The First Book of Farming

Early white potatoes, early cabbage, water melons, musk-melons, tomatoes and other early truck and market garden crops are also grown on light soil holding from five to seven per cent. of water. The main crop of potatoes and cabbage and the canning crop of tomatoes are grown on the loam soils holding from ten to eighteen per cent. of water. Such soils produce a later though much larger yield.

Upland cotton produces best on a deep loam that is capable of furnishing a uniform supply of about ten or twelve per cent. of water during the growing season.

Sea Island Cotton grows best on a light, sandy soil holding only five per cent. of water.

On light, sandy soils the Upland Cotton produces small plants with small yield of lint, while on clay and bottom land, which are apt to have large amounts of water, the plants grow very large and produce fewer bolls, which are very late in maturing.

The grasses and small grains do best on cool, firm soils holding eighteen to twenty-two per cent. of water.

Sorghum or "Molasses Cane" grows best on good corn soil, while the sugar cane of the Gulf States requires a soil with twenty-five per cent. of water for best growth.

While the amount of water which a soil will hold is determined largely by texture, it is also considerably influenced by the amount and frequency of rainfall and the location of the soil as to whether it be upland or bottom land.

The average percentage of water held by a soil during the growing season may be approximately determined in the following manner:

Sample the soil in one of the following methods:

Take to the field a spade, a box that will hold about half a bushel, and a pint or quart glass jar with a tight cover. If a cultivated field, select a place free from grass and weeds. Dig a hole one foot deep and about eighteen inches square. Trim one side of the hole square. Now from this side cut a slice about three inches thick and one foot deep, quickly place this in the box and thoroughly break lumps and mix together, then fill jar and cork tightly.

Take the sample, by whatever method obtained, weigh out ten or twenty ounces of the moist soil and dry it at a temperature just below 212 degrees. When it is thoroughly dry weigh again. The difference between the two weights will be the amount of water held by the sample. Now divide this by the weight of the dry sample and the result will be the per cent. of water held by the soil.

Several samples taken from different parts of the field will give an average for the field. Repeat this every week or oftener through the season and an approximate estimate of the water-holding capacity of the soil will be obtained and consequently an indication of the crops to which the soil is best adapted.

This soil held a little over twelve per cent. of water. If this soil continues to give about the same result for successive tests during the growing season, the results would indicate a soil adapted to cotton, late truck or corn.

We learned in a former chapter that during their growth farm plants require an amount of water equal to from 300 to 500 times their dry weight. Weeds require just as much water and some of them probably more than the cultivated plants. This water is largely absorbed by the roots and sent up to the leaves where it is transpired into the air and is lost from the soil, and therefore is unavailable to the growing crop until it again falls onto the soil.

In some parts of the country, particularly the semi-arid West, the rainfall is not sufficient to supply the soil with enough water to grow such crops as it could otherwise produce. In the moister regions the rainfall is not evenly distributed throughout the growing season, and there are longer or shorter intervals between rains when the loss of water through evaporation and weeds is apt to be greater than the rainfall. For these reasons it is best to check these losses and save the water in the soil for the use of the crops.

SAVING THE WATER

This can be done by:

Preventing the growth of weeds and by checking losses by evaporation with a soil mulch.

A seedling plant is easiest killed just as it has started into growth. The best time to kill a plant starting from an underground stem or a root is just as soon as it appears above the surface in active growth.

The best time to cultivate, then, to kill weeds is as soon as the weeds appear. At this time large numbers can be killed with the least of effort. Do not let them get to be a week or two old before getting after them.

In planting some crops the ground between the rows becomes trampled and compact. This results in active capillarity which brings water to the surface and it is lost by evaporation.

Every rainfall tends to beat the soil particles together and form a crust which enables the capillary water to climb to the surface and escape into the air. This loss by evaporation should be constantly watched for and the soil should be stirred and a mulch formed whenever it becomes compact or a crust is formed.

The proper time to cultivate, then, to save water is as soon as weeds appear or as soon as the surface of the soil becomes compact or crusted by trampling, by the beating of rain or from any other cause, whether the crop is up or not. The cultivation should start as soon after a rain as the soil is dry enough to work safely.

TOOLS FOR AFTER-CULTIVATION

The main objects of after-cultivation are to destroy weeds and to form a soil mulch for the purpose of controlling soil moisture. These ends are secured by shallow surface work. It is not necessary to go more than two or three inches deep. Deeper work will injure the roots of the crop. Therefore the proper tools for after-cultivation in the garden are the hoe and rake and for field work narrow-toothed harrows and cultivators or horse-hoes which stir the whole surface thoroughly to a moderate depth. These field tools are supplemented in some cases by the hand hoe, but over wide areas of country the hoe never enters the field.

A light spike-toothed harrow can be used on corn, potatoes, and similar crops, and accomplish the work of cultivation rapidly until they get to be from four to six inches high; after that cultivators which work between the rows should be used.

There is a larger class of hand wheel hoes which are very useful in working close planted garden and truck crops. They either straddle the row, working the soil on both sides at the same time, or, running between the rows, work the soil to a width of from six to eighteen inches.

For best results with the weeder and hand wheel hoes the soil should be thoroughly prepared before planting by burying all trash with the plow and breaking all clods with harrow and roller.

The objection made to the deep-working implements, like the plow, is that they injure the crop by cutting its feeding roots, and this has been found by careful experiment and observation to diminish the crop.

Some farmers object to using a light harrow for cultivation in the early stages of the crop because they say the harrow will destroy the crop as well as the weeds. This danger is not so great as it seems. The seeds of the crop are deeper in the soil than the seeds of the weeds which germinate and appear so quickly. The soil has also been firmed about them. Hence they have a firmer hold on the soil and but few of them are destroyed if the work is carefully done.

HILLING AND RIDGING

Except in low, wet ground, the practice of hilling or ridging up crops is now considered by those who have given the matter thorough study, to be unnecessary, flat and shallow culture being cheaper. It saves more moisture, and for this reason, in the majority of cases, produces larger crops.

Sometimes during very long-continued periods of wet weather weeds and grass become firmly established among the plants of the crop. Under such circumstances it is necessary to use on the cultivator teeth having long, narrow sweeps that will cut the weeds just beneath the surface of the soil. Sometimes a broad-toothed tool is used that will throw sufficient soil over the large weeds near the rows to smother them.

The condition to be met and the effect of the operation should always be given serious thought.

We have considered after-cultivation as influencing soil fertility by checking a loss of water by evaporation and weed transpiration, and this is its main influence but other benefits follow.

Of these two classes of manures the farmer should rely chiefly on the farm manures letting the commercial fertilizers take a secondary place because:

Farm manures are complete manures; that is they contain all the necessary elements of plant food.

Farm manures add to the soil large amounts of organic matter or humus.

The decay of organic matter produces carbonic acid which hastens the decay of mineral matter in the soil and so increases the amount of available plant food.

The organic matter changes the texture of the soil.

It makes sandy soils more compact and therefore more powerful to hold water and plant food.

It makes heavy clay soils more open and porous, giving them greater power to absorb moisture and plant food. This admits also of better circulation of the air in the soil, and prevents baking in dry weather.

Farm manures influence all of the conditions necessary for root growth while the commercial fertilizers influence mainly the plant food conditions.

The farm manures are good for all soils and crops.

They are lasting in their effects on the soil.

Barn or stable manure consists of the solid and liquid excrement of any of the farm animals mixed with the straw or other materials used as bedding for the comfort of the animals and to absorb the liquid parts.

The liquid parts should be saved, as they contain more than half of the nitrogen and potash in the manure.

The value of barn manure for improving the soil conditions necessary for root growth depends in a measure upon the plant food in it, but chiefly upon the very large proportion of organic matter which it contains when it is applied to the soil.

These factors are influenced somewhat: by the kind of animal that produces the manure; by the kind of food the animal receives; by the kind and amount of litter or bedding used; but they depend particularly on the way the manure is cared for after it is produced.

LOSS OF VALUE

Improper care of the manure may cause it to diminish in value very much.

Loss by leaching.

Loss by heating or fermenting.

When barn manure is thrown into piles it soon heats and throws off more or less steam and gas. This heating of the manure is caused by fermentation or the breaking down of the materials composing the manure and the forming of new compounds. This fermentation is produced by very small or microscopic plants called bacteria.

The fermentation of the manure is influenced by the following conditions:

A certain amount of heat is necessary to start the work of the bacteria. After they have once started they keep up and increase the temperature of the pile until it gets so hot that sometimes a part of the manure is reduced to ashes. The higher the temperature the more rapid the fermentation. This can be seen particularly in piles of horse manure.

The bacteria which produce the most rapid fermentation in manure need plenty of air with its oxygen. Therefore fermentation will be more or less rapid according as the manure is piled loosely or in a close compact mass.

A certain amount of moisture is necessary for the fermentation to take place, but if the manure is made quite wet the temperature is lowered and the fermentation is checked. The water also checks the fermentation by limiting the supply of air that can enter the pile.

Now when the manure ferments a large part of the organic matter in it is broken down and changed into gases. The gas formed most abundantly by the fermentation is carbonic acid gas, which is produced by the union of oxygen with carbon of the organic matter. The formation of this gas means a loss of humus. This loss can be noticed by the fact that the pile gradually becomes smaller.

The next most abundant product of the fermentation is water vapor which can often be seen passing off in clouds of steam.

When manure ferments rapidly the nitrogen in it is changed largely into ammonia. This ammonia combines with part of the carbonic acid gas and forms carbonate of ammonia, a very volatile salt which rapidly changes to a vapor and is lost in the atmosphere. This causes a great loss of nitrogen during the rapid decomposition of the manure. This loss can be detected by the well known odor of the ammonia which is particularly noticeable about horse stables and piles of horse manure.

Besides these gases a number of compounds of nitrogen, potash, etc., are formed which are soluble in water. It is these that form the dark brown liquid that sometimes oozes out from the base of the manure heap.

"Four thousand pounds of manure from the horse stable were placed out of doors in a compact pile and left exposed from April 25th to September 22d. The results were as follows:"

This shows a loss of more than half the bulk of the manure and more than half the plant food contained in it.

CHECKING THE LOSSES

The first step to be taken in preserving the manure or in checking losses is to provide sufficient bedding or litter in the stable to absorb and save all the liquid parts.

The losses from fermentation of hot manures like horse manure may be largely checked by mixing with the colder manure from the cow stable.

Losses from fermentation may also be checked.

By piling compactly, which keeps the air out.

By moistening the pile, which lowers the temperature and checks the access of oxygen.

Gypsum or land plaster is often sprinkled on stable floors and about manure heaps to prevent the loss of ammonia.

Copperas or blue stone, kainite and superphosphate are sometimes used for the same purpose. There is, however, nothing better nor so good for this purpose as dry earth containing a large percentage of humus.

Losses from washing or leaching by rain may be prevented by piling the manure under cover or by hauling it to the field as soon as produced and spreading it on the surface or plowing it under.

APPLYING THE MANURE TO THE SOIL

From ten to twenty tons per acre is considered a sufficient application of barn manure for most farm crops. Larger amounts are sometimes applied to the soil for truck and market garden crops.

Barn manures are applied to the soil by these methods:

The manure is sometimes hauled out from the barn and placed in a large pile in the field or in many small piles where it remains for some time before being spread and plowed or harrowed in.

It is sometimes spread as soon as hauled to the field and is immediately plowed in or mixed with the soil. This last is the safest and most economical method so far as the manure alone is concerned.

When the manure is left in a large pile it suffers losses due to fermentation and leaching.

At the Cornell University Agricultural Experiment Station, five tons of manure from the cow stable, including three hundred pounds of gypsum which was mixed with it, were exposed in a compact pile out of doors from April 25th to September 22d. The result was as follows:

If coarse manures are mixed with light, sandy soils it is best to follow with the roller, otherwise the coarse manure may cause the soil to lie so loose and open that both soil and manure will lose moisture so rapidly that fermentation of the manure will be stopped and the soil will be unfit for planting.

If it is desired to apply manure directly to delicate rooted truck and vegetable crops it is best to let it stand for some time until the first rank fermentation has taken place and the manure has become rotten.

A good practice is to apply the manure in its fresh condition to coarse feeding crops like corn, and then follow the corn by a more delicate rooted crop which requires the manure to be in a more decomposed condition than is necessary for the corn. In this case the corn is satisfied and the remaining manure is in proper condition for the following crop when it is planted.

Another practice is to broadcast the coarse manure on grass land and then when the hay is harvested the sod and remaining manure are plowed under for the following crop.

There may not be a single farm where it will be possible to carry out to the letter these principles applying to the treatment and application of barn manures.

This is because climate, crops and conditions vary in different parts of the country and on different farms. Therefore we should study carefully our conditions and the principles and make our practice so combine the two as to produce the best and most economical results under the circumstances.

If we can get manure out in the winter it will very much lessen the rush of spring work.

In some parts of the country on account of deep snows, heavy rainfall and hilly fields, it is not advisable to apply manure in the winter. This will necessitate storing the manure.

If conditions are such that we can get the manure on to the land as soon as it is made, it should be applied to land on which a crop is growing or land which is soon to be planted. If land is not intended for an immediate crop, put a cover crop on it.

COMPOSTS

The object of composting these materials is to hasten their decay and render available the plant food in them.

There are certain disadvantages in composting, namely:

Expense of handling and carting on account of bulk.

Low composition.

Loss of organic matter by fermentation.

Compost heaps serve as homes for weed seeds, insects and plant diseases.

Nevertheless, all waste organic matter on the farm should be saved and made use of as manure. These materials when not too coarse may be spread on the surface of the soil and plowed under; they should never be burned unless too coarse and woody or foul with weed seeds, insects and disease.

Besides adding humus and nitrogen to the soil the legumes, being mostly deep-rooted plants, are able to take from the subsoil food which is out of reach of other plants. This food is distributed throughout the plant and when the plant is plowed under the food is deposited in the upper soil for the use of shallow-rooted plants.

BENEFITS

The benefits derived from green crop manuring then are as follows:

We add to the soil organic matter or humus which is so helpful in bringing about the conditions necessary for root growth.

By using the legumes for our green manure crops we may supply the soil with nitrogen taken from the air.

We return to the surface soil not only the plant food taken from it but also plant food brought from the subsoil by the roots of the green manure plants.

CHARACTER OF BEST PLANTS FOR GREEN CROP MANURING

THE TIME FOR GROWING GREEN MANURE CROPS

Green manure crops may be grown at any time that the soil is not occupied by other crops, provided other conditions are suitable. Land which is used for spring and summer crops often lies bare and idle during fall and winter. A hardy green manure crop planted after the summer crop is harvested will make considerable growth during the fall and early spring, and this can be plowed under for the use of the following summer crops. If there is a long interval of time during spring or summer when the land is bare, that is a good time for a green manure crop.

Green manure crops are often planted between the rows of other crops such as corn or cotton at the last working of the crop for the benefit of the crop which is to follow.

It is advisable to arrange for a green manure crop at least once in three or four years.

LEGUMINOUS GREEN MANURE CROPS

It is a tender annual, that is, it is killed by frost and makes its entire growth from seed to seed in a single season. It should therefore be planted only during the spring and summer. This crop not only has power like the other legumes to take nitrogen from the air, but it is also a strong feeder, that is, it can feed upon mineral plant food in the soil that other plants are unable to make use of. For this reason it will grow on some of the poorest soils, and is a good plant with which to begin the improvement of very poor land. It is a deep-rooted plant. On the farm of the Hampton Normal and Agricultural Institute cowpea roots have been traced to the depth of sixty-one inches.

Cowpeas will grow on almost any land that is not too wet. From one and one-half to three bushels of seed are used per acre. These are sown broadcast and harrowed in or are planted in drills or furrows and cultivated a few times. Aside from its value as a green manure crop the cowpea is useful as food for man and the farm animals. The green pods are used as string beans or snaps. The ripened seeds are used as a food and the vines make good fodder for the farm animals.

"It is now grown in all the States south of the Ohio River, and in 1899 there were planted nearly 800,000 acres to the crop. Basing our estimate on the amount of nitrogen stored in the soil by this crop, it is fair to say that fully fifteen million pounds of this valuable substance were collected and retained as a result of the planting of the cowpea alone. This at fifteen cents per pound (the market price of nitrogen) would be worth something more than $2,000,000 for nitrogen alone."—Year Book of the Department of Agriculture, 1902.

The Clovers.—These are the most extensively grown plants for green manure purposes in the United States. They are deep-rooted, and are able to use mineral food that is too tough for other plants. They furnish large crops of hay or green forage and a good aftermath and sod to turn under as green manure, or the entire crop may be plowed under.

Mammoth Red Clover, also called sapling clover and pea-vine clover, closely resembles the red clover, but is ranker in growth and matures two or three weeks later. It is better adapted to wet land than the red clover.

Crimson Clover, also called German clover and Italian clover, is a valuable green manure crop in the central and southern States east of the Mississippi. It is a hardy annual in that section and is generally sown from the last of July to the middle of October, either by itself or with cultivated crops at their last working. Fifteen and twenty pounds of seed are used to the acre. It makes a good growth during the fall and early winter and is in blossom and ready to cut or plow under in April or May. It grows at a season when the cowpea will not live. Crimson clover will grow on soils too light for other clovers.

White Sweet Clover, white melitot or Bokhara clover, grows as a weed from New England to the Gulf of Mexico. In the Gulf States it is regarded as a valuable forage and green manure plant. One or two pecks of seed per acre are sown in January or February.