Tillage is the preparing and stirring of the soil with the object to make it more congenial to the growth of plants. On the wise management of the soil depends the perpetuation of the human race.
Objects of tillage (King).
Stated in the broadest and briefest way, the purpose of tillage is to develop and maintain beneath the surface of the field a commodious and thoroughly sanitary home and feeding ground for the roots of crops and for the soil organisms that help to transform the organic matter and the less soluble forms of the mineral plant-food materials of the soil into more soluble and suitable conditions adapted to the immediate needs of plants. But to make the habitable part of the soil of a field commodious and sanitary, and at the same time to maintain within it a sufficiently rapid development of readily water-soluble plant-food materials so conditioned as to be highly available to the crop, requires careful attention to many essential details. Some of the chief objects of tillage are: (1) To secure a thorough surface uniformity of the field, so that an equally vigorous growth may take place over the entire area.
(2) To develop and maintain a large effective depth of soil, so that there shall be ample living room, an extensive feeding surface and large storage capacity for moisture and available plant-food materials.
(3) To increase the humus of the soil through a deep and extensive incorporation of organic matter, so that there may be a strong growth of soil micro-organisms and the maintenance of a high content of water-soluble plant-food materials.
(4) To improve the tilth and maintain the best structural condition in the soil, so that the roots of the crop and the soil organisms may spread readily and widely to place themselves in the closest contact with the largest amount of food materials.
(5) To control the amount, to regulate the movement, and to determine the availability of soil moisture, so that there shall never be an excess or a deficiency of this indispensable carrier of food materials to and through the plant.
(6) To determine the amount, movement, and availability of the water-soluble plant-food materials present in the soil, so that growth may be both rapid, normal, and continuous to the end of the season.
(7) To convert the entire root zone of the soil into a commodious sanitary living and feeding place, perfectly adapted to the needs of the roots of the crop and to the soil organisms, — adequately drained, perfectly ventilated, and sufficiently warm.
(8) To reduce the waste of plant-food materials through the destruction of weeds, and the prevention of their growth, through prevention of surface washing and drifting by winds.
Jordan's rules of fertility.
1. Thorough tillage, with efficient machinery, to be given if possible when the moisture conditions of the soil admit of satisfactory pulverization.
2. Frequent surface tillage at times of scanty rainfall, in order to conserve the supply of soil moisture.
3. A sufficiently rapid rotation of crops to insure good soil texture, to allow the necessary frequency of applying fertilizing material, and as a main result to secure a paying stand of crops.
4. The introduction into the soil at frequent intervals of an amount of organic matter necessary to proper soil texture and water holding power, either by application of farm manures, by plowing down soiling crops, or by the rotting of the turf.
5. The scrupulous saving of all the excrement of farm animals, both solid and liquid.
6. The purchase of plant-food with due reference to the needs of the farm and to the system of farm management prevailing.
7. The maintenance in the soil of those conditions of drainage and aeration which promote the growth of desirable soil organisms, and the introduction into the soil, when necessary, of such organisms as are essential to the growth of particular plants.