National Academy of Agricultural Sciences (NAAS)
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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Universal extractant is a term used to designate reagents or procedures to extract several elements or ions to assess soil fertility status or levels of toxicity. The extraction procedure should be rapid, reproducible, inexpensive, adaptable to soils from different regions, and extract the labile forms of nutrients which might be potentially available to plants. Most of the extractants in use are fall short of these requirements. Modified M3 method for simultaneous extraction of macro and micro nutrients in arable land soils and it was found to be greatly correlated with the existing methods for NO3-N, available P, Zn, Cu and B, exchangeable K, Ca and Mg and easily reducible Mn. A new, easily applicable soil extraction method has been developed using the coffee percolator principle and the results are in close correlation with those of conventional soil testing methods and with the nutrient uptake of the sunflower and ryegrass used as test crops. Several techniques using cation or anion exchange resins which allow the simultaneous extraction of Ca, Mg, K, Al, Mn and P from soil were assessed and all the resin procedures have the potential to reduce the time required for analysis of Ca, Mg, K, Mn and P in soil. Despite of these developments, today the challenge is to select an appropriate extractant that take full advantage of multi-element analysers such as the ICP, suitable for a range of soil characteristics, such as pH, texture, organic matter content, and having an established significant relationship between elemental level and crop response. Therefore evaluation of various extraction methods for use under particular soil conditions, in various regions or within specific cropping situations is still needed.
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