To mulch or not to mulch? Effects of gravel mulch toppings on plant establishment and development in ornamental prairie plantings

Abstract

In recent years, North American prairie vegetation has served as a design model for highly attractive, low-cost and low-maintenance plantings in German urban green spaces. Where mixed-planting techniques, gravel mulch toppings and non-selective maintenance techniques such as mowing are used, prairie plantings are considered to be cost-effective alternative design concepts for public green space management. In this study, we investigated the establishment success of different mixtures of prairie species plantings on two sites with different soil conditions: topsoil and topsoil with graywacke gravel topping. We documented significantly higher average mortality rates on gravel mulch sites in the first year after establishment. Further development of mortality was not significantly different between sites. Weed species were always more numerous on topsoil sites and had an obvious effect on the visual impact of the plantings. The mulch created an effective barrier for wind-dispersed germinators. Soil temperatures down to 30 cm were significantly higher on gravel mulch sites throughout the year, stimulating more vital plant growth and a prolonged growing season. Our results emphasize the importance of considering these kinds of practical issues during the planning process as they are critical to the success or failure of the design.

Effect of different soil amendments on soil buffering capacity

“…Our P plot had reductions in buffering capacity, organic carbon, CaCO 3 content, and clay, and a slight increase in pH (KCl) compared to the control (N). It should be noted that the quality of the mulch has a significant impact on its effect on the soil [ 45 ]. The organic carbon content in our P plot probably declined because of the pine mulch had a poor composition, particularly an inappropriately high C:N ratio.…”

Effect of various mulches on soil physico—Chemical properties and tree growth (Sophora japonica) in urban tree pits

“…In China, gravel (cobblestone) is the inorganic mulch widely used in landscapes [9]. It reduces water evaporation, moderates soil temperature, and suppresses weeds [10, 11]. Further, barks are used as the major organic mulch in landscapes.…”

Fresh-marketable tomato yields enhanced by moderate weed control and suppressed fruit dehiscence with woodchip mulching

“…Comparing organic mulches with plastic mulches, polyethene lm is able to well suppress weed growth 10,38 . In particular, black polyethene lm has strong effects on weed control 39 because the light-dependent seed germination from seed banks is effectively suppressed by the dark shading 21 . However, the number of dehiscent tomato fruits may be increased by polyethene mulching, as seen in the weed-free treatment.…”

“…In agroforestry, the effective use of pruned woody shoots is generally desired. Currently, woodchip mulches are applied to urban gardens, fruit farms and greenbelts along roadsides globally 9,21 . In silviculture, woodchip mulches are known to improve the survival and establishment of planted tree seedlings 26 .…”

“…Even with organic mulches, the soil water contents and temperature can be maintained at adequate constant levels by reducing evaporation 20,21 . Furthermore, dead plant parts, cover crops and other organic matter are well mixed in the soil after the cropping season, increasing the soil nutrient levels [22][23][24][25] .…”