Soil Sampling Unfamiliar Land

Landowners, producers and crop consultants are sometimes faced with the challenge of creating a soil sampling plan for unfamiliar land with limited cropping history, yield data or other pertinent information that might normally be used to build management zones or properly position sampling points.  This update will highlight a few sources of aerial maps, soil data and cropping information available online usually for free or very little cost.

A good starting point would be an aerial image and soil survey layer that is available from WebSoilSurvey.  https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm Users can identify the predominant soil types, descriptions and physical properties, locations and the number of acres of each type within a field.  It can also be used to mark boundaries, measure linear distances and measure field acres within a boundary.

Google earth https://www.google.com/earth/ can be used to view historical satellite images and the colors shown can indicate which crops were grown each year, and might give clues about previous planting dates, reduced crop stands, flood events and prevent plant years.  If the user has general knowledge of local growing conditions in a particular year, such as the severe drought in many areas in 2012, these satellite views can show the crop grown and how various areas performed under harsh conditions.  Try to search for images from a corn year grown under very wet conditions and a corn year grown under very dry conditions and attempt to do the same for soybeans or other crops.

USDA DataGateway https://datagateway.nrcs.usda.gov/GDGOrder.aspx offers a wide range of high-resolution aerial images, climate and precipitation records and lidar elevation maps at the county level.  Many of these are large files that must be ordered and then downloaded through an email link later.  It requires extra time to perform the initial setup, but subsequent orders are quick and easy.

Historical aerial imagery can reveal old building sites, fence lines, ponds, forested areas, abandoned oil wells and other artifacts that might impact current crop production.  Several of these sites are reviewed here.  https://gisgeography.com/free-historical-imagery-viewers/

There are several tools available that can add to your knowledge base about a new and unfamiliar land area, A few hours spent gathering imagery can help you develop a quality soil sampling plan.