Which of the following is a method to assess soil nutrient content?

Soil testing is a scientifically validated method to assess soil nutrient content. This process involves collecting soil samples from specific areas of a field and analyzing them in a laboratory to determine the levels of essential nutrients such as nitrogen, phosphorus, potassium, and micronutrients. The results provide precise information about nutrient deficiencies or excesses, enabling farmers to make informed decisions about fertilization needs and soil amendments. This method is essential for effective crop management and maximizing yield while minimizing environmental impact.

In contrast, visual inspection relies on the observation of plant health and soil characteristics, which may provide some insight but lacks the precision needed to quantify nutrient levels accurately. Growing test plots can help gauge how crops respond to varying conditions, but they don't directly measure soil nutrient content. Sampling pest populations focuses on pest management and does not relate to nutrient assessment at all.