UNDERSTANDING SOIL EROSION

1-30-17il-jan-blogIn this video, you will see that the soil sample on the left starts to crumble and wash away with the water.  This is because the soil has been tilled, or the lower soil is being mixed with the visible soil.  The soil on the right is from a no-till field, which is where the soil is left as it is, and the bottom and visible soil isn’t mixed.

Many factors go into the decision.  Let us first start by explaining why farmer till their land.  Some of the reasons that a farmer may decide to till their land are to mix the soil, create a flat surface, control weeds, and aerate the soil, or creating air space in previously compacted soil so water can penetrate it.  Aerating the soil would be when the soil becomes compact, and people will create space so air and water can penetrate.

1-30-17notillplanterTillage has been used since around the 17th century, and no-till has been used on a small scale starting in the 1940s. This means that today, many farmers today are accustomed to tillage.  No-till also requires more herbicide because as stated before tilling the soil is used as a weed control. No-till requires special planting equipment that many farmers don’t have and can cost over $100,000, but no-till also reduces production cost they don’t have to pay for the labor or fuel for plowing.

1-30-17soil-texture-triangleAlso, no-till not only reduces soil erosion, but it also can help with conserving water and increases soil microbes.  This could reduce chemical runoff because fewer chemicals are being applied and the leftover plant material helps water absorb into the ground, but this doesn’t happen the first year it is implemented it take a long time.  Every farm is different too.  This is a photo of the soil texture triangle which has all the different types of soils.  You can tell from this photo that there are many varieties of soil, and not every variety works best with no-till.

If you have further interest in the subject, this video by Matt Helmers with the Department of Agricultural and Biosystems Engineering at Iowa State University which demonstrates the difference in soil erosion between no-till, conservation tillage, and intense tillage during a heavy rainstorm would be of use.  Conservation tillage would be when the farmers only till the area that they are planting.  This video is very intriguing because it not only shows surface run-off, but surface drainage as well.

Every farm and farmer are different, and no-till is a great option to help reduce soil erosion, but every farmer needs to evaluate the positive and consequences of no-till for their particular piece of land.  Because if we compare a farm in California with a farm in Illinois it would be like comparing a Red Delicious apple with a Granny Smith- there are similarities but also very different.

mary-marsh

Mary Marsh
University of Illinois

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