Multinutrient Extraction – Need of the Hour – A Review

Abstract

A Multi nutrient extractant is a standardized reagent which is capable of extracting several elements or ions simultaneously to facilitate quick estimation of soil macro and micronutrients saving time, labour and resources. The procedure for extraction should be rapid, consistent, less expensive, reliable and considerate of the soil physico-chemical properties. Progressive research on developing such an extractant and an extracting procedure has resulted in various extractants such as Morgan reagents, Mehlich reagents, Diethylene Triamine Pentaacetic Acid (DTPA), ammonium bicarbonate- DTPA(AB-DTPA) and various other formulations. This article presents a comprehensive review of all the multinutrient extractants developed so far and their advantages and limitations in the extraction of soil macro and micronutrients, their efficiency in the extraction of nutrients and correlation with standard extraction procedures. Also, the potential utility of multi nutrient analysers such as Inductively Coupled Plasma – Optical Emission Spectrometry and Atomic Absorption Spectrometers can be achieved by employing appropriate multi nutrient extractants in the estimation of soil nutrients which could establish significant relationship between estimated nutrients and crop response. The selection of an appropriate multi nutrient extractant and the standard extracting procedure is commendable and is the need of the hour to support the fertilization schedule for crop cultivation and sustainable maintenance of soil health which has direct implication on food and nutrition security and ecological sustainability.