Soil Sampling Advice.

No-Till Farmer gives advice out of Kansas State offering seven tips on soil sampling. The advice is not terrible.  It mentions using the factors of soil formation, but it really does not get into how.  The advice about lots of samples is good.  I have seen research results that indicates 15 cores per sample is the way to go.  Many grid samplers only get 3 to 5 probes per sample.  The also don't mention that the sample needs to be well mixed by grinding or crushing to get a representative sample.  Sometimes high clay soils are too wet to get them mixed well.  We dry those samples and crush or grind before they go to the lab.  The article also mentions seasonal variability.  The causes of variability that I have seen are moisture and temperature related.  Sampling conditions may not always be perfect, but data is better than no data when making your fertility decisions.  For precision farming, defining your sample areas is critical.   You also need the technological expertise to make variable rate maps. Maybe some of this information leads you to hire a consultant.