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Correction published on 25 October 2023, see Horticulturae 2023, 9(11), 1166.
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Article

Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials

by
Susanne Herfort
1,*,
Kerstin Pflanz
1,
Marina-Sandra Larsen
1,
Thomas Mertschun
2 and
Heiner Grüneberg
3,*
1
Institute of Agricultural and Urban Ecological Projects, Humboldt-Universität zu Berlin (IASP), 10115 Berlin, Germany
2
Uabg Society for Environmental Analysis Soil and Water Protection mbH, 12459 Berlin, Germany
3
Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Urban Ecophysiology of Plants, 14195 Berlin, Germany
*
Authors to whom correspondence should be addressed.
Horticulturae 2023, 9(3), 384; https://doi.org/10.3390/horticulturae9030384
Submission received: 30 January 2023 / Revised: 1 March 2023 / Accepted: 5 March 2023 / Published: 15 March 2023 / Corrected: 25 October 2023
(This article belongs to the Special Issue Soil Science, Water and Nitrogen Management in Horticultural Production)
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Versions Notes

Abstract

:
Vegetation mats for horticulture and landscaping usually consist of coconut fibre and straw. They have hardly any available nutrients and serve only as a carrier material for plant growth. Water capacity is low. By incorporating raw sheep‘s wool, nutrients, such as nitrogen, potassium, and sulphur can positively influence the nutrient content of the carrier material. Water storage and water holding capacity are increased by the wool. In this study, three different thick-layered vegetation mats with different proportions of sheep’s wool and coir fibres were developed for the pre-cultivation of perennials. The focus is on the evaluation of sheep’s wool as a carrier material compared to pure coconut fibre as well as the plant growth of the eight perennial species used (Achillea clypeolata ‘Moonshine’, Achnatherum calamagrostis ‘Algäu’, Anaphalis triplinervis, Aster dumosus ‘Prof. Anton Kippenberg’, Aster dumosus ‘Silberball’, Centranthus ruber ‘Coccineus’, Coreopsis verticillata, Salvia nemorosa ‘Rosakönigin’). The vegetation mats with sheep’s wool (V1–V3) contained 192.6, 154.0, and 283.5 g nitrogen (N)/m2 and the coir mats (V4) contained 7.5 g N/m2. The water content ranged from 16.0 to 22.1 vol% for the sheep’s wool mats and 12.6 vol% for the coir mat at pF1 (is equal to matrix potential at −10 hPa). The air content ranged from 71.9 to 77.0 vol% for the sheep’s wool mat and 79.4 vol% for the coir mat at pF1. On all vegetation mats containing sheep’s wool, the overall impression of the perennials was better than in the control. Especially good were Asters. At the end of the trial, the assessment scores of Asters on the sheep’s wool mats were two scores higher than on the coir mat. Aster dumosus ‘Prof. Anton Kippenberg’ achieved an average plant height between 35.8, 35.8, and 36.5 cm on the sheep’s wool mats and 14.4 cm on the coir mat. Aster dumosus ‘Silberball’ yielded 41.3, 42.3, and 44 cm on the sheep’s wool mats and 26.7 cm on the coir mat. No significant differences regarding plant height between the different variants of sheep’s wool mats emerged. Therefore, these mats can be used as alternative planting concepts for landscaping.

Graphical Abstract

1. Introduction

1.1. History of Vegetation Mats

Vegetation mats or erosion protection mats have been used in biological engineering since the 1970s [1,2,3]. They are mainly used in hydraulic and road construction and can protect slopes, banks, and embankments from erosion directly after installation [4,5,6]. The greening normally happens after placement using the hydroseeding technique [7].
Since the 1980s, pre-cultivated vegetation mats are increasingly used in extensive roof greenings. This offers the advantage of tackling greening challenges, e.g., providing light-weighted and thin-layered systems [4]. For pre-cultivation, the vegetation mats are scatter-coated with a thin layer of substrate and seeds or seedlings are inserted. Currently, mosses, Sedum species, grasses, and/or herbs are common plants in roof greening [4]. Once a total coverage of 75% is achieved, the vegetation mats can be installed [8].
Pre-cultivation of perennials can be carried out on vegetation supports similar to those used for extensive green roofs. This has been demonstrated by investigations of thin-layer, latexed coconut fibre mats [9]. If young plants are to be pre-cultivated on vegetation mats, thicker-layered coconut mats are chosen [10]. Some of the benefits of using pre-cultivated vegetation mats are an early high coverage ratio of ≥75% [8] and lower maintenance effort due to the mulch effect of the fibre mat, which decreases the emergence of weeds.

1.2. Deployment of Natural Fibres

Currently, in gardening and landscaping, vegetation mats are usually made of coconut fibres or rock wool. Considering climate change and the scarcity of resources, it is increasingly important to make use of environmentally friendly and sustainable materials [11]. The materials that are used in horticulture, such as coconut fibre, haven been proven to be a good carrier material [12], though they entail ecological and economic disadvantages. Coirs are not produced in Germany and are, therefore, imported from Asia. Therefore, transport costs are high, and they are expected to increase further. In addition, the production process requires a large amount of water for cleaning the coconut fibres, which also makes the use of the fibres more expensive, as water will become an increasingly scarce resource in the future. Especially with regard to ecological sustainability, native organic and fully biodegradable substrates are gaining importance in horticulture [13]. Sheep’s wool is a local and renewable resource that is often a waste material and it has come to the fore in gardening and landscaping services.
It is increasingly available, as it is being replaced more and more by synthetic fibres in the textile market. Furthermore, the last wool scouring facility in Germany was shut down in 2009 [14]. Raw wool processing is now outsourced to countries, such as Belgium, Italy, or Austria, which still operate those facilities. The number of sheep in Germany is continuously decreasing and reached its low in 2021 at 1.5 million sheep [15].
The global sheep population in 2020 was 1.26 billion [16]. On a global scale, the sheep population increased in the last years, where China accounts for a large share with approx. 173 million sheep. India, with a sheep population of 68 million, also expanded their amount in recent years. Together with China and Australia, these countries make up the largest share of sheep in the world [17]. Sheep’s wool is mainly used in the textile industry in China and India [18].
Due to the high compatibility between fabric properties and the physiological requirements of plants, sheep’s wool can be applied in horticulture without washing being a prerequisite. The coarse wool or the wool from the abdomen or the legs—or rather, the cast wool—are often residual materials, which makes them available for horticultural purposes. Raw wool contains important nutrients for plant physiology, such as nitrogen (10.4–10.7%), potassium (4.6–4.9%), and sulphur (2%) [19]. Phosphorus (0.1–0.2%) is only present in small quantities [19]. Sheep’s wool has quite a high pH value: between 7.5 and 9 [20]. The maximum water capacity is more than triple the gross weight [21].
Innovations indicating the valuable material properties of raw sheep’s wool concerning plant physiological requirements have been promoted since the 2000s. Product developments, such as thin-layered vegetation mats for horticultural purposes [22], are described in the utility model for “Vegetationsträger aus organischen verrottbaren Fasermaterialien” (translation: “Vegetation carrier made from organic and biodegradable fibre materials“) [23]. The procedure stipulates shredding and, when appropriate, mixing the unpurified, hygienised, raw sheep’s wool with coir. Subsequently, the thin-layered vegetation mat is fabricated with the aerodynamic layering of fleece. Additionally, the gardening and landscaping industry and horticulture are using vegetation systems involving sheep’s wool that is manufactured with the Kemafil® Technology or as needled fleece [24,25,26,27]. The utilisation of local sheep’s wool can consequently reduce the coir import and thereby decrease transport costs.
Several scientific investigations have found an advantageous fertilising effect of sheep’s wool, resulting in enhanced plant growth in various cultures (ornamental plants, vegetables, herbs, cereals, and grasses) [20,28,29,30,31,32,33,34,35,36,37]. In most trials, raw sheep’s wool was used as a fertiliser. The development and production of fertilisation pellets from sheep’s wool [20,21], in conformity with the utility model of “Organisches Düngemittel” (translation: Organic fertiliser) [37], also supports the application of sheep’s wool in horticulture. Furthermore, sheep’s wool pellets can be used in agriculture to improve soil [29].
Within the framework of this research project, vegetation mats made of sheep’s wool and coconut fibres are being developed and investigated with regard to the plant growth of perennials. There is a high demand for sustainable products in horticulture, and new distribution channels for sheep’s wool are needed. In response to this, the goal of the present work was to use the developed vegetation mats to cultivate perennials and thereby promote alternative planting concepts for urban green, prospectively. According to horticultural practice, vegetation mats must be pre-cultivated before the relocation to the target area in public urban green. Therefore, the investigations in this study were performed during pre-cultivation.
The hypothesis implied that sheep’s wool would be more suitable as a carrier material for vegetation mats than coconut fibre due to its advantageous nutrient composition and high water absorption capacity [19,21]. Through trials, the influence of the proportion of sheep’s wool in vegetation mats on the plant growth of different perennial plants was evaluated and compared to conventional coir vegetation mats. Supplementarily, the chemical and physical properties of the utilised raw materials and their interaction with the plants’ development are determined.

2. Materials and Methods

2.1. Utilised Sheep’s Wool Vegetation Mats and Their Properties

The raw wool from Germany was hygienised according to a standard hygienisation procedure (EU-regulation Nr. 142/2011 [38]) before processing. After hygienisation, the wool was shredded with a machine specifically designed for raw wool.
The nitrogen content of the sheep’s wool and the coir was analysed as a mixed sample with a triple repetition, as per the VDLUFA II.1, 3.5.2.7 (2000) method [39].
The production of the vegetation mats with the aerodynamic web forming was then carried out by MST-Dränbedarf GmbH (Twistringen, Germany). The processed fibres were air-dried. The vegetation mats were approximately 5 cm thick and were fabricated as a 1 m wide fleece coil (length approx. 10 m). Subsequently, they were cut into 1 m × 1 m squares. For sufficient stability, the 1 m2 mats were reinforced with 400 g of coir fabric on both sides. Three different kinds of vegetation mats containing sheep’s wool and coir were produced and examined.
The variant 1 (V1) and 2 (V2) mats consisted of mixed fibre fleeces. The mat of variant 3 (V3) consisted of two fibre fleeces with 100% sheep’s wool and was covered with a mixed-fibre fleece containing 30% sheep’s wool and 70% coir from below and above (i.e., sandwiched). The mat of variant 4 (V4) served as a control, consisted of a thick-layered fleece of 100% coir, and was likewise reinforced with coir fabric on top and below (Table 1).

2.2. Physical Properties

The investigations of the maximum water capacity as a function of the suction tension were carried out in accordance with DIN EN 13041:2012-01 [40].
For sampling, 100 mL stainless steel sampling cylinders were filled to the top with the various fibre mixtures. The materials were analysed as shown in Table 1 after being air-dried initially.
For the determination of the maximum water capacity, the cylinders with the fibre samples were saturated with six-fold repetition for at least 24 h in water and then drained for five seconds on a filter fleece. The cylinders were then weighed.
The investigations of the maximum water capacity were carried out at pF values of 0.0; 0.4; 1.0; 1.5, 1.8, and 2.0 in the sandbox of Eijkelkamp (Giesbeek, Netherlands). Here, the dimensionless pF value (=log cm water column) describes the energy with which the soil water is held in the soil (substrate) against gravity [41]. Field capacity describes the amount of water that the soil can hold against gravity for two to three days and is determined at a pF value of 1.8 [42]. Air capacity was calculated as the difference between the volume of the cylinders, the amount of water taken up, and the volume taken up by the fibres at pF 1.0 [43].
After testing, the samples were dried at 105 °C until displaying weight constancy. Then, the dry mass of the fibres and the bulk density were determined. The bulk density of the sheep’s wool at 1.32 g/cm3 and that of the coconut fibre at 1.15 g/cm3 were used for the calculations of fibre volume [44].

2.3. Experimental Conditions during Pre-Cultivation

Pre-cultivation of the vegetation mats was carried out at the experimental site of the Albrecht Daniel Thaer-Institute of the Humboldt-Universität zu Berlin in Berlin-Dahlem. The test site belongs to the northeast German lowlands and is located 51 m above sea level (geographical coordinates: 52°28′ N; 13°18′).
The prevailing temperate climate at the test site is characterized by the transition from the maritime to the continental climate zone due to its eastern location. Temperatures during the experimental period from June to October 2015 were, on average, 0.5 K higher than the 30-year mean (1981–2010). Precipitation was 84% of the 30-year mean. Global radiation in the experimental period was 2402 MJ/m2 and was 12% higher than the 30-year mean [45].

2.4. Selection of Perennial Plants

The selected perennials have different nutrient requirements. The perennials were chosen so that the entire range of nutrient requirements of the perennials could be covered. The perennial mix also varied in plant height and flowering time. The aim was to investigate whether sheep wool, with its slow release of nutrients, is suitable for all perennials.
The young plants used for pre-cultivation were grown in P9 pots (0.5 L) and were supplied by the perennial nursery Lux-Staudenkulturen in Pirna (Germany). The plants showed a uniform growth pattern and height. Eight different perennial species were used for the sunny location following the perennial mixture “Veitshöchheimer Blütentraum” with double repetition per mat (1 m2) (Table 2).

2.5. Pre-Cultivation

Pre-cultivation was performed with six replicates from 10 June 2015 (Figure 1a) to 27 October 2015 (Figure 1b) for each mat. The 24 vegetation mats of 1 m2 each were laid randomly on the experimental area. Subsequently, 16 planting holes were cut in each mat and eight perennials were planted in duplicate.

2.6. Pre-Cultivation Conditions

Irrigation was initially carried out with an oscillating sprinkler from Gardena® (GARDENA Deutschland GmbH, Ulm, Germany) and, from July 2015, with an irrigation system(single-drip hoses) from NetafimTM (NETAFIM Deutschland GmbH Innovative Bewässerung, Frankfurt, Germany), irrigated twice a day with a total volume of 4 L/m2, adjusted according to weather conditions and according to [47]. Each mat (1 m2) received 50 mL of fertiliser dissolved in 5 L of irrigation water with 1.4 g of dissolved nitrogen weekly during the pre-cultivation period. A total of 28 g of nitrogen per m2 was applied over the experimental period. The fertilised nitrogen was neglected in the analysis of the correlation between plant height and the nitrogen content of the mats.

2.7. Data Collection

The plants were assessed every 14 days from July to October 2015. Overall impressions and plant heights were recorded as indicators of vitality [48]. In the assessment, each individual plant was evaluated using subjective visual observation with regard to its overall impression. This was done by assigning scores taking into account the respective stage of development (grades: BN 1 = plant failure, BN 3 = sufficient, BN 5 = satisfactory, BN 7 = good, BN 9 = very good).
Plant height (stem height) was measured with a folding rule with a measuring accuracy of 0.5 cm.
In addition, the number of shoots and the flowers/buds of each perennial were recorded on all assessment dates, but these were not evaluated here due to the abundance of data.

2.8. Statistical Analysis

Statistical analyses were performed with SPSS (28.0). The median of the assessment scores was calculated, and the distribution of the values in relation to the mat varieties and the plants was determined. The plant height of the plants was evaluated in relation to the vegetation mat using analysis of variance (ANOVA) tests. Significant differences were calculated using Tukey’s test at a significance level of p < 0.05, with different lowercase letters denoting significance. Mean variability was indicated by standard deviation, denoted by ± or by error bars.
The physical parameters of the vegetation mats were averaged, and the mean variability was labelled.
To detect interactions between the total nitrogen content of different vegetation mats and the plant height, linear correlations between two variables were calculated using Pearson correlation (r) with a significance level of p < 0.05. In addition, the correlation between water capacity at pF 1 and the plant height was calculated using Pearson correlations (r) with a significance level of p < 0.05.

3. Results and Discussion

3.1. Nitrogen Content of the Vegetation Mats

The analysis of total nitrogen showed 10.4% for the sheep’s wool fibres and 0.3% for the coconut fibres. The subsequently calculated nitrogen content in the four vegetation mat types averaged between 7.5 g of nitrogen (variant 100c) and 283.5 g of nitrogen (sandwiched variant) per m2 vegetation mat (Table 3).

3.2. Water Content

Depending on their origin, the water content of organic substrate constituents for growing media at a suction tension of pF 1.0 was between 8–12 vol% for coir fibres and between 67–83 vol% for raised bog peat, H6–8. The air content at matrix potential pF1 was between 83–90 vol% (coir fibres) and between 9–25 vol%. (Raised bog peat, H6–8) [49]. For peat, the degree of decomposition was given from H1 to H10 [50]. It provides information on the degree of decomposition of the peat-forming vegetation. H6–8 means that the degree of decomposition was strongly advanced (1/2 to 2/3 peat substance).
The investigations showed (Figure 2, Table 4), that the water content of coir was lowest at pF 0.0 with 59 vol% and at pF 1.0 with 13 vol%. The vegetation mats consisting of a mixture of sheep’s wool and coir had a water content of 65–82 vol% at pF 0.0 and 16–22 vol% at pF 1.0. This was slightly higher than the water content of pure coir. The air content of the vegetation mats with sheep’s wool was between 71.9 and 77.0 vol% at pF 1.0 and was 79.4 vol% for the coconut fibre mat.
All values were tested with Tukey’s HSD test. Different small letters indicate significant differences (p < 0.05). In terms of water content and total pore volume, sheep’s wool in combination with coconut fibre was a suitable growing medium. It absorbed more water than pure coconut fibre and retained it for a longer period of time, which is consistent with the results of [22]. It can be seen that, as the pF value (matrix potential) increased, the water content of the sandwich mat was always the highest compared to the other vegetation mats (Figure 2).

3.3. Overall Impression of the Perennials during Pre-Cultivation

As shown in Table 5, the median of the awarded scores of all perennials grown on vegetation mats with sheep’s wool was “7” on the first assessment date, whereas the perennials grown on the coir mat yielded a score of “6”. During the assessment period, the perennials developed well on all vegetation mats, although the scores of the perennials on the coconut fibre mats deteriorated towards the end of the vegetation period.
The individual scores for the first evaluation showed (Figure 3a) that the selected perennials were able to establish themselves well immediately after planting on the vegetation mats with sheep wool. Scores of “7” and “9” were given much more often (between 71% and 73%) than on the coconut fibre mats (12%). A score of “5” was given to 23–27% of the perennials on the vegetation mats with sheep’s wool, whereas 44% of the perennials (i.e., almost half of all perennials) received a score of “5” on the coconut fibre mat.
A score of “3” was the highest awarded on the coconut fibre mat, with 44% signifying that pre-cultivation of the perennials was not optimal from the beginning. It became clear that the perennials could not develop optimally at the beginning of the pre-cultivation. On the other hand, the vegetation mats incorporating sheep’s wool showed a very low proportion of plants with a score of “3” (1–4%).
In the further cultivation period, the vegetation mats with sheep’s wool showed a slight deterioration of the overall impression. The seventh assessment at the end of September 2015 showed (Figure 3b) that scores of “9” and “7” on the vegetation mats with sheep’s wool were significantly lower than in the first assessment (46–54%), whereas, on the coconut fibre mats, they increased somewhat (18%). A score of “5” was awarded to about a quarter to a third of all mats (25–33%). It was also noticeable that, at the end of the growing season, half of all perennials on the coconut fibre mats (50%) received a score of “1” or of “3”, whereas, on the sheep’s wool mats, this proportion was only between 17% and 25%.
The selected perennials were less suitable for pre-cultivation on coir mats than on sheep’s wool mats. The better plant growth on the sheep’s wool mats could be due to both the better water capacity of the sheep’s wool and the high nitrogen content. These results correspond with those of an investigation of the pre-cultivation of sheep’s wool vegetation mats for extensive roof greening [52].
Comparing the scores of the eight perennial species at the seventh assessment date at the end of September 2015, the following can be observed:
Plant failure was observed in 30% of Achillea clypeolata ‘Moonshine’ growing on sheep’s wool mats (Figure 4a). Seemingly, this plant was only suitable for growing on sheep’s wool vegetation mats to a limited extent. This might be due to its occasional drier requirements, which are better provided by coir mats or vegetation mats with a high proportion of coir [46].
Achnatherum calamagrostis ‘Algäu’ (Figure 4b) showed the best appearance on the coconut fibre mat. The sheep’s wool mats seemed to be unsuitable, possibly due to the high nutrient content and high water capacity. Lower nutrient and drier sites are more suitable for this plant [46].
Anaphalis triplinervis (Figure 4c) showed the best overall performance on the 30sw/70c and 50sw/50c variants, although it tends to prefer dry soil [46]. Plant failures were observed only on the coir mat.
Aster dumosus ‘Prof. Anton Kippenberg’ (Figure 4d) tended to display the best appearance on vegetation mats 50sw/50c and 30sw/70c, even though the sandwich variant also seemed suitable. Perennials on the coir mat scored lower, on average, by at least two scores, possibly due to the lower nutrient content and lower water capacity of the mat. It should be emphasized that there was no plant failure on any of the vegetation mats.
Aster dumosus ‘Silberball’ (Figure 4e) showed the best overall impression on all vegetation mats with sheep’s wool. Here, too, the perennials on the coir vegetation mat were, on average, at least 2 scores lower. There was no plant failure on any vegetation mat. Since asters have high nutrient requirements [46], they seem to be well-suited for cultivation on sheep’s wool mats.
Centranthus ruber ‘Coccineus’ (Figure 4f) prefers rather dry and nutrient-poor soils [46]. Nevertheless, this perennial grew predominantly well to very well on the sandwich mat and much better than on the coir mat, where only 8% of the perennials were able to achieve a good overall impression. The highest number of plant failures were noted on the 50sw/50c and 30sw/70c, so this species seems unsuitable for these variants.
Coreopsis verticillata (Figure 4g) developed satisfactorily on all vegetation mats. There was no plant failure. This confirms the adaptability of the perennial [46]. The best overall impression was observed on variant 30sw/70c, which may be used for cultivating this perennial, prospectively.
Salvia nemorosa ‘Rosakönigin’ (Figure 4h) developed satisfactorily to well on all mats; once more, the good adaptability of the perennial to the different substrates was evident [46]. There was no plant failure.
According to the assessment scores, the results showed that perennial mats with sheep’s wool were suitable for pre-cultivation—especially for Aster dumosus ‘Prof. Anton Kippenberg’ and Aster dumosus ‘Silberball’—and, to a limited extent, for Coreopsis verticillata and Salvia nemorosa ‘Rosakönigin’. Achillea clypeolata ‘Moonshine’ and Coreopsis verticillata were suitable for pre-cultivation on coconut mats; the other perennials, rather, were not.

3.4. Plant Height of the Individual Perennials

The positive development of the perennials can be seen not only in the awarding of a higher score but also in plant growth.
At the seventh assessment, the vertical growth of the eight perennials was good on all vegetation mats containing sheep’s wool, partly even better than on the coir mat (Table 6). There were significant differences in plant height of Achillea clypeolata ‘Moonshine’, Aster dumosus ‘Prof. Anton Kippenberg’, Aster dumosus ‘Silberball’, and Salvia nemorosa ‘Rosakönigin’ cultivated on sheep’s wool mats compared to coir mats. Plant growth was not significantly different on the three sheep’s wool mat variants. In particular, the growth pattern of Aster dumosus ‘Prof. Anton Kippenberg’ (Figure 5a) and Aster dumosus ‘Silberball’ (Figure 5b) illustrate the advantage of sheep’s wool mats compared to coir mats.
The most significant correlations between the nitrogen content of the vegetation mat and plant height (Table 7), as well as between the water capacity at pF 1.0 and plant height (Table 8), could be observed for Aster dumosus ‘Silberball’ and Aster dumosus ‘Prof. Anton Kippenberg’’ for all assessment dates. Significant correlations also occurred for Salvia nemorosa ‘Rosakönigin’ (1st–7th date) and Achillea ‘Moonshine’ (7th date).
The data show (Table 4,Table 5 and Table 6 ) that mixed fleeces consisting of sheep’s wool and coconut fibres should be used, in particular, for the pre-cultivation of perennials. Perennials with high nutrient requirements should be pre-cultivated on sheep’s wool mats with at least 50% sheep’s wool content.
The test results suggest that vegetation mats consisting of sheep’s wool and coconut fibres lead to better height growth compared to conventional coconut fibre mats (Table 6, Figure 5). In the cultivation of perennials, the soil type and structure—in this case, the vegetation mat—is a contributing factor as well as the water and nutrient content [53]. Here, the use of sheep’s wool is advantageous.
Although all vegetation mats received the same amount of irrigation and the same amount of liquid fertiliser during pre-cultivation, there was an additional positive fertiliser effect from the sheep’s wool. Aster dumosus ‘Prof. Anton Kippenberg’ and Aster dumosus ‘Silberball’, especially, displayed strengthening and improved plant growth due to the sheep’s wool and the associated higher water content (Figure 2, Table 4). However, the composition of the vegetation mats with sheep’s wool or the amount of sheep’s wool used was not significantly different for better plant growth (Table 5, Figure 3). Hence, it is necessary to choose the vegetation mat that is the most cost-effective for the manufacturing process, prospectively.

4. Conclusions

Further investigations should be carried out regarding the optimal amount of liquid fertiliser and irrigation during the pre-cultivation of sheep’s wool mats, in order to be able to show a potential saving of fertiliser and water, if necessary. Not having to apply fertiliser weekly would also help reduce the required amount of labour, though the method of pre-cultivation (the planting of young plants on vegetation mats and regular irrigation) should remain.
Another question is whether thinner vegetation mats made of sheep’s wool can also be used for the pre-cultivation of perennials to optimize the use of fibres and nitrogen input. In this way, different levels of nutrient requirements of perennials can be accommodated. It is important to determine which other perennial species are suitable for cultivation on sheep’s wool mats.
In the future, the question of what advantages perennial mats with sheep’s wool bring after installation in a target area should be investigated. The focus would be on the nutrient supply of the vegetation mats, as well as on the water capacity and water retention ability, in order to better buffer dry periods. A multi-year trial design is planned.

Author Contributions

Conceptualization, S.H.; methodology, S.H.; investigation, S.H. and T.M.; formal analysis, S.H.; writing—original draft, S.H.; project administration, S.H.; supervision, H.G.; writing—review & editing, H.G., K.P. and M.-S.L. All authors have read and agreed to the published version of the manuscript.

Funding

This project was funded by the German Federal Ministry of Economics and Technology (BMWi) within the program INNO-KOM-OST, a module market-oriented R&D project (MF), Project executing agency: EuroNorm GmbH, Reference number: MF140035. The article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)–491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.

Data Availability Statement

Data are contained within the article.

Acknowledgments

We would like to thank Sigrun Witt from the Division of Teaching and Research, Station Greenhouse Area for their technical support during the experiments. We would also like to thank Jan Häbler, Olga Gorbachevskaya, and Steffi Tschuikowa from the IASP, who provided us with their knowledge and support during the experiments, in statistical analyses, and in chemical analyses.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Waldenfels, G. Frhr. von. Erosionsschutzmatte zur Begrünung von insbesondere humusarme Böden. Bundesrepublik Deutschland Deutsches Patentamt DE000002134306A, 1 February 1973. [Google Scholar]
  2. Czerwinsky, P.; Holst, D.; Gößling, E.-G. Erosionsschutzmatte. Deutsche Demokratische Republik Amt für Erfindungs- und Patentwesen GDR DD000000104115A5, 2 February 1974. [Google Scholar]
  3. Jankowiak, E.M.; Brandt, G.H. Straw mats for soil erosion control. United States Patent US000003867250A, 18 February 1975. [Google Scholar]
  4. Krupka, B. Dachbegrünung: Pflanzen und Vegetationsanwendung an Bauwerken; Eugen Ulmer: Stuttgart, Germany, 1992; 436p. [Google Scholar]
  5. Kirmer, A.; Tischew, S. Handbuch naturnahe Begrünung von Rohböden; Teubner: Wiesbaden, Germany, 2006; 36p. [Google Scholar]
  6. Tischew, S. Renaturierung nach dem Braunkohleabbau; Springer Fachmedien: Wiesbaden, Germany, 2004; 254p. [Google Scholar]
  7. DIN 18918:2021-08; Vegetationstechnik im Landschaftsbau–Ingenieurbiologische Sicherungsbauweisen–Sicherungen durch Ansaaten, Bepflanzungen, Bauweisen mit lebenden und nicht lebenden Stoffen und Bauteilen, kombinierte Bauweisen, Beuth. Deutsches Institut für Normung e.V.: Berlin, Germany, 2021; p. 21.
  8. FLL–Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. Dachbegrünungsrichtlinien: Richtlinien für Planung, Bau und Instandhaltung von Dachbegrünungen; Ausgabe: Bonn, Germany, 2018; p. 87. [Google Scholar]
  9. Bouillon, J.M. Entwicklung und Optimierung von vorkultivierten Staudenmatten für bodengebundene Begrünungen im urbanen Grün. Ph.D. Thesis, Universität Hannover, Hannover, Germany, 2005; p. 25. [Google Scholar]
  10. Helix Pflanzen GmbH. Produkte. Available online: https://www.helix-pflanzen.de/pflanzensysteme/produkte (accessed on 9 March 2023).
  11. Die Bundesregierung. Deutsche Nachhaltigkeitsstrategie: Weiterentwicklung 2021. Stand 15, December 2020, Berlin, Germany. 2020, p. 355. Available online: https://www.bundesregierung.de/resource/blob/998194/1875176/3d3b15cd92d0261e7a0bcdc8f43b7839/deutsche-nachhaltigkeitsstrategie-2021-langfassung-download-bpa-data.pdf (accessed on 9 March 2023).
  12. Ali, M. Coconut Fibre: A Versatile material and its applications in engineering. J. Civ. Eng. Constr. Technol. 2010, 2, 125–137. [Google Scholar]
  13. Bundesminsiterium für Bildung und Forschung (BMBF), Bundesministerium für Ernährung und Landwirtschaft (BMEL). Nationale Bioökonomiestrategie, Berlin, Germany. 2020, pp. 41–45. Available online: https://biooekonomie.de/sites/default/files/2022-04/bmbf_nationale_biooekonomiestrategie_langfassung_DE_22.pdf (accessed on 9 March 2023).
  14. dpa/mk. Bremer Wollkämmerei muss schließen. WELT PRINT. 2008. Available online: https://www.welt.de/welt_print/article2830777/Bremer-Wollkaemmerei-muss-schliessen.html (accessed on 9 March 2023).
  15. Statistisches Bundesamt. Schafbestände mit leichten Schwankungen, Germany. 2022. Available online: https://www.destatis.de/DE/Themen/Branchen-Unternehmen/Landwirtschaft-Forstwirtschaft-Fischerei/Tiere-Tierische-Erzeugung/schafe.html (accessed on 9 March 2023).
  16. IWTO Market Information. World Sheep Numbers & Wool Production. 2021. Available online: https://iwto.org/wp-content/uploads/2022/04/IWTO-Market-Information-Sample-Edition-17.pdf (accessed on 9 March 2023).
  17. Food and Agriculture Organization of the United Nations. Livestock Manure. 2020. Available online: https://www.fao.org/faostat/en/#data/EMN (accessed on 9 March 2023).
  18. Kumar, A.; Prince, L.L.; Jose, S. Sustainable Wool Production in India. In Sustainable Fibres and Textiles; The Textile Institute Book Series; Elsevier: Duxford, England, 2017; pp. 87–115. [Google Scholar]
  19. Herfort, S.; Grüneberg, H.; Böhme, M. Düngepellets aus Schafwolle. In Dega Produktion Handel; Eugen Ulmer: Stuttgart, Germany, 2009; pp. 41–42. [Google Scholar]
  20. Böhme, M.; Pinker, I.; Grüneberg, H.; Herfort, S. Sheep wool as fertiliser for vegetables and flowers in organic farming. Acta Hortic. 2012, 933, 195–202. [Google Scholar] [CrossRef]
  21. Ordiales, E.; Gutiérrez, J.I.; Zajara, L.; Gil, J.; Lanzke, M. Assessment of utilization of sheep wool pellets as organic fertilizer and soil amendment in processing tomato and broccoli. Mod. Agric. Sci. Technol. 2016, 2, 20–35. [Google Scholar]
  22. Böhme, M.; Schevchenko, J.; Pinker, I.; Herfort, S. Cucumber grown in sheepwool slabs treated with biostimulator compared to Other Organic and Mineral Substrates. Acta Hortic. 2008, 779, 299–306. [Google Scholar] [CrossRef]
  23. Twistringer RBM Dränfilter GmbH & Co. KG.; Institut für Agrar- und Stadtökologische Projekte an der Humboldt-Universität zu Berlin (IASP). Vegetationsträger aus organischen verrottbaren Fasermaterialien. Bundesrepublik Deutschland Deutsches Patent DE202005004354U1, 25 August 2005. [Google Scholar]
  24. GEOTEX Holland-Moritz GbR. Geomatte. Bundesrepublik Deutschland Deutsches Patent DE202007012632U1, 3 January 2008.
  25. Broda, J.; Gawłowski, A.; Przybyło, S.; Biniaś, D.; Rom, M.; Grzybowska-Pietras, J.; Laszczak, R. Innovative Wool Geotextiles Designed for Erosion Protection. J. Ind. Text. 2018, 48, 599–611. [Google Scholar] [CrossRef]
  26. Smith, G.M. Hair Felt. International patent, World Intellectual Property Organization WO002005004578A1, 20 January 2005. [Google Scholar]
  27. Labhart, D. Pflanzenziegel, dessen Herstellung sowie die Verwendung von Pflanzenziegeln zur Erstellung einer Pflanzendecke. European Patent Office EP2452555A3, 12 November 2014. [Google Scholar]
  28. Gousterova, A.; Nustorova, M.; Goshev, I.; Christov, P.; Braikova, D.; Tishinov, K.; Haertlé, T.; Nedkov, P. Alkaline hydrolysate of waste sheep wool aimed as fertilizer. Biotechnol. Biotechnol. Equip. 2003, 17, 140–145. [Google Scholar] [CrossRef]
  29. Garz, K. Identifizierung und Charakterisierung natürlicher Rohstoffe als Bodenverbesserungsmittel sandiger Substrate: Untersuchungen mit Schafwolle und Biertreber an Mais und Weizen. Ph.D. Thesis, Humboldt-Universität, Berlin, Germany, 2017. [Google Scholar]
  30. Koch, R.; Emmel, M.; Lohr, D.; Frankenberg, A.; Degen, B.; Meinken, E.; Haas, H.; Fischinger, S.I. Organische Dünger in Topfkulturen auf dem Prüfstand–wie steht es mit der Stickstofffreisetzung? In Beiträge zur 14. Wissenschaftstagung Ökologischer Landbau, N-Düngung und Verluste; Dr. Köster: Berlin, Germany, 2017; pp. 334–337. [Google Scholar]
  31. Nustorova, M.; Braikova, D.; Gousterova, A.; Vasileva-Tonkova, E.; Nedkov, P. Chemical, microbiological and plant analysis of soil fertilized with alkaline hydrolysate of sheep’s wool waste. World J. Microbiol. Biotechnol. 2006, 22, 383–390. [Google Scholar] [CrossRef]
  32. Gupta, S.; Sharma, A.; Sharma, S.; Bhogal, N. Growth, macro and micronutrient concentration in clusterbean (Cyamposis Tetragonoloba), plant tissue as well as in soil when amended with wool as fertilizer. J. Environ. Res. Dev. 2014, 8, 607–613. [Google Scholar]
  33. Tiwari, V.N.; Pathak, A.N.; Lehri, L.K. Response to differently amended wool-waste composts on yield and uptake of nutrients by crops. Biol. Wastes 1989, 28, 313–318. [Google Scholar] [CrossRef]
  34. Zheljazkov, V.D. Assessment of wool waste and hair waste as soil amendment and nutrient source. J. Environ. Qual. 2005, 34, 2310–2317. [Google Scholar] [CrossRef]
  35. Zheljazkov, V.D.; Silva, J.L.; Patel, M.; Stojanovic, J.; Lu, Y.; Kim, T.; Horgan, T. Human hair as a nutrient source for horticultural crops. Horttechnology 2008, 18, 592–596. [Google Scholar] [CrossRef]
  36. Zheljazkov, V.D.; Stratton, G.W.; Pincock, J.; Butler, S.; Jeliazkova, E.A.; Nedkov, N.K.; Gerard, P.D. Wool-waste as organic nutrient source for container-grown plants. Waste Manag. 2009, 29, 2160–2164. [Google Scholar] [CrossRef] [PubMed]
  37. IfN Anwenderzentrum GmbH.; Institut für Agrar- und Stadtökologische Projekte an der Humboldt-Universität zu Berlin (IASP). Bundesrepublik Deutschland Deutsches Patent DE202007002569U1, 3 May 2007.
  38. Europäische Kommission. Verordnung (EU) Nr. 142/2011 der Kommission vom 25, L54/1-254. 2011. Available online: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2011:054:0001:0254:DE:PDF (accessed on 9 March 2023).
  39. VDLUFA. VDLUFA Methodenbuch II; VDLUFA: Darmstadt, Germany, 2000. [Google Scholar]
  40. DIN EN 13041:2012-01; Bodenverbesserungsmittel und Kultursubstrate–Bestimmung der physikalischen Eigenschaften–Rohdichte (Trocken), Luftkapazität, Wasserkapazität, Schrumpfungswert und Gesamtporenvolumen. Deutsches Institut für Normung e.V.: Berlin, Germany, 2012.
  41. Amelung, W.; Blume, H.-P.; Fleige, H.; Horn, R.; Kandeler, E.; Kögel-Knabner, I.; Kretzschmar, R.; Stahr, K.; Wilke, B.-M. Scheffer/Schachtschabel: Lehrbuch der Bodenkunde; Springer-Verlag GmbH Deutschland: Berlin, Germany, 2018; pp. 282–284. [Google Scholar]
  42. Durner, W.; Iden, S. Skript Bodenphysikalische Versuche. Institut für Geoökologie, Abteilung Bodenkunde und Bodenphysik, Technische Universität Braunschweig, Braunschweig, Germany. 2011, p. 34. Available online: http://www.soil.tu-bs.de/lehre/Bachelor-Labormethoden/2011/2011.Skript.Bodenphysik.pdf (accessed on 9 March 2023).
  43. Wessolek, G.; Kaupenjohann, M.; Renger, M. Bodenphysikalische Kennwerte und Berechnungsverfahren für die Praxis; Bodenökologie und Bodengenese, Technische Universität Berlin: Berlin, Germany, 2009; p. 80. [Google Scholar]
  44. Fuchs, H.; Albrecht, W. Vliesstoffe; Wiley-VCH: Weinheim, Germany, 2012; p. 22. [Google Scholar]
  45. Chmielewski, F. Climate Data in Berlin-Dahlem; Humboldt-Universität: Berlin, Germany, 2015. [Google Scholar]
  46. Götz, H.; Häussrmann, M.; Sieber, J. Die Stauden-DVD; Eugen Ulmer: Stuttgart, Germany, 2011. [Google Scholar]
  47. FLL–Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V. Bewässerungsrichtlinien: Richtlinien für die Planung, Installation und Instandhaltung von Bewässerungsanlagen in Vegetationsflächen; FLL–Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau: Bonn, Germany, 2015; p. 36. [Google Scholar]
  48. Thelen-Germann, M. Entwicklung eines Bewertungsschemas zur Beurteilung krautiger Pflanzen bei vegetationstechnischen Aufnahmen. Ph.D. Thesis, Universität für Bodenkultur, Wien, Austria, 2015. [Google Scholar]
  49. Schmilewski, G.K. Kultursubstrate und Blumenerden–Eigenschaften, Ausgangsstoffe, Verwendung; Industrieverband Garten e.V.: Düsseldorf, Germany, 2018; pp. 31–32. [Google Scholar]
  50. DIN 19682-12:2007-11; Bodenbeschaffenheit–Felduntersuchungen–Teil 12: Bestimmung des Zersetzungsgrades der Torfe. Deutsches Institut für Normung e.V.: Berlin, Germany, 2007; p. 6.
  51. Schindler, U.; Lischeid, G.; Müller, L. Hydraulic Performance of Horticultural Substrates—3. Impact of substrate composition and ingredients. Horticulturae. 2016, 3, 7. [Google Scholar] [CrossRef]
  52. Herfort, S.; Tschuikowa, S. Der Einsatz von Schafrohwolle zur Nutzung als Trägermaterial im Garten- und Landschaftsbau. In Neue Landschaft; Patzer: Berlin, Germany, 2006; pp. 44–49. [Google Scholar]
  53. Hansen, R.; Stahl, F.; Duthweiler, S. Die Stauden und ihre Lebensbereiche; Eugen Ulmer: Stuttgart, Germany, 2016; p. 42. [Google Scholar]
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Figure 1. Experimental arrangement of perennial mats: (a) start of pre-cultivation (June 2015) (b) end of pre-cultivation (October 2015).
Figure 1. Experimental arrangement of perennial mats: (a) start of pre-cultivation (June 2015) (b) end of pre-cultivation (October 2015).
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Figure 2. Influence of vegetation mats on the relationship between matrix potential and water content; V = variant of matte.
Figure 2. Influence of vegetation mats on the relationship between matrix potential and water content; V = variant of matte.
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Figure 3. Influence of vegetation mats on overall impression during the course of the trial; 1 = plant failure, 3 = sufficient, 5 = satisfactory, 7 = good, 9 = very good of (a) 1st date of evaluation (7 July 2015) and (b) 7th date of evaluation (29 September 2015).
Figure 3. Influence of vegetation mats on overall impression during the course of the trial; 1 = plant failure, 3 = sufficient, 5 = satisfactory, 7 = good, 9 = very good of (a) 1st date of evaluation (7 July 2015) and (b) 7th date of evaluation (29 September 2015).
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Figure 4. Influence of vegetation mats on overall impressions of individual perennials at the 7th assessment date (end of September 2015): 1 = plant failure, 3 = sufficient, 5 = satisfactory, 7 = good, 9 = very good for (a) Achillea clypeolata ‘Moonshine’, (b) Achnatherum calamagrostis ‘Algäu’, (c) Anaphalis triplinervis, (d) Aster dumosus ‘Prof. Anton Kippenberg’, (e) Aster dumosus ‘Silberball’, (f) Centranthus ruber ‘Coccineus’, (g) Coreopsis verticillata, and (h) Salvia nemorosa ‘Rosakönigin’.
Figure 4. Influence of vegetation mats on overall impressions of individual perennials at the 7th assessment date (end of September 2015): 1 = plant failure, 3 = sufficient, 5 = satisfactory, 7 = good, 9 = very good for (a) Achillea clypeolata ‘Moonshine’, (b) Achnatherum calamagrostis ‘Algäu’, (c) Anaphalis triplinervis, (d) Aster dumosus ‘Prof. Anton Kippenberg’, (e) Aster dumosus ‘Silberball’, (f) Centranthus ruber ‘Coccineus’, (g) Coreopsis verticillata, and (h) Salvia nemorosa ‘Rosakönigin’.
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Figure 5. Effect of the different vegetation mats on the average plant height of (a) Aster dumosus ‘Prof. Anton Kippenberg’ and (b) Aster dumosus ‘Silberball’.
Figure 5. Effect of the different vegetation mats on the average plant height of (a) Aster dumosus ‘Prof. Anton Kippenberg’ and (b) Aster dumosus ‘Silberball’.
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Table 1. Composition of vegetation mats and their weight proportion of air-dry fibres.
Table 1. Composition of vegetation mats and their weight proportion of air-dry fibres.
Mat VariantComposition of FleeceProportion Sheep’s Wool (kg/m2)Proportion Coir (kg/m2)Total Weight (kg/m2)
V1: 50sw/50c50% sheep’s wool and 50% coir1.81.83.6
V2: 30sw/70c30% sheep’s wool and 70% coir1.42.84.2
V3: Sandwich30% sheep’s wool and 70% coir,
Core: 100% sheep’s wool		2.70.93.6
V4: 100c (control)100% coir0.02.52.5
Table 2. Overview of the selected perennials for sunny positions and nutritional requirements.
Table 2. Overview of the selected perennials for sunny positions and nutritional requirements.
Botanical NameNutritional Requirements [46]
Achillea clypeolata ‘Moonshine’low
Achnatherum calamagrostis ‘Algäu’low
Anaphalis triplinervislow
Aster dumosus ‘Prof. Anton Kippenberg’high
Aster dumosus ‘Silberball’high
Centranthus ruber ‘Coccineus’low–middle
Coreopsis verticillatamiddle
Salvia nemorosa ‘Rosakönigin’middle
Table 3. Calculated nitrogen content of the fibres (air dry) of the used vegetation mats.
Table 3. Calculated nitrogen content of the fibres (air dry) of the used vegetation mats.
Mat VariantN-Content of Sheep’s Wool
Fibres in the Vegetation Mat (g/m2)		N-Content of Coconut Fibre in the Vegetation Mat (g/m2)Total N-Content of Fibres in the Vegetation Mat (g/m2)
V1: 50sw/50c187.25.4192.6
V2: 30sw/70c145.68.4154.0
V3: Sandwich280.82.7283.5
V4: 100c07.57.5
Table 4. Physical properties of substrates.
Table 4. Physical properties of substrates.
SubstrateDensity
(gcm−3)		Measured Bulk Density
(g 100 cm−3)		Calculated Total Pore Volume
(vol%)		Measured
Water Content at pF0 (vol%)		Measured
Water Content at pF1 (vol%)		Measured Air Content at pF1 (vol%)
V1: 50sw/50c1.247.9 ± 0.0593.6 ± 0.0469.4 ± 1.51 b17.6 ± 0.50 b75.9 ± 0.47 b
V2: 30sw/70s1.208.5 ± 0.0393.0 ± 0.0265.1 ± 1.41 b16.0 ± 0.27 b77.0 ± 0.28 b
V3: Sandwich1.287.7 ± 0.0293.9 ± 0.0181.8 ± 1.10 c22.1 ± 0.46 c71.8 ± 0.45 a
V4: 100c1.159.2 ± 0.0192.0 ± 0.0159.3 ± 0.98 a12.6 ± 0.20 a79.4 ± 0.19 c
Other substrate constituents 60–98 [49]71.8–87.1 [51]8–83 [49]9–90 [49]
Table 5. Medians of the awarded scores of all perennials on the different vegetation mats on the 1st, 3rd, 5th, and 7th assessment dates.
Table 5. Medians of the awarded scores of all perennials on the different vegetation mats on the 1st, 3rd, 5th, and 7th assessment dates.
Mat VariantScore
(1st Date)		Score
(3rd date)		Score
(5th Date)		Score
(7th Date)
50sw/50c7775
30sw/70c7775
Sandwich7755
100c6754
Table 6. Average plant height (± SE) of all perennials on different mat variants at the 7th assessment.
Table 6. Average plant height (± SE) of all perennials on different mat variants at the 7th assessment.
Mat Variants50sw/50c30sw/70cSandwich100c
Perennial Plant Height (cm)
Achillea clypeolata ‘Moonshine’25.3 ± 0.6 b24.6 ± 1.2 b25.1 ± 1.6 b17.5 ± 1.3 a
Achnatherum calamagrostis ‘Algäu’46.5 ± 2.1 a49.9 ± 1.5 a45.7 ± 1.5 a46.9 ± 1.2 a
Anaphalis triplinervis28.8 ± 2.0 a29.8 ± 1.6 a25.6 ± 2.3 a25.3 ± 1.3 a
Aster dumosus ‘Prof. Anton Kippenberg’35.8 ± 0.6 b35.8 ± 0.8 b36.5 ± 0.6 b14.4 ± 1.8 a
Aster dumosus ‘Silberball’42.3 ± 1.1 b41.3 ± 1.3 b44.0 ± 0.9 b26.7 ± 1.6 a
Centranthus ruber ‘Coccineus’51.0 ± 2.0 b40.5 ± 5.8 ab49.5 ± 2.2 ab37.0 ± 3.8 a
Coreopsis verticillata32.4 ± 1.4 a29.2 ± 1.3 a28.8 ± 2.2 a29.0 ± 1.5 a
Salvia nemorosa ‘Rosakönigin’35.5 ± 1.9 b37.5 ± 1.7 b34.4 ± 2.7 b22.2 ± 3.7 a
All values were tested with Tukey’s HSD test. Different small letters indicate significant differences (p < 0.05).
Table 7. Pearson correlation between nitrogen content and plant height.
Table 7. Pearson correlation between nitrogen content and plant height.
1st Date3rd Date5th Date7th Date
Achillea clypeolata ‘Moonshine’
Sig. (2-tailed)		-
-		-
-		-
-		0.617 **
<0.001
Aster dumosus ‘Prof. Anton Kippenberg’
Sig. (2-tailed)		0.542 **
<0.001		0.808 **
<0.001		0.878 **
<0.001		0.834 **
<0.001
Aster dumosus ‘Silberball’
Sig. (2-tailed)		0.572 **
<0.001		0.817 **
<0.001		0.792 **
<0.001		0.807 **
<0.001
Centranthus ruber ‘Coccineus’
Sig. (2-tailed)		-
-		-
-		0.372 **
0.009		-
-
Salvia nemorosa ‘Rosakönigin’
Sig. (2-tailed)		0.437 **
0.002		0.536 **
<0.001		0.561 **
<0.001		0.446 **
<0.002
** The correlation is significant at a level of 0.01 (2-tailed).
Table 8. Pearson correlation between water capacity at pF 1.0 and plant height.
Table 8. Pearson correlation between water capacity at pF 1.0 and plant height.
1st Date3rd Date5th Date7th Date
Achillea clypeolata ‘Moonshine’
Sig. (2-tailed)		-
-		-
-		-
-		0.546 **
<0.001
Aster dumosus ‘Prof. Anton Kippenberg’
Sig. (2-tailed)		0.494 **
<0.001		0.699 **
<0.001		0.770 **
<0.001		0.722 **
<0.001
Aster dumosus ‘Silberball’
Sig. (2-tailed)		0.530 **
<0.001		0.747 **
<0.001		0.714 **
<0.001		0.722 **
<0.001
Salvia nemorosa ‘Rosakönigin’
Sig. (2-tailed)		0.459 **
0.001		0.459 **
0.001		0.494 **
<0.001		0.355 *
0.014
** The correlation is significant at a level of 0.01 (2-tailed). * The correlation is significant at a level of 0.05 (2-tailed).
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Herfort, S.; Pflanz, K.; Larsen, M.-S.; Mertschun, T.; Grüneberg, H. Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials. Horticulturae 2023, 9, 384. https://doi.org/10.3390/horticulturae9030384

AMA Style

Herfort S, Pflanz K, Larsen M-S, Mertschun T, Grüneberg H. Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials. Horticulturae. 2023; 9(3):384. https://doi.org/10.3390/horticulturae9030384

Chicago/Turabian Style

Herfort, Susanne, Kerstin Pflanz, Marina-Sandra Larsen, Thomas Mertschun, and Heiner Grüneberg. 2023. "Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials" Horticulturae 9, no. 3: 384. https://doi.org/10.3390/horticulturae9030384

APA Style

Herfort, S., Pflanz, K., Larsen, M. -S., Mertschun, T., & Grüneberg, H. (2023). Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials. Horticulturae, 9(3), 384. https://doi.org/10.3390/horticulturae9030384

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