Soil Management
Methods have been used to combat the erosion of soils, specifically when it comes to agriculture. We have learned a lot from past events, and employ some very good, ecological techniques. You will read about some of the past issues in the next blog, but here we will discuss the techniques to prevent them from happening. These managements strategies are put in place to sustain and restore fertility and increase economic benefits and crop yield.
Cover Crops
Cover crops are crops that are planted alongside the target crop to increase soil quality and fertility and decrease soil eroision along with other benefiting factors such as pest and disease control. A cover crop will be planted in a field with the target crop, and may be plowed underneath the ground to provide nutrients to the crops surrounding it. Often times the cover crops are legumes (beans/peas), as these types of plants take nitrogen from the air, and "fix" it into a form that plants can use. Here is a picture of cover crops placed alongside the target crop.
Cover crops also improve the amount of organic matter in the soil, by replacing what would just be empty space of dirt with vegetation that contributes to the nutrients of the soil. They decrease soil erosion and improve water retention of the soil by covering up exposed soil (less soil leaves in runoff) and thus providing a way for water to trickle down through the soil.
Crop Rotation
Crop rotation is the practice of planting different crops during consecutive growing seasons. By doing this the following benefits are applied to the soil and plants:
- The nutrients used by one set of crops may be different than those utilized by another. By rotating crops that differ in their nutrient requirements, the soil will be less likely to be diminished of these nutrients upon harvesting. If cover crops are planted every other season, then the nitrogen content can be increase for the target crops.
- Different crops have different root lengths, so rotating crops can have the effect of the crops taking nutrients and water from different levels over the seasons, resulting in a lower need for fertilizers and irrigation.
- Pests and disease tend to foster if one crop is left in an area for too long. By rotating crops, farmers can limit the amount of these and, thus, increase yield and decrease the amount of pesticide used.
Nutrient Management
Nutrient management is the practice of not "over fertilizing" plants. The farmer studies the amount of nutrient his/her crops needs and tests the soil to determine the amount of fertilizer to spread. Too much fertilizer can result in run-off of the fertilizer, which can have a negative effect on surrounding water bodies. Not enough nutrient will cause the crops to not grow, loose soils, and erosion. By practicing nutrient management, farmers can optimize their crop management.
Tillage Management
Tillage is the agitation of soil after harvesting. It basically breaks up the soil and aerates it, which has been used to "prepare" it for the next growing season. While it does provide aeration and preparation of the soil, tillage also leaves soil open to erosion, can destroy the organic layer of the soil, and destroys the water capacity of the soil. No-till methods aerate the soil without tillage, and methods that decrease the amount of tillage are recommended for soil health.
Water Management
We will talk more about this in the hydrosphere unit, but it is obvious that over-watering a crop area will result in erosion of soil. Over-watering is done at many crops areas and results in flooded fields and eroded soils. To counteract this farmers can plant crops native to the area that do not require external irrigation or employ minimal water techniques, such as drip-irrigation - the process of only watering the crops themselves by using a hose with small holes at each crop. Here is an graphic of a drip irrigation system:
Tillage is the agitation of soil after harvesting. It basically breaks up the soil and aerates it, which has been used to "prepare" it for the next growing season. While it does provide aeration and preparation of the soil, tillage also leaves soil open to erosion, can destroy the organic layer of the soil, and destroys the water capacity of the soil. No-till methods aerate the soil without tillage, and methods that decrease the amount of tillage are recommended for soil health.
Water Management
We will talk more about this in the hydrosphere unit, but it is obvious that over-watering a crop area will result in erosion of soil. Over-watering is done at many crops areas and results in flooded fields and eroded soils. To counteract this farmers can plant crops native to the area that do not require external irrigation or employ minimal water techniques, such as drip-irrigation - the process of only watering the crops themselves by using a hose with small holes at each crop. Here is an graphic of a drip irrigation system:
Shelter Belts
Shelter belts are lines of trees planted around crop areas to cut wind erosion. The trees block the wind and reduce the amount of soil that is eroded.
Contour Farming
Crops are planted on the contour (slope) of the land as to follow the water flow pattern. This minimizes flooding of the crop area, and regulates the water flow, thereby reducing erosion.
Specific Profiles
There are a few specific profiles that you need to know in order to understand the diversity of soils through the globe. (Also, the may be on your exam...) Here you will read about each. Please click on each link...you may want to write down differences between the profiles.
Temperate Podzols (Poor Growing)
Brown Earths (Good Growing)
Rain Forest Soils - About halfway down the page
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