If the crops and management methods are the same, one sample per field is usually sufficient.However, if you want to compare the biological properties in one field based on the presence or absence of diseases, etc., divide the field and sample separately and conduct a comparison test.
Incidentally,When conducting an input test of materials, be sure to create a symmetrical section (one that does not contain the materials to be tested) and perform a comparative analysis.Repeated tests are recommended for external report materials.
Please feel free to contact us for consultation on test design.