Disc harrow

Name variations:
– In some regions of the United States, farmers refer to disc harrows as just discs or disks.
– The term “harrow” is reserved for lighter types of harrows like chain and tooth harrows in these regions.
– Disc plows are often considered a separate class of implement from disc harrows in the United States.
– The distinction between plowing, disking, and harrowing as separate tillage steps is common among farmers.
– Disc harrows are used as secondary tillage tools.

History:
– Before modern tractors, disc harrows were typically horse-drawn with no hydraulic power.
– Early disc harrows had two sections and adjustable discs for transport and ease of use.
– Overuse of disc harrows in the early 20th century in the High Plains of the United States may have contributed to the Dust Bowl.

Today:
– Modern disc harrows are tractor-driven and raised by a three-point lift or hydraulically by wheels.
– Large disc harrows have side sections that can be raised vertically or folded for transport.
– Hydraulic systems in modern disc harrows provide easier operation and adjustment compared to older horse-drawn models.

Uses:
– Heavy-duty disc harrows are used to break up virgin land and incorporate material into the topsoil.
– Secondary disc harrows help incorporate residue left by primary harrows and loosen packed soil.
– Disc harrows promote decay of dead plant material and aid in fertilizer incorporation.
– They are used before plowing to prepare the land and reduce clogging during plowing.
– Disc harrows are effective in incorporating agricultural lime and gypsum into the soil for root development.

Secondary uses:
– Worn down disc harrow blades are repurposed as hand tool blades for firefighters, farmers, and trail-building crews.

Offset disc harrow:
– Heavy-duty disc harrows with large diameter blades and increased disc spacings are used for primary tillage.
– Secondary disc harrows with narrow disc spacing are used to break down soil clods for better water penetration and soil aeration.
– Soil type and moisture content are crucial factors in choosing secondary tillage equipment.
– Lighter secondary disc harrows enhance soil biota activity and create a suitable seed bed for planting.