From the book, Farming for Profit, published in Springfield Illinois in 1947. Original chapter title, Necessary Equipment. The author dedicates this book to: Those who would profit at farming, and to Reuben R. Boynton, who helped me do so.
Since half of our population live directly or indirectly by agriculture, things that affect agricultural income quickly reflect in national economy. When soil is wasted by erosion or by being “over-cropped,” its potential wealth for future generations is ruined, and the buying power of people living upon that land declines; with such decline, a land’s production is forced down; accentuated, it brings about wide unemployment. It is essential for all of us, farmer and city dweller, to understand soil conservation and to do everything possible to practice it.
KINDS AND TYPES OF SOILS
There are three layers of soil: the topsoil, the sub-soil, and the rock formation. One type of topsoil is clay soil. It is impervious to root growth, useless for practical agriculture. It is only good for pottery making, for tile, or for other ceramic work. In wet weather, it is muddy and sticky. In dry weather, it is hard and flinty. Farmers in the horse-and-buggy days carried an axe in rainy weather to have handy to chop the mud from the buggy or wagon wheels when they got solid, as they often did in just a short distance. This was clay soil and poor farm land.
At the other extreme is the sandy soil. Water penetrates sandy soil so quickly that it carries away all fertile elements that are in solution. The surface of such sandy soil dries out almost immediately. You can walk out of your cottage on the shores of Lake Michigan or on Maryland’s famous Eastern Shore right after a storm and not muddy your white shoes.
These are the two extremes in topsoils. Between these extremes is the soil called loam. If it has more sand than clay, we call it sandy loam; if it has more clay than sand, we call it clay loam. That loam which lies halfway between these extremes is the most fertile and easiest to cultivate. However, a cupful of clay and a cupful of sand placed in your flower pot will not make the most perfect soil in which to plant your geranium. To this mixture must be added humus. Humus is decayed vegetable matter.
A farmer can add humus to his fields by plowing under corn, or clover fields, or even a growth of weeds and trash.
|After this farmer is done with the harvest, he will plow under the corn stubble to add humus to the soil. (Courtesy of the Oliver Corporation.)|
Humus makes a “dead” soil come back to life by increasing the number of bacteria that are working in the soil. It also keeps soil from becoming too compact and solid by retaining moisture.
Humus is so valuable to fertility that there should be a law forbidding any farmer to burn stalks, straw, or trash. It is often easier to burn than plow under but it should be plowed under. The only excuse for burning is in the case where bugs or disease have taken your crop. Even then I am not sure that it kills the bugs or cures the disease. To treat the seed with chemicals is a more effective way to combat the diseases than trying to burn the spores. And some bugs are so mean that not even fire will burn them.
For example, take the chinch bug. We were baling straw from a wheat field that was heavily infested with chinch bugs. A cigarette, carelessly thrown, started a fire in one corner of the field. Fortunately the wind was in the right direction. We got a plow out quickly and ran a furrow around the fire. Only a few acres of straw and a number of bales were lost. The baler and the rest of the field were saved. I gained a certain amount of satisfaction from the thought that, at least, I had killed some chinch bugs. But my satisfaction was short lived. I walked across the charred surface and the little bugs seemed to be just as thick as ever. In fact, the mountain of flame that had passed over them just seemed to warm them up and make them more energetic than ever.
You can change the fertility of the top soil. There is nothing practical a good farmer can do to change nature’s subsoil. If it consists of a hardpan of clay or a layer that is impervious to root or water penetration, your crop will become waterlogged. Outcroppings of rock are bad. They indicate a shallow topsoil with a bedrock for a subsoil. Here you find the springs or boggy places on the sides of hills.
For successful farming you should have a deep loamy soil with a subsoil having available moisture storage and good aeration and drainage.
One chief problem of today’s farmer—apparent even to his city cousins—is this matter of soil conservation. All of a sudden we are discovering the parasitic profligacy of our indifferent ancestors. While they cut down our forests, they did not plant others. The result: less wood; eroded land; vast floods. During World War I, experimentalists broke up the sod of our western grazing land to plant wheat. This resulted in tremendous—unbelievable—wind erosion and the Great Dust Bowl.
These were both great sins, but before we criticize others too freely, we should look at the way our own generation is depleting our reserves of iron and oil! This may result in a more serious future problem than those which confront us.
But our biggest job is to correct these errors of commission made by our parents and grandparents. EROSION CONTROL is a good place to begin.
Cover crop. Planting a cover crop (wheat, other small grain, or a permanent cover crop of grass or legumes) is the most valuable method of preventing erosion by wind or by water. The roots hold the soil and actually keep soil from blowing or washing away. Gradually more and more of us are reclaiming land by planting cover crops (see Table 4).
|Table 4. Information on Date and Date of Seeding of Those Crops Commonly Used as Winter of General Cover Crops.|
Contour Farming. Contour farming on sloping land prevents erosion. In preparing the seed bed and in tilling the crop, the plowman follows the contour of the land. Because each furrow forms a small terrace, water is caught and held. Although this looks difficult to the farmer whose father was a farmer, once your contour line is made, it is far easier to farm and at once requires less power than straight row farming.
|Working on the contour to prevent erosion, a spring-tooth harrow follows the disk in preparing the seedbed for corn. (Courtesy of Caterpillar Tractor Co.)|
Any farmer can lay out a key contour line. All he needs is a carpenter’s level, a small mirror, a man to hold the rod for him, and a bunch of stakes. At one end of his field and about one-third of the way down the hill, the farmer places the level on a tall stake and even with his eye.
The mirror is fastened to one side of the level to see the bubble more easily. The man with the rod moves across the field. At every twenty-five feet, the farmer sights him with his level and motions him either up or down. When the rod is straight with the level, the man puts a stake in the ground and then advances another twenty-five feet. Then, every one hundred feet or so the farmer has to move his level forward. The stakes mark the line of contour. It is simple, easy, practical (see Fig. 20).
|Fig.20 A guide in laying out key contour lines and establishing grassed waterways. (a) Position of men and instruments on hillside. (b) Close-up of the carpenter’s level.|
Strip Cropping. But if contour farming is not successful, strip cropping may be tried. Under this scheme, plant narrow strips of grasses or small grain between larger strips of corn or beans. For example, on a long slope that is not too severe, wheat, oats, or rye can be planted between the corn at the top of the slope, and the soybeans partway down. Then plant another strip of wheat and, where the ground levels off, plant corn again. Where the slope is more severe, alfalfa or lespedeza should be substituted for the small grain. Erosion is much greater in cornfields and soybeanfields than it is with more closely sown seed. Soybeans particularly loosen up the soil: As soybean planting over the country has increased in the last few years, our erosion has increased!
Terraces. And if neither of these methods are successful in holding the soil in place, terraces can be built. These are built with a special machine that resembles a road scraper. They are usually owned and loaned by the local farm bureau. But I see no reason why the road commissioner, if he has time, could not build a very adequate terrace with the machinery at his disposal. They are built close or far apart depending upon the severity of the slope and the porousness of the soil. They may be level or slope gently to a diversion ditch. Keep these diversion ditches sodded and clean. Sometimes merely grassed waterways will serve to carry the excess of water.
Grassed Waterways. A grassed waterway can be planted when the rest of the field is in meadow or clover. Then, when the field is plowed, the waterway is left in grass. It should never be less than twelve feet in width and usually it is better if it is wider. These waterways should be cut and hay made from the grass. This will make a better sod and leave a cleaner waterway. In fields where small ditches are formed every spring and fall to carry away the excess water, a grassed waterway is the best solution. Most farmers argue that such a ditch dries up and can be crossed most of the year. But there is loss of topsoil and the possibility of a gully forming, both of which can be prevented by leaving a grass waterway.
Dams and Barricades. If a gully has already broken through in a field, dams or barricades can be built across the ditch to catch the silt as it is washed down. This is as important as it is simple to do. If it is a gentle slope, say a quarter of a mile in length, as many as five or six barricades may be necessary. I think the best, cheapest barricades can be built with fence posts, old discarded woven wire fences, and brush.* But be sure the two outside posts are placed far enough apart across the ditch so that there is no danger of the water running around the barricade and breaking a new ditch through. * Even better, if not too expensive to haul: concrete from old city or county highways, boiler plates, concrete wedges.
Tiling. A good system of tiling will carry much of the water off under ground and help to prevent erosion. But tiling is not enough if there is much slope to the field. I had a field that was tiled that had two such deep gullies that it had to be plowed in three “lands.” I began putting barricades across those gullies twelve years ago. Two sets of barricades are completely buried by the soil that has washed down upon them and we have built a third set. No longer are they gullies. The tractor can cross them at any spot. But we plow across only one of them. The more severe one of the two, we do not plow: we still leave a grass waterway. And we continue to use the barricades because these spots are potential gullies even if they do look almost level.
Rotation of crops is practiced on all grain farms where the experienced farmer wishes to maintain or build up fertility of the soil, or control the growth of weeds and eliminate ever-increasing insects.
Incidentally, rotation makes for better utilization of farm labor and brings a cash income at different times during the year. (Farm aphorism number one: Never put all of your eggs in one basket if you wish to avoid failure.)
But a few years ago there was a time when all good farmers stuck to their fixed rotations. For instance, if they had a five year rotation of corn, corn, oats, wheat, and clover, they divided their farm into five fields and each field was planted to one of these selected crops. The next year it was planted to the next crop in this fixed rotation. And so two-fifths of your tillable acreage was always in corn, one-fifth—in clover, etc.
In Table 5 you will find many other popular rotations. But all rotations should contain a soil conserving crop, that is, a legume. A certain amount of flexibility was necessary in case of a crop failure. Your stand of clover might be poor (although even a half a stand should be left), and that might necessitate planting an annual and plowing it under green.
|Table 5. Popular Crop Rotations.|
But, in general, in the Middle West it was not too difficult to adhere to the crop rotation until we began to plant soybeans. Beans at first were looked upon by many of us as a soil conserving crop. But if they are cut for hay they deplete the soil, and, if the seed is taken, there is only a slight increase in nitrogen (see Fig. 30). It is only when they are plowed under green that they are soil conserving. But many farmers have set aside two fields, rotating annually corn and beans, and have carried another rotation on the rest of the farm. This has not proved very satisfactory.
While farmers were still experimenting with bens and trying to introduce them into a satisfactory rotation, the Agricultural Adjustment Act began to function. Its main object was to increase the soil conserving acreage and to decrease the soil depleting crops. In principle, this coincided with our ideas of good farming. But it was difficult to put into practice.
This act did not say that every farmer must plant 25 per cent of his acreage to a legume and that 50 per cent should be planted to corn and 25 per cent to another soil depleting crop. It was not so simple. A base was established for EACH FARM, arrived at by using the past history of each farm! So each farm increased its soil conserving and decreased its soil depleting acres. This handicapped the good farmer, for he was already practicing soil conservation and had had a large percentage of his farm in a soil conserving crop.
The other difficulty in complying with the Act was with the program in changing the size of the fields. Heretofore the farmer had tried to have his fields about the same size, usually in round figures. Then the A.A.A. gave him a corn base of, say, 37.8 acres, with another equally STRANGE FIGURE for wheat, and for clover, and for soybeans. What’s more, your allotment was changed every year and your fields were measured annually and there was a penalty for over-planting. The result was that in a few years your fields became very chopped up and uneven.
However, the program did a great deal of good in forcing the ignorant farmer (if he cared to participate in the plan, and it was made attractive enough by its cash payments to make it worth his while), to plant more soil conserving acres! This experience taught him the value of building up and maintaining the productivity of the soil.
Our entrance into the war brought not only the end of the A.A.A. restrictions on planting, but actually their encouragement to over-plant! This has hindered our resuming a fixed crop rotation.
But an organized and intelligent effort should be made to establish and carry out a good crop rotation. I have mentioned only the value of the soil conserving crop. Always remember, repeated planting of corn not only depletes the nitrogen in the soil but it encourages the growth of corn-root worms and aphids and increases the farmer’s chances for erosion.
Yet, on the other hand, a cultivated crop in your rotation is valuable. It will enable the farmer to keep the weeds under control. If wheat alone is planted, weeds that go to seed before the wheat is ripe will become very prolific.
In conclusion, all crop rotations should include:
1. A legume to increase the nitrogen.
2. A cultivated crop to control the growth of weeds.
3. As large a cash crop as possible.
4. Sufficient hay or pasture for farm animals.
5. Fields of equal size.*
* Government economists and best laid plans of the A.A.A. to the contrary.
USE OF ARTIFICIAL RESTORATIVES
Maintain or increase the fertility of the soil by using artificial restoratives to increase the soil’s organic matter: such as, commercial fertilizer and limestone.
Commercial Fertilizers. Commercial fertilizers may be individual fertilizer material* or may contain two or all three of the plant food constituents: nitrogen, phosphoric acid and potash. But because of their cost they are not generally used in the Corn Belt except by truck farmers. Truck farmers! Their plantings look good. Why not take a lesson? * Nitrate of soda, sulphate of ammonia, calcium nitrate, calcium cyanamide, and urea; rock phosphate or bones; murate of potash or sulphate of potash.
Practically: Nitrogen shortage can be more easily fulfilled by using legumes. The commercial nitrates are too expensive to be applied on large scale operations.
Phosphoric acid can be supplied by the use of rock phosphate or super-phosphate. It is expensive, too, because most of it is shipped north to the central and middlewest states from Florida and Tennessee. Chemical tests should be made first to determine the actual need. Rock phosphate is spread with a lime spreader. It takes a while, possibly a year to saturate the soil, but its benefits will be seen for about four years after application. Super-phosphate is a concentrate. Spread it when you sow the seed by using a fertilizing attachment on your drill or your planter. Thus it falls directly on the seed. However it is good for just that one crop. The use of phosphates has shown phenomenal increases in the corn yield, particularly when used in conjunction with manure and lime.
Remember: when corn brings a good price, the farmer can well afford the extra cost of phosphate.
Fortunately most soils in central and middle-western states have an adequate supply of potash for the kind of crops grown.
Potatoes require a large supply of potash. Hence, all too often, the farmer in the black lands of Iowa and Illinois wonders why corn does so well and potatoes so poorly. But Illinois and Iowa farmers make a living growing corn, not potatoes.
Limestone. All plants need calcium for growth. Particularly is this true of the Legumes. Many legumes (sweet clover, red clover, alfalfa) will not grow at all on a sour soil. Others, making a brave start, die out under the summer sun-heat or are frozen out in winter. The use of limestone is the only means of correcting this acidity in the soil. Remember: lime is not a fertilizer. It is merely an aid to the growth of legumes.
The soil should be tested before any lime is applied to learn the amount necessary. This can be done by the farmer himself, by the county farm bureau, or by most of the local township high schools in their agricultural classes. Samples should be numbered and a map made to check the results (see Fig. 21). The surface samples should be taken, two tablespoonfuls, at the depth of two or three inches. Five subsoil tests should be made at fifteen to eighteen inches deep. Be sure that all of your samples are dry.
|Fig. 21. Diagram for sampling a 40-acre field.|
|Table 6. Color Chart for Reading Acidity test.|
Obtain enough uniform vials from the local drugstore in which to place the samples. A bottle of 4 per cent solution of pure potassium thiocyanate in alcohol is satisfactory for a testing solution. The vials are filled: with soil, with testing solution, then shaken thoroughly. After ten minutes the results can be recorded on the map as to the degree of color.
Adequate treatment of lime on the farm should last ten to fifteen years. Adequate treatment will show a white vial or a sweet soil on testing the field one year after the lime has been applied.
Since most fields vary considerably as to their degree of acidity, this map may not only save you many tons of limestone but will also direct you to the areas of greatest need (see Fig. 22). (For a more detailed analysis of soil testing, refer to Test Your Soil for Acidity, a University of Illinois bulletin.)
|Fig 22. Map shaded to show degree of acidity.|
USE OF NATURAL RESTORATIVES
Organic matter in the soil is restored—and should be restored by every farmer worth his salt—by the use of manures: animal manure or green manure.
Animal Manure. Animal manure is a cheap means of adding nitrogen, phosphorus, and potash to the soil as well as improving its physical condition by adding humus. Its favorable organisms aid in decomposing the organic matter in the soil and in liberating plant-food elements.
But spread manure regularly so that there is no loss from leaching. Leaching occurs very rapidly if it stands unprotected from the weather (rains, wind, freezing, thawing, etc.).
Green Manure. A green manure is obtained by plowing under any green growth. However, legumes contain a higher percentage of organic matter than weeds and grasses. Legumes are plants that have the ability of taking nitrogen from the air for their growth, instead of from the soil. They store up nitrogen in the form of nitrates in nodules on their roots. Of course, the amount of nitrogen left in the soil from a legume crop will vary according (1) to the type of legume used, (2) to the amount of plant growth, (3) to the length of time it has been growing, and (4) to the time that it is turned under.
It is quite easy to understand that a plant that grows profusely will benefit the soil more greatly than one of scanty growth. It is logical, too, that a clover that has stood over a year will have a larger root growth than if it is plowed under the first year.
The time to turn under a legume is when it is still green, either in the fall before a frost or in the spring when it has had its first growth. I have called it a green manure crop. Its benefit is infinitely greater when it is green because of the increased number of bacteria and the amount of moisture present which makes for speedy and thorough decomposition.
However, let a few weeks elapse between the time the green growth is turned under and the seed crop is sown, if possible, for decomposition to begin. Some farmers have crop failures when the seed is sown immediately. They blame this failure upon gases caused by green manure. But usually it is really due to lack of moisture. Often there is not enough summer rain to carry a crop. It is dependent upon the spring and winter rains which are stored in the subsoil. By capillary attraction this water is brought to the surface. If the roots of the plant are obstructed by a heavy sod between the topsoil and the subsoil, it cannot reach the water and the plant does not develop properly. This trouble can be prevented if, after you have plowed the field, you seal it well with a harrow, so there are no air pockets. Then decomposition will be rapid and complete.
Legumes: Sweet Clover. Sweet clover, a biennial, was long considered a weed. It grows profusely along the roadsides and in gullies often when it will not grow in the nearby field. That is because sweet clover insists upon a sweet soil. Sweet clover will thrive in soils too high in alkali for alfalfa, or, in fact, for most cultivated crops. Note: roadsides, of course, have always been in sod and so have not lost lime through erosion and are therefore usually sweet soil. But the fields nearby, through years of cultivation, have had the lime washed away. Often the lime will have to be restored to the field in order to get a good stand of sweet clover. So make careful tests before you sow clover seed.
|Fig. 23. On sweet soil, sweet clover absorbs more atmospheric nitrogen, and so improves the soil faster than any other legume.|
Sweet clover seed must be inoculated if it is to attain good germination and to make good use of atmospheric nitrogen. If not inoculated, the plant will turn yellow in the summer and will die. You may not believe it, but a good crop may contain 100 or more pounds of nitrogen per acre.
Sweet clover does not demand a soil as rich in phosphates as does either alfalfa or red clover.
Sweet clover is usually sown in the spring of the year on small grain. You use about one bushel to five acres. If you wish to sow on winter wheat in January or February, unscarified, unhulled seed should be used. Scarified seed is used for late spring sowing. The most popular method is to sow it at the same time and in the same drill as your spring grain. The seed attachment to the drill can be set to drop the seed on top of the ground. Then the disks on the drill cover the seed sufficiently. If you fear too great a growth, wait two or three weeks after sowing your oats or barley before sowing your clover.
Sweet clover is used as a forage crop in regions where it does not grow too profusely. It does not make as good hay as red clover or alfalfa because its stalks get woody and coarse. It can be grazed early in the season, but, if grazed heavily or clipped often, it stools and makes better pasture. The seed is cheaper than other clover seeds and it is usually abundant in every field. I have found it very difficult to thresh out the seed: the seeds ripen unevenly and the green stuff makes combining almost impossible.
The principal importance of sweet clover in the Corn Belt is for soil improvement. Here it ranks first among the legumes. Corn following sweet clover makes greater increases in yields than if it follows any other legume.
If you do not want to lose a year of cash crops, you can sow sweet clover in your oats or wheat in the spring. It will make a good growth the coming fall. Then, the following spring, when it is green, turn it under and plant corn. Remember: almost as much good has been done the soil by this treatment as you would have done by letting your red clover stand over one year.