When root traits emerge: soaking solutions for washing perennial grass roots
Citation
Thivierge, M.-N., Royer, I., Halde, C., Chantigny, M.H., Bélanger, G., Lachance, C., and Lavergne, S. 2020. When root traits emerge: soaking solutions for washing perennial grass roots. Proceedings of the 28th European Grassland Federation General Meeting, Helsinki, Finland, October 19–21, 2020. In Grassland Science in Europe, vol. 25, pp. 565–567.
Plain language summary
Root traits provide valuable information when studying grassland ecophysiology. Fibrous roots of perennial grasses are challenging to separate from the soil. This study aimed at comparing five soaking solutions [sodium bicarbonate, sodium chloride, disodium ethylenediamine tetraacetic acid (disodium EDTA), distilled water, and sodium hexametaphosphate] and three soaking durations (15 min, 2 h, and 16 h) for their effectiveness in facilitating the washing of timothy roots. Soaking duration did not affect the mass and length of roots recovered after washing. The sodium bicarbonate solution allowed recovering the larger root biomass. Sodium hexametaphosphate, however, removed the most residual soil from the roots. This study revealed a trade-off in selecting soaking solutions between root recovery and root contamination by soil particles.
Abstract
Root traits provide valuable information when studying grassland ecophysiology. With their fibrous
architecture, roots of perennial grasses are particularly challenging to separate from the surrounding
soil. We assessed the effect of five soaking solutions (sodium hexametaphosphate, sodium bicarbonate,
sodium chloride, ethylenediaminetetraacetic acid, and distilled water) and three soaking durations (15
min, 2 h, and 16 h) on root recovery and root tissue elemental composition after washing. Root samples
were collected by soil coring in a 3-yr-old timothy (Phleum pratense L.) sward on a silty loam with 24
replications of each combination of soaking solution and duration for a total of 360 samples. After
soaking, roots were washed, dyed, and digitized to measure morphological traits and, then, analysed
to determine their elemental composition. Soaking duration did not affect root recovery. The greatest
recovery of ash-free root biomass and total root length was obtained with sodium bicarbonate, whereas
sodium hexametaphosphate led to the lowest root contamination by soil particles, as measured by root
tissue concentrations for ash and for major and trace elements. This study revealed a trade-off in selecting
soaking solutions between root recovery and root contamination by soil particles.