Wish you would have covered the "getting dirt core out of tool" better. Cause the dirt in my core tool is jammed in there. 10 seconds to take core. 10 minutes to dig all the dirt out.
For a single soil sample, (assuming you are doing chemistry, pH, and organic matter only) the lab needs maybe 1/4 cup. However, that is after drying and screening, so most labs will ask for 1-2 cups and do the drying and screening at the lab. She did not cover how to sample an entire field in this particular video. Because soil varies, you need to take numerous cores/slices randomly through the field, put them in a bucket, mix them up very well, and send the volume your lab requests from that bucket. The real challenge is knowing what areas should be combined or separated to define a field, and how large a field can be. This varies greatly with where you live, the soil maps for your property, how the fields are managed, and the soil movement history for your property. For example, giant corn fields In Iowa may be all one soil type, managed the same, and extremely similar throughout the entire field. A small old farm in New England may have 6-8 soil types on the same property, and may have a manufactured loam that was brought in one area by an excavator during a construction project to replace soil contamination from lead paint flaking off the old colonial barn and farmhouse. The Iowa farmer can do a single soil sample and test for many acres, and the New England farmer needs to do multiple samples using her soil survey maps, her knowledge of the property history, how she manages the plots, and observed obvious differences in the soil. New England soils are like a patchwork quilt of many soil types, because the soil in the region is “glacial till”, created by the soil getting pulled into glacial ice and tumbled slowly, and the deposited and sorted by the melting glacier and resulting water flows. The glacier literally wore the tops of the Appalachian mountains way down, churned everything up, and left a rubble field in its wake. This creates the charming New England landscape, and an advanced soil puzzle for farmers.
