[Ill.u.s.tration: FIG. 52.--_C_, STRAIGHT KNIFE COULTER.]

[Ill.u.s.tration: FIG. 53.

An iron beam-plow, with rolling coulter and double clevis.]

[Ill.u.s.tration: FIG. 54.--A ROLLING COULTER HARROW.]

[Ill.u.s.tration: FIG. 55.--SPRING-TOOTHED HARROWS.]

In many parts of the South the farmers use very small plows and small animals to draw them. The result is that the soil is not prepared to a sufficient depth to allow of the large root development necessary for large crops. These farmers need larger tools and heavier animals if they expect to make much improvement in the yield of their crops.

These small plows and this shallow plowing have done much to aid the washing and gulleying of the hill farms by rain. The shallow layer of loose soil takes in the rain readily, but as the harder soil beneath does not take the water as readily, the shallow plowed soil soon fills, then becomes mud, and the whole ma.s.s goes down the slope. The land would wash less if it had not been plowed at all, and least of all if it were plowed deep, for then there would be a deep reservoir of loose soil which would be able to hold a large amount of water until the harder lower soil could take care of it.

BREAKING OUT THE MIDDLES

Some farmers have a way when getting the land ready for a crop, of plowing the rows first and then "breaking out the middles" or s.p.a.ces between after the crop is planted. This is a poor practice, as it interferes with thorough preparation of the soil. The ground can be more thoroughly plowed and broken up before the crop is planted than afterwards. This practice of leaving the middles interferes with proper harrowing and after-cultivation.

THROWING THE LAND UP IN RIDGES

Many farmers throw the land up into ridges with the plow and then plant on the ridge. When land is thrown into ridges a greater amount of surface is exposed to the air and a greater loss of moisture by evaporation takes place, therefore ridge culture is more wasteful of soil water than level culture. For this reason dry soils everywhere and most soils in dry climates should, wherever practicable, be left flat. On stiff, heavy soils which are slow to dry out, and on low bottom lands it may be desirable to ridge the land to get the soil dried out and warmed quicker in the spring. Late fall and early planter truck crops are often planted on the southern slopes of low ridges thrown up with the plow for warmth and protection from cold winds.

TIME TO PLOW

The time of plowing will depend somewhat on the nature of the soil, climate and the crop.

More plowing is done in the spring just before planting spring and summer crops than at any other time, excepting in localities that plant large areas of winter grain and truck. This spring plowing should be done early, for the spring plowing tends to dry the loosened soil somewhat and allows it to become warm at an earlier date, and at the same time the loosened soil tends to hold water in the lower soil for future use by the crop and allows the soil to take in spring rains more readily. If a cover crop or green manure crop is to be turned under in the spring it should be done early so as to prevent the crop to be turned under from pumping too much water out of the soil and thus interfering with the growth of the crop for which the land is being prepared.

There are some particular advantages to be gained by fall plowing in heavy soils:

Immediately after harvest the land is usually dry and easy to work.

The soil plowed at this time and left rough is acted upon physically by frost which pulverizes it, and chemically by rain and air which renders plant food available.

Insects are turned up and exposed to frost and birds.

A great number of weeds are destroyed and the land is more easily fitted for crops in the spring. Fall plowing should be done as early as possible, especially in the dryer regions, to catch all water possible. It is not advisable to plow sandy soils in the fall lest plant food be washed out of them.

When possible a cover crop should be put on fall plowed land where there is likely to be loss of plant food by leaching.

BARE FALLOW

The term "fallowing" is sometimes applied to the operation of plowing, and sometimes the land is left bare without a crop sometime after plowing; this is called "bare fallowing" the land.

Bare fallowing should not be practiced on all soils. It is adapted:

To dry climates and dry seasons where it is desirable to catch and save every possible drop of rainfall, and where plant food will not be washed out of the exposed soils by rains.

To heavy clay lands.

To lands that are foul with weeds and insects.

To sour soils which are sweetened by exposure to air and rain.

Light sandy soils should not be subjected to bare fallow unless they are very foul with weeds. They should always be covered with a crop to prevent loss of plant food by leaching.

CHAPTER XII

HARROWING AND ROLLING

HARROWING

After spading or plowing the next operation in the preparation of the soil is generally raking, harrowing or dragging. The objects of these operations are:

To break lumps and clods left by the plow and spade and to further pulverize the soil.

Harrowing and raking aid in controlling soil ventilation, and put the soil in better condition to absorb moisture.

They check the loss of moisture by making a mulch of fine loose earth on the surface.

The harrow and rake destroy the weeds.

The harrow brings about conditions favorable to the even distribution of seeds.

It is also the tool generally used to cover seeds sown broadcast.

Harrowing is generally done just before planting, and with some crops just after, to cover seeds or to smooth the ground. Harrowing is also done in the first stages of growth of some crops to kill weeds and make a soil mulch. The harrow should always follow the plow within a few hours unless it is desired to leave the land in a bare fall or winter fallow. At other times of the year the lumps of earth are apt to dry out and become hard and difficult to break. If there is but one work team on the farm it is a good plan during the plowing season to stop the plow in time to harrow the day's plowing before the day's work ends.

HARROWS

There are several types of harrows in use. They may be cla.s.sified according to the style of their teeth or cutting parts; they are as follows:

Rolling cutter harrows.

Spring-toothed harrows.

Spike-toothed harrows.

Coulter-toothed harrows.

Chain harrows.