Compaction effects on evaporation and salt precipitation in drying porous media

Abstract

Abstract. Compaction and salinization of soils reduce croplands fertility, affect natural ecosystems, and are major concerns worldwide. Soil compaction alters soil structure and affects the soil's hydraulic properties, and it therefore may have a significant impact on evaporation and solute transport processes in the soil. In this work, we investigated the combined processes of soil compaction, bare soil evaporation, and salt precipitation. X-ray computed microtomography techniques were used to study the geometrical soil pore and grain parameters influenced by compaction. The impact of compaction on evaporation and salt precipitation was studied using column experiments. We found that compaction reduced the average grain size and increased the number of grains, due to the crushing of the grains and their translocation within the compacted soil profile. Changes in pore and grain geometry and size were heterogeneously distributed throughout the soil profile, with changes most apparent near the source of compaction, in our case, at the soil surface. The column experiments showed that the presence of small pores in the upper layer of the compacted soil profile leads to higher evaporation loss and salt precipitation rates, due to the increase of hydraulic connectivity to the soil surface and the prolongation of the first stage of evaporation.

Dynamics of soil penetration resistance, moisture depletion pattern and crop productivity determined by mechanized cultivation and lifesaving irrigation in zero till blackgram

“…The surface soil compaction caused by the combined harvester through ground contact pressure and sub soil compaction due to the axle load of seed drill would have damaged the soil structure and as a result of soil compaction, the moisture retention capacity was reduced, which has been seen in the soil moisture depletion rate throughout the crop period. The results are in accordance with the observation of [ 36 ] that soil compaction and wheel traffic decrease the moisture retention capacity and hydraulic conductivity.…”

“…The wheel traffic of harvester and seed drill would have also decreased the water infiltration rate when supplemental irrigation was given. Reference [ 36 ] also in an opinion that the compacted soil profile contains small pores in the upper layer, which leads to higher evaporation loss and poor moisture retention. Further increase in soil penetration resistance and reduced water uptake due to drying of top soil was also documented by Ref.…”

Cavitation‐Associated Water Evaporation From Porous Media Through In Situ NMR Characterization

“…These observations of water initially vaporized from the bottom part seems to contradict intuition, but have also been reported (Assouline & Narkis, 2019;Goldberg-Yehuda et al, 2022;Shokri et al, 2010) when water evaporates from a layered porous medium consisting of a fine layer overlaying a course layer. Based on the conceptualized model in Shokri (2010), it is the difference of air entry pressure between coarse and fine layers that leads to the capillarity-assisted water transfer from coarse layer to evaporation surface.…”

Cultivar-dependent differences in tuber growth cause increased soil resistance in potato fields

“…Soil water content was originally hypothesized to be lower in compacted soils, as these have reduced water holding capacity ( Smith et al., 2001 ) due to reduced pore density ( Batey, 2009 ). Furthermore, compacted soil loses water via evaporation up to 50% faster than uncompacted soil with the same soil moisture ( An et al., 2018 ) as mean pore size is decreased, increasing capillary suction ( Goldberg-Yehuda et al., 2022 ). However, compacted soil was wetter than uncompacted soil across both trials at time of harvest ( Figure 5 ).…”