Pages

Equestrians Speak up:

Equestrians Speak up:
Don't look away, point fingers!

Monday, September 29, 2008

"Soil Compaction " Beware of Big Wheels !

Due to structural and technological developments in cultivation of fields the agricultural sector has been subjected to profound changes over the last 30 years. The use of ever heavier machines left its “footprints’ on the way farmers are forced to do business these days.
We call this footprint “Soil Compaction” and it could be one of the reasons why today’s farmers are complaining about heavy losses in yields. “Soil Compaction” is one of the major problems we are dealing with in “modern technology farming”, because losses in harvest caused by this phenomenon could go all the way up to 20%.


So what is “Soil Compaction”?

Soil compaction occurs when weight of livestock or heavy machinery compresses soil, causing it to lose pore space. Soil compaction changes pore space size, distribution, and soil strength. Affected soils become less able to absorb rainfall, thus increasing runoff and erosion. Growth of plants is slowed down in compacted soil, because with pores closed by compression of soil there is little space left for air and water, which are essential for root development.

There are several forces, natural and man-induced, that compact a soil. This force can be great, such as from a tractor, combine or tillage implement, or it can come from something as small as a raindrop. Listed below are several types of soil compaction and their causes.


  1. Raindrop impact - This is certainly a natural cause of compaction, and we see it as a soil crust (usually less than 1/2 inch thick at the soil surface) that may prevent seedling emergence. Rotary hoeing can often alleviate this problem.

  2. Tillage operations - Continuous moldboard plowing or disking at the same depth will cause serious tillage pans (compacted layers) just below the depth of tillage in some soils. This tillage pan is generally relatively thin (1-2 inches thick), may not have a significant effect on crop production, and can be alleviated by varying depth of tillage over time or by special tillage operations.

  3. Wheel traffic - This is without a doubt the major cause of soil compaction. With increasing farm size, the window of time in which to get these operations done in a timely manner is often limited. The weight of tractors has increased from less than 3 tons in the 1940's to approximately 20 tons today for the big four-wheel-drive units. This is of special concern because spring planting is often done before the soil is dry enough to support the heavy planting equipment.

  4. Minimal Crop Rotation - The trend towards a limited crop rotation has had two effects: 1.) Limiting different rooting systems and their beneficial effects on breaking subsoil compaction, and 2.) Increased potential for compaction early in the cropping season, due to more tillage activity and field traffic.

Greater axle loads and wet soil conditions increases the depth of compaction in the soil profile. Compaction caused by heavy axle loads (greater than 10 tons per axle) on wet soils can extend to depths of two feet or more. Since this is well below the depth of normal tillage, the compaction is more likely to persist compared to shallow compaction that can be largely removed by tillage.
What is the conclusion ?


  1. Well, thinking about farming for a global market ? Forget it !!

  2. Thinking about farming for a local community ? Way to go !!!

  3. Is bio-diesel a real alternative ? Not at all, folks.

Soil Compaction is accompanied by an extensive use of fertilizers in order to gap the bridge of harvest loses. It also is a contributing factor towards erosion and many other negative effects on plants and animals. Bio-fuels for example are based on large scale farming, a non sustainable form of agriculture.

As equestrians we need to pay attention to these things, too:We need to be much more selective when buying feeds for our horses, reconsidering current diets and maybe replacing them with more common and more economical, but better feeds from local farmers.
We need to manage our land more carefully, we need to promote small scale farming for and organic farming with workhorses in our communities.
With 9,6 million horse-owners in the US and many more world-wide we do have a voice loud enough to be heared !


No comments: