Soil Recycling of Waste Biomass in the Production of Malus domestica Fruit Tree Seedlings

Abstract

The production of fruit tree seedlings generates waste wood biomass, which results from the pruning of budded rootstocks in the first year of the two-year production cycle. This study proposes a new method of managing this biomass by recycling the wood chips (2, 3 and 5 t ha⁻¹) back into the soil. The impact of different wood chip doses on selected physicochemical soil properties after the production process (especially soil organic carbon content (SOC), as well as the quantity and quality of the produced Malus domestica fruit tree seedlings, was determined. The recycling of waste biomass contributed to enriching the soil with additional components, mainly organic carbon with the potential for biotransformation into humic substances. The applied doses of wood chips, in amounts of 2, 3, and 5 t ha⁻¹, resulted in an increase in SOC content compared to the control by 21.5%, 22.5%, and 35.8%, respectively. Additionally, the recycling of waste biomass introduced other compounds important for plant growth and development into the soil, particularly iron, zinc, magnesium, and manganese. It should be noted that the proposed method of managing waste biomass generated during the apple tree seedling production stage resulted in reduced production costs while maintaining high production indices.

1. Introduction

One of the primary indicators of soil quality is the content of organic matter in its composition, especially humus, which plays a significant role in shaping its properties: physically (density, aggregate stability, water retention), physicochemically and chemically (ion exchange, buffering capacity, solubility and migration of elements, environmental detoxification), as well as biologically (providing nutrients and energy for microorganisms, biostimulation of plant growth and development, regulation of biodiversity) [1,2,3,4]. The most important components of soil organic matter are humic substances, which are formed as a result of the humification of organic residues. Organic substances can be supplied to the soil from external sources, such as natural and organic fertilisers. The source of organic substances can also be waste biomass from plant production. One of the sources of plant waste biomass is nursery production and fruit-growing [5,6]. Cultivation and maintenance practices in orchards, as well as ornamental and forest nurseries, lead to the accumulation of woody waste biomass [7]. One of the methods of utilising such biomass, mainly that from coniferous trees, is its shredding (chipping) and subsequent application to the soil [8,9]. Previous studies have confirmed that wood chips of this type can successfully be used as a soil improver [8,10]. Their impact on the soil is associated with a significant improvement in water retention properties, as well as protection against excessive evaporation, which improves water relations [11,12]. The use of wood chips contributes to an increase in the abundance of soil mesofauna and is also commonly used in the reclamation of degraded forest and urban soils [13]. Wood chips are mainly used for mulching the soil, as they protect against the excessive evaporation of water from the soil and prevent the excessive growth of undesirable plants (weeds). They also protect against water erosion [14]. Wood chips mixed with soil, used as organic fertiliser, can improve the physical properties of the soil, increase microbial activity as expressed by enzymatic activity, and serve as a source of organic carbon, macro- and microelements in the soil. On the other hand the use of wood chips may contribute to an increase in soil acidity, depletion of soil nitrogen, or due to the tannins contained in these materials, inhibit the growth of plants fertilised with them [15].

A complex analysis of the technology of fruit tree production involving the budding of rootstocks revealed that woody waste biomass is generated during this process, which must be disposed of. Until now, the collected woody biomass from the plantations has been thermally disposed of. Moreover, it has been shown that it contains large amounts of biogens, which may indicate its potential suitability for other purposes, including fertilisation in fruit tree production. However, these aspects require further detailed studies, especially under field conditions. For this reason, this study presents the multidirectional impact of the soil incorporation of waste biomass generated during the cutting of rootstocks. It was hypothesised that the introduction of this biomass would have influence on the quantity and quality of the produced apple tree seedlings (Malus domestica), as well as the physicochemical properties of the soil after the production process. The proposed study should generate implications for the overall environment and society.

2. Materials and Methods

2.1. Field Experiment Designed

Three-year, micro-plot experiments were conducted in the south-eastern part of Poland (Podkarpackie Voivodeship 50°07′56″ N 21°19′37″ E). The experiment was established using a randomised block design with three replications on Eutric Cambisol soil with a sandy loam (SL) texture [16]. The soil before the experiment was characterised by acidity measurement (pH = 4.61 ± 0.32), total nitrogen content (10.9 ± 0.07 g kg⁻¹ of soil), soil organic carbon (SOC) (9.19 ± 0.21 g kg⁻¹ of soil), high levels of available phosphorus (15.1 ± 1.24 mg P₂O₅ 100 g⁻¹), medium levels of available potassium (10.0 ± 0.86 mg K₂O 100 g⁻¹), and high levels of available magnesium (8.1 ± 0.94 mg Mg 100 g⁻¹) [17]. The soil planned for the study was acidic, and therefore, in the autumn before the experiment, liming was carried out using carbonate lime in the form of granulated Polcalc fertiliser (Polcalc; Lubień Kujawski, Poland) (93–98% CaCO₃) at a dose of 3.0 t CaO ha⁻¹. During the experiment, constant fertilisation with NPK and Mg was applied, with doses determined based on soil fertility and the fertilisation needs of the fruit tree rootstocks. The following were applied: 120 kg N ha⁻¹ in the form of ammonium nitrate (34%) in two doses (first dose in the last decade of May—60 kg N ha⁻¹ and second dose at the end of June—60 kg N ha⁻¹), 80 kg K₂O ha⁻¹ in the form of potassium salt (60%), and a growth biostimulator in the form of foliar spraying with Asahi SL (UPL Poland; Warsaw, Poland), applied in two treatments at a dose of 0.5 L ha⁻¹ each. The previous crop was field pea. The propagation material used in the field experiment was certified C/1. During the growth and development of the plants in the experiment, observations of diseases and pests were conducted, and chemical protection was applied using plant protection products approved for use in apple production. In the first decade of August each year of the experiment, apple rootstocks were budded using the “chip budding” method. The autumn variety ‘Champion’ was selected for budding. Budding was performed 20 cm above ground level. In the second decade of September, the success of the grafting of the rootstocks and the chip buds [%] was assessed. The apple tree saplings obtained in the second year were evaluated in terms of the percentage of first and second-grade trees [%]. The size of the plot for harvesting was 12.5 m². The variable factor studied was the soil incorporation of waste biomass from nursery production at four levels:

▪

0—control;

▪

I—2 t ha⁻¹;

▪

II—3 t ha⁻¹;

▪

III—5 t ha⁻¹.

2.2. Meteorological Conditions during Study Period

From an agricultural perspective, the analysis of meteorological conditions during the growing season, as key yield-forming factors, is very important. Therefore, an assessment of the variability of thermal and pluviometric conditions over the years was conducted, based on the Sielianinov hydrothermal coefficient [18], which is defined as:

$$\mathit{k}={\displaystyle \frac{\mathit{P}}{\mathbf{\sum }\mathit{t}·\mathbf{0.1}}}$$

where:

▪

P—the sum of atmospheric precipitation for a given decade [mm],

▪

Σt—the sum of average daily air temperatures for a given decade [°C].

The moisture characteristics of the months during the growing seasons in the years of the experiments were determined [19], using the following classification of k values:

▪

extremely dry—k ≤ 0.4

▪

very dry—0.4 < k ≤ 0.7

▪

dry—0.7 < k ≤ 1.0

▪

fairly dry—1.0 < k ≤ 1.3

▪

optimal—1.3 < k ≤ 1.6

▪

fairly humid—1.6 < k ≤ 2.0

▪

humid—2.0 < k ≤ 2.5

▪

very humid—2.5 < k ≤ 3.0

▪

extremely humid—k > 3.0

2.3. Characteristics of Waste Biomass Used in the Experiment

The waste biomass used in the experiment was characterised by a significant content of total organic carbon (TOC), averaging 49.8%. The average nitrogen and sulphur contents were 1.19% and 0.08%, respectively. Additionally, the waste biomass used in the experiment had a wide C:N ratio, averaging 41.8. Along with the waste biomass from nursery production, significant amounts of potential plant nutrients were introduced into the soil. The content of the total forms of macronutrients in the analysed wood chips—Ca, K, Mg, and P—averaged 6.59, 4.87, 1.42, and 1.87 g kg⁻¹, respectively. The wood chips used in the experiment also had a considerable content of micronutrients. Among the analysed elements, Fe had the highest content (65.4 mg kg⁻¹), while Cu had the lowest (7.64 mg kg⁻¹) (

Table 1. Characteristics of the wood chips from waste biomass used in the experiment (mean ± SD).

Parameters
TOC	N	S	C:N	Ca	K	Mg	P	Fe	Mn	Zn	Cu
%			-	g kg−1 d.m.				mg kg−1 d.m.
49.8 ± 3.4	1.19 ± 0.4	0.08 ± 0.02	41.8 ± 8.9	6.59 ± 0.45	4.87 ± 0.34	1.42 ± 0.12	1.87 ± 0.43	65.4± 6.3	73.8 ± 6.2	23.1 ± 2.3	7.64 ± 0.36

).

2.4. Soil Analysis

To determine the effects of the applied wood chips from waste biomass on the physicochemical properties of brown soil, soil samples were collected each autumn (depth up to 30 cm). Upon arrival at the laboratory, the samples were air-dried for approximately one week, then ground and sieved through 2 mm mesh sieves. In these prepared samples, the following analyses were conducted:

▪

pH in 1 mol dm⁻³ KCl—determined by the potentiometric method using a Hanna Instruments 4221 pH meter (Nusfalau; Romania), maintaining a soil-to-solution ratio of 1:2.5;

▪

Electrical conductivity (EC) of aqueous soil extracts—determined by the potentiometric method using a Hanna Instruments HI 2316 conductivity meter (Hanna Instruments; Nusfalau, Romania), maintaining a soil-to-solution ratio of 1:5;

▪

Organic carbon content (SOC)—determined by the oxidation-titration method [20]; In the conducted studies, soil organic carbon (SOC) was defined as the pool of organic carbon present in the soil, which also included carbon originating from undecomposed fragments of wood chips introduced into the soil. Even if the organic matter was coarse, if it passed through a 2 mm mesh, it was classified as soil organic matter. This represents a potential pool of organic matter that, through further processes, will be transformed into soil humus.

▪

Total nitrogen content—determined by the Kjeldahl method [20];

▪

Content of available forms of macroelements and microelements (P, K, Mg, Fe, Mn, Zn, Cu)—phosphorus in extracts was determined colorimetrically using a Schimadzu 2600 UV-VIS spectrophotometer (Tokyo, Japan), while the remaining elements were determined by atomic absorption spectrometry (AAS) using a HITACHI Z-2000 apparatus (HITACHI; Tokyo, Japan) [20].

2.5. Statistical Analysis

The results of the research (influence of wood chips dose on selected soil parameters) were analysed using the Statistica 13.3 software (StatSoft, Tulsa, OK, USA). To identify the homogeneous groups of objects (α = 0.05), Tukey’s HSD multiple comparison test was conducted following one-way analysis of variance (ANOVA).

3. Results and Discussion

3.1. The Metrological Data

Based on the Sielianinov hydrothermal coefficient, a detailed assessment of thermal and pluviometric conditions during the growing seasons in which the field experiments were conducted was performed (

Table 2. Moisture characteristics of the growing season months depending on the value of the Sielianinow hydrothermal coefficient.

Year	Parameter	Month
		IV	V	VI	VII	VIII	IX	X	Mean
I	Kvalue	0.99	2.09	0.98	0.92	0.84	0.70	0.80	1.04
	Humidity characteristics	Dry	Humid	Dry	Dry	Dry	Dry	Dry	Quite dry
II	K value	0.99	2.11	0.16	0.85	0.09	1.05	1.58	0.97
	Humidity characteristics	Dry	Humid	Extremely dry	Dry	Extremely dry	Fairly dry	Optimum	Dry
III	K value	1.70	0.46	0.73	0.53	0.63	1.06	2.55	1.09
	Humidity characteristics	Fairly humid	Very dry	Dry	Very dry	Very dry	Fairly dry	Very humid	Fairly dry
Mean I–III	K value	1.23	1.55	0.62	0.77	0.52	0.94	1.64	1.03
	Humidity characteristics	Fairly humid	Optimum	Very dry	Dry	Very dry	dry	Fairly humid	Fairly dry
Mean 1986–2002	K value	1.96	1.93	1.71	1.61	1.26	1.92	1.97	1.76
	Humidity characteristics	Fairly humid	Fairly humid	Fairly humid	Fairly humid	Fairly dry	Fairly humid	Fairly humid	Fairly humid

). Periods of drought were identified as those when the plant uses twice as much water for evaporation as it receives from precipitation. The analysis of average hydrothermal coefficient values during the growing season in the years of the experiments, compared to the same period over the long term (1986–2002), and showed a decrease in k values in all analysed months, except for October, which was considered fairly humid both in the years of the experiments and over the long term. The moisture conditions in the analysed years were unfavourable in terms of plant water requirements. The most unfavourable moisture conditions (extremely dry) occurred in June and August of the first year of the study. May, July, and August of the second year were also very dry. In contrast, May was a humid month in both the first and second years, while October of the third year was very humid.

3.2. Soil pH and the Content of Available Forms of Macronutrients

During the production of one-year-old fruit trees, after the budding process of rootstocks (the first year of a two-year cycle of fruit tree production), the above-ground biomass is cut directly above the budding site. This biomass becomes a production by-product that must be appropriately disposed of (removed from the plantation) or managed. The standard technology for fruit tree seedling production only involves the removal of this biomass from the plantation. A common use for such biomass is its utilisation for energy purposes due to its calorific value, which averages 18 MJ kg⁻¹ [21]. However, as noted by Matłok and Gorzelany [21], considering the subsequent costs associated with its energy use, including the processes of shredding, drying, and pelletising, such utilisation is economically unjustifiable. One of the proposed innovative methods of managing this biomass could be its soil application, which, as stated by Matłok and Gorzelany [21], positively impacts the profitability of fruit tree production. Given the average organic carbon content in such biomass from fruit trees, it can be postulated that its soil application could result in the significant modification of soil properties, primarily through the generation of additional organic matter and the enrichment of soil nutrients. This biomass can only be applied to the soil in the form of wood chips, which necessitates changes in agricultural practices related to the cutting of rootstocks onto which noble apple tree varieties have been budded (Figure 1).

In the proposed technology, the manual cutting of rootstocks using secateurs has been replaced by an automatic rootstock cutting system that simultaneously shreds the cut biomass into chips and applies it to the soil. The elimination of manual labour in this process significantly reduced the production costs of one-year-old fruit trees [21]. The shredded biomass left on the soil surface is then incorporated into deeper layers using cultivators, where its natural decomposition and transformation take place. During these transformations, the physicochemical parameters of the soil change due to the microbiological biotransformation of the soil-applied biomass. One of the main indicators of the progress of biomass biotransformation in the soil is the change in its pH and hydrolytic acidity. This process is particularly observed during the formation of forest soils, which mainly arise from the biotransformation of organic matter generated from decaying plant and tree fragments (leaves, broken tree branches, etc.) [22]. In the case of biomass decomposition, especially from coniferous trees, significant soil acidification is observed. Demonstrating a similar effect of biomass decomposition from the cutting of fruit tree rootstocks would be an undesirable outcome from the perspective of nursery production, which requires soils with a pH of 6–6.5.

In the soil samples studied, the soil pH was measured as a result of the soil incorporation of waste biomass from the cutting of rootstocks (Figure 2).

The incorporation of waste biomass from nursery production into the soil did not cause significant changes in soil pH compared to the control plots, which justifies the rationality of such a method for managing the obtained waste biomass in a two-year cycle of fruit tree production. The average soil pH value in the control plots was 4.41, while in the plots where biomass chips were applied, the pH ranged from 4.45 (3 t of chips ha⁻¹) to 4.46 (2 and 5 t ha⁻¹ of chips). Similar results were obtained by Tahboub et al. [15], where fresh pine sawdust (5–8 m³ per 100 m²) was applied to the soil surface (pH 4.4) and then ploughed to a depth of about 35 cm. Subsequently, in the spring, after re-ploughing and harrowing the soil, one-year-old Scots pine seedlings were planted. Three years after the experiment was established, the average pH value in the control plot was 5.2, while in the plots where sawdust was used, it was 5.7. Incorporating plant biomass into the soil in the form of crop residues or other plant waste can affect not only the soil’s pH but also its nutrient content. Determining the content of major macronutrients (nitrogen, potassium, phosphorus, calcium, magnesium, and sulphur) in the soil is one of the most important criteria for assessing soil fertility. From the perspective of crop production, the most crucial factor is the content of available (ionic) forms of these elements in the soil [23].

Fruit tree seedling production, even at the stage of rootstock growth, onto which noble varieties are budded, requires intensive fertilisation. This leads to the accumulation of various elements in the above-ground biomass (waste biomass after rootstock cutting), which in standard technological solutions was removed from the plantation.The soil recirculation of such biomass may increase the content of these elements in the soil. However, it should be noted that this biomass contains significant amounts of water, while other components are present at low levels [24]. When introducing doses of waste biomass chips after rootstock cutting at a level of 3–5 t ha⁻¹, small amounts of various elements, except for carbon, oxygen, and hydrogen, are introduced into the soil [9]. Based on studies determining the content of available forms of potassium, phosphorus, and magnesium in the soil (Figure 3), no significant impact of the applied dose of waste biomass chips on potassium content in the soil was found (Figure 3B), while the content of the other components increased significantly.

One of the most important indicators of soil fertility is the content of organic matter [25]. The content of soil organic carbon (SOC) increased relative to the control as the applied dose of waste biomass chips increased (Figure 4).

The average SOC (soil organic carbon) content in the soil of the control plots was 9.23 g kg⁻¹ of soil (Figure 4). After the application of waste biomass chips (2, 3, and 5 t ha⁻¹), an increase in SOC in the fertilised soil was recorded compared to the control by 21.5%, 22.5%, and 35.8%, respectively. A positive effect of fertilisation with conifer sawdust on the organic carbon content was also observed in the studies by Rajor et al. [26], who reported that the application of sawdust with the addition of sanitising lime positively influenced the increase in SOC in the soil compared to the control plot. The average increase in organic carbon content in the soil after three years of research was reported to be between 3.3 and 4.8 g SOC kg⁻¹ of soil. The increase in SOC content should be highlighted as one of the most important mechanisms of soil fertilisation with the proposed technology. The only limitation to the implications of this study was a lack of soil microbial activity detonation. Such a study would allow estimating the rate of bioconversion of the waste biomass.

Plant biomass always contains proteins with a relatively high nitrogen content [27]. However, the content of these proteins is small relative to polysaccharides and other organic components, which is why no significant changes in nitrogen content in the soil were observed under the influence of the applied doses of waste biomass chips (Figure 3D). Similar relationships were observed in the analysis of biomass from fruit trees in Croatian orchards, where the nitrogen content was only 0.77% of dry matter [28]. Since wood chips have a high carbon-to-nitrogen ratio, the initial phase of their decomposition may increase the availability of carbon for microorganisms, and thus also increase the demand for nitrogen. These mechanisms can have negative effects on crops due to the nitrogen deficiency for plants, which should be considered when using wood chips [15].

3.3. Content of Soluble Forms of Micronutrients

Fruit and nursery production involves a large number of treatments with the use of plant protection products, which can lead to the accumulation of metals (Zn, Cu, Mn, Fe, Ni) both in plant biomass and in the surface layers of soils [29]. The content of soluble metals in various solutions indicates their presence in the soil in mobile forms, and therefore easily absorbable by plants. Consequently, an important criterion for assessing potential soil contamination with heavy metals is determining the content of their soluble or plant-available forms [30].

In the soil samples collected during the field experiments on the management of waste biomass from the cutting of apple tree rootstocks, the content of selected heavy metals, which could have been introduced into the soil with the applied biomass, was determined. Figure 5 shows the average content of Fe, Mn, Zn, and Cu in the soil samples depending on the applied soil dose of waste biomass chips.

The soil in the control plots was characterised by an average zinc content of 36.12 mg kg⁻¹ of soil. However, with the application of waste biomass chips, a significant increase in the content of this element was observed. The average zinc content in the soil fertilised with 2, 3, and 5 t ha⁻¹ of chips was higher by 12.6%, 17.1%, and 13.4%, respectively, compared to the soil in the control plots. In the case of the average copper content in the soil, no significant differences were found depending on the applied dose of chips. The average copper content in the tested soil ranged from 8.27 mg kg⁻¹ of soil (at a dose of 5 t ha⁻¹ of chips) to 8.50 mg kg⁻¹ of soil (at a dose of 2 t ha⁻¹ of chips), with the average content of this element in the control soil being 8.49 mg kg⁻¹ of soil.

In the soil where waste biomass chips were applied at 2, 3, and 5 t ha⁻¹, a slight increase in the average manganese content was observed compared to the control (203.04 mg kg⁻¹ of soil). The application of waste biomass chips also increased the concentration of iron in the fertilised soil. The content of this micronutrient in the control soil averaged 7.62 mg kg⁻¹ of soil. However, in the soil plots where the tested doses of chips were applied at 3 t ha⁻¹ and 5 t ha⁻¹, there was a significant increase in this component in the soil. It should be noted that foliar fertilisation with preparations containing the tested metals is used in the production of fruit trees, including the fertilisation of rootstocks from which the waste biomass was obtained. This fertilisation likely contributed to the increased content of these metals in the soil, correlated with the applied soil dose of biomass.

3.4. The Effect of Fertilisation with Waste Biomass Chips on the Quantity and Quality of Nursery Stock Obtained

During the implementation of controlled micro-plot experiments on the fertilisation of apple rootstocks with waste biomass chips from nursery production, measurements were taken from the percentage (%) successfully budded shields (Figure 6). The highest average (%) of successfully budded apple shields was recorded with the application of 3 t ha⁻¹ of biomass chips, amounting to 93.32%. The lowest average percentage of successfully budded shields (91.48%) was observed in the production of trees where no fertilisation with waste biomass chips was applied (control). The average percentage of successfully budded shields, regardless of the soil-applied dose of chips, was 92.63% during the years of the study. Based on the obtained results regarding the analysis of bud take, it can be concluded that the recirculation of waste biomass from cutting rootstocks above the budding site is not a factor influencing this indicator. The main factor determining the percentage of successful bud takes is the course of meteorological conditions during the winter-spring period. The occurrence of significant temperature drops during this period without accompanying snow cover results in the freezing of shields, which directly affects the percentage of successful bud takes [31]. The field studies conducted as part of the experiments for all tested variants were carried out in a single location where analogous weather conditions prevailed.

The fruit-growing planting material (one-year-old fruit tree seedlings) obtained from field experiments was evaluated in terms of the number of first- and second-grade apple trees obtained (Figure 7). In the analysed years, no statistically significant differences were found in the average number of first- and second-grade seedlings, depending on the dose of wood chips used in the soil fertilisation of apple rootstocks. The highest percentage of top-quality (‘first-grade’) ‘Champion’ apple trees was obtained in the control (85.57%) and when applying 5 tons of wood chips per hectare (85.50%). The lowest percentage of first-grade trees, amounting to 84.60%, was noted when fertilising the apple rootstocks with 2 tons of wood chips per hectare. The average share of first-grade apple trees for the analysed doses of biomass wood chips over the years of the experiment was 85.25%. These results are not surprising considering the lack of significant differences in soil nitrogen (N) content depending on the amount of recirculated biomass into the soil (Figure 4). The main factor influencing the growth of one-year-old trees (seedling height, thickness of the main shoot, number of side branches, etc.) is the soil’s available N content, as well as the applied nitrogen fertilisation [32].

The rational use of waste biomass as organic fertiliser in nursery plant cultivation was also confirmed by the economic analysis conducted by Matłok et al. [21]. The authors confirmed that the proposed innovative technology of producing one-year-old apple trees, which involves using waste biomass as natural fertiliser in the following year of fruit tree production, not only solves the problem of biomass disposal but also results in the lowest total production cost of seedlings, amounting to EUR13,559.5 per hectare. This technology, in contrast to the previously used method, which involved cutting the budded rootstocks above the grafting site in spring and then removing the resulting biomass from the plantation and its thermal disposal in a heap, was cheaper by EUR120.8 per hectare. The application of the developed apple tree production technology reduced production costs while maintaining the previous level of seedling production efficiency [21].

4. Conclusions

This study proposed an innovative method of utilising waste biomass from cutting rootstocks for fruit tree production by recirculating it into the soil as wood chips. Previous technological solutions involved only removing the resulting biomass from the plantation, which required its disposal and generated additional costs and environmental burdens. The proposed method allows for the introduction of wood chips derived from the waste biomass generated during the cutting of rootstocks above the grafting site into the soil in a single agricultural operation. This enriched the soil with additional components especially SOC with the potential for biotransformation into humic substances, up to ~36% in the case of applying 5 tons of chips per hectare. It is also important to note that along with the recirculation of waste biomass into the soil, other elements essential for plant growth and development, particularly iron, zinc, and manganese, were introduced. It should be highlighted that the application of the developed technology reduces production costs while maintaining the previous level of seedling production efficiency and quality. Considering the regulations in force in the EU related to the promotion of a circular economy and regenerative agriculture, the proposed modification of fruit tree production offers a sustainable way to address the issue of waste biomass disposal while maintaining high production indices and reducing production costs. The study and its results, as presented herein, generate implications for the overall environment and our society.