When the rains come the water is held in these grooves and it finds its way down the whole depth of the furrow slice carrying air with it and moistening every particle of trash clear to the bottom of the furrow.
Such conditions are ideal for the work of the different forms of bacteria to break down plant fibre contained in the roots and trash and work it into humus, which is in turn manipulated by other forms of soil bacteria to produce soil water which is the only food of growing plants.
_Jointer Plows._--American plow makers also have recognized the necessity of mixing humus with soil in the act of plowing. To facilitate the process and at the same time turn a wide furrow, the jointer does fairly good work when soil conditions are suitable. The jointer is a little plow which takes the place of the coulter and is attached to the plow-beam in the same manner. The jointer turns a little furrow one inch or two inches deep and the large plow following after turns a twelve-inch or fourteen-inch furrow slice flat over, throwing the little jointer furrow in the middle of the furrow bottom in such a way that the big furrow breaks over the smaller furrow.
If the work is well done, cracks as wide as a man"s hand and from three to five inches deep are left all over the field. These cracks lead air and moisture to rot the trash below. This is a much quicker way of doing a fairly good job of plowing. Such plows loosen the soil and furnish the conditions required by nature; and they may be operated with much less skill than the old-fashioned narrow-furrowed Scotch plows.
Good plowing requires first that the soil be in proper condition to plow, neither too dry nor too wet, but no man can do good plowing without the proper kind of plow to fit the soil he is working with.
PLOWING BY TRACTOR
Under present conditions farm tractors are not intended to replace horse power entirely but to precede horses to smooth the rough places that horses may follow with the lighter machines to add the finishing touches. Light tractors are being made, and they are growing in popularity, but the real business of the farm tractor is to do the heavy lugging--the work that kills horses and delays seeding until the growing season has pa.s.sed. The actual power best suited to the individual farm can only be determined by the nature of the land and the kind of farming.
In the Middle West where diversified farming is practiced, the 8-16 and the 10-20 sizes seem to be the most satisfactory, and this is without regard to the size of the farm. The preponderance of heavy work will naturally dictate the buying of a tractor heavier than a 10-20. The amount of stationary work is a factor. In certain communities heavy farm tractors are made to earn dividends by running threshing machines after harvest, silo fillers in the fall and limestone crushers in the winter.
Here is a cla.s.sified list of jobs the medium size farm tractor is good for:
Clearing the Land--pulling up bushes by the roots, tearing out hedges, pulling stumps, grubbing, pulling stones.
Preparing Seed Bed and Seeding--plowing, disking, crushing clods, pulling a land plane, rolling, packing, drilling, harrowing.
Harvesting--mowing, pulling grain binders, pulling potato digger.
Belt Work--hay baling, corn sh.e.l.ling, heavy pumping for irrigation, grinding feed, threshing, clover hulling, husking and shredding, silo filling, stone crushing.
Road Work--grading, dragging, leveling, ditching, hauling crops.
Miscellaneous--running portable sawmill, stretching wire fencing, ditch digging, manure spreading.
Generally speaking, however, the most important farm tractor work is preparing the seed-bed thoroughly and quickly while the soil and weather conditions are the best. And the tractor"s ability to work all day and all night at such times is one of its best qualifications.
To plow one square mile, or 640 acres, with a walking plow turning a twelve-inch furrow, a man and team must walk 5,280 miles. The gang-plow has always been considered a horse killer, and, when farmers discovered that they could use oil power to save their horses, many were quick to make the change.
It requires approximately 10 horsepower hours to turn an acre of land with horses. At a speed of two miles, a team with one plow in ten hours will turn two acres. To deliver the two horsepower required to do this work, they must travel 176 feet per minute and exert a continuous pull of 375 pounds or 187.5 pounds per horse.
One horsepower equals a pull of 33,000 pounds, moved one foot per minute. Two-mile speed equals two times 5,280 or 10,560 feet per hour, or 176 feet per minute. Sixty-six thousand divided by 176 equals 375 foot pounds pull per minute. One horsepower is absorbed in 88 feet of furrow.
Horse labor costs, according to Government figures, 12-1/2 cents per hour per horse. On this basis ten hours" work will be $1.25, which is the average daily cost of each horse. An average Illinois diversified farm of 160 acres would be approximately as follows: Fifty acres of corn, 30 acres of oats and wheat, 20 acres of hay, 60 acres of rough land, pasture, orchard, building and feed lots.
This average farm supports six work horses or mules and one colt.
According to figures taken from farm work reports submitted by many different corn belt farmers, the amount of horse-work necessary to do this cropping would figure out as follows:
Fifty acres of corn land for plowing, disking, harrowing, planting, cultivating and harvesting would amount to a total of 1,450 horsepower hours. Thirty acres of wheat would require a total of 330 horsepower hours. Twenty acres of hay would require 110 horsepower hours. In round figures, 1,900 horsepower hours at 12-1/2 cents would amount to $237.50.
Elaborate figures have been worked out theoretically to show that this work can be done by an 8-16 farm tractor in 27-3/4 days at a cost for kerosene fuel and lubricating oil of $1.89 per day. Adding interest, repairs and depreciation, brings this figure up to about $4.00 per day, or a total of $111.00 for the job. No account is kept of man power in caring for either the horses or the tractor. The actual man labor on the job, however, figures 12-1/3 days less for the tractor than for horses.
We should remember that actual farm figures are used for the cost of horse work. Such figures are not available for tractor work.
The cost of plowing with a traction engine depends upon so many factors that it is difficult to make any definite statement. It depends upon the condition of the ground, size of the tractor, the number of plows pulled, and the amount of fuel used. An 8-16 horsepower tractor, for instance, burning from 15 to 20 gallons of low grade kerosene per ten hour day and using one gallon of lubricating oil, costs about $1.90 per ten hours work. Pulling two 14-inch plows and traveling 20 miles per day, the tractor will plow 5.6 acres at a fuel and an oil cost of about 30 cents per acre. Pulling three 14-inch plows, it will turn 8.4 acres at a cost for fuel and oil of about 20 cents an acre.
The kind and condition of soil is an important factor in determining the tractor cost of plowing. Comparison between the average horse cost and the average tractor cost suggests very interesting possibilities in favor of tractor plowing under good management.
Aside from the actual cost in dollars we should also remember that no horse gang can possibly do the quality of work that can be accomplished by an engine gang. Anxiety to spare the team has cut a big slice off the profits of many a farmer. He has often plowed late on account of hard ground, and he has many times allowed a field to remain unplowed on account of worn-out teams. Under normal conditions, late plowing never produces as good results as early plowing. Many a farmer has fed and harnessed by the light of the lantern, gone to the field and worked his team hard to take advantage of the cool of the morning. With the approach of the hot hours of midday, the vicious flies sapping the vitality from his faithful team, he has eased up on the work or quit the job.
In using the tractor for plowing, there are none of these distressing conditions to be taken into consideration, nothing to think of but the quality of work done. It is possible to plow deep without thought of the added burden. Deep plowing may or may not be advisable. But where the soil will stand it, deep plowing at the proper time of year, and when done with judgment, holds moisture better and provides more plant food.
The pull power required to plow different soils varies from about three pounds per square inch of furrow for light sand up to twenty pounds per square inch of furrow for gumbo. The draft of a plow is generally figured from clover sod, which averages about seven pounds per square inch. Suppose a plow rig has two 14-inch bottoms, and the depth to be plowed is six inches. A cross section of each plow is therefore 14 by 6 inches, or 84 square inches. Twice this for two bottoms is 168 square inches. Since, in sandy soil, the pressure per square inch is three pounds, therefore 168 times 3 pounds equals 504 pounds, the draft in sandy soil. 168 times 7 pounds equals 1,176 pounds, the draft in clover sod. 168 times 8 pounds equals 1,344 pounds, the draft in clay sod.
The success of crop growing depends upon the way the seed-bed is prepared. The final preparation of the seed-bed can never be thoroughly well done unless the ground is properly plowed to begin with. It is not sufficient to root the ground over or to crowd it to one side but the plow must really turn the furrow slice in a uniform, systematic manner and lay it bottom side uppermost to receive the beneficial action of the air, rain and sunshine.
The moldboard of a plow must be smooth in order to properly shed the earth freely to make an easy turn-over. The shape of the shear and the forward part of the moldboard is primarily that of a wedge, but the roll or upper curve of the moldboard changes according to soil texture and the width and depth of furrow to be turned. Moldboards also differ in size and shape, according to the kind of furrow to be turned. Sometimes in certain soils a narrow solid furrow with a comb on the upper edge is preferable. In other soils a cracked or broken furrow slice works the best. When working our lighter soils a wide furrow turned flat over on top of a jointer furrow breaks the ground into fragments with wide cracks or openings reaching several inches down. Between these extremes there are many modifications made for the particular type or texture of the soil to be plowed. We can observe the effect that a rough, or badly scratched, or poorly shaped moldboard has on any kind of soil, especially when pa.s.sing from gravelly soils to clay. In soil that contains the right amount of moisture, when a plow scours all the time, the top of the furrow slice always has a glazed or shiny appearance.
This shows that the soil is slipping off the moldboard easily. In places where the plow does not scour the ground is pushed to one side and packed or puddled on the underside instead of being lifted and turned as it should be. A field plowed with a defective moldboard will be full of these places. Such ground cannot have the life to bring about a satisfactory bacteria condition necessary to promote the rapid plant growth that proper plowing gives it.
Cultivated sandy soils are becoming more acid year after year. We are using lime to correct the acidity, but the use of lime requires better plowing and better after cultivation to thoroughly mix the trash with the earth to make soil conditions favorable to the different kinds of soil bacteria. Unless we pay special attention to the humus content of the soil we are likely to use lime to dissolve out plant foods that are not needed by the present crop, and, therefore, cannot be utilized. This is what the old adage means which reads: "Lime enricheth the father but impoverisheth the son." When that was written the world had no proper tillage tools and the importance of humus was not even dreamed of.
Not so many years ago farm plows were made of cast iron. Then came the steel moldboard, which was supposed to be the acme of perfection in plow making. Steel would scour and turn the furrow in fluffy soils where cast iron would just root along without turning the ground at all. Later the art of molding steel was studied and perfected until many grades and degrees of hardness were produced and the shape of the moldboard pa.s.sed through a thousand changes. The idea all the time was to make plows that would not only scour but polish in all kinds of soil. At the same time they must turn under all of the vegetable growth to make humus, to kill weeds and to destroy troublesome insects. Besides these requirements the soil must be pulverized and laid loose to admit both air and moisture.
These experiments gradually led up to our present high grade plows of hardened steel and what is known as chilled steel.
Besides the hardness there are different shapes designed for different soils so that a plow to work well on one farm may need to be quite different from a plow to do the best work in another neighborhood. The furrow slice sliding over a perfect moldboard leaves the surface of the upturned ground as even as the bottom of the furrow. By using a modern plow carefully selected to fit the soil, gravel, sandy, stony or muck soils, or silt loams that contain silica, lime, iron and aluminum oxide can be worked with the right plow to do the best work possible if we use the necessary care and judgment in making the selection.
One object of good plowing is to retain moisture in the soil until the growing crop can make good use of it.
The ease with which soils absorb, retain or lose moisture, depends mostly on their texture, humus content, physical condition, and surface slope or artificial drainage. It is to the extent that cultivation can modify these factors that more soil water can be made available to the growing crop. There are loose, open soils through which water percolates as through a sieve, and there are tight, gumbo soils which swell when the surface is moistened and become practically waterproof. Sandy soils take in water more readily than heavier soils, hence less precaution is necessary to prevent run-off.
Among the thousands of plows of many different makes there are plenty of good ones. The first consideration in making a selection is a reliable home dealer who has a good business reputation and a thorough knowledge of local soil from a mechanical standpoint. The next consideration is the service the plow will give in proportion to the price.
DISK HARROW
For preparing land to receive the seed no other implement will equal a double disk. These implements are made in various sizes and weights of frame. For heavy land, where it is necessary to weight the disk down, an extra heavy frame is necessary. It would probably be advisable to get the extra strong frame for any kind of land, because even in light sand there are times when a disk may be used to advantage to kill quackgra.s.s or to chew up sod before plowing. In such cases it is customary to load on a couple of sacks of sand in addition to the weight of the driver.
When a disk is carrying 300 or 400 pounds besides its own weight the racking strains which pull from different directions have a tendency to warp or twist a light frame out of shape. To keep a disk cultivator in good working order it is necessary to go over it thoroughly before doing heavy work. Bolts must be kept tight, all braces examined occasionally, and the heavy nuts at the ends of the disk shafts watched. They sometimes loosen and give trouble. The greatest difficulty in running a disk harrow or cultivator is to keep the boxings in good trim. Wooden boxes are provided with the implement. It is a good plan to insist on having a full set of eight extra boxes. These wooden boxes may be made on the farm, but it sometimes is difficult to get the right kind of wood. They should be made of hard maple, bored according to size of shaft, and boiled in a good quality of linseed oil. Iron boxings have never been satisfactory on a disk implement. Wooden ones make enough trouble, but wood has proved better than iron. On most disk cultivators there are oil channels leading to the boxings. These channels are large enough to carry heavy oil. The lighter grades of cylinder oil work the best. It is difficult to cork these oil channels tight enough to keep the sand out. Oil and sand do not work well together in a bearing. The manufacturers of these implements could improve the oiling device by shortening the channel and building a better housing for the oil entrance. It is quite a job to take a disk apart to put in new boxings, but, like all other repair work, the disk should be taken into the shop, thoroughly cleaned, repaired, painted and oiled in the winter time.
Some double disk cultivators have tongues and some are made without.
Whether the farmer wants a tongue or not depends a good deal on the land. The only advantage is that a tongue will hold the disk from crowding onto the horses when it is running light along the farm lanes or the sides of the fields with the disks set straight. Horses have been ruined by having the sharp disks run against them when going down hill.
Such accidents always are avoidable if a man realizes the danger.
Unfortunately, farm implements are often used by men who do very little thinking. A spring disk sc.r.a.per got twisted on a root and was thrown over the top of one of the disks so it sc.r.a.ped against the back of the disk and continued to make a harsh, sc.r.a.ping noise until the proprietor went to see what was wrong. The man driving the disk said he thought something must be the matter with the cultivator, but he couldn"t tell for the life of him what it was. When farmers are up against such difficulties it is safer to buy a disk with a tongue.
_Harrow Cart._--A small two-wheel cart with a spring seat overshadowed with a big umbrella is sometimes called a "dude sulky." Many sensitive farmers trudge along in the soft ground and dust behind their harrows afraid of such old fogy ridicule. The hardest and most tiresome and disagreeable job at seeding time is following a harrow on foot. Riding a harrow cart in the field is conserving energy that may be applied to better purposes after the day"s work in the field is finished.
KNIFE-EDGE PULVERIZERS
A knife-edge weeder makes the best dust mulch pulverizer for orchard work or when preparing a seed-bed for grain. These implements are sold under different names. It requires a stretch of imagination to attach the word "harrow" to these knife-edge weeders. There is a central bar which is usually a hardwood plank. The knives are bolted to the underside of the plank and sloped backward and outward from the center to the right and left, so that the knife-edges stand at an angle of about 45 to the line of draught. This angle is just about sufficient to let tough weeds slip off the edges instead of dragging along. If the knives are sharp, they will cut tender weeds, but the tough ones must be disposed of to prevent choking. The proper use of the knife-edge weeder prevents weeds from growing, but in farm practice, sometimes rainy weather prevents the use of such a tool until the weeds are well established. As a moisture retainer, these knife-edge weeders are superior to almost any other implement. They are made in widths of from eight to twenty feet. The wide ones are jointed in the middle to fit uneven ground.
CLOD CRUSHER
The farm land drag, float, or clod crusher is useful under certain conditions on low spots that do not drain properly. Such land must be plowed when the main portion of the field is in proper condition, and the result often is that the low spots are so wet that the ground packs into lumps that an ordinary harrow will not break to pieces. Such lumps roll out between the harrow teeth and remain on top of the ground to interfere with cultivation. The clod crusher then rides over the lumps and grinds them into powder. Unfortunately, clod crushers often are depended on to remedy faulty work on ordinary land that should receive better treatment. Many times the clod crusher is a poor remedy for poor tillage on naturally good land that lacks humus.
[Ill.u.s.tration: Figure 140.--Land Float. Clod crushers and land floats belong to the same tribe. Theoretically they are all outlaws, but some practical farmers harbor one or more of them. Wet land, containing considerable clay, sometimes forms into lumps which should be crushed.]