Soil sampling and testing is very vital in any agriculture field before planting. Because it gives you details and characteristics of that soil including the average nutrient availability within a defined area, the spatial and temporal variability of soil properties and soil physical properties.
How to sample
- Consider variability introduced by soil series, previous field subdivision, presence of old farmsteads with a history of livestock.
- Define sampling areas according to field history.
Soil testing refers to the process of taking the samples from the field to the laboratory to analyze different soil aspects. A soil test determines the soil’s nutrient supplying capacity by mixing soil during the analysis with a very strong extracting solution (often an acid or a combination of acids). The soil reacts with the extracting solution, releasing some of the nutrients. As soil supplies most of the mineral nutrition for higher plants through the plant’s root system, the extracted nutrient concentration is evaluated based on research that relates plant utilization to soil nutrient concentrations. This works well for some nutrients but is less accurate for others. Nutrients supplied from soil organic matter (OM) decomposition (such as nitrogen and sulphus) depend more on the rate of OM decomposition than on extractable levels of these nutrients.