will begin to look black again. My guess it that two to five years will be necessary. In the meantime, the succession of green manure crops will be planted twice a year and disced in before the weed seeds have matured. Then we shall be in a position to speak of the "when" as well as the "how" of weed control.14. Mother Earth Can Smile Again
IN the preceding chapters the mouldboard plough has been shown to be the villain of the world's agricultural drama. In the United States it is suspected of wasting from the ploughsole enough plant food to sustain crops with which to feed half the other peoples of the world -- a suspicion based upon official reports. Elsewhere the record is less clearly defined; for nowhere else are mouldboards of the sizes common in the United States in general use. The "bigger and better" the plough, the more devastating its effect.
When this appraisal of the plough has become official, as eventually it must, American agriculture will undergo drastic revision. It is hardly possible to make a blueprint, or even to hint at one, in terms more trustworthy than the usual perspective of greener pastures elsewhere. In this spirit, therefore, I undertake now to forecast some of the changes that are likely to result from the new agricultural scheme.
The pastures of the land will be greener, literally; crops will grow in better fashion, with immeasurably less attention than they have customarily been given in the past, the vitamins and minerals our foods used to contain in abundance will again be present in similar measure, and in consequence we shall undoubtedly be healthier, some of the tensions of civilization will be relaxed, and our lives should be more comfortable.
This is the favourable aspect of the picture. That the benefits will not be the same for all people, especially in the initial phases of change, is a perfectly admissible deduction from history. Technological change always brings temporary maladjustments; from the individual standpoint, they may even be considered disasters. Thus, when we begin to apply our new agricultural principles, which acknowledge the co-operation of the eternal forces of growth against which we have hitherto been working, many people will be adversely affected. The position of some of them will be made almost completely untenable, until the wisdom of government has found a satisfactory solution.
The swiftest and most perceptible disturbance will occur in the economic field -- specifically, the price structure of unprocessed farm commodities. As soon as crop yields several times as great per acre as our customary averages begin to come into the world's markets, prices will decline. This does not mean necessarily that those who practice the new agronomy will be the losers; their cost of production will be so low that their position will be greatly improved. It does mean, however, that those who do not take advantage of the new methods will suffer, and those who are now considered marginal producers will lose out entirely.
Moreover, renewed thought will have to be given to the so-called economy of abundance. There is such a thing as an upper limit to the amount of food that can be consumed by the population of the United States and by the now undernourished populations elsewhere in the world. For this reason, as the new methods of agriculture are applied generally, it may be found necessary to reduce the acreages devoted to staple food crops. It is not at all unlikely that the farmer whose land produced five times as much the first year, under the new methods, may realize a tenfold increase the second on the same land. Such possibilities preclude any prompt and completely effective economic curbs by acreage reduction. What would the farmer do with the acres withdrawn from the production of the given crop? Up to this time he has been told to devote the surplus acres to land-improving crops. If the basic principle of the new agricultural method proposed in this book is recalled, it will be clearly seen that the older methods of land improvement do not apply. Hence the impasse that appears when we resort to traditional methods of meeting the threat of crop surpluses.
Part of the result will be that the chemurgists are given an opportunity to take over and find economic uses for large areas of land that will not be needed for the production of food crops. Since, under the methods proposed in this book, the land so utilized will produce raw materials for the chemurgist at a mere fraction of the previous cost, vast opportunities are open to those who perfect and bring into production the countless products and commodities for which there will be a ready market among producers and consumers of fabricated goods.
In this connection, it must be remembered that we have literally been living on borrowed time. Consider the rate of the use of forests. If we have used far more timber than Nature can allow us for such traditional things as we know, it is likely that the new uses which have been developed in the last ten years will exhaust our available timber at an even greater rate. The outlook for wood plastics is very intimately connected with the prospect that, under newer agricultural practice releasing land from food crops, we shall have areas which can profitably be returned to woodland.
Petroleum reserves, too, have been distributed with a lavish hand. That our large coal reserves might supplement our dwindling oil reservoirs is scarcely as happy a thought as the possibility that surplus lands may be used for the production of materials easily distilled into fuels. And from this comes the easy corollary that the waste products from the refiner's retorts might be restored to the land as fertilizer. We should then experience a condition which the world has never before known in connection with the land -- soil cropped annually without loss of virtue. For it should be clear by now, from the contents of this book, that cropping can build soil instead of destroying it.
Other influences will operate to modify the American landscape. With the invention of suitable mechanical equipment for use by the suburbanite in coaxing from his home site the foods his family needs, a gentle transformation of urbanities into suburbanites may be expected. There is nothing new about this, of course, except that what has heretofore been a fancy which could be indulged only by the well-placed may be open to the many. Thus, the decentralization of populations, urged for reasons of individual health and efficiency by industrialists and for reasons of defence by military authorities, may well become a reality. The beneficial effects on American civilization are sufficiently apparent to obviate discussion of them.
It is not enough that we should have in prospect supplies of food which would eliminate man's historic worry about shortages. With cheap production of foodstuffs, we should be able to look forward to the lowest-cost standard of living. We in America have hitherto boasted of the "high standard of living", but we have neglected to interpret that claim in the light of what our achievement has cost us. Food and other products of agriculture have figured prominently in the high costs of our present living standard. There is an intimate connection, moreover, between the cost of man's bread and the cost of everything else he produces. Despite the rejection by economists and humanitarians (and justly so) of the so-called subsistence theory of wages, perhaps insufficient thought has been devoted to the disproportionate expenditures for the products of the soil and the relation of these to costs of operation in every other field of human activity.
If all the other benefits to be derived from a revitalized agricultural method could be dismissed, the one which would attract us still is the physical well-being of man himself. Foods are the sources of the vitamins, proteins, carbohydrates, and minerals by which man lives. He thrives or he fares ill in proportion to the availability of these essentials in the foods which are supplied him from farms and gardens of the land. Agronomists as well as nutritionists are aware that lands which have been exhausted of their essentials produce foodstuffs which are deficient in the end-products required by human beings. It is not too much to expect that, by the restoration of the vital ingredients needed by our lands for the production of lush, vigorous, healthy crops, the vitality of man himself may be enormously enhanced, his deficiency diseases greatly reduced or eliminated, and his life expectancy increased. This result, if no other were envisaged, would be adequate justification for a "new" agriculture which is in reality very old.
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