The impact of various mulch types on soil properties controlling water regime of the Haplic Fluvisol

Abstract A long-term application of various mulch materials may lead to changes in certain soil properties, which mostly remain unreviewed. Therefore, our study focused on the mulch effect on a larger group of Haplic Fluvisol properties. The experiment was performed on 27 perennial patches covered by eight different mulch materials (bark chips, wood chips, wheat straw, cardboard, paper foil, decomposable matting, nonwoven fabric covered by bark chips, and crushed basalt) and control patches without any mulch during the 4 year period. The highest daily ranges of soil temperature were found in control patches without mulch, lower temperature ranges below foils mulches, and the lowest below organic mulches. Mulches preserved water storage in soil mainly during spring before vegetation integration and after perennials’ cutting. Organic carbon content (Cox), aggregate stability, and pH mostly did not show any trends over time, except for Cox and aggregate stability from patches with bark or wood chips and wheat straw. In these cases, decomposed organic matter significantly increased both properties. On the other hand, the soil hydraulic properties (mostly due to no-till practice) considerably changed in all patches. The saturated and residual water contents, saturated hydraulic conductivity, and reciprocal of the air-entry pressure head increased. Correspondingly, the bulk density decreased. Soil water retention curves from the patches with bark or wood chips were more gradual than those from other patches, which indicates higher water retention capacity for lower pressure heads. However, the physical quality of soils under organic mulches expressed by the slope at the retention curve inflection point was lower than that for other scenarios. Readily available water under organic mulches was also lower than that for other setups. This suggests that organic mulches have largest impacts on soil conditions, which can be either favourable or adverse.