What you should know about Soils and Site Characteristics
The proper management of a farm’s natural characteristics is key to safe water and healthy, productive soil. The potential for groundwater and surface water contamination on an operation is primarily determined by natural characteristics such as soil texture, slope, and depth to an aquifer. The potential for soil to be eroded by wind and water is also based on natural characteristics.
To maintain a good relationship between agriculture and the environment, you need to use management practices that work within these limits. Chapter 1 offers a process for you to identify and evaluate the natural characteristics of your operation and consider the associated risks. It also acts as an ideal foundation for the development of an EFP. In the following chapters, you can measure how your management practices suit the natural characteristics of your farm and then make adjustments or changes as needed.
Natural characteristics. The landscape (topography) and the soil on your farm influence the type of farming you can do, the inputs you need, and the results you get. These natural features also affect the potential for environmental risks, such as soil erosion by wind or water, and contamination of ground and surface water.
Soil type. Some soils allow water, pesticides, fuels and other substances to move quickly through them. Sands and loamy soils have larger pore spaces between the soil particles than do clay soils and silts. Water quickly percolates through these large pores, carrying other substances to groundwater.
Soils with smaller pore spaces, such as clays and silts, slow the movement of water and any substances it carries. The fine soil particles act as a natural filter. Pesticides and other farm inputs move slowly through the soil, so bacteria and other organisms have more time to break them down before they reach groundwater.
Erosion. Loss of valuable topsoil decreases productivity. It can also cause deterioration of surface water quality if soil particles and associated fertilizers and pesticides reach streams or lakes. Sandy-textured soils are prone to wind erosion, especially in areas where windbreaks or sufficient plant residue for protection are absent. The potential for water erosion on fine-textured soils is high, especially on sloping land and bare soils.
The best way to start your environmental review is to assess the natural risks on your farm. This will allow you to choose farming methods that reduce risks to the environment.