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.