Agrophysics

"Agrophysics is a branch of science bordering on agronomy and physics, whose objects of study are the agroecosystem - the biological objects, biotope and biocoenosis affected by human activity, studied and described using the methods of physical sciences." - Wikipedia

We use these guidelines and testing methods outlined by the Soil Quality for Environmental Health.
Together with Modern advancements in soil testing

Statistical Correct Soil Testing Method for Use in Agrophysics

  1. Field interview with grower, noticeable difference in texture, torque needed to pull equipment, changes in field over the years, bush cleared, fence line moved, pile buried, seeding pattern. Find out how each crop is seeded and Seedbed utilization and application methods and farming practises
  2. On-field map look at possible locations to take a sample and mark them representing 80% of the average conditions of the fields. If 80% similarities cannot be achieved, then 2 or 3 different zones may have to be sampled separately. This should only occur in special situations, ridge in field, peat soil, and escarpment and only at the grower’s recommendation. 
  3. Take samples minimum of 2 full seeder pass from any headlands or in-field equipment steering direction changes, eg rock pile, damage ditch.

Sample slice of soil should to a 90-degree angle to the seeding row.

Slice should be taken exactly the same way with each sample site. Two slices to be taken, one on each side of the GPS position. 

Each slice should cover 50% of the seeding row, eg 12-inch rows, two 6 inch cutes each taken the seed row into the sample as well as mid-row. If the grower was seeing corn at 30-inch spacing a slice of 15 inches must be taken on each side to get one correct sample. 

Each slice is then expected to see for anything that may not represent an average sample and notes taken. On an average field I fine an average of one slice that is rejected because it would not be an accurate representations of the field. This is usually causes by a large disposition of a substance not seen in other samples. Eg, chuck of animal waste, deer droppings, rocks, chunk of straw..ec.

The first slice should be taken from a small hole to see subsoil and make note on filtrations and make up of sub soil. This will also help when separating each A horizon of soil from B horizon in an accurate sample. The separation of these two layers is easy taught and very important in accuracy of sample. This layer can be easy identified because it is usually the soil profile the producer works to the depth of his equipment. By taking note of sub soil important changes like from a gravel to a clay subsoil will change the management of the field and maybe cause to recommend separate zones in a field. 

Each slice taken is examined, cleaned from obstructions, roots do not eat rocks, and larvae’s, etc. 

An earthworm count should also be done and once cleaned of all particles that may not represent the average of the field placed in a 5 gallon pail. I place all the driver side samples in one pail and all the passage door side in another. 

A sampling point (2 slices, expanding the seeding operation) should never exceed more than 20 acres of the fields. 
80 acres has minimum 4 sampling points 

This represents the standards set by USDA, United Nations, Universities, that a 1 one inch probe of soil extracted on each acres moving to 1 probe every 2 acres when the sampling acre exceeds 80 one inch probes. 
160-acre fields without zones minimum 8 sample point

Each 6-inch slice represent the same A horizon soil extraction as 6 to 10 soil probes, each in perfect row, perfect depth to get one unison representation of the soil sample. 

Example

80 acres Corn seeded on 30-inch rows

One 15 inch slice on each side of GPS coordinate.

4 GPS point, 120 inch of soil slices all right angle to farmers seeing practice

Each pail will have 2 to 3 gallons of soil in them. They are hand mixed and then each pail is mixed to the same procedure that a grain sample would be mixed to create one unison sample to represent his harvest. Place that into a bag that represents a static representation of all particles that make up the A horizon of his soil. Each particle of sand, silt, clay, organic matter, fertilizer, past application and present  

In order to do this with a soil probe is impossible. I have tested thousands of fields with a probe and once compacted into a pellet in the probe it hard to see what’s A and what’s B horizon let alone all the cross-contamination and never knowing what you’re really getting. 

To take 120 soil probes all in one line to one depth and have the knowledge of what each particle your gathering looks like, impossible and yet we can extract samples as fast as any probe.

If your soil was a horse and it was sick and you needed a horse doctor, what kind of horse doctor would you want?

 

Well now your dirt is sick, what kind of dirt doctor would you want? A vet who is hands-on or someone who has no idea what they are doing hoping that computer data will figures out a bad sample. 

NO program no lab,  no one can do anything will a sample that is not accurate…the end.

The same conclusion was made 30 years ago on the difference between a plant sample and a feed sample. The Plant sample was a probe of that spot when its roots were. The feed represented a mixture of many plants and many roots making the feed accurate sample and the plant sample only represent that plant nutrient content.

Eg. When sampling hay bales a sample is taken into hardcore which represent then a band of plants making it statically correct of the same should be taken across a softcore of the bale, it would only represent a plant and not the bale.

All note on insects or conditions on roots and stems to be informed to grower data. This helps knowing levels of infestation to help plan treatments or rotation changes.

I have 30 years plus of real data showing these results.
Reinhard

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