The main protagonist of the conference organized by the Landscape Architecture Association will be.... soil — "a lifeline in the worsening climate crisis and biodiversity loss". What don't we know about it, and why do we keep forgetting about it?
The symposium will be held as part of the Contemporary Landscape Architecture series this November 10th at the Congress Center of the Agricultural University in Krakow, the event will also be accompanied by study tours (the tours will be led by Kasper Jakubowski, Małgorzata Tujko, Marcin Gajda and Łukasz Pawlik), a discussion on the profession of landscape architecture and cooperation with other industries (the debate, led by Agnieszka Kalinowska-Sołtys, will include Nicola Watte, Joanna Rayss, Katarzyna Kobierska and Marek Kaszyński) and the IFLA Europe exhibition, during which their authors — Marcin Gajda of Pracownia Architektury Krajobrazu, Angelika Kuśmierczyk-Jędrzak of a+f space design and Urszula Forczek-Brataniec of eM4 — will talk about the awarded works.
Detailed information and program are available on the event website: LINK
We talk about the importance of soil and how to take care of it with Anna Gałecka-Drozda, Katarzyna Kobierska, Aleksander Lech and Karol Podyma, board members of the Landscape Architecture Association
Ola Kloc: Why will the Contemporary Landscape Architecture conference be about the soil?
Anna Gałecka-Drozda, Katarzyna Kobierska, Aleksander Lech, Karol Podyma: It is one of the most important elements of the ecosystem and components of landscape design, while so often overlooked in investment processes. On the order of the day are visible practices of covering the soil with "black rag" (agrotextile and geotextile), which stops soil processes, access to sunlight and natural plant growth. It does not allow water to penetrate deep into the soil, especially used on slopes. About the harmfulness of this method, fortunately, many nurserymen have already written. From the soil everything begins, and on it everything ends. It is there that the organic matter and minerals needed for life are found, providing food for vegetation. The dying vegetation, if it has a chance to decompose in the soil (certainly not in a situation where we use agrotextiles) with the help of organisms that feed on dead debris, the so-called saprophages, provides food back to the soil. This self-perpetuating cycle works if we design with our heads. It is certainly not helped by plant monocultures, where agrotextiles lead the way, protecting against "unwanted" plants, because, after all, in such a monoculture bed, spontaneous vegetation that grew from a dormant seed bank in the soil or was brought in by animals will look strange and paradoxically even unnatural. Therefore, plants and water, which healthy soil drinks like a sponge, are inextricably linked to soil conservation and construction. Water and plants are other topics in the triad that we plan to develop in next year's series of our flagship WAK (Contemporary Landscape Architecture) conferences, initiated by our former president Joanna Rayss.
Ola: What role does soil play in green space design?
Anna, Katarzyna, Aleksander, Karol: The primary one. First, it is from the soil that plants take up nutrients, food, such as nitrogen, phosphorus, potassium and many others. Soil structure affects the development of roots and their ability to take up water and nutrients. Well loosened soil facilitates root growth and improves water availability. Soil pH affects the availability of nutrients for plants. Some plants prefer acidic soils, while others grow better in alkaline soils. On sands, we will not design plants from moisture-loving communities. A fresh meadow will tolerate variegated areas, while a Molinia meadow needs fairly constant moisture. All these parameters are provided by soil analysis. It is worth recognizing it in order to design a healthy and almost cost-free in maintenance greenery. If we have a highly permeable soil, and we want to retain rainwater in a particular place for a longer time, we can enrich it with clay, and conversely loosen the soil with sand. The richness of the soil in humus greatly affects its retention capacity, retaining water in the soil, so if we want to create "sponge cities", we should take care of healthy soil first.
Ola: What are the biggest soil challenges facing landscape architects today?
Anna, Katarzyna, Aleksander, Karol: From the perspective of landscape architecture, it is primarily degradation, erosion, soil contamination. An everyday problem on construction sites is also its excessive compaction, especially in the crown zone of trees, which leads to the restriction of oxygen to the roots, as well as the improper execution or lack of proper preparation of technical routes, which should prevent its compaction. A common phenomenon, especially on slopes with paved walkways, stairs, is soil erosion caused by soil leaching. In places where soil leaching is cyclical, no vegetation cover can support itself. The reason is usually inadequate rainwater management. In traffic routes with steep longitudinal gradients, rainwater should be slowed down and only then introduced into the ground. Slowing down can be various forms of thresholds, the use of aggregates and other methods depending on the case. By properly managing rainwater, we are able to restore it to the soil.
The challenge, in creating healthy soil, is also to select the right vegetation, forming one well-functioning habitat with it, and the right methods of building healthy soil, including the correct selection of mulching material. Natural methods of soil enrichment are slowly entering the projects, for example, leaving a pile of branches, dead stumps, enriching it with compost, natural mulching materials like hay, straw. It is important to identify the soil, which can be done by initially analyzing the vegetation cover on the existing site, and deeper, analyzing the soil composition itself, its pH, abundance and granulometric composition and associated saturation, soil retention capabilities (sorptive properties). As landscape architects, we also analyze the technical parameters and structural stability of the soil by commissioning tests from relevant specialists (geotechnical boreholes), not only to select appropriate road layers, but also to identify habitat conditions, including, for example, for a planned rain garden.
Ola: How can we take care of the soil?
Anna, Katarzyna, Aleksander, Karol: Soil is the most vital and at the same time the most delicate structure covering the surface of our globe. It requires proper treatment so that it can perform many ecosystem services (including water retention, CO2 sequestration and supporting biodiversity). Unfortunately, in many situations it is unreflectively degraded by the construction industry or intensive agriculture, among others.
One of the most important issues in soil protection is to ensure that the soil is protected from the adverse effects of external conditions, i.e. UV radiation, wind erosion or surface water runoff. Therefore, it is very important to cover the soil with mulches. The best way to do this is to use natural materials in the form of wood chips, bark, compost and even grass clippings. Nature has developed its own defense mechanism. Under natural conditions, the soil never remains bare. When there is a "wound" caused by a cataclysm or human activity, it quickly begins to overgrow with annual plant species stored in the soil seed bank. This is a process that we have been fighting for centuries, growing food. We want the field or garden beds to be free of "weeds". Nowadays, we have at our disposal a variety of equipment and a whole arsenal of chemical weapons that will kill soil life on the planet on a scale never seen in the past. Simply digging or plowing the soil causes a huge disruption of the soil ecosystem and loss of organic matter. Experts say that with the current way of managing soil in agricultural areas, we have 60 vegetation cycles left, after which the earth's food production system will collapse in the wake of soil degradation. That's why there is more and more talk about "no-dig" farming methods without digging and stopping the use of chemicals.
Another process that negatively affects the soil is soil compaction by large agricultural machinery or heavy equipment on construction sites. Compacted soil is unable to breathe and absorb water, causing it to die. That's why it's important to designate traffic routes and use road plates to prevent compression. It is also impossible not to mention, in the case of construction work, the fact of using the soil as a place to store trash and unnecessary construction materials, caressingly called "earth banks" by builders, which are uncovered later when planting crops or sowing flower meadows.
Ola: Thank you for the interview.
