The Effects of Soil Compaction on the Production of Processing Vegetables and Other
Cash Crops:
A Review
Researcher: C.K. Stevenson, RCAT, Principal Researcher;
G.S. Iler
Funding: $15,000
- To conduct a literature review on the effect of soil compaction
on the production of processing vegetables (i.e., tomatoes, sweet
corn, green peas and green and wax beans) and other cash crops and
to survey the state of the art for the prevention and relief of
this problem.
- The summary of research findings would help to illustrate the
significance of and improve the awareness of soil compaction among
growers.
- The literature review could act as a stepping stone to applied
research on soil compaction.
- To create a current state of the art knowledge base. From this
base future research strategies could be better targeted to modify
current production practices.
- Information gathered can be used to emphasize the importance
to extension workers and farmers, of the serious effects that soil
compaction has on the soil when intensive cash cropping occurs.
In recent years, increased mechanization and rationalization has
increased the risk of soil compaction in Ontario's processing crop industry.
Reports from the field are confirming the compaction damage from increased
field traffic.
Soil compaction is a reorganization of soil particles resulting from
external compression forces on the soil. Compaction increases the bulk
density of soil due to a decrease in the number and volume of large
pores, which in turn alters aeration, water infiltration, and hydraulic
conductivity, and increase soil strength.
Soil compactibility is dependent on soil texture, with well graded
soils compacting more tightly than poorly graded soils.
Soil compaction will increase with increases in soil water content,
tire contact pressure, and vehicle weight, or axle load. Compaction
will decrease with increased vehicle speed, reduced or controlled traffic,
and increased number of wheels carrying the vehicle. The use of tracks
to replace tires may reduce soil compaction. At great depth, the stress
caused by traffic mainly depends on the axle load. Present data show
axle loads above 10 tonnes per axle should never be used otherwise soil
may be damaged permanently.
Lightly or moderately compacted soil may not cause reduced yields
and may improve yields, especially in dry soil conditions. Yield increases
in dry years result from improved soil water and nutrient transport.
Severely compacted soil impedes root growth and development. This
restricts a plant's ability to utilize soil water and nutrients by reducing
the soil volume utilized by roots. In very wet or very dry soil, compaction
multiplies the impact of stress on the plant and reduces plant yield.
However, if adequate moisture and nutrients are supplied to the reduced
root system, the effect of compaction will be negligible.
Soil compaction can affect nutrient availability. It can increase
incidence of soil borne plant diseases and reduce the beneficial microbial
population.
There has been relatively little research done on the effect of soil
compaction on the yield of processing vegetable crops. Compaction can
reduce yield by reducing the quality, weight and size of the fruit.
It can delay plant development and maturity, reduce plant stand, height
and seedling emergence. Subsoil compaction can reduce yields by delaying
planting and other field operations.
The reduction in crop yield and quality due to soil compaction is
an economic cost to growers and processors. Compaction also increases
input costs.
The alleviation of compacted conditions can result from freezing/thawing
and wetting/drying cycles but this effect is limited to the upper layers
of soil, especially in the short term. Research has shown that the effects
of subsoil compaction persist for some time even in years with heavy
frost. The alleviation of subsoil compaction may result from the growth
of plant roots or the action of earthworms.
Subsoiling, as examined by research, has shown mixed results, with
in-row subsoiling showing the greatest benefits. The placement of fertilizer
to compensate for compaction-reduced yield reductions has benefits and
is receiving attention.
Further research is needed to better understand the nature of soil
under compression, the mechanics of plant growth under compacted soil
conditions, and the process of compaction alleviation. To reduce the
risk of soil compaction new machinery and crop production systems need
to be developed.
Created: 03-23-1996
Last Revised:
Tuesday, May 10, 2011 12:45:55 PM
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