Disking

the working of the upper layer of the soil with disk implements, such as disk harrows and shallow plows. The depth of loosening and the degree to which the soil is broken up, mixed, and turned over depend on the angle at which the disks are set in relation to the line of thrust (the “angle of attack”), the shape and sharpness of the disks, the weight of the implement, and the properties of the soil. If the angle of attack is decreased there is less loosening and breaking up of the soil, and less soil is mixed and turned over.

Disking is done before and after plowing. Heavily sodded soils are disked before plowing to ensure the rapid breaking up of the sod; weakly sodded soils are disked after plowing, across the furrows or at a sharp angle to the direction of plowing. Disking is indispensable in the reclamation of marshy peat soils and peat bogs after they have been plowed with a marsh plow. Disking is used extensively for presowing soil preparation. Disking before fall plowing kills young weeds and agricultural plant pests that winter on stubble and weeds and in the upper layers of the soil. Moreover, it protects the soil against loss of moisture.

Disking is an effective method for combating pernicious weeds such as wild oats, quack grass, and sedge. Careful fall disking at a depth of 5-7 cm is done to combat wild oats. To combat quack grass, disking is done in two directions at a depth of 10-12 cm, followed by the plowing under of the broken up rootstocks. To combat sedge, disking is done after plowing.

When working clean fallow in arid regions, disking is less effective than cultivation with subsoilers. Disking clean fallow during the summer is especially dangerous since it will inevitably intensify wind erosion. It is a good way to maintain meadows and areas planted with perennial grasses, especially old alfalfa fields. Disking is usually done by the shuttle method. The quality of disking is evaluated on the basis of the evenness of depth, the degree of soil cultivation, the absence of flaws, and the time required.