What method is used to estimate the availability of Copper, Iron, Manganese, and Zinc in soil?

The method that is used to estimate the availability of Copper, Iron, Manganese, and Zinc in soil is DTPA extraction. DTPA, or diethylenetriaminepentaacetic acid, is a chelating agent that effectively extracts these micronutrients from the soil, allowing for analysis of their availability to plants. This method is specifically suited for assessing trace elements because it can mobilize them from the soil matrix, providing a more accurate picture of the forms that are accessible to crops.

Soil sampling refers to the process of collecting soil samples for analysis, and while it is an important step in understanding soil properties, it does not directly measure nutrient availability. Soil testing encompasses a broader range of analytical techniques and can include various methods, such as pH testing, but it does not specify the particular extraction technique relevant for assessing these micronutrients. Macro nutrient analysis typically focuses on the larger essential nutrients—nitrogen, phosphorus, and potassium—and does not apply to the evaluation of trace elements like Copper, Iron, Manganese, and Zinc, which are classified as micronutrients.