In a non-uniform field, soil sampling should be conducted by which method?

In a non-uniform field, soil sampling is best conducted using the grid method because it allows for a systematic and structured approach to collecting samples across the entire field. The grid method involves dividing the field into a series of smaller, equal-sized squares or grids. Samples are then taken at specified intervals within these grid squares. This technique helps to capture the spatial variability of soil properties more accurately by providing a representative sample of the diverse conditions present in the field.

The grid method facilitates the identification of specific areas that might need different management practices or inputs, based on the variations in soil fertility, moisture, or texture. This level of detail supports precision agriculture practices, ultimately improving crop management and productivity.

While other methods like zone sampling might work in fields with defined management zones, the grid method is particularly useful for non-uniform fields where variability might not be easily defined. Random and composite sampling methods may overlook significant variations or lead to misleading averages, as they do not provide the structured approach necessary to understand the complexity of such fields effectively.