Tillage

Tillage disrupts soil aggregates, and repeated disruption destroys soil structure. It also causes a long-term decline in soil organic matter, which further destabilizes soil structure. Tillage disrupts the continuity of large soil pores and restricts the movement of water through the soil profile, creating soil drainage problems. Repeated use of tillage tools operating at the same depth, or when the soil is too wet, results in the formation of compacted zones which restrict both water movement and root development. 

Secondary tillage operations performed to prepare fine seedbeds usually cause the formation of impermeable crusts on light-colored silt loam soils such as Blount and Crosby. These crusts reduce seedling emergence, air exchange and water intake, all of which reduce yields. When thick crusts form, disrupting them by rotary hoeing or cultivation often improves yield, particularly in dry years. 

Tillage is one of the largest out-of-pocket expenses used for crop production and often does not generate enough yield to make the tillage profitable. While no-till can reduce production costs and increase profits, it also creates problems that producers must solve with proper management of the other inputs and production practices. Some of these problems are colder, wetter soil at planting, more root rot disease, slower emergence and growth, dealing with crop residues and the diseases they contain, etc. There are times when tillage is warranted, and will likely be profitable. Here is a partial listing of some of the situations when tillage may be needed: 

  1. Use tillage when inadequate soil drainage leads to serious yield loss due to root rot diseases, poor stand establishment or late planting. 
  2. Use tillage to bury crop residue and thus reduce pathogen and insect survival that can infect a following crop. 
  3. Use tillage as a prelude to land leveling, rock removal, and for the incorporation of soil amendments such as lime or very high rates of fertilizer. 
  4. Use tillage to mitigate compacted soil layers or zones that interfere with water movement into and through the soil which may delay planting, harvesting and other field operations. 

The cost to perform various tillage operations and the yield increases needed to pay for those operations can be found in Table 5-1. 

Table 5-1: Cost of Various Tillage Operations and the Yield Increases of Corn, Soybean and Wheat Required to Pay the Cost. 

Operation* 

Typical cost 

Yield increase (bu/ac) required to pay for tillage** 

Column1

($/ac) 

Corn 

Soybean 

Wheat 

Chisel Plow 

17.8

4.7

2

3.9

Disk Chisel 

17.85

4.7

2

3.9

Field Cultivator 

13.55

3.6

1.5

2.9

Land Leveling 

13.5

3.6

1.5

2.9

Moldboard Plow 

21.25

5.6

2.4

4.6

Strip Tillage 

17.25

4.5

1.9

3.8

Sub-Soiling 

19.85

5.2

2.2

4.3

V-Ripping 

20.45

5.4

2.3

4.4

*Cost of tillage operations from Ohio Farm Custom Rates 2016 available at: aede.osu.edu/about-us/publications/ohio-farm-custom-rates-2016 

**Based on corn, soybean and wheat prices of $3.80, $8.85 and $4.60 per bushel, respectively.