Abstract:
Objective The conventional method of determining the total amount of soil water-soluble salts in batches has some obvious disadvantages including inconsistent water quality and low testing efficiency, which was caused by slow acquisition of the extraction solution, high liquid absorption and long evaporation time.
Method The different soil samples with different levels of salt content from different regions were selected to study the optimal extracting method, the optimal absorbed amount of extraction solution, and the quality of testing water based on gravimetric method.
Result The results showed that the determination accuracy and efficiency could both be improved under moderate and lower saline soil conditions though changing the extraction method from suction filtration to centrifugation when 4000 r and 8 min were chosen as the centrifugal parameters. Independent of the salt content level of the extraction solution, reducing absorbed amount of extraction solution from 50 or 100 ml to 20 ml could both ensure the precision and accuracy of the salt determination results, and meanwhile reduce the evaporation time. Replacing CO2-removed distilled water or ultrapure water with distilled water as extraction water could not only reduce the time cost of further water preparation, but also further reduce the monetary cost of the determination.
Conclusion The existing method can be effectively improved from the aspects of test accuracy, efficiency and cost under the suitable conditions for the improved determination method.