Simple determination of NPK in the soils
1999
Tasnee Attanandana | Chairerk Suwannarat | Somchai Kritapirom | Boonsan Tealnugutoom (Kasetsart Univ., Bangkok (Thailand). Faculty of Agriculture. Dept. of Soil Science)
Results showed that the determination of nitrogen and phosphorus in the soils using the spectrophotometer was significantly correlated with the respective standard color charts. Fifty five samples of soils were used for nitrogen and phosphorus determination. Exactly two humdred samples of acidic and alkaline soils with a textrual range from clayey to sandy soils were used in the case of potassium determination. The highly significant correlation between NH4OAc extractable K using atomic absorption spectrophotometer (A.A.) and Mehlich 1 extractable K using standard color chart was observed in all soils except the alkaline coarse testered soils in which no correlation was observed. The aim of this research is to allow farmers and extension workers to visually differentiate low, medium, and high soil ammonium (NH4), nitrate (NO3), phosphate (PO4) and potassium (K) levels in the field, using the respective standard color chart. The necessary equipment and reagents for extraction and determination of NPK was subsequently developed into a portable test kit.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Thai National AGRIS Centre, Kasetsart University
