Soil Basics

A handful of soil is filled with thousands if not millions of life forms working together to create nutrients and aereate the soil. Soil is a natural resource that is commonly overlooked because we see it everywhere, yet the kind of soil needed for food production is being lost rapidly across the country and the world. Urban development and land use changes are removing productive agricultural land from our soil base. Today, roughly 40% of the soils in Marion County are ideal for agriculture. The state has zoned these resources specifically for agricultural uses. Efforts to increase production however are causing erosion.

Soil conservation starts with the property owner. If property owners understand how the soil works they can begin to improve it and more easily identify and correct problems. All rural property owners and agricultural producers should be aware of their role in protecting this vital resource.

Importance of Soil

Soil is a medium for plant life and its quality is directly related to the success of that plant. The types of soil on your property have a huge influence on:

• Type and quantity of crops your land can support.
• Ability to absorb water, determining when and how much you will need to irrigate.
• Ability to construct buildings with foundations.
• Soil erosion runoff

The attributes that determine soil productivity are: soil type, compaction, pH level, and nutrient levels. People who identify these characteristics for their soil will have a good understanding of what can be grown on their property and can determine if the soil needs any amendments. Many resources are available to help property owners identify their soil profile. 4R stewardship provides a framework to achieve cropping goals. Make sure to use the Right source at the Right rate at the Right time and in the Right place.

Soil Types

Soils consist of organic material, minerals and air space, and are classified into three basic types, or textures:

• Clay Soils, fine-grained, nutrient rich, heavy, under-draining.
• Sandy Soils, coarse-grained, light, easy to work, over-draining.
• Silty Soils, fine but coarser grains than clay, high in nutrients.

Individually these three types may present some challenges for irrigation and workability. Loam, a combination of the three, is the ideal soil type. Clay is a common soil type in the county that doesn’t drain or provide water to plants well. Adding compost or organic material to your soil is a good idea and will help improve drainage, prevent erosion, and balance the pH levels of most soils.

Soil Tests

Soil testing can help property owners understand their soils’ nutrient deficiencies, and identify soil characteristics that can be improved for a better growing environment. There are several ways you can test your soil to determine the physical properties and nutrient levels. These include: “Do it yourself” home tests, home commercial soil testing kits, and professional soil testing laboratories. The home commercial test can be purchased at a local gardening store for a relatively low cost (~$20) given the money one can save from fully understanding the irrigation and amendment needs of their soil.

The “do-it-yourself” methods can provide fairly good results if done correctly; soil type, compaction, pH, and biological health are the four characteristics of a soil that can be tested with these methods.

The NRCS or the OSU Extension office can assist property owners with information on collecting a soil sample and locating a testing lab.

Nutrient Management

Nutrient Management is used to manage the amount, source, placement, form and timing of the application of plant nutrients and soil amendments. The goal is to optimize crop yields and minimize non-point source pollution while maintaining or improving soil conditions. The most common soil nutrient amendments are: nitrogen (N), phosphorous (P), and potassium (K). Nutrient Application should be done in response to a plant’s uptake characteristics, while considering weather and climate conditions to minimize runoff.

• Apply nutrients uniformly
• No direct nutrient application in established buffer areas
• Don’t apply to frozen, snow-covered or saturated soils
• Don’t apply dry manure when there is potential for wind-driven loss
• Delay application if heavy rain event is forecasted within 24 hours of the time of application
• Avoid applying upwind of occupied structures