A novel soil wetting technique for measuring wet stable aggregates

• It combined the advantages of existing wetting procedures; soil samples and dispersing agents are de-aerated synchronously over a short duration.
• It reduced the variability of wet aggregate stability (WAS) measurements and provided the most reliable and accurate description for of WAS.
• This novel technique was easy to conduct and without a large time requirement, and can be applicable to a large range of soils with different soil organic matter.

The measurement of aggregate size distribution and stability has been widely used to evaluate soil quality, yet there exists large variation in measured values from various pre-wetting methods. The most widely used technique, the high vacuum slow wetting (HVSW) method, could minimize the variability in wet aggregate stability (WAS) of samples, but is laborious and time consuming. In this paper, we introduced a novel soil wetting method and compared its performance with three other widely used pre-wetting techniques on a group of soil samples with organic matter content ranging from 21.0 to 61.0 g kg−1 and from two tillage systems. The new method combined the advantages of existing wetting procedures; soil samples and dispersing agents are de-aerated synchronously over a short duration. Statistical analysis showed that the new wetting method significantly diminished the breakdown of large aggregates (0.5–10 mm), had the lowest coefficient of variation and variance of WAS, which assured the reliability and reproducibility of aggregate stability measurements.