Soil conservation is one of the most overlooked issue regarding our environment. Soil erosion is continuously occurring and not much is being done to prevent it. Soil is the most basic unit that gives rise to all living things. We would be nothing without the soil. Improper soil management practices cause many problems regarding soil conservation. One of the biggest problems is the loss of soil organic matter.
Organic matter is the portion of the soil that is made up of dead and decaying plants and animals. It contains most of the nutrients that plants need to grow and be healthy. Organis matter also has many other advantages. One is the ability of organic matter to hold water so that it is more readily available to plants. With less organic matter the soil does not have the ability to hold as much water. Organic matter also promotes root development and houses organisms that are beneficial to the soil. Without organic matter, soils are much less fertile and generally do not support much plant life.
There are many ways in which soil organic matter can be depleted from improper management techniques. One of these techniques involves leaving plant residue on the soil surface for ground cover. This plant residue is the main source of new organic matter for the soil. The ground cover also helps to protect the soil from erosion by wind and water. Erosion is a major factor that leads to loss of organic matter so with more ground cover erosion is reduced and less organic matter is lost.
Another way that organic matter is lost from the soil is through improper tillage techniques. Whenever the soil is tilled it is allowed to come into contact with the air. When more air is added to the soil the oxygen in the air reacts with the carbon in organic matter. This results in the depletion of organic matter and the release of carbon dioxide into the atmosphere which creates a whole other issue. Because of this tillage should be reduced and should only be done when it is necessary.
Organic matter can also be lost if crops are not rotated properly. Different crops have different effects on the soil. Different crops take up different nutrients from the soil and put certain nutrients back into the soil. When improper combinations of crops are planted in consecutive years certain nutrients are being utilized a lot more than others and the soil is not receiving the proper nutrients in return. This is becoming more and more of a problem because corn prices are so high. Farmers want to plant corn on the same land year after year. When situations like this occur, plants are utilizing more and more of the organic matter in the soil and it becomes depleted.
I have lived on a farm for most of my life so I know how essential the soil is. I help to make management decisions on my parents farm and we are always implementing techniques that ensure that very little organic matter is lost and promote soil conservation. I believe that more people should take a deeper look into this issue and really think about what is best for the soil when they are making management decisions.
References:
http://www.extension.iastate.edu/publications/pm1871.pdf
3 comments:
I agree, proper management is important to keep the fertility of the soil. It seems to me to be a fairly simple price-practicing proper management techniques-to pay to keep the soil viable. Especially when sustained soil would be able to support crops indefinitely while the eroded soil eventually won't grow crops.
Is it the organics or the mineral particles or both that add to water pollution when they erode away? I was not aware that tilling also leads to the loss of organics.
Paula Michels
I couldn't agree more with the need for soil conservation practices. Large scale agriculture is completely degrading the prairie soils of the Midwest. USDA reports from as far back as the 40's and 50's showed evidence that food harvested from repeatedly farmed soils has less nutritional quality. Today we try to supplement that with fertilizer, but do nothing to rebuild the soil and replenish organic matter. I have heard a lot about no till practices, and you say they should only be used when necessary. Why do people till in the first place and when would it be necessary?
Joe Malinowski
Paula,
it is mainly the mineral particles in the soil that run off and cause water pollution. These minerals or nutrients come from fertilizers, pesticides, or herbicides that are applied to the soil. When organic carbon is lost it is lost into the atmosphere as carbon dioxide, which also contributes to the greenhouse effect.
Joe,
farmers often till their land in order to turn under plant debris that is on the soil surface. They also till to prepare a good seedbed for their crops. Tillage is either done in the fall after harvesting or in the spring before planting.
Post a Comment