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Article

Converting an Established Sida hermaphrodita Field into Arable Farming

by
Nicolai David Jablonowski
1,*,
Benedict Ohrem
1,
Michael Gitzen
1 and
Tobias Kollmann
2
1
Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
2
Project Management Jülich, PTJ-ESN: Energiesystem: Nutzung, D-52425 Jülich, Germany
*
Author to whom correspondence should be addressed.
Agronomy 2024, 14(3), 411; https://doi.org/10.3390/agronomy14030411
Submission received: 29 January 2024 / Revised: 14 February 2024 / Accepted: 16 February 2024 / Published: 20 February 2024
(This article belongs to the Special Issue Sustainable Cropping Systems and Biomasses for Energy and Biorefinery Applications)
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Abstract

:
The long-term performance of perennial energy crops and their elimination is important for long-term planning and use of agricultural land. In this study, the elimination of a six-year-old Sida hermaphrodita (hereafter referred to as Sida) stock for agricultural reclamation was investigated over three years. Crop rotation using maize, winter wheat, and sugar beet, a catch crop, as well as mechanical–chemical treatments were employed according to agricultural practices. After soil grubbing at the beginning of the experiment and prior to further treatments, on half of the former Sida planting area, visible Sida roots were manually removed in addition to determining their potential effect on total resprouting. Prior to each crop harvest, resprouted Sida plants were counted. At harvest, by the end of the first year, 476 versus 390 resprouted Sida plants were found in the investigated areas of 315 m2 each, where preceding manual root removal either took place or not, respectively. This accounted for 76% and 62% of the initial Sida planted. In the second year, the overall number of resprouted Sida declined significantly, accounting for 15 and 11 plants (i.e., 2.4% and 1.8% of initially planted), and in the third year, only two and four residual plants (i.e., 0.3% and 0.6%) were found, representing an almost 100% Sida elimination rate. We conclude that additional root removal did not result in a significant difference in Sida regrowth compared to the mechanical–chemical treatments only. No impediments to harvesting and no loss of yield in any crops were observed due to resprouted Sida in the existing field crops. No Sida plants were found outside the initial field, indicating a low dispersion potential and invasiveness. The results show that successful recultivation of an established Sida stock is possible through common agricultural practices and that resprouting Sida plants did not negatively affect the subsequent crops.

1. Introduction

The use of biomass for sustainable energy production has always played a crucial role. The growing awareness of the dramatic effects of climate change has brought the use of biomass back into the focus of energy use. In this context, many plants, such as grasses, perennial shrubs, and fast-growing trees, have been studied for their suitability for energy production. Among them are some species non-native to Europe, such as Sida hermaphrodita (L.) Rusby, also known as Virginia fanpetals or Virginia mallow, is recently also synonymous with Ripariosida hermaphrodita (L.) Weakley & D.B.Poind [1] (in the following referred to as Sida), a perennial mallow species originating from Northern America.
Sida was originally introduced in the former USSR in the 1930s as a forage plant before being further cultivated in Poland in the 1950s [2]. There, Sida has been grown primarily as an energy crop in recent decades because its biomass, which dies off and dries out over the winter, is well suited as a solid fuel for combustion [3]. Recent studies on Sida showed that Sida biomass is very suitable as a solid fuel, with the advantage of good processability (harvesting, pelleting, briquetting), good combustion properties, a high ash melting temperature, and an overall good comprehensive life cycle assessment [4,5]. In an earlier study, the use of Sida biomass for biogas production was also investigated, but the energy yield is clearly inferior to that of its use as a solid fuel, considering the dry biomass [6]. Furthermore, it has been shown that regular harvesting of fresh Sida biomass at the vegetative stage to be used as a biogas feedstock reduces emergence in subsequent years [7]. This is probably due to the fact that the plants cut in summer cannot transport sufficient assimilates back into the root system to have adequate energy for full resprouting in the following year. Sida biomass is increasingly being discussed and investigated as a promising feedstock for biorefinery applications and as a supplier of lignocellulose [8,9,10]. Further, Sida appears to be a potential feedstock supplier for the pulp and paper industry and a suitable alternative to wood [11].
Depending on soil conditions, planting density, and fertilizer applications, reported Sida biomass yields from established stands account for up to 20 t/ha, but also yields of up to 28 t/ha have been observed [2,12,13,14,15]. In addition, it has been shown that Sida can also grow well on marginal, sandy substrates, particularly when ameliorated with organic fertilizers [16,17]. In particular, organic fertilizers such as digestate placed in the root zone, inspired by the Controlled Uptake Long Term Ammonium Nutrition (CULTAN) procedure [18], resulted in successful emergence and good biomass production in pure sand [19]. The sustainable cultivation of biomass on non-productive and non-arable, especially marginal lands, is of growing importance also with regard to social–ecological aspects [20]. This makes the development and use of set-aside land for biomass production or the redevelopment and amelioration of abandoned land important. Many studies have successfully demonstrated the cultivation of Sida on contaminated soils and even sewage sludge, allowing a dual use of this crop for biomass production for energy applications on the one hand and stabilization of such soils and affected areas on the other [21,22,23,24,25].
In addition to the potential high yields, another advantage of Sida is the fact that the above-ground biomass, i.e., the lignified stalks or stems, dies off and dries over the winter. Unlike wood chips or wood sawdust, for example, this fact reduces the need for subsequent drying of the biomass to a minimum or makes additional drying even unnecessary. Accordingly, this reduces further energy input, resulting in a net energy yield increase. Sida biomass can be harvested in spring with conventional maize choppers before resprouting and subsequently processed for pellet and/or briquette production, as pellets were found to have the best combustion properties [4]. Cultivation of Sida by direct seeding employing conventional seeders is not recommended due to poor seed germination. Further, Sida seedlings are sensitive to weed competition and excessive drought, so care must be taken to ensure good soil preparation and, if necessary, additional irrigation in the first year. Thus, young Sida plants or root cuttings are recommended to allow for a successful plant establishment [26]. As shown in a recent study on the establishment of Sida, the use of a biodegradable mulch film resulted in significantly greater plant growth compared to the control without film [27]. This could be primarily attributed to the effective weed suppression by the mulch film, among other plant growth-supporting factors. After the successful establishment and rapid growth of the Sida plants under favorable conditions, a dense stand occurs from the second year onwards. At this stage, the Sida stand may not require further weed-control measures, since the dense foliage suppresses competing plants.
Among the outlined advantages of Sida, however, knowledge about the removal of perennial biomass plants after their productive life phase and its possible impact on subsequent crops is important for planning and acceptance by the farmer. In the case of Miscanthus (Miscanthus x giganteus), another important perennial biomass and bioenergy crop belonging to the Poaceae family, a combination of the broad-spectrum herbicide glyphosate application and tillage in spring contributed to a significant reduction in biomass growth [28]. Nevertheless, in accordance with the cited study, several treatments appear to be necessary to eliminate a mature Miscanthus stand. Another study on herbicide efficiency and application timing to eliminate an existing Miscanthus stand showed that glyphosate, in particular, led to 100% elimination if the herbicide was applied during the active growth phase in June or July [29]. Nevertheless, the use of chemical herbicides such as glyphosate is of concern; therefore, alternatives should be found for the eradication of perennial biomass crops under ecological and sustainable criteria. As a recent study demonstrated, a perennial Miscanthus stand could be eradicated by a combination of tillage and grass herbicides from maize cultivation and subsequent cultivation of maize and winter wheat [30].
Comparable studies and information on the eradication of existing Sida stocks do not yet exist. However, these are important in order to promote the acceptance and cultivation of this biomass plant. As a non-native plant species in Europe, Sida is largely unexplored in terms of its invasiveness, eradication, and recultivation potential on agricultural land. However, the extent to which elimination and recultivation of an existing Sida stand are possible without affecting subsequent crops is of crucial importance to the practitioner and farmer.
Thus, in this study, we monitored and investigated the reclamation of a six-year-old, successfully established Sida stock using common mechanical–chemical agricultural practices over a total of three consecutive years. The aims of this study were to investigate the following: (1) how far an elimination of the established Sida field is possible by means of the applied conventional mechanical–chemical agricultural practices; (2) if resprouted Sida plants impede the productivity of subsequent crops used in this study, i.e., maize, winter wheat, and sugar beet; (3) if resprouted Sida plants hinder harvesting of the following crops; and (4) if Sida shows an invasive nature in the agricultural area of investigation.

2. Materials and Methods

2.1. Experimental Field and Background Information

The experimental field used for this study served as a Sida field trial from 2015 to 2021. The area of investigation was initially established by planting two Sida root cuttings per square meter. Detailed information about the field and the earlier study on Sida biomass use as a solid energy carrier for combustion have been published previously [4]. Briefly, the field was located in Titz Sevenich, Germany (100 m a.s.l., 50°58′13.0″ N 6°23′31.0″ E). The soil was composed of 5.6% sand, 79.0% silt, and 15.4% clay, classified as a clayey silt with pH 7.0 and a humus content of approx. 2.3%. The soil value (in German, “Bodenwertzahl”, used as an indicator for soil quality and profitability) of the field of experimentation accounts for 90 and is, therefore, of very high quality [31,32]. Except for a single nitrochalk application in March 2016 (equaling 27 kg N/ha) to promote initial Sida growth, no fertilizers were applied to the Sida field trial until its termination in 2021. While in the earlier study, only part of the entire field was used for yield investigations at three different Sida planting densities, this study considered the remaining Sida field of approx. 1100 m2 with a planting density of two plants per square meter for recultivation.

2.2. Final Sida Harvest and Experimental Field Preparation

In February 2021, the established Sida stand was terminated, and recultivation of the field was initiated to return the field to common agricultural use. It was decided to meet the increasing demand for locally produced cash crops.
Prior to first soil treatments, a final Sida biomass harvest was conducted on 19 February 2021. For this purpose, three biological replicates, i.e., entire individual plants, were taken completely by cutting the shoots directly above the soil surface. The number of shoots was counted, and the fresh and dry biomass was determined for each replicate plant. The final biomass determination was considered necessary to compare the Sida yield after six years of standing with yield values from the previous years, as presented earlier [4].
Subsequently, all remaining Sida plants were cut by operating a conventional flail mower. The soil was then cultivated over the entire area with a grubber to expose the Sida roots and bring them to the surface, followed by a molding cutter treatment. Details of all measures applied are listed in Table A1, provided in the Appendix A. Visual impressions of the Sida at final harvest and the field after grubber treatment are provided in Figure 1.
The entire field where, initially, two Sida plants per square meter were planted was divided into two areas, A and B, each approx. 550 m2 in size. Three plots within area A (namely A1, A2, A3) and B (namely B1, B2, B3), each 5.25 × 20 m (=105 m2 each) in size, were implemented to facilitate the counting and statistical analysis of the resprouted Sida plants. For technical reasons, complete randomization of the plots within the field had to be omitted. These reasons include work organization and practical agricultural workflows. Due to the use of heavy agricultural equipment, regular soil cultivation, and chemical measures, as well as harvesting the crops, it was not possible to establish small, randomized, and clearly defined subplots in the field in the long term. However, results from plots A and B were not significantly different, and a randomization would not have changed the outcome of this study.
In all of area A, before any further mechanical and chemical measures were taken (Table A1), all clearly visible and vital Sida roots lying on the soil surface were removed by hand. This amounted to a total of approx. 400 kg of Sida root cuttings, equaling approx. 0.7 kg roots/m2 (≈7 t fresh root biomass per ha). Visual impressions of the removed Sida rootstocks and roots are provided in Figure 2.
In area B, no Sida roots were manually removed prior to any further treatments, as listed in detail in Table A1. The purpose of this step was to investigate whether excessive removal of exposed Sida roots influenced the number of resprouting Sida plants compared to a purely mechanical–chemical treatment following common conventional agricultural practice. Subsequently, the entire field was treated with a rotary tiller in two different depths, first at 6 cm depth and second at 10 cm depth, with opposite directions of travel. The objective of this was to shred the Sida roots and stimulate resprouting in order to achieve sufficient Sida leaf area for a herbicide application before the first field crop maize was sown. All further mechanical and chemical agricultural measures throughout the three-year study period are listed in Table A1 and were carried out in both areas A and B. No additional or specially adapted work steps were carried out from the time of seedbed preparation for maize sowing in 2021. All work steps carried out were in accordance with common agricultural practices for all crops.

2.3. Data Collection on Sida Resprouting and Applied Crop Rotation

To determine the number of resprouted Sida plants in the plots in areas A and B and in the entire surrounding field, regular monitoring walks were carried out in the field, and all resprouted Sida plants within the plots in areas A and B were recorded. The decisive factor was the number of Sida plants counted at each crop harvest. The year and each planted crop for the respective year were as follows:
2021: maize (Zea mays L., SUCORN DS1710C, SAATEN-UNION GmbH, Isernhagen, Germany), using 9 grains m2 (90,000 grains per ha) with a row spacing of 75 cm; 2022: winter wheat (Triticum aestivum, RGT REFORM Winterweizen, Getreidefonds Z-Saatgut e. V. (GFZS), Bonn, Germany), using 310 grains per m2 with a spacing of 12.5 cm per row; 2023: sugar beet (Beta vulgaris subsp. vulgaris, Altissima-Gruppe, BTS 6975 N, Betaseed GmbH, Frankfurt am Main, Germany), using approx. 11 seeds m2 (105,000 seeds per ha) with a spacing of 50 cm per row. In addition, a catch crop mixture (DSV TerraLife® BetaSola, Deutsche Saatveredelung AG, Lippstadt, Germany) was used during the months of September 2022 until January 2023 (Table A1).
To assess whether the six-year-old Sida stand could have adverse effects on yields of succeeding crops, harvest results of the respective crops from the former Sida field trial and the surrounding fields grown under the same environmental conditions were recorded. These values were used for estimation and comparison with official statistical yield data from the region, provided by “Landesbetrieb, Information und Technik Nordrhein-Westfalen, Statistisches Landesamt” (Statistical Office of the Federal State North Rhine-Westphalia), Düsseldorf, Germany (www.landesdatenbank.nrw.de/ldbnrw/online, accessed on 13 December 2023, search keyword “Feldfrüchte”, search result: “Erntebericht: Hektarerträge nach ausgewählten Fruchtarten (12)—kreisfreie Städte und Kreise—Jahr; Düren”).

2.4. Data Processing and Image Design

Microsoft Excel 2019 (Redmond, WA, USA) was used to analyze the data. Independent samples t-tests were applied to evaluate the variances between regrown Sida plants in areas A and B, as well as to assess the statistical significance of differences in crop yield averages in the local area (“Düren region”) and those obtained from the field of investigation.

3. Results

3.1. Yield Evaluation and Plant Parameters at Final Sida Harvest

The final Sida yield estimation in 2021, six years after the Sida plantation took place in 2015, accounted for 11.2 (±0.2) t/ha dry mass (DM), with a mean number of 19 (±1.4) shoots per plant and a mean height of 287 (±17.0) cm of the longest shoots.

3.2. Development of Sida and Its Response to the Applied Measures

At harvest, by the end of the first year in 2021, a total of 476 resprouted Sida plants were found in the plots of area A, where manual root removal took place prior to the mechanical–chemical treatments, versus 390 plants in the plots of area B, where only mechanical–chemical treatments were employed. These numbers accounted for approx. 75% and 62% of the initial Sida planted when considering an initial planting density of two plants per square meter (Table 1). Differences in counted Sida plants among the two areas A and B were not statistically different (p > 0.6) throughout the study period by means of a two-sided t-test, comparing the mean values of the counted Sida plants per year from plots A1–A3 with those from plots B1–B3.
Repeated disruption of growth by the applied mechanical–chemical treatments, in conjunction with strong resource competition from the planted crops, allowed for an almost complete elimination of Sida already by the second year of this study in 2022, accounting for 15 and 11 remaining Sida plants in the plots of areas A and B, respectively. This equals approx. 2.4% and 1.8% of the plants that were initially planted when considering an initial planting density of two plants per square meter (Table 1). In 2023, only two and four residual plants, i.e., approx. 0.3% and 0.6% of initially planted plants, were found in the plots of areas A and B, respectively, implying an elimination rate for Sida of almost 100% (Table 1). These plants originated in approximately equal parts from roots and seeds and were found in the ruts or headlands only. A visual impression of resprouted Sida plants in sugar beet in 2023 is given in Figure 3.

3.3. Mutual effects of Sida, the Applied Crop Rotation and Crop Yield

All crops grown in rotation, i.e., maize, winter wheat, and sugar beet, were not inhibited in their growth by the partially resprouted Sida plants. Cash crop yields from the recultivated Sida field did not differ from yields of the same crops in each respective year from surrounding fields and accounted for approximately 70.2 t fresh mass/ha for maize (2021), harvested as whole plant silage to be used as a feedstock for biogas production at 32% dry matter content, 11.5 t/ha for winter wheat (2022), and 91.9 t/ha for sugar beet (2023), respectively, as shown in Table 2. These values are 7.8% higher for maize and 19.8% higher for winter wheat than the comparable values from the Düren region (for further details, see Section 2.3 and www.landesdatenbank.nrw.de/ldbnrw/online (accessed on 13 December 2023). Table 2 presents the yield data from the former Sida trial field and from adjacent fields in direct proximity characterized by the same soil value of 90, as well as the official cash crop yield values for the Düren region provided by the State Office for Information and Technology North Rhine-Westphalia—State Statistical Office, Düsseldorf, Germany. As shown in Table 2, these values amount to 65.1 t/ha for maize in 2021 and 9.6 t/ha for winter wheat in 2022, respectively. Reliable data for sugar beet from 2023 were not yet available from the State Statistical Office when the manuscript was submitted and are not expected to be available until April 2024. Nevertheless, the sugar beet yield of 91.9 t/ha from the former Sida field in 2023 is 17% higher than the four-year (2019–2022) average value of 78.5 t/ha from the Düren region (Table 2).
When comparing the average yield values from 2019 to 2022 from the former Sida field and from fields in the immediate vicinity of the Sida trial field, the yields for winter wheat and sugar beet were significantly higher at 10.7 (±0.67) t/ha (p = 0.009) and 91.5 (±3.73) t/ha (p = 0.01) compared to the yield data from the same period from the Düren region, which correspond to 8.7 (±0.56) t/ha and 78.5 (±4.64) t/ha, respectively. The average maize yield of 60.5 (±7.48) t/ha from the fields around the former Sida trial field was approx. 12% higher than the four-year average value of 54.2 (±7.92) t/ha from the Düren region but was not significant (p = 0.46).

4. Discussion

4.1. General Remarks

Perennial biomass/energy crops play an important role in energy security and the overall energy mix and could contribute to agro-biodiversity and overall landscape aesthetics, stimulating landscape heterogeneity and providing additional ecosystem services [20]. However, a sensitive balance between cash crop production to maintain food/feed security and perennial crop production for energy and feedstock should be considered. Advantages for soil health, organic carbon sequestration, resilience, and biodiversity were found in numerous perennial energy crops [33,34,35], making such plants a promising tool for maintaining agricultural sustainability. Irrespective of these advantages, knowledge about the possible reintegration into crop rotation is crucial for the acceptance of perennial energy crops such as Sida. Among local demands, the additional motivation to return an established Sida field to crop production can be a decline in yield as a result of drought, pests and plant diseases, dominant weed pressure, or age of the crop. As documented, Sida yield increased in the first 4–5 years [3,12]. While it was stated that Sida could remain productive for 20 years [36], only one study so far documented the Sida yield over a period of thirteen successive years, showing a rapid and rather constant decrease from year six onwards due to adverse biological and abiotic circumstances [3]. However, the reported findings might have been site-specific. It is, therefore, of importance to anticipate possible eventualities before establishing a perennial Sida stand and to better assess possible consequences for the subsequent crops. The presented results of this study can be useful in the decision-making process, providing information on the behavior of Sida in crop rotation and agricultural practice.

4.2. Final Sida Harvest and Biomass Yield

Established, full-grown Sida plants have assimilated reserves in their large root systems so that resprouting of the plants from their roots is possible. The biomass yield obtained at the final harvest of the Sida plants was slightly lower when compared with the earlier reported values from this Sida stock in 2017 (12.2 t/ha DM) and 2018 (13.9 t/ha DM), i.e., two and three years after planting [4]. This yield decline might be due to manifold reasons and could be associated with a lack of water due to hot and dry summer seasons in the previous two years, a potential depletion of soil nutrients over time, and a simultaneous increase in resource competition by weeds. Considering flood plains and riverine areas as the natural habitat of Sida [37], drought was found to severely affect Sida growth and biomass allocation, particularly in young plants still missing a deep-reaching root system [38,39]. This may become crucial for commercial Sida biomass production in terms of climate change, which is apparent by more frequent heat waves and estimated drought events.
With regard to the available literature, the further yield development on the Sida field of investigation would have been speculative. It remains unknown whether the Sida stand would have remained productive or whether the yield would have decreased successively, as demonstrated earlier [3,36]. As stated by Kwiatkowski et al., among drought, severe detrimental factors influencing Sida growth and yield over time were associated with a shortened growing season due to late spring frosts and Sclerotinia stem rot infections caused by the fungus Sclerotinia sclerotiorum [3]. Whether an early termination of a perennial Sida stand, characterized by an excessive biomass decline due to biotic or abiotic factors, makes sense can only be decided on a situational basis and according to local needs. However, the high establishment efforts could also justify waiting for further development and possible recovery of the Sida stock.

4.3. Effects of Mechanical–Chemical Treatments

The almost complete elimination of Sida was achieved by a total of 15 mechanical soil treatments in combination with a total of five herbicide applications in the studied areas during the period of investigation. These treatments were part of the conventional agricultural cultivation measures and were carried out independently of the earlier Sida plantation. All mechanical operations carried out from the seedbed preparation of maize onwards were standard measures for the cultivation of maize, wheat, catch crops, and sugar beets. Over the three-year duration of this study, these treatments were subdivided into nine mechanical and one chemical treatments in 2021, three mechanical and one chemical treatments in 2022, and three mechanical and three chemical treatments in 2023 (Table A1).
From an agronomic point of view, other options would have been available for the eradication of Sida, such as the use of broad-spectrum herbicides, e.g., glyphosate, or other crop rotations with more intensive mechanical–chemical treatments necessary. Accordingly, we assume that the approach followed in this study was rather conservative in nature and that Sida can be eliminated even faster and more thoroughly by harsher treatments. However, the agricultural measures applied in our study led to the elimination of the existing Sida stand to a very large extent, allowing for a successful recultivation of the investigated area for cash crop production. Interestingly, all residual Sida plants found grew only in the ruts or headlands and not in the closed beet stand. Ruts are obviously predestined for Sida resprouting because there was less competition for light, nutrients, etc., from the beets, and also, the effect of the soil herbicide was reduced due to various passes of machinery.
Among all the following field operations and measures applied, mechanical tillage and herbicide applications are considered the primary reasons for the successful repression of the Sida plants during the years of investigation. This was particularly pronounced for the used herbicides Goltix Titan, Metafol, and Betasana as applied to the Sida field in the third year of investigation, 2023, containing the active compounds Metamitron (4-Amino-3-methyl-6-phenyl-1,2,4-triazine-5-on), and Phenmedipham (Methyl-3-(3-methylcarbaniloyloxy)carbanilate), respectively.
Overall, the available literature on herbicides in the context of Sida is very limited. Field studies on the herbicide sensitivity of Sida demonstrated that a large number of commonly used herbicides were not or only poorly tolerated [40]. However, the cited study was conducted on young Sida plants 4–5 weeks after emergence or earlier only. The herbicides Metamitron, Phenmedipham, and their mixtures, as also applied in our study in the third year, induced medium damage in the postemergence period. A similar field study with variation in the herbicides used, including Metamitron, was conducted in Poland, using juvenile Sida plants at the 1–2 and 3–4 leaf stages [41]. The cited study concluded that the most important factor, apart from the herbicide active compound, was the developmental stage of Sida at the time of herbicide application. With regard to the existing literature, it can, therefore, be said that juvenile, underdeveloped Sida plants, in particular, react sensitively to herbicides.
The used herbicide Metamitron in the cited studies is a standard for the control of annual eudicotyledonous weeds, primarily in sugar beet production. It acts through both the roots and the leaves. In the pre-emergence application, the effect is mainly achieved via the roots of the plants. In postemergence, the effect is additionally exerted via the leaves, which causes the plant to die off more quickly. Metamitron causes the inhibition of photosynthesis, which in turn results in less nutrients stored and electrons being transported within the plant, finally resulting in plant death [42]. Even though Metamitron application on young Sida plants induced only medium damage in the cited studies above, it can be assumed that Metamitron, as a soil-active herbicide applied among others in the third year of the presented study, resulted in a further elimination of the mature but weakened Sida plants.
In a non-agricultural context, a previous study tested the sensitivity of Sida to the herbicide glyphosate as an endangered non-target macrophyte in Canada [43]. The authors reported that the growth of the main shoot was toxicologically sensitive to glyphosate and recommended that the main shoot length should be considered for assessing Sida responses to herbicides applied via foliar spray. Since in the cited study, only four-week-old Sida plants were used, a direct comparison with our six-year-old, mature Sida plants regarding their herbicide sensitivity and ability to resprout from the densely developed root system is not appropriate.

4.4. Soil Quality Determines Crop Yield Rather than Residual Sida Effects

In the entire Düren region where this study was executed, a strong local soil heterogeneity can be observed, ranging from soil values as low as 20 to up to 90 (https://grundsteuer-geodaten.nrw.de/, accessed on 4 December 2023). On average, the soil value accounts for 70 in the entire Düren region [44]. The arable land of the former Sida trial field, as well as the adjacent fields from which the cash crop yield data were collected, has a soil quality of 90. The observed differences in yield values for the respective crops from the former Sida field could, therefore, be attributed to this very high soil value. Consequently, the higher yields obtained for each cash crop when compared with the statistical average values for the larger region of Düren can be attributed to the local soil differences and the very high soil value on the former Sida field and its adjacent fields.
The obtained yield values demonstrate that neither the crop yield nor the crop harvest was negatively influenced by the resprouted Sida plants in the respective years. However, influences of locally varying precipitation, soil moisture, and dryness, as well as fertilization, were not taken into account in the given yield values. Due to the large amount of underlying data for the Düren region, these eventualities can possibly be averaged out.
In 2021, the resprouted Sida plants were harvested together with the maize and subsequently used for ensilaging as feedstock for biogas production. It can be assumed that silage maize or other fast- and tall-growing plants are ideal as a subsequent crop for the reclamation of an existing Sida stand. Maize is characterized by fast and tall growth that interferes with resprouting and growth of Sida. In addition, resprouted Sida plants do not interfere with harvest or product, as the total biomass is used as silage for feed or biogas substrate. This assumption corresponds with earlier findings on the reintegration of Miscanthus fields into crop rotation, indicating that maize cultivation suppressed Miscanthus regrowth most successfully [45]. Also here, maize was particularly efficient in Miscanthus suppression due to a combination of both crop management (harrowing before sowing) and crop competition due to greater plant height, making maize also a suitable crop for cultivation following a perennial Miscanthus stock.

4.5. Observations on Sida Invasiveness at Agricultural Field Conditions

Due to our observations on the spreading and invasiveness of Sida in the field of experimentation, this plant could be considered to be of low ecological risk. A report on environmental risk analyses of non-native biomass crops in the Netherlands from 2015 classified Sida as a plant with “likely ecological risk to the categories dispersion potential and invasiveness and colonization of high value conservation habitats” but also a “deficient data risk classification to the categories adverse impacts on native species and alteration of ecosystem functions” [46]. As stated in the cited report, this is mainly due to deficient data for most risk assessment categories.
However, it should be noted that the term “invasive” needs to be differentiated more clearly between arable land and near-natural ecosystems where invasive species may outcompete species of the native natural vegetation. In this study, conclusions could only be drawn from the arable land of investigation. In such field studies on arable land, the term “perennial plant species of high economic relevance” might further be considered instead.
The results of this study could contribute to a better assessment of Sida invasiveness and its ecological risk at the agricultural level. However, it should be noted that Sida is a wild plant species. It is generally known from wild plants that seeds present in the soil can remain vital for long periods and could germinate even after many years. According to the presented findings, it can be assumed that Sida plants germinating from seeds have no chance for a thorough establishment under conventional agricultural field cultivation. In future years, the observation of the possible resprouting of remaining Sida roots in the field will be continued.

5. Conclusions

The measures employed in this study achieved a successful elimination and reclamation of a six-year-old, fully established Sida stand for conventional crop production. Nevertheless, the results shown are a result of the treatments applied in this study. To what extent a different crop rotation or other mechanical–chemical measures can also successfully eradicate Sida remains unclear at this point and needs further research. However, it can be assumed that regular soil cultivation and crop rotation will lead to a relevant repression of Sida plants within the general framework of conventional agricultural practice. Resprouted Sida plants neither impeded the productivity of subsequent crops used in this study, i.e., maize, winter wheat, and sugar beet, nor did they hinder the harvesting of the crops. Overall, Sida did not show an invasive nature in the agricultural area of investigation throughout the study period of three consecutive years. Knowledge and information on the behavior of perennial, neophytic biomass plants such as Sida and their eradication are important for biomass producers, decision-makers, and ecologists. Such information is important for the practical management of biomass plant species and should, therefore, be carried out in parallel with yield studies in the future. More research is needed to show that purely mechanical measures in the context of, e.g., organic farming can also successfully repress Sida so that farmland can again be used to grow conventional crops without the risk of crop losses due to excessive competition from remaining Sida plants.

Author Contributions

N.D.J.: conceptualization of the study, methodology employed, software application, data validation, formal data analysis, investigation, resources, data curation, writing—original draft preparation, writing—review and editing, visualization, supervision, and project administration. B.O.: methodology employed, software application, data validation, formal data analysis, investigation, data curation, writing—review and editing, and visualization. M.G.: methodology employed, software application, data validation, formal data analysis, investigation, data curation, writing—review and editing, and visualization. T.K.: conceptualization of the study, methodology employed, data validation, investigation, resources, data curation, and writing—review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The original contributions presented in the study are included in the Appendix A, further inquiries can be directed to the corresponding author.

Acknowledgments

We kindly acknowledge the help and assistance of Jens Cohnen, Susanna Schmitz, and Stefan Gelderie. The constructive comments, critiques, and discussions on our manuscript, the study design, and statistical data evaluation prior to submission by Moritz Nabel, Hendrik Poorter, Moritz von Cossel, and Johannes Postma are highly appreciated. The authors also thank the IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, a member of the Helmholtz Association, Germany, for providing institutional support and funding.

Conflicts of Interest

The authors declare no conflict of interest.

Appendix A

Table A1. Overview of the timeline and applied treatments during the recultivation of the established, 6-year-old Sida stand under agricultural conditions. Active compounds are provided for the herbicides only.
Table A1. Overview of the timeline and applied treatments during the recultivation of the established, 6-year-old Sida stand under agricultural conditions. Active compounds are provided for the herbicides only.
Year of Investigation/Timeline/Treatments
202120222023
TimeTreatmentTimeTreatmentTimeTreatment
20.02.2021Sida plants chopped by flail mulcher02.03.2022Fertilization (SSA with 170 kg/ha = 36 kg N/ha and 40 kg S/ha).07.01.2023Catch crop mulched
25.02.2021Total area treated with grubber to 15 cm depth16.03.2022Fertilization (AHL with 193 kg/ha = 58 kg N/ha09.01.2023Total area plowed
26.02.2021Surface processed with molding cutter to 15 cm depth28.03.2022Herbicide application: Broadway 1 (160 g/ha), active compounds: 68.3 g/kg Pyroxsulam (B; 2); 22.8 g/kg Florasulam (B; 2); 68.3 g/kg Cloquintocet-mexyl 3; 0.7 L/ha CCC: 720 g/L Chlormequatchlorid 2*15.04.2023Fertilizer application: AHL 369 kg/ha = 111 kg N/ha
22.03.2021Soil cultivation on the whole field by means of grubber16.04.2022Fertilization AHL with 98 kg/ha = 29 kg N/ha17.04.2023Tillage seedbed combination
23.03.2021Manual roots removal from entire area A, ca. 400 kg root pieces (approx. 0.7 kg roots/m2)20.04.2022Plant protection: 1 L/ha Ampera 1; 0.15 L/ha Moddus 2*; micronutrients (Ca, S, Si).18.04.2023Tillage power harrow plus roller; Sugar beets (BTS6975) sowing, approx. 11 seeds m2 (105,000 seeds per ha) with a spacing of 50 cm/row
24.03.2021Milling of the whole field (A and B) in two different depths. 1.: 6 cm depth, and 2.: 10 cm depth in opposite direction of travel09.05.2022Leaf fertilization: 30 L/ha Neco (+Si)11.05.2023Herbicide application (L/ha): 1.4 L Goltix Titan (active compound: 525 g/L Metamitron (45.1 w.-%), 40 g/L Quinmerac (3.4 w.-%)); 0.9 L Metafol SC (696 g/L Metamitron); 0.45 L Oblix (500 g/L Ethofumesat); 0.3 L Kantor (additive); 1.4 L Betasana SC (160 g/L Phenmedipham) *
08.05.2021Fertilizer application (450 kg/ha KAS = 120 kg N/ha)13.05.2022Plant protection: 0.65 L Gigant 1 0.4 L Camane 1; 0.05 L Moddus 2*17.05.2023Herbicide application (L/ha): 0.9 L Goltix Titan (525 g/L Metamitron (45.1 w.-%), 40 g/L Quinmerac (3.4 w.-%)); 0.9 l Metafol SC (696 g/L Metamitron); 0.4 l Oblix (500 g/L Ethofumesat); 0.3 L Kantor (additive); 1.3 L Betasana SC (160 g/L Phenmedipham); 30 g Debut (500 g/L Triflusulfuron-Methyl: Sulfonylharnstoff) + FHS 0.15 L Venzar (500 g/L Lenacil) *
10.05.2021Total area treated with grubber to 15 cm depth21.05.2022Fertilization (AHL 143 kg/ha = 43 kg N/ha)19.05.2023Insecticide application against aphids: 300 g Pirimor *
11.05.2021Seedbed preparation using a power harrow25.05.2022Fungicide treatment: 1.3 L Sirena 1*27.05.2023Herbicide application (L/ha, only on the edges on 3 m): 2 L Targa Gold (46.3 g/L Quizalofop-P); 0.6 L Spectrum (720 g/L Dimethenamid-P, 64 w.-%) *
14.05.2021Sowing maize: variety: “Sucorn”; 9 plants per m2, 75 cm row distance, including application of sub-foot fertilizer (18 kg N/ha + 25 kg P2O5/ha)19.07.2022Winter wheat harvest (approx. 11.5 t/ha) and straw collection30.05.2023Herbicide application (L/ha): 1.5 L Metafol SC (696 g/L Metamitron); 0.55 L Oblix (500 g/L Ethofumesat); 0.3 L Kantor (additive); 1.5 L Betasana SC (160 g/L Phenmedipham); 23 g Debut (500 g/L Triflusulfuron-Methyl: Sulfonylharnstoff) + FHS; 0.3 L Venzar (500 g/L Lenacil) *
07.06.2021Herbicide application: 1.1 L MaisTer + 1.1 L Aspect *, active compounds: 30.0 g/L Foramsulfuron (as Na-salt 31.5 g/L); 9.77 g/L Thiencarbazone (as Methylester 10 g/L); 0.85 g/L Iodosulfuron (as Methylester-Na 1 g/L); 15 g/L Cyprosulfamide (Safener); 333 g/L Terbuthylazin; 200 g/L Flufenacet)27.07.2022Tillage on total area with grubber to 10 cm depth14.06.2023Foliar fertilizer application: 1 L Wuxal-Boron; 0.2 L silicon; 0.4 L CaB Top
15.10.2021Maize harvest as whole plant silage (approx. 70.2 t FM/ha at 32% DM)09.08.2022Digestate application and incorporation 9.9 t/ha = 60 kg N/ha14.07.2023Fungicide application (L/ha): 1 L Amistar Gold 1; 1.9 L CUS 1*; + 9 L Folistim N-fertilizer
20.10.2021Maize stubbles were mulched, crushing also the Sida plants that survived the maize chopper07.09.2022Tillage with grubber on total area to 15 cm depth07.08.2023Fungicide application (L/ha): 0.92 L Diadem 1; 1.9 L CUS 1*; 9 L Folistim N-fertilizer
21.10.2021Grubber treatment on total area at 30 cm depth07.09.2022Sowing catch crop (DSV TerraLife® BetaSola catch crop mixture, Deutsche Saatveredelung AG, Lippstadt, Germany, 30 kg/ha, using a power harrow combi)28.08.2023Fungicide application (L/ha): 1 L Domark + 0.91 L Grifon
23.10.2021Sowing winter wheat: RGT Reform, 310 grains/m2, using a power harrow combination 18.09.2023Fungicide application (L/ha): 0.4 L SCORE
28.11.2023Sugar beet harvest (approx. 91.9 t/ha)
* in 250 L water/ha; KAS = “Kalkammonsalpeter”: calcium ammonium nitrate; FM = fresh mass; DM = dry mass; SSA = “Schwefelsaures-Ammoniak”: Sulfuric acid ammonia; AHL = “Ammoniumnitrat-Harnstoff-Lösung”: Ammonium nitrate urea solution; FHS = formulation adjuvant. 1 Fungicide; 2 Growth regulator; 3 Safener.

References

  1. Weakley, A.S.; Poindexter, D.B.; LeBlond, R.J.; Sorrie, B.A.; Karlsson, C.H.; Williams, P.J.; Orzell, S.L.; Weeks, A.; Flores-Cruz, M.; Gann, G.D.; et al. New combinations, rank changes, and nomenclatural and taxonomic comments in the vascular flora of the southeastern United States. II. J. Bot. Res. Inst. Tex. 2017, 11, 291–325. [Google Scholar] [CrossRef]
  2. Borkowska, H.; Molas, R. Two Extremely Different Crops, Salix and Sida, as Sources of Renewable Bioenergy. Biomass Bioenergy 2012, 36, 234–240. [Google Scholar] [CrossRef]
  3. Kwiatkowski, J.; Graban, L.; Stolarski, M.J. The Energy Efficiency of Virginia Fanpetals Biomass Production for Solid Biofuel. Energy 2023, 264, 126180. [Google Scholar] [CrossRef]
  4. Jablonowski, N.D.; Kollmann, T.; Meiller, M.; Dohrn, M.; Mueller, M.; Nabel, M.; Zapp, P.; Schonhoff, A.; Schrey, S.D. Full Assessment of Sida (Sida hermaphrodita) Biomass as a Solid Fuel. GCB Bioenergy 2020, 12, 618–635. [Google Scholar] [CrossRef]
  5. Schonhoff, A.; Jablonowski, N.D.; Zapp, P. Environmental Competitiveness Evaluation by Life Cycle Assessment for Solid Fuels Generated from Sida hermaphrodita Biomass. Biomass Bioenergy 2021, 145, 105966. [Google Scholar] [CrossRef]
  6. Jablonowski, N.D.; Kollmann, T.; Nabel, M.; Damm, T.; Klose, H.; Mueller, M.; Blaesing, M.; Seebold, S.; Krafft, S.; Kuperjans, I.; et al. Valorization of Sida (Sida hermaphrodita) Biomass for Multiple Energy Purposes. GCB Bioenergy 2017, 9, 202–214. [Google Scholar] [CrossRef]
  7. Von Cossel, M.; Lewin, E.; Lewandowski, I.; Jablonowski, N.D. Energy Yield Decline of Sida hermaphrodita Harvested for Biogas Production. Renew. Sustain. Energy Rev. 2024, 190, 114069. [Google Scholar] [CrossRef]
  8. Damm, T.; Pattathil, S.; Gunl, M.; Jablonowski, N.D.; O’Neill, M.; Grun, K.S.; Grande, P.M.; Leitner, W.; Schurr, U.; Usadel, B.; et al. Insights into Cell Wall Structure of Sida hermaphrodita and Its Influence on Recalcitrance. Carbohydr. Polym. 2017, 168, 94–102. [Google Scholar] [CrossRef] [PubMed]
  9. Damm, T.; Grande, P.M.; Jablonowski, N.D.; Thiele, B.; Disko, U.; Mann, U.; Schurr, U.; Leitner, W.; Usadel, B.; Dominguez de Maria, P.; et al. OrganoCat Pretreatment of Perennial Plants: Synergies between a Biogenic Fractionation and Valuable Feedstocks. Bioresour. Technol. 2017, 244, 889–896. [Google Scholar] [CrossRef] [PubMed]
  10. Schrey, S.D.; Martinez Diaz, J.; Becker, L.; Mademann, J.A.; Ohrem, B.; Drobietz, D.; Chaloupsky, P.; Jablonowski, N.D.; Wever, C.; Grande, P.M.; et al. Cell Wall Composition and Biomass Saccharification Potential of Sida hermaphrodita Differ between Genetically Distant Accessions. Front. Plant Sci. 2023, 14, 1191249. [Google Scholar] [CrossRef] [PubMed]
  11. Hoeller, M.; Lunze, A.; Wever, C.; Deutschle, A.L.; Stucker, A.; Frase, N.; Pestsova, E.; Spiess, A.C.; Westhoff, P.; Pude, R. Meadow Hay, Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. as Potential Non-Wood Raw Materials for the Pulp and Paper Industry. Ind. Crop. Prod. 2021, 167, 113548. [Google Scholar] [CrossRef]
  12. Borkowska, H.; Molas, R. Yield Comparison of Four Lignocellulosic Perennial Energy Crop Species. Biomass Bioenergy 2013, 51, 145–153. [Google Scholar] [CrossRef]
  13. Bury, M.; Rusinowski, S.; Sitko, K.; Krzyzak, J.; Kitczak, T.; Mozdzer, E.; Siwek, H.; Wlodarczyk, W.; Zieleznik-Rusinowska, P.; Szada-Borzyszkowska, A.; et al. Physiological Status and Biomass Yield of Sida hermaphrodita (L.) Rusby Cultivated on Two Distinct Marginal Lands in Southern and Northern Poland. Ind. Crop. Prod. 2021, 167, 113502. [Google Scholar] [CrossRef]
  14. Nabel, M.; Schrey, S.D.; Poorter, H.; Koller, R.; Jablonowski, N.D. Effects of Digestate Fertilization on Sida hermaphrodita: Boosting Biomass Yields on Marginal Soils by Increasing Soil Fertility. Biomass Bioenergy 2017, 107, 207–213. [Google Scholar] [CrossRef]
  15. Šiaudinis, G.; Jasinskas, A.; Šarauskis, E.; Steponavičius, D.; Karčauskienė, D.; Liaudanskienė, I. The Assessment of Virginia Mallow (Sida hermaphrodita Rusby) and Cup Plant ( Silphium perfoliatum L.) Productivity, Physico–Mechanical Properties and Energy Expenses. Energy 2015, 93, 606–612. [Google Scholar] [CrossRef]
  16. Kitczak, T.; Jarnuszewski, G.; Lazar, E.; Malinowski, R. Sida hermaphrodita Cultivation on Light Soil-A Closer Look at Fertilization and Sowing Density. Agronomy 2022, 12, 2715. [Google Scholar] [CrossRef]
  17. Nabel, M.; Temperton, V.M.; Poorter, H.; Luecke, A.; Jablonowski, N.D. Energizing Marginal Soils—The Establishment of the Energy Crop Sida hermaphrodita as Dependent on Digestate Fertilization, NPK, and Legume Intercropping. Biomass Bioenergy 2016, 87, 9–16. [Google Scholar] [CrossRef]
  18. Sommer, K. CULTAN-Düngung: Physiologisch, Ökologisch, Ökonomisch Optimiertes Düngungsverfahren für Ackerkulturen, Grünland, Gemüse, Zierpflanzen und Obstgehölze; Mann: Gelsenkirchen, Germany, 2005; ISBN 978-3-7862-0151-9. [Google Scholar]
  19. Nabel, M.; Schrey, S.D.; Poorter, H.; Koller, R.; Nagel, K.A.; Temperton, V.M.; Dietrich, C.C.; Briese, C.; Jablonowski, N.D. Coming Late for Dinner: Localized Digestate Depot Fertilization for Extensive Cultivation of Marginal Soil with Sida hermaphrodita. Front. Plant Sci. 2018, 9, 1095. [Google Scholar] [CrossRef]
  20. Von Cossel, M.; Wagner, M.; Lask, J.; Magenau, E.; Bauerle, A.; Von Cossel, V.; Warrach-Sagi, K.; Elbersen, B.; Staritsky, I.; Van Eupen, M.; et al. Prospects of Bioenergy Cropping Systems for A More Social-Ecologically Sound Bioeconomy. Agronomy 2019, 9, 605. [Google Scholar] [CrossRef]
  21. Antonkiewicz, J.; Kolodziej, B.; Bielinska, E.J. Phytoextraction of Heavy Metals from Municipal Sewage Sludge by Rosa Multiflora and Sida hermaphrodita. Int. J. Phytoremediat. 2017, 19, 309–318. [Google Scholar] [CrossRef]
  22. Borkowska, H.; Wardinska, K. Some Effects of Sida hermaphrodita R. Cultivation on Sewage Sludge. Pol. J. Environ. Stud. 2003, 12, 119–122. [Google Scholar]
  23. Kocon, A.; Jurga, B. The Evaluation of Growth and Phytoextraction Potential of Miscanthus x giganteus and Sida hermaphrodita on Soil Contaminated Simultaneously with Cd, Cu, Ni, Pb, and Zn. Environ. Sci. Pollut. Res. 2017, 24, 4990–5000. [Google Scholar] [CrossRef] [PubMed]
  24. Tran, K.-Q.; Werle, S.; Trinh, T.T.; Magdziarz, A.; Sobek, S.; Pogrzeba, M. Fuel Characterization and Thermal Degradation Kinetics of Biomass from Phytoremediation Plants. Biomass Bioenergy 2020, 134, 105469. [Google Scholar] [CrossRef]
  25. Suric, J.; Brandic, I.; Peter, A.; Bilandzija, N.; Leto, J.; Karazija, T.; Kutnjak, H.; Poljak, M.; Voca, N. Wastewater Sewage Sludge Management via Production of the Energy Crop Virginia Mallow. Agronomy 2022, 12, 1578. [Google Scholar] [CrossRef]
  26. Kurucz, E.; Fári, M.G.; Antal, G.; Gabnai, Z.; Popp, J.; Bai, A. Opportunities for the Production and Economics of Virginia Fanpetals (Sida hermaphrodita). Renew. Sustain. Energy Rev. 2018, 90, 824–834. [Google Scholar] [CrossRef]
  27. Von Cossel, M.; Ohrem, B.; Gandamalla, G.; Neuberger, M.; Jablonowski, N.D. Sida hermaphrodita Establishment on Highly Weed-Infested Soil Using Biodegradable Mulch Film. J. Clean. Prod. 2024, 435, 139786. [Google Scholar] [CrossRef]
  28. Anderson, E.K.; Voigt, T.B.; Bollero, G.A.; Hager, A.G. Miscanthus × giganteus Response to Tillage and Glyphosate. Weed Technol. 2011, 25, 356–362. [Google Scholar] [CrossRef]
  29. Barksdale, N.; Byrd, J.D.; Zaccaro, M.L.M.; Russell, D.P. Evaluation of Herbicide Efficacy and Application Timing for Giant Miscanthus (Miscanthus x giganteus) Biomass Reduction. Weed Technol. 2020, 34, 371–376. [Google Scholar] [CrossRef]
  30. Lewin, E.; Kiesel, A.; Magenau, E.; Lewandowski, I. Integrating Perennial Biomass Crops into Crop Rotations: How to Remove Miscanthus and Switchgrass without Glyphosate. GCB Bioenergy 2023, 15, 1387–1404. [Google Scholar] [CrossRef]
  31. Schrey, H.P. Bodenkarte von Nordrhein-Westfalen 1:50.000: BK 50; [Inhalt, Aufbau, Auswertung]; Geologischer Dienst Nordrhein-Westfalen: Krefeld, Germany, 2014; ISBN 978-3-86029-712-4. [Google Scholar]
  32. Finanzverwaltung des Landes Nordrhein-Westfalen, Ministerium der Finanzen des Landes Nordrhein-Westfalen. 2023. Available online: https://Grundsteuer-Geodaten.Nrw.De/ (accessed on 5 December 2023).
  33. Dheri, G.S.; Lal, R.; Moonilall, N.I. Soil Carbon Stocks and Water Stable Aggregates under Annual and Perennial Biofuel Crops in Central Ohio. Agric. Ecosyst. Environ. 2022, 324, 107715. [Google Scholar] [CrossRef]
  34. Sanford, G.R.; Jackson, R.D.; Booth, E.G.; Hedtcke, J.L.; Picasso, V. Perenniality and Diversity Drive Output Stability and Resilience in a 26-Year Cropping Systems Experiment. Field Crops Res. 2021, 263, 108071. [Google Scholar] [CrossRef]
  35. Feledyn-Szewczyk, B.; Matyka, M.; Staniak, M. Comparison of the Effect of Perennial Energy Crops and Agricultural Crops on Weed Flora Diversity. Agronomy 2019, 9, 695. [Google Scholar] [CrossRef]
  36. Molas, R.; Borkowska, H.; Kupczyk, A.; Osiak, J. Virginia Fanpetals (Sida) Biomass Can Be Used to Produce High-Quality Bioenergy. Agron. J. 2019, 111, 24–29. [Google Scholar] [CrossRef]
  37. Spooner, D.M.; Cusick, A.W.; Hall, G.F.; Baskin, J.M. Observations on the distribution and ecology of Sida hermaphrodita (L.) Rusby (Malvaceae). SIDA Contrib. Bot. 1985, 11, 215–225. [Google Scholar]
  38. Franzaring, J.; Holz, I.; Kauf, Z.; Fangmeier, A. Responses of the Novel Bioenergy Plant Species Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. to CO2 Fertilization at Different Temperatures and Water Supply. Biomass Bioenergy 2015, 81, 574–583. [Google Scholar] [CrossRef]
  39. Borkowska, H.; Molas, R.; Kupczyk, A. Virginia Fanpetals (Sida hermaphrodita Rusby) Cultivated on Light Soil; Height of Yield and Biomass Productivity. Pol. J. Environ. Stud. 2009, 18, 563–568. [Google Scholar]
  40. Hartmann, A.; Burmeister, J.; Fritz, M.; Walter, R. Dauerkulturen—Aufzeigen Der Bayernweiten Anbaueignung; Berichte aus dem TFZ; Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe (TFZ): Straubing, Germany, 2018; p. 244. [Google Scholar]
  41. Sekutowski, T.; Rola, J.; Rola, H. Selectivity and effectiveness of herbicides applied in Virginia mallow (Sida hermaphrodita Rusby) intended for energy purposes. Prog. Plant Prot./Postępy W Ochr. Roślin 2011, 51, 1864–1869. [Google Scholar]
  42. Schmidt, R.R.; Fedtke, C. Metamitron Activity in Tolerant and Susceptible Plants. Pestic. Sci. 1977, 8, 611–617. [Google Scholar] [CrossRef]
  43. Sesin, V.; Davy, C.M.; Stevens, K.J.; Hamp, R.; Freeland, J.R. Glyphosate Toxicity to Native Nontarget Macrophytes Following Three Different Routes of Incidental Exposure. Integr. Environ. Assess. Manag. 2021, 17, 597–613. [Google Scholar] [CrossRef] [PubMed]
  44. Oberfinanzdirektion Nordrhein-Westfalen. Referat für Kommunikation und Strategie. Anfrage Zu Bodengüte Kreis Düren (Inquiry about Soil Quality in the District of Düren); Oberfinanzdirektion Nordrhein-Westfalen: Münster, Germany, 2023. [Google Scholar]
  45. Mangold, A.; Lewandowski, I.; Kiesel, A. How Can Miscanthus Fields Be Reintegrated into a Crop Rotation? GCB Bioenergy 2019, 11, 1348–1360. [Google Scholar] [CrossRef]
  46. Matthews, J.; Beringen, R.; Huijbregts, M.A.J.; van der Mheen, H.J.; Odé, B.; Trindade, L.; van Valkenburg, J.L.C.H.; van der Velde, G.; Leuven, R.S.E.W. Horizon Scanning and Environmental Risk Analyses of Non-Native Biomass Crops in the Netherlands; Department of Environmental Science, Faculty of Science, Institute for Water and Wetland Research, Radboud University: Nijmegen, The Netherlands, 2015. [Google Scholar]
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Figure 1. Sida field in 2021 (a) at harvest and (b) after grubber and molding cutter treatment.
Figure 1. Sida field in 2021 (a) at harvest and (b) after grubber and molding cutter treatment.
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Figure 2. Sida roots at time of root collection on 23 March 2021: (a) mature Sida root stock; (b) resprouting Sida root.
Figure 2. Sida roots at time of root collection on 23 March 2021: (a) mature Sida root stock; (b) resprouting Sida root.
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Figure 3. Resprouted Sida plant between the sugar beets on (a) 20 July 2023 and (b) 19 October 2023. All resprouted Sida plants along the entire field were found only in the ruts.
Figure 3. Resprouted Sida plant between the sugar beets on (a) 20 July 2023 and (b) 19 October 2023. All resprouted Sida plants along the entire field were found only in the ruts.
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Table 1. Number of total counted resprouted Sida plants in the plots of investigation (A1–3: preceding manual root removal; B1–3: no additional root removal). Final counting was conducted at time of crop harvest for maize (2021), winter wheat (2022), and sugar beet (2023). No significant differences (p > 0.6) in the number of resprouted Sida plants among the investigated areas and years were detected by means of an independent samples t-test.
Table 1. Number of total counted resprouted Sida plants in the plots of investigation (A1–3: preceding manual root removal; B1–3: no additional root removal). Final counting was conducted at time of crop harvest for maize (2021), winter wheat (2022), and sugar beet (2023). No significant differences (p > 0.6) in the number of resprouted Sida plants among the investigated areas and years were detected by means of an independent samples t-test.
Counted Sida at Harvest
Area/Plot202120222023
A121840
A29292
A316620
Sum
Mean/m2
% of initially planted		476
≈1.5 plants/m2
75.56%		15
≈0.05 plants/m2
2.38%		2
≈0.006 plants/m2
0.32%
B1174100
B24304
B317310
Sum
Mean/m2
% of initially planted		390
≈1.2 plants/m2
61.90%		11
≈0.03 plants/m2
1.75%		4
≈0.01 plants/m2
0.63%
Table 2. Cash crop yield values from the former Sida trial field and surrounding fields and average values from the Düren region. Data from the Düren region were obtained from “Landesdatenbank NRW, Landesbetrieb Information und Technik Nordrhein-Westfalen—Statistisches Landesamt” (https://www.landesdatenbank.nrw.de, accessed on 13 December 2023), search keyword “Feldfrüchte”, result: Code 41241-01d, content: “Erntebericht: Hektarerträge nach ausgewählten Fruchtarten (12)—kreisfreie Städte und Kreise—Jahr”. Values are given in t/ha (metric ton, equal to 1000 kg, i.e., one megagram). SD: standard deviation, n = 4. n.a.: data not available.
Table 2. Cash crop yield values from the former Sida trial field and surrounding fields and average values from the Düren region. Data from the Düren region were obtained from “Landesdatenbank NRW, Landesbetrieb Information und Technik Nordrhein-Westfalen—Statistisches Landesamt” (https://www.landesdatenbank.nrw.de, accessed on 13 December 2023), search keyword “Feldfrüchte”, result: Code 41241-01d, content: “Erntebericht: Hektarerträge nach ausgewählten Fruchtarten (12)—kreisfreie Städte und Kreise—Jahr”. Values are given in t/ha (metric ton, equal to 1000 kg, i.e., one megagram). SD: standard deviation, n = 4. n.a.: data not available.
Former Sida Trial Field and Adjacent Fields (t/ha)Four-Year Mean Value ± SD (t/ha)Former Sida Trial Field (t/ha)
Cash Crop2019202020212022 2023
Maize59.2n.a.70.252.060.5 ± 7.5-
Winter wheat10.311.19.811.510.7 ± 0.7-
Sugar beet92.990.896.386.091.5 ±3.791.9
Reference Values of Düren Region (t/ha)Mean Value of Four Years ± SD (t/ha)Reference Values of Düren Region (t/ha)
2019202020212022 2023
Maize50.748.9 *65.146.754.2 ± 7.9n.a.
Winter wheat8.78.68.09.68.7 ± 0.6n.a.
Sugar beet76.672.284.980.278.5 ± 4.6n.a.
* In 2020, the Sida experimental field was still used for the Sida study. Maize was also not grown on the adjacent fields in this year. Accordingly, no yield data for maize are available for 2020 for the former Sida trial field and the adjacent fields. Therefore, for a comparison with the yield values from the former Sida trial field, the value for maize from the Düren region in 2020 was not included in the statistical calculations. n.a.: data not available.
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Jablonowski, N.D.; Ohrem, B.; Gitzen, M.; Kollmann, T. Converting an Established Sida hermaphrodita Field into Arable Farming. Agronomy 2024, 14, 411. https://doi.org/10.3390/agronomy14030411

AMA Style

Jablonowski ND, Ohrem B, Gitzen M, Kollmann T. Converting an Established Sida hermaphrodita Field into Arable Farming. Agronomy. 2024; 14(3):411. https://doi.org/10.3390/agronomy14030411

Chicago/Turabian Style

Jablonowski, Nicolai David, Benedict Ohrem, Michael Gitzen, and Tobias Kollmann. 2024. "Converting an Established Sida hermaphrodita Field into Arable Farming" Agronomy 14, no. 3: 411. https://doi.org/10.3390/agronomy14030411

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