Are the soils degraded by the photovoltaic power plant?

Abstract

New photovoltaic panels are installed on agricultural land every day and yet their effect on the quality of the soil has not yet been fully verified. Unfortunately, there are not many scientific works that focus on the effect of photovoltaic panels on real soil in real conditions. The presented work intended to establish the basic principles through which the placement of photovoltaic panels changes the quality of the surrounding soil. Since the soil is a very complex system, six basic soil properties were worked on, which were labeled as soil ‘master properties’ in the work by Kuzyakov and Zamanian. It was found that the photovol power plants can have a positive effect on the soil under certain conditions. According to our conclusions, it can be assumed that the placement of PV panels will have a positive effect on a number of soil properties, we can mainly expect an increase in the stability of soil aggregates, an increase in the content of organic matter and an increased development of the microbial community.

Graphical Abstract

Keywords:

• Soil
• soil biota
• photovoltaic power plant
• photovoltaic panel

REVIEWING EDITOR:

• Manuel Tejada, Universidad de Sevilla, Spain

SUBJECTS:

• Agriculture & Environmental Sciences
• Agriculture and Food
• Soil Sciences

1. Introduction

The International Energy Agency (IEA) released the World Energy Outlook 2020 in 2020, in which it is assumed that world energy consumption will increase at an average rate of 1.3% per year until 2040. Significant growth in energy consumption is expected especially in Asia, where urbanization and raising the standard of living of the population will continue. One of the options to cover these growing energy demands is the use of renewable energy sources such as solar or wind. Using solar energy is the cleanest technology for capturing energy (Gong et al., 2019; Hayat et al., 2019; Javadi et al., 2020; Kumar et al., 2015). Jäger-Waldau et al. (2017) state that solar panel prices have decreased significantly in recent years. For example, in 2016 the price of solar panels in Europe reached an average of around 0.5 Euro/W, which is a significant reduction compared to the average price of 4 Euro/W in 2010. This price reduction was due to the growth of the photovoltaic system market, technological progress and improvements in production processes. The International Renewable Energy Agency (IRENA) reports that in 2020 the prices decreased to 0.16–0.19 USD/Watt.

According to estimates by the International Renewable Energy Agency (IRENA), it would theoretically be possible to cover the entire world with solar panels covering a total area of about 496,805 km² (representing about 0.3% of the land surface) to provide enough energy for the entire planet. Despite this promising information, we should be careful about the effect of FVE on the environment, especially our nature. The most of scientific work was based on the determined effect of FVE on local microclimate (Teng et al., 2022), rain infiltration (Jahanfar et al., 2019), or carbon footprint (Q. Guo et al., 2019). Just a few studies were focused on the analyzed effect of FVE on soil quality (Rodriguez et al., 2023). However, none of them compares the impact of PV panels on soils compared to conventional farming. Furthermore, these works do not consider the long-term perspective of the effect of PV panels on the soil below them. We consider the low number of scientific works devoted to this issue to be the main limiting factor of the presented research.

A very strong and valid argument against FVE is that solar power plants are often installed on arable land which should serve to cover the demands for crops (Tawalbeh et al., 2021). What more before installing FVE in most cases biomass is removed from the soil in some cases could be used pesticides or other substances to control biomass production and finally soil is placed heavy photovoltaic panels (Lambert et al., 2022). All of these operations could decrease soil quality but very important is defined against which the condition is compared. The quality decrease is highly probable for soil without anthropic effect, in the case of arable land, especially under conventional agronomic techniques could be a very different situation.

Part of conventional agriculture is using chemical substances (pesticides, herbicides, inhibitors, fertilizers) and heavy agriculture machinery (Obulamah et al., 2022). Moreover, sowing practices are often selected about economic situations, not about soil quality (Kumar et al., 2015; Francis & Clegg, 1990). Because of these reasons, soils under conventional agriculture are losing organic carbon, soil biota, and infiltration capacities and there is a reduction in buffering capacities (Kuzyakov & Zamanian, 2019). Despite all this biomass production is high but only thanks to huge inputs of fertilizers. This system is unsustainable not only from an environmental point of view but also from the point of view of economic demands.

So on one side of the scales we have soil that is subsidized by chemicals and degraded by improper management (Khusainov et al., 2021) and on the other side soil that may be degraded during the installation of the panels, but decades follow, when it can lead to the restoration of the balance in such important soil properties as bulk density, soil biota or aggregate stability.

In some countries, the idea where farmers do agriculture with supporting photovoltaic systems is called Agrifotovoltaics. In this system, farmers profit not just from plant production (regardless of whether he plant biomass for food or energy) but also from using and catching solar energy. Meaningful is about balance between positive effects (saving plants from wind, hailstorms, or excessive sunlight) and negative effects (erosion which can be discovered after removing vegetation or destroying habitat for soil biota). According to some works, for example, connection to a PV power plant can ensure not only profit for farmers from the sale of electricity, but this electricity can also be used directly in agricultural operations (for example, for drying commodities or heating animal farms (Dipta, 2022; Weselek et al., 2019).

Evaluation of soil quality under different farming systems, in this work arable soil in conventional agriculture and fallow with photovoltaics panels are focused on Kuzyakov & Zamanian, 2019, where authors establish 6 soil forming factors, which are called ‘master properties’. More below in Section 4.

Is the boom in photovoltaic power plants really a threat to the soil? Does placing the panels on the ground really reduce the quality of the soil? isn’t it rather the case that soil compaction during the installation of the panels is not a bigger problem than, for example, plowing (which, moreover, does not occur once, but regularly in a conventional farm? Doesn’t the soil get more time to regenerate under the panels and, with a bit of exaggeration, breathe properly again? The answer to these questions sets the work apart from all those published so far

2. Bibliographical research methods

To identify relevant literature, a wide range of keywords related to the article’s topic were employed. These keywords encompassed key concepts and terms associated with the research. Some of the keywords included soil, solar systemt, PVE, degradation, master properties, soil quality. The keywords were grouped into several categories, facilitating better organization of the literature and enabling a systematic overview of available sources. Search Engines: Specialized databases and search tools covering the research area were used to search for relevant literature. Some of the utilized search engines included Web of science and Science direct.

3. Soil degradation by the installation of solar panels

In the first step of the research, the question ‘how does the placement of PV panels potentially affect the soil’ was asked, while not only the operation of the panel but also the construction was considered. Based on the answers to this question, several points were determined at which soil disturbance may occur (Reindl & Palm, 2021; Zapałowicz & Zeńczak, 2021; Ghazi & Ip, 2014).

During the installation of photovoltaic power plants, there are a few steps that will probably hurt soil quality:

1. Placing PV into nature is accompanied by disruption of natural ecosystems. Rate depends on local conditions, the size of PV, and approach of builders (Lambert et al., 2021),

2. according to geometry PV creates an imbalance in the infiltration of rainwater (Elamri et al., 2018; Lambert et al., 2021),

3. Composition and development of plant community are different under the panel and out of the panel (Marrou et al., 2013),

4. panel have effect on local microclimate,

5. Solar panels can influence bulk density in a few ways, firstly during the construction of solar power plants companies can use different systems (for example shooting of the solar panels or manual or mechanical burying of panels, including, for example, ground comparison, concreting) in case of soil under panels. They can remove vegetation plow soil or they can use a system which just ‘shoots’ the structure into the ground which is not too much damage to the soil (Pisinaras et al., 2014).

4. Establish PV on conventional arable soils, a hole in the system?

Few works about the effect of Solar power plant on soil quality was published. So far, none of them have focused on the effect of PV on conventionally farmed land. Marrou et al. (2013), aim them work on the effect of PV on influence water flows in a soil–crop system. They found then in Mediterranean soil covered soil by panels cost decreased demand for irrigation water because evapotranspiration was under solar panels lower. Lambert et al. (2021) established an experiment that cover pinewood, shrubland, and abandoned croplands – former vineyards by solar panels. they measured the effect on microclimate, soil quality (21 soil properties), and CO₂ effluxes. Physical, chemical, and general soil quality indexes were lower in a solar park than in the same locality without solar panels. The authors state then according to them results PV should be built on Technosols (WRB) because, in the first step of construction, soil lost part of its structure and fertility. Armstrong et al. (2016) monitored microclimate and vegetation quality during 12 months under PV, in places between individual panels – no cover and in reference to natural places closed to PV panels and they found seasonal and diurnal variations in air and soil microclimate. During the summer authors found lower temperature (5.2 °C) and soil drainage and in winter temperature was about 1.7 °C warmer than in places between panels. Places under panel production have low biomass and low biodiversity as well. Choi et al. (2020) in the work found then rainwater is concentrated along the lower edges of panels and they concluded then should be considered in plant consortium compilation

5. Theoretical evaluation of PV on soil ‘master properties’

Because of the insufficient amount of paper focused on the effect PV systems have on soil quality we assume the effect according to traditional soil regularities. We established 6 soil properties which were marked by Kuzyakov and Zamanian (2019) as soil ‘master properties’. In Table 1, we indicated of summary of ecosystem functions of individual master properties.

Table 1. Summary of ecosystem functions of individual master properties.

Master properties	Controlled ecosystem functions of soil	Explanation	Source
The bulk density	Nutrient Cycling	It can influence the availability and mobility of essential nutrients, which in turn impacts nutrient cycling processes in ecosystems.	Topa et al., 2021
	Water regulation	Soil with lower bulk density typically has higher porosity and can retain more water, influencing water availability for plants and groundwater recharge.	Verheijen et al., 2019
	Root growth and Proliferation	Lower bulk density allows roots to penetrate deeper and access nutrients and water, which is essential for plant growth and ecosystem productivity.	Atkinson et al., 2020
	Biodiversity and Habitat	Lower bulk density provides a more hospitable environment for a diverse range of soil organisms, contributing to biodiversity.	Mokany et al., 2020
	Physically stability and support	Lower bulk density can enhance soil structure, reducing the risk of soil erosion and promoting stable soil conditions for vegetation.	Kranz et al., 2020
	Filttering and buffering of soil	Bulk density affects this filtration capacity and the soil’s ability to buffer pollutants and contaminants.	Patiño et al., 2021
	Biological regulation	Changes in bulk density can impact the activity and diversity of soil organisms, which play a crucial role in nutrient cycling and decomposition processes	Phalempin et al., 2021
	Carbone strage and turnover	Low bulk density allows for better incorporation and retention of organic matter, influencing carbon sequestration.	Tautges et al., 2019
Macroaggregates	Carbon sequestration	Macroaggregates protect soil organic carbon from decomposition and erosion, promoting carbon sequestration in soils.	Huang et al., 2022
	Nutrient Retention	Macroaggregates can trap and retain essential nutrients, preventing their leaching and loss from the ecosystem.	Hartmann & Six, 2023
	Water regulation	They can enhance water infiltration and storage, reducing surface runoff and erosion.	Yan et al., 2023
	Habitat for soil organisms	Provide a structured environment within the soil that serves as habitat for soil organisms.	Yudina & Kuzyakov, 2023
	Erosion control	Help prevent soil erosion by stabilizing soil particles.	Khan & Rahman, 2023
	Microbial activity	Create microenvironments within the soil, influencing microbial activity and nutrient cycling.	Sun et al., 2021
	Soil structure stability	Contribute to soil structure stability, reducing compaction and improving aeration.	Mondal & Chakraborty, 2022
Soil organic matter	Nutrient Cycling	Soil organic matter serves as a reservoir of essential nutrients such as nitrogen, phosphorus, and sulfur.	Bashir et al., 2021
	Carbone strage	Soil organic matter is a significant component of the global carbon cycle. It sequesters carbon dioxide from the atmosphere, helping mitigate climate change by storing carbon in the soil	Baveye et al., 2020
	Soil structure stability	Soil organic matter contributes to soil structure by improving aggregation and reducing compaction	Gursoy, 2021
	Microbial activity	Soil organic matter provides a source of energy and nutrients for soil microorganisms.	Gunina & Kuzyakov, 2022
	Water retention	Organic matter increases the soil’s water-holding capacity, reducing the risk of drought stress for plants	N. Ullah, Ditta, et al., 2021
	Biodiversity support	Soil organic matter provides habitat and resources for a diverse range of soil organisms, contributing to overall biodiversity in terrestrial ecosystems	Sokol et al., 2022
	Erosion control	The presence of organic matter in the soil enhances its resistance to erosion, preventing soil loss and maintaining the stability of landscapes	Jangir et al., 2019
	pH buffering	Organic matter can act as a buffer, helping to stabilize soil pH levels. This is important for ensuring suitable conditions for plant growth and microbial activit	Hussain et al., 2023
	Disease suppression	Some organic compounds in soil organic matter have been shown to suppress soil-borne plant diseases, contributing to healthier plant communities	Lamichhane et al., 2023
The ratio of carbon to nitrogen in the soil,	Nutrient mineralization	The C:N ratio affects the decomposition of organic matter and nutrient mineralization in soils	Hicks et al., 2021)
	Plant Growth	The C:N ratio in plant tissues influences plant growth and health	Y. Liu et al., 2020
	Microbial activity	Soil microbial communities are highly sensitive to the C:N ratio. Microbes require an appropriate C:N ratio in organic matter for their growth and metabolic activities
	Soil Fertility	The C:N ratio is a crucial indicator of soil fertility. It influences the availability of nutrients like nitrogen and phosphorus for plant uptake	Xu et al., 2020
	Carbon seqestration	Ecosystems with a high C:N ratio tend to sequester more carbon, which can contribute to carbon storage in soils and help mitigate climate change by reducing atmospheric carbon dioxide levels	Schlesinger, 2022
	Eutrophication	In aquatic ecosystems, the C:N ratio of organic matter influences the potential for eutrophication.	Jiang et al., 2022
	Carbon- Nitrogen balance	The C:N ratio is critical for maintaining the balance between carbon and nitrogen in ecosystems	Cai et al., 2022
Soil reaction (pH)	Nutrient Availability	Soil pH affects the availability of essential nutrients to plants	Pasley et al.,2019
	Microbial activity	Soil pH influences the composition and activity of soil microorganisms.	Xu et al., 2020
	Plant species composition	Soil pH can determine which plant species can thrive in a particular area.	Sokol et al., 2022
	Toxic elements mobility	Soil pH affects the mobility of toxic elements like aluminum and heavy metals.	Kicińska & Wikar, 2021
	Biodiversity	Soil pH influences soil biota composition.	Joseph et al., 2021
	Soil structure	Alkaline soils tend to have better soil structure and aggregation, which can influence water infiltration and root growth.	Y. Wang et al., 2023
	Carbone storage	Soil pH can impact the decomposition of organic matter. Acidic soils may slow down decomposition, leading to greater carbon storage in the soil.	Chowdhury et al., 2021
	Soil remediation	Soil pH is a critical factor in soil remediation efforts. Adjusting pH levels can enhance the effectiveness of remediation techniques for contaminated soils	Naz et al., 2022
Soil microorganisms	Nutrient Cycling	Microorganisms decompose organic matter, releasing essential nutrients such as nitrogen, phosphorus, and carbon back into the soil.	Raza et al., 2023
		Microbial activities, including the secretion of organic substances and the formation of biofilms, contribute to soil aggregation and the maintenance of soil structure.	Guhra et al., 2022
	Decomposition	Microorganisms break down dead plant material, organic debris, and animal remains, facilitating the decomposition process	Bhattacharyya et al., 2022
	Disease supression	Soil microorganisms influence carbon sequestration by decomposing organic matter and converting it into stable forms of carbon, which can be stored in the soil for extended periods, helping mitigate climate change.	Wei et al., 2019
	Biological nitrogen fixation	Nitrogen-fixing bacteria convert atmospheric nitrogen into ammonia, which is a form of nitrogen that plants can use for growth.	Lawal, 2022
	Toxin degradation	Some microorganisms are capable of degrading pollutants and toxins in the soil, contributing to soil remediation and reducing environmental contamination.	Xiang et al., 2022
	Symbiotic relationships	Microorganisms form symbiotic relationships with plants, such as mycorrhizal associations, which enhance plant nutrient uptake and stress tolerance.	Khaliq et al., 2022
	Erosion control	Soil microorganisms stabilize the soil, reducing erosion by wind and water. Their activities help maintain soil structure and prevent soil loss.	Kheirfam & Asadzadeh, 2020
	Biogeochemical cycles	Microbes are essential for driving biogeochemical cycles, including the carbon, nitrogen, phosphorus, and sulfur cycles	Basu et al., 2021
	Plant diversity	Soil microorganisms can influence plant diversity and community composition by affecting nutrient availability and competition among plant species.	Cui et al., 2021
	Drought resistance	Some microbial communities enhance soil water-holding capacity and improve plant drought resistance by forming biofilms and increasing soil organic matter.	Mondal & Chakraborty, 2022

The bulk density of soil has a very significant influence on water and especially the air regime of soil which is crucial not just for the existence of soil structure but for biological activities as well. Too high a density can lead to an insufficient supply of soil moisture, which can limit the growth and metabolic activities of microorganisms. Soil bulk density affects the availability of space for plant roots to grow. Too high a density can inhibit root growth and limit their access to water and nutrients in the soil (Armstrong et al., 2016).

Unfortunately, conventional farming practices increased bulk density by using heavy machinery and inappropriate sowing systems (Sokol et al., 2022).

Macroaggregates are soil particle with size higher than 0,25 mm they are essential for soil structure because microaggregates are produced from them and Soil which loosing macroaggregates are threatened by erosion (Ramkissoon et al., 2021). Decreasing concentrations of macroaggregates are common accompaniments in conventional agriculture especial because of the missing using of organic additives such as manure or compost which is connected with the fact that then core of soil macroaggregates are formed by soil organic matter (Mouazen & Al-Asadi, 2018). Natural decomposition are from macro aggregates produce micro aggregates which are essential for living in soil. (Kpemoua et al., 2022; Rillig et al., 2017; Six et al., 2004). Macroaggregates create a more stable soil structure, which benefits plant roots by providing better aeration and water infiltration. This improved soil structure allows plant roots to penetrate deeper, access nutrients, and grow more effectively (Duan et al., 2021).

Lose of Soil organic matter (SOM) is probably the most mentioned soils problems closely connected with erosion and with losing soil fertility (Robinson et al., 2022). Many environmental factors drive the quality of soil organic matter and this quality finally drives many other important soil properties. The dominant effect in arable soil is farming management, As Gerke (2022) conventional farming costs decreased the concentration of SOM. Krause et al. (2022) compared till and non till systems with results that under no till soil carbon increased independently of decreased of biomass production. Research indicates that macroaggregates play a crucial role in storing soil organic carbon. They comprise a substantial proportion of the SOC pool, contributing significantly to its storage. In some studies, macroaggregates have been found to encompass up to 87.3% of the SOC stock, demonstrating their importance in carbon sequestration (W.-X. Liu et al., 2022).

The ratio of carbon to nitrogen in the soil, known as the soil C/N ratio, has a significant effect on soil processes and overall soil health. Since the C/N ratio affects the decomposition processes of organic matter in the soil, it can have an impact on plant growth and soil quality (Brempong et al., 2022). A low soil C/N ratio means that nutrients are more quickly mineralized and released to plants, which can lead to better plant growth. Conversely, a high C/N ratio can lead to slower decomposition of organic matter, which can affect soil quality and plant growth (H. Zhang et al., 2022).

Soil reaction (pH): the importance of soil pH is that it affects many processes in the soil and affects plant growth. Acidic or alkaline soil can affect the soil’s ability to retain and release nutrients, which affects plant nutrition. If the soil is too acidic or alkaline, it can lead to a lack of certain nutrients, such as phosphorus, potassium, or calcium, and this can affect plant growth (H. Zhang et al., 2023). Soil pH also affects the activity of microorganisms in the soil, which can have an impact on the decomposition of organic matter and the release of nutrients (Błońska et al., 2023). Some microorganisms prefer an acidic environment, while others prefer an alkaline environment. Therefore, it may be important to maintain an optimal pH to support the growth and activity of beneficial microorganisms. Soil pH affects root development and root hair formation. Plants may struggle to establish healthy root systems in soils with extreme pH levels, hindering their ability to access water and nutrients (Y. Liu et al., 2015; Shahid et al., 2017; Yu & Liu, 2022).

Soil microorganisms play a crucial role in maintaining soil health and contribute to crop performance by performing fundamental functions such as nutrient cycling, breaking down crop residues, and stimulating plant growth. The soil microbiome is the most biologically diverse community in the biosphere, holding at least a quarter of Earth’s total biodiversity (Sokol et al., 2022). The soil food web includes a wide range of organisms such as beetles, springtails, mites, worms, spiders, ants, nematodes, fungi, bacteria, and other organisms. These organisms improve the entry and storage of water, resistance to inorganic pesticides, and the stability of the soil structure (Hesami et al., 2014). Additionally, soil biota responds rapidly to soil management and land use changes and can influence soil organic matter, nutrient cycling, soil pollutant degradation, and the formation and stability of soil structure. it can therefore be argued that the soil biota to a certain extent determines the overall development and quality of the soil (Kibblewhite et al., 2008; Tahat et al., 2020)

Kuzyakov and Zamanian (2019) they introduced the idea of Agropedogenesis – humankind as a soil-forming factor. In this section, the effect of PV on individual master properties is discussed. We are aware that all the properties mentioned below are related to each other to some extent. The effort was to put these soil master properties about the soil change that accompanies the placement of PV on the soil. From up mentioned work focused on the effect of PV on soil we establish a few influences on soil:

a) Sheltering, b) Correlation in water gradient – Areas without the effect of falling drops and vertical infiltration and Areas with areas absorbing precipitation from the entire surface of the panel, c) Correlation with biomass d) Correlation with temperature

4.1. Shade

Soil sheltering can have a few effects on bulk density (a) reduction of soil drying, which cost increased bulk density this is especially true for soils that contain swelling minerals (Kubicki & Ohno, 2020; Sarker et al., 2020; Shi et al., 2021; Zhao et al., 2021), (b) soil are less heated which is connected with increase of bulk density of soil (D. Zhang et al., 2021), (c) Shelter has an effect on plant production and plant product substances which changes soil structure (improve) so growing of roots has positive effect on bulk density as well (Y. Li et al., 2020; S. Wang et al., 2020), (d) Shading can affect microbial activity as well as soil organic matter content, which can affect soil bulk density, probably increased bulk density (Ding & Su, 2010; Lal, 2018).

Soil shading can affect macroaggregates in several ways. A decrease in the intensity of solar radiation can slow down biological activity in the soil and reduce the rate of decomposition of organic matter, which is an important component of macroaggregate formation (Cui et al., 2021), and as a result of the preservation of organic matter, there is an increase in the formation of macroaggregates.

Furthermore, soil shading may be associated with lower soil temperature and less water vapor, which may lead to higher organic matter content and improved soil physical properties, including the formation of macroaggregates (Six et al., 2004).

If the soil is shaded, this can lead to lower soil temperature and less water evaporation from the soil, which can slow down the decomposition of soil organic matter and the development of microorganisms. This can lead to an increase in the amount of organic matter in the soil, as the decomposition of organic matter is slower and the organic matter thus accumulates (Chia et al., 2022). Another factor is soil moisture retention, which can help retain organic matter in the soil and protect it from degradation (Mukherjee, 2022b).

In some cases, soil shading can also increase the input of organic matter to the soil in the form of leaf litter and dead plant roots (Lin et al., 2022). However, in some cases shading the soil can also lead to a reduction in the amount of organic matter in the soil, especially if there are plants in the shaded area that are very competitive for water and nutrients in the soil (Yu & Liu, 2022). In this case, plants can take nutrients and water from the soil, preventing organic matter from accumulating in the soil. Land shading can also affect the amount and type of plants that grow in that area. Plants with higher light requirements may be more affected by shading and may become less competitive with other plants (J. Zhang et al., 2023).

As a result, there may be changes in the species composition of the vegetation in the shaded area and this may be reflected in the amount of plant exudates produced (Fineschi & Loreto, 2020). Another factor that influences the effect of shading on soil organic matter content is soil type. Some soil types are more prone to organic matter accumulation than other soil types. Soils with a high clay content and or (semi) hydrologic soils with a higher SOM content have a greater capacity to store and maintain organic matter in the soil (Heck et al., 2020). Shading can also affect the inputs of nutrients to the soil, which can affect the decomposition rate of organic matter. For example, if plants in a shaded area are less active and grow less, this can lead to a reduction in the input of organic matter to the soil. This can slow down the decomposition of organic matter and can lead to an increase in its content in the soil (Lan et al., 2020).

When the soil is shaded by solar panels, the intensity of solar radiation falling on the soil is reduced (X. Guo, Yang, et al., 2022). This effect can result in a decrease in plant photosynthesis and thus a lower input of organic matter into the soil (Y.-Y. Zhang et al., 2019). Organic matter in the soil is an important source of carbon and nitrogen for soil organisms, which break it down and release nutrients for plants (Ontl & Schulte, 2012). If there is a decrease in the content of organic matter in the soil, there may also be a decrease in the soil C/N ratio (Ontl & Schulte, 2012). However, the effect of shading by solar panels on the soil C/N ratio is not clear-cut and depends on many factors. For example, in areas with low humidity and high temperature, the effect of shading by solar panels on the soil C/N ratio may be less than in areas with higher humidity and lower temperature, where plant photosynthesis is more influenced by sunlight (Nikita-Martzopoulou, 1981; Sieber et al., 2022).

Soil shading can affect soil pH in different ways. When plants are shaded, less sunlight penetrates the soil surface (Y. Wang, Zhang, et al., 2021). This lowers soil temperature and slows the rate of biological processes in the soil, such as organic matter decomposition and nutrient mineralization. As organic matter slowly decomposes, acidic matter such as humic and fulvic acids are released, which can lower soil pH (C. Wang, Morrissey, et al., 2021). On the other hand, when the soil is exposed to direct sunlight, the temperature of the soil and the rate of biological processes increase (Teng et al., 2022). This can lead to increased mineralization of organic matter with different options: on the one hand, can release more basic compounds such as ammonium ions (NH⁴⁺) or calcium (Ca²⁺), which can increase soil pH (C. Wang, Morrissey, et al., 2021); on the other hand, with higher mineralization microorganisms produce a higher amount of CO₂, which can react with water and form weak carbonic acid. This acid can increase weathering rate, this could release other elements needed in the nutrition of communities of microorganisms/plants. We suppose a predominantly positive effect on most agricultural lands (Gadikota, 2021; Scott et al., 2021).

The effect of shade on soil microbial activity is complex and depends on many factors. One factor is the type of microorganisms in the soil. Different types of microorganisms have different requirements for light, temperature, and humidity (Fenchel, 2013). Some types of microorganisms can grow in less-lighted areas, while others are adapted to higher light (Miller & Zachary, 2017). Another factor is the composition of the soil. Different types of soil have different abilities to retain moisture and heat (Wells, 2013). If the soil is well-watered, it can help keep soil microorganisms active even when shaded by the sun (Koestel & Schlüter, 2019). If the soil is dry or poorly supplied with nutrients, microbial activity can be reduced even with moderate shading. The intensity and duration of shading are other factors that can affect microbial activities in the soil (Fonseca & Tavares, 2011; Mitra et al., 2018). If shading is significant and lasts for more than a few hours a day, it can lead to a decrease in soil temperature and moisture, which can affect microbial activities. However, if shading is mild and short-lived, its effect on microbial activities may be less (Guttières et al., 2021). Climatic conditions are also an important factor that affects microbial activities in soil. Temperature, humidity, and lighting are key factors that can affect microorganisms in the soil. If the climatic conditions are favorable for microorganisms, they may be able to adapt to shading from the sun and maintain their activity (Lehmann et al., 2021).

4.2. Correlation in water gradient

Precipitation unevenness can have different effects on soil bulk density. The concentration of rain water in one place can cost erosion and because of it increased bulk density, especially to depletion of organic matter (Y. Wang, Zhang, et al., 2021; Z. Zhang et al., 2020). If the soil is located in a dry area, the addition of water can lead to a decreased in bulk density, as moisture helps to loosen the bond between soil particles and thereby increase the gaps between them. The result can be a reduction in soil density and an increase in water and air permeability, which has a positive effect on plant growth and other biological processes in the soil (W. Liu, Liu, et al., 2021; Pan et al., 2020). On the other hand, in areas where precipitation is not absorbed, i.e. directly under the panels, the soil is dried, the spaces between the soil particles are reduced, and thus the bulk density increases (W. Liu, Chen, et al., 2021; Pan et al., 2020). Soil conditions should be considered when seeking a more detailed view.

Uneven infiltration of precipitation can lead to a different distribution of moisture in the soil, which can affect the stability of macroaggregates (Acharya et al., 2005; X. Yang & Vanapalli, 2021). If there is a high concentration of water in a certain part of the soil, the stability of the macroaggregates that are formed there can be disturbed. For example, under the influence of water, individual particles can be separated and macroaggregates will thus disintegrate (Semeniuk, 2013). On the other hand, in places with low humidity, macroaggregates may decrease in size or disappear (Howe & Smith, 2021). The influence of uneven precipitation infiltration on the stability of macroaggregates may depend on various factors, such as the type of soil, the type and intensity of precipitation, the length of the drying period, temperature, the presence of plant roots, and others. It is important to take into account other factors that can influence the formation and stability of macro aggregates, such as the content of organic matter in the soil, the type and amount of microorganisms, the content of mineral substances, and others (Howe & Smith, 2021; Lehmann et al., 2021).

On the other hand, an even distribution of precipitation can have a positive effect on the stability of macroaggregates and overall soil quality. If precipitation is distributed evenly in the soil, macroaggregates can be well introduced into the soil environment, which can lead to better development of the plant root system and better plant nutrition. Overall, therefore, an even distribution of precipitation can be favorable for the stability of macroaggregates, but uneven distribution itself is not necessarily negative but can affect the overall structure of the soil (Amézketa, 1999; W. Wang, Kravchenko, et al., 2013).

Uneven infiltration of precipitation can have a significant effect on the content of organic matter in the soil. If the soil absorbs precipitation unevenly, this can lead to different areas in the soil with different moisture content (Gasmo et al., 2000). This can affect the microbes and plants that live in these areas and can lead to different levels of decomposition of organic matter in the soil (Morbidelli et al., 2018).

When there is uneven infiltration of rainfall, some areas of the soil may be too dry and others too wet. In areas that are too dry, organic matter decomposes more quickly. This is because the microorganisms that are responsible for breaking down organic matter need water to function. If there is a lack of water, microorganisms cannot fully develop and the decomposition of organic matter slows down (Sofo et al., 2020). If some parts of the soil are exposed to a prolonged period of drought, organic matter loss can occur in these areas (Patel et al., 2021). In addition, there may be a reduction in the quality of organic matter, which may hurt soil fertility. When there is a lack of soil moisture, plants may also suffer and may be forced to cope with the lack of water by reducing their growth and production of organic matter. As plants grow more slowly and produce less organic matter, the total organic matter content of the soil also decreases (Morugán-Coronado et al., 2019).

On the other hand, in areas that are too wet, anaerobic decomposition of organic matter can occur (C. Wang, Zhao, et al., 2013). Anaerobic decomposition occurs when the microorganisms that break down organic matter do not have access to sufficient oxygen. This usually happens in areas of high humidity where there is a lot of water but little oxygen. Anaerobic decomposition releases methane, which is a powerful greenhouse gas. This can lead to a reduction in the total organic matter content of the soil (Achinas et al., 2020). Overall, it can be said that uneven infiltration of precipitation can hurt the content of organic matter in the soil by affecting the activity of microorganisms and plants in the soil. These factors can lead to organic decline (Brady et al., 2008).

The infiltration of precipitation into the soil is an important process that affects the entry of organic matter into the soil, the decomposition of organic matter, and nitrogen mineralization. If there is insufficient infiltration of precipitation into the soil, plant growth may be limited and thus the input of organic matter to the soil may be reduced, which may lead to a decrease in the carbon content of the soil and an increase in the soil C/N ratio (Huang et al., 2022). On the other hand, if there is too intensive infiltration of precipitation into the soil, there may be leaching of nutrients from the soil and loss of organic matter, which may also lead to changes in the soil C/N ratio (Brust, 2019).

With uneven infiltration of rainwater, soil pH can change depending on how much of the soil has been affected by rainfall. If precipitation penetrates the soil unevenly, a more pronounced decrease in pH may occur in areas with limited infiltration (Sehler et al., 2019). These areas can become acidic, which can hurt plants and microorganisms in the soil. An acidic environment can also cause organic matter in the soil to decompose, which can lead to the release of acidic substances (Yadav et al., 2020). Conversely, if rainfall is heavy and regular. However, if rainfall is too intense and the soil is unable to absorb water, surface erosion can occur and, as a result, wash away nutrients and increase the risk of surface water pollution (Long et al., 2018). Overall, it can be said that the unevenness of rainwater infiltration can affect soil pH, and its changes can have different consequences for the growth of plants and microorganisms in the soil (B. Li et al., 2016). It is important to consider all factors such as soil type, rainwater composition, and rainfall frequency when assessing the impact of rainfall on soil pH and implementing measures to optimize land use and protect the environment (Veldkamp et al., 2020).

Microorganisms in the soil are dependent on the presence of moisture for their growth and activity. If soil moisture is too low or too high, it can affect microbial activities.

In the case of uneven absorption of precipitation, dry and wet areas are formed in the soil (Kannojia et al., 2019). In dry areas (directly under the panels) microbial activity may be limited because the moisture is insufficient for the growth and activity of microorganisms. On the contrary, in wet areas (in the areas between the panels where precipitation from the panels flows), microbial activity can be affected by a lack of oxygen, because excess water can leach oxygen from the soil (Alp & Bulantekin, 2021; Pandey et al., 2022).

Uneven rainfall infiltration can also affect the decomposition of organic matter in the soil. Organic matter in the soil is decomposed by microorganisms, but this process requires optimal conditions, including the right moisture. If microorganisms are exposed to dry areas, the decomposition of organic matter may be limited (Pandey et al., 2022).

Another factor that can be affected by the uneven absorption of precipitation is the occurrence of various types of microorganisms in the soil. Different types of microorganisms have different moisture requirements and can adapt to different conditions. Some types of microorganisms can grow in less humid areas, while others prefer wetter environments.

Overall, it can be said that uneven infiltration of precipitation can hurt microbial activities in the soil. To maintain healthy soil and microbial activity, it is important to ensure uniform infiltration of precipitation and optimal soil moisture for microbial growth and activity (Tamilselvi et al., 2022).

4.3. Correlation with biomass

Soils under solar panel power plants are left fallow and so they are populated by native species for the given habitat. As Winter and Pereg (2019) show plant consortium in first years drawing succession changes every year, because plant changes their habitat into the steps when it is acceptable to them. If the solar panel only shades a small part of the area, there may be small changes in the plant community, but overall it should not have a significant impact. However, if shading is extensive and long-term, significant changes in plant growth and distribution can occur. For example, in areas with strong shading, the amount of solar radiation could be reduced, which could affect plant photosynthesis and reduce overall biomass production. However, solar panels can also provide protection from wind and sun, which in some cases can lead to a positive effect on plant growth (de Carvalho et al., 2021; Wilson et al., 2021) and thus to a reduction in bulk density of soil. Naturally occurring plants are usually better adapted to the climate and soil conditions of a given area because they have evolved and adapted to those conditions over thousands of years (H. Zhang et al., 2022). Unlike intentionally planted plants, which are often selected for aesthetic, production, or other practical reasons, naturally occurring plants are evolutionarily adapted to the area and can function better as part of the local ecosystem. Naturally occurring plants also provide greater biodiversity and promote diversity in the ecosystem (Cabrera et al., 2022). These plants tend to form stable ecosystems that provide food, shelter, and suitable conditions for the growth and survival of other organisms in the ecosystem (Tahir et al., 2022). This natural process is important for preserving biodiversity and maintaining ecological stability. In addition, naturally occurring plants usually do not require additional fertilization, pesticides, or other chemicals that can hurt the environment. These plants can naturally adapt to local conditions and can grow without the need for human intervention (Bernhard, 2010).

Naturally occurring plants tend to develop denser and more multi-layered root systems, which can help improve the stability and formation of macroaggregates in the soil (Dietz & Herth, 2011). These plants also often produce larger amounts of root matter and organic matter that can provide the necessary nutrients and energy for macroaggregate formation. Another factor that can influence the formation and stability of macroaggregates is the amount and diversity of the soil microbial community (Awasthi & Laxmi, 2021). Naturally occurring plants can provide a suitable microenvironment for the diversity of soil microorganisms, which can help create more stable macroaggregates. Last but not least, naturally occurring plants can help improve soil stability by preventing erosion and retaining soil moisture (Mo et al., 2014). This process can contribute to the formation and maintenance of macroaggregates in the soil. Overall, therefore, naturally occurring plants can play an important role in the formation and maintenance of soil macro aggregates, thereby contributing to the sustainability and productivity of the soil ecosystem (Zhou et al., 2021).

Naturally occurring plants are generally more suitable for maintaining and improving the soil organic matter content of the soil than artificially planted plants. There are several reasons why this is so (Assefa & Tadesse, 2019). First, native plants are usually better adapted to local conditions and soil types and species than artificially planted plants. This means that native plants can use soil nutrients more efficiently and produce more organic matter that remains in the soil (Parikh & James, 2012). Conversely, artificially planted plants may be more susceptible to problems such as diseases and pests and may require greater amounts of artificial fertilizers and pesticides, which can negatively affect the organic matter content of the soil. Second, natural plants usually have longer roots than artificial plants. This allows native plants to penetrate deeper into the soil and improve soil structure (Bastida et al., 2021). The improved soil structure then makes it possible to increase the content of organic matter in the soil. Third, native plants can often be part of a local ecosystem and interact with other types of organisms, such as fungi and bacteria, that help maintain high soil organic matter. However, artificially planted plants may be isolated from the local ecosystem and may be less able to interact with local species of organisms (H. Zhang et al., 2022). Naturally occurring plants have a significant effect on the soil C/N ratio. Plants take in nutrients and water from the ground and use energy from the sun during photosynthesis to produce organic matter that is stored in their roots, stems, and leaves. Organic matter causes an increase in the carbon content of the soil, which leads to an increase in the soil C/N ratio (Zhou et al., 2021). Different types of plants have different abilities to absorb and store carbon and nitrogen in the soil. For example, plants with a high lignin content (e.g. oaks) have a relatively low nitrogen uptake capacity and may have a high soil C/N ratio. On the other hand, fast-growing plants such as grasses tend to take up nitrogen more quickly and may have a lower soil C/N ratio. Furthermore, it is important to mention that the natural flora in different soil types has a different ability to influence the soil C/N ratio (S. Yang et al., 2021). For example, soils with high organic matter content (e.g. organic soils) generally have a lower soil C/N ratio because organic matter contains high amounts of carbon and low amounts of nitrogen. On the other hand, soils with low organic matter content (e.g. sandy soils) generally have a higher soil C/N ratio because they contain less organic matter and may have less ability to store nitrogen (Rani et al., 2013). Overall, it can be said that natural flora has a significant effect on the soil C/N ratio. However, the differences in soil C/N ratio between different plant species and soils are large and can be influenced by many factors such as climatic conditions, geographical locations, soil types, and other factors (C. Wang, Zhao, et al., 2013).

Plants can affect soil pH through their root system, which can change the amount and types of ions that are released into the soil, and this can affect soil pH (Nye, 1981; Y.-Y. Zhang et al., 2019). For example, some plants can release hydrogen ions (H+) into the soil, which can increase soil acidity and lower pH. On the other hand, some plants can release hydroxide ions (OH–) into the soil, which can increase the alkalinity of the soil and raise the pH. Some plants are able to grow in a wide pH range, including acidic and alkaline soils. These plants can be important in maintaining soil quality and can help regulate pH in different soil types (Msimbira & Smith, 2020). So far, no work has been published that states that, from the point of view of soil pH, it would be more appropriate to leave the land fallow than to use it for agriculture. if the plot is left to succession, then over time the pH will return to normal values for the site. However, these values may not be in the neutral range, some localities may be naturally acidic (Lintemani et al., 2020).

From the perspective of microbial activities, it is difficult to determine whether naturally occurring plants or crops are preferable because microbial activities are affected by many factors including the type of plants and the type of soil in which they are grown (Sanjuan et al., 2020). However, in general, naturally occurring plants, such as those of native ecosystems, may tend to support a higher diversity and number of microorganisms in soil compared to crops. This may be because natural ecosystems provide a diverse range of nutrients and substrates for microbes and therefore support a greater diversity of microorganisms (Meslier & DiRuggiero, 2019). On the other hand, crops often require the use of fertilizers and pesticides, which can affect the composition of microorganisms in the soil and can lead to a lower diversity of microorganisms (Saha et al., 2022). In the case of intensive agriculture, the soil can often be subjected to high pressure, and the use of mechanization can lead to a decrease in soil porosity and a disruption of the soil microbial ecosystem. At the same time, however, it can be said that crops can be purposefully grown about the needs of microorganisms, such as crops grown in the agroforestry manner, which combine the cultivation of woody plants and crops and provide suitable conditions for the growth and development of microorganisms. Overall, therefore, the question of whether naturally occurring plants or crops are more suitable from the point of view of microbial activities is very complex and depends on many factors such as soil type, climatic conditions, crop type, and farming method (Hussain et al., 2023; Pandey et al., 2022).

4.4. Correlation with temperature

Solar panels can have an effect on the temperature of the soil below them, they can lower the temperature by shading from direct sunlight, thus reducing the heat load on the soil as we mentioned above. At the same time, however, they can reduce heat removal from the soil, which can lead to an increase in temperature (D. Zhang et al., 2021).

A decrease in air temperature can affect soil bulk density for several reasons. First, as temperature decreases, soil air contracts, and fewer gases escape from the soil, increasing soil density (Mukherjee, 2022a). Second, lower temperatures cause a slower metabolism of microorganisms in the soil, which can lead to reduced numbers of microorganisms and an increase of soil density. In addition, cooler temperatures can cause soil moisture to change and more mineral particles to settle, which also increases soil bulk density (Lambert et al., 2021).

The formation and stability of macroaggregates are determined by many physical, chemical, and biological processes, some of which are strongly influenced by temperature (X. Guo, Yang, et al., 2022).

Dissolution of organic and mineral substances in the soil:

• Temperature can affect the solubility of these substances in the soil. As the temperature increases, organic substances can dissolve faster and minerals can be more dissolved. This can affect the binding of particles and the formation of macroaggregates. Activity of microorganisms (Buchan, 2011; H. Yang et al., 2019).

• Temperature affects the activity of microorganisms in the soil. As the temperature increases, microorganisms can multiply faster and thus increase activity in the soil. This can lead to increased formation and stability of macroaggregates (Frey et al., 2013; Gentry et al., 2021).

• Soil moisture: Temperature can also affect soil moisture. As the temperature increases, evaporation can increase and thus reduce soil moisture. This can affect the binding of particles and the formation of macroaggregates. Soil expansion and contraction (Al-Kayssi et al., 1990; Wu et al., 2022).

• Temperature can affect soil expansion and contraction. When the temperature increases, the soil can expand, and when it decreases (Zhou et al., 2021).

Soil temperature affects various processes in the soil, including the decomposition of organic materials, the formation of humus, and the activities of microorganisms that are responsible for the decomposition of organic matter and the release of nutrients for plants (Kannojia et al., 2019). High soil temperature can cause rapid decomposition of organic materials, resulting in less organic matter in the soil. If the soil temperature is too high, the microorganisms responsible for the decomposition of organic matter may die or become inactive. This means that organic matter may not break down as quickly, which can lead to the accumulation of organic matter in the soil (Simpson & Simpson, 2017). On the other hand, low soil temperature can cause slow decomposition of organic materials. If the soil temperature is too low, microorganisms are often inactive and cannot effectively break down organic matter. This leads to the accumulation of organic matter in the soil but also increases the risk of anaerobic decomposition, which can lead to unpleasant odors and root rot. The optimum soil temperature for the decomposition of organic matter and the formation of humus is usually between 15 and 30 °C (Ni et al., 2021; C. Wang et al., 2019). In this temperature range, microorganisms are active and effectively break down organic matter, which leads to the release of nutrients for plants and the formation of humus. Soil with an optimal temperature promotes plant growth and improves the soil’s ability to hold water and nutrients (Eldridge et al., 2023; Khusainov et al., 2021).

The temperature has a significant effect on the soil C/N ratio because it affects the rate of biological processes in the soil (H. Zhang et al., 2022). All processes that take place in the soil are affected by temperature, such as mineralization, humification, denitrification, and others (Carey et al., 2016). Mineralization is the process of decomposition of organic substances, during which organic compounds are converted into inorganic substances such as nitrates, phosphates, and others. This process is accelerated at higher temperatures because heat increases the activity of the microorganisms responsible for mineralization (Thangarajan et al., 2015). On the other hand, humification is the process of creating stable organic matter that accumulates in the soil and serves as a nutrient supply for plants. This process occurs more slowly than mineralization and is accelerated at lower temperatures because the activity of the microorganisms responsible for mineralization is reduced at lower temperatures (X. Guo, Yang, et al., 2022). These opposing effects on mineralization and humification affect the soil’s C/N ratio. At higher temperatures, organic matter decomposes faster and releases carbon into the atmosphere, which increases the soil C/N ratio. On the other hand, at lower temperatures, organic matter decomposes more slowly and accumulates in the soil, reducing the soil C/N ratio (Fuentes et al., 2020; Kicińska et al., 2022).

In general, increasing soil temperature can accelerate chemical reactions that affect soil pH (Buchan, 2011). For example, as the temperature increases, enzymes that catalyze the oxidation of organic matter in the soil may be activated more rapidly, which may lead to a decrease in soil pH (Hartley et al., 2021). However, these effects are usually quite small and can be influenced by many other factors such as soil type, moisture, and nutrient availability. However, in some cases, high soil temperature can have a more significant effect on soil pH, especially if extreme temperature conditions are involved. For example, in soils with a high organic matter content, high temperature can lead to rapid decomposition of these substances and the release of acidic products into the soil, which can lower soil pH. Likewise, in extremely dry soils where salts can accumulate, high temperatures can cause the soil to dry out and increase salt concentration, which can affect soil pH (Whitford & Duval, 2020; A. Ullah, Bano, et al., 2021).

Microorganisms are temperature dependent because the enzymes they use for metabolism have a specific temperature optimum (Nadaroglu & Polat, 2022). When the temperature changes, it can lead to changes in the rate of enzymatic reactions, which can affect microbial activities. At low temperatures (e.g. in the winter months), microbial activity decreases. This is because the enzymes required for microbial metabolism are less active at lower temperatures. However, some microorganisms can survive and even become active in extreme conditions, such as melting permafrost or snow-covered soils (Marrou et al., 2013). Conversely, high temperatures can also affect microbial activities in the soil. If the temperature exceeds a certain limit, enzymes can lose their structure and functionality, leading to the degradation of microbial populations (Munawar et al., 2021). In addition, extreme temperatures can lead to soil dehydration, limiting water availability for microbes and reducing their activity (Bastida et al., 2021). The effect of temperature on soil microbial activities can be dependent on many factors such as soil type, organic matter content, pH, nutrient availability, and water. These factors can influence the temperature optimum of microbes and their ability to adapt to extreme conditions (Jahanfar et al., 2019). Research shows that temperature changes can have significant effects on microbial activities in soil. For example, in some regions, increasing temperature can cause changes in microbial communities that can affect nutrient cycling and soil water. As a result, the overall productivity and stability of ecosystems may change. As climate change is currently leading to an increase in temperature in many regions of the world, it is important to monitor the effect of these changes on soil microbial activities and the resulting impacts on ecosystems (D’Alò et al., 2021) (Table 2).

Table 2. Assumed effect of PV on soil master properties (summary of conclusions of Sections 4.1–4.2).

Predict effect of PV	Master properties	Effect
Shade	Bulk density	Decreased or increased plant production	Reduction of soil drying	Less heating
	Macroagregates	Shading can reduce biological activity and SOM decomposition	Lower soil temperature and less water vapor – higher SOM
	Soil organic matter	Lower soil temperature and less water evaporation	Soil moisture retention	Effect on plant – litter decomposition, exudates production ect.
	C/N ration	Not clear
	pH	Slowes rate of biological process and releases acidic matter
Water gradient	Bulk density	Place out of solar panels are dangered by erosion	The soil dries out directly under the panels
	Macroagregates	Place out of solar panels are dangered loosing agregates stability	The soil dries out directly under the panels which can cost loosin macroagregate structure
	Soil organic matter	Place out of solar panels aro more wet and can be in anaerobic condition	In Places under panels Som is degrdated faster
	C/N ration	The sanme as SOM	The sanme as SOM
	pH	Place out of solar panels coul de acidificated	Places under panels – soil can by erodet and loosing bazic cationts
Biomass	Bulk density	decreased bulk density by protectiom biomass from wind and extrem sun	Increased bulk density by desrtoy biomass concorsium	Naturaly occurs plants can produce higher biomass so incresed bulk density
	Macroagregates	Naturaly occurs plants produce larger amounts of root matter and organic matter. What more it cost higher biodiverzity os soil biota
	Soil organic matter	Naturally ocurs plants They thrive better and produce that way more SOM	Naturally ocurs plants have longer hair roots and produce more exudates	Naturaly occurs plants cbetter cooperate with other parts of living soil and cost stabilization of Som
	C/N ration	Naturally ocurs plants are very diverse group of organisms and they can decresased od increased of C/N ratio
	pH	Naturally ocurs plants are very diverse group of organisms and they can produce H + and (OH–) asswal
Temperature	Bulk density	Soil air contacts	Lower temperatures cause a slower metabolism of microorganisms
	Macroagregates	Temperature increases, organic substances can dissolve faster and minerals can be more dissolved	Temperature increases, microorganisms can multiply faster	Soil expandion and contraction
	Soil organic matter	Faster decomposition of SOM	Destruction of soil biota
	C/N ration	Lower temperature = faster humification	Higher temperature = faster mineralization
	pH	Higher temperature = faster oxidation	High temperature = Faster decomposition of SOM produce acid substances	Soil to dry out and increase salt concentration

In the table, one master property, namely microorganisms, is intentionally omitted. This category is so heterogeneous that in the case of all predicted effects of PV on master properties, one can always assume improvement or deterioration, the degree depending on the specific situation.

5. Conclusion

While writing reviews, we encountered problems related to the heterogeneity of the environment countless times. it is not possible to unequivocally assume the effect of solar panels on the soil. This is because calmness is crucially reflected in this issue – whether it is an arid, semi-arid, or temperate zone. Despite this, we dare say that the negative impact of solar panels on the soil is unlikely. On the contrary, if the solar panels are installed sensitively, processes leading to soil regeneration can occur under them. We consider it a risk if solar power plants are built on areas with too much of a slope, due to which soil erosion may occur in places where the water flowing from the solar panels falls. solar panels are on the rise and more time than ever needs to be devoted to this issue. It is necessary to verify the effect of these structures on different soil types in different climatic conditions. It should also be mentioned that placing panels on the ground can be a mutually beneficial solution for both landowners and environmentalists. Farmers, for understandable reasons, do not want to leave their land fallow because they lose profit if they place panels on the land they can economically cover the time needed to regenerate the soil quality. In conclusion, it is necessary to mention again the low number of published works on the topic of the influence of PV panels on soil quality. For this reason, part of the work is only theoretical and comprehensive research on the effect of PV panels on the soil or better in general the environment and the soil as a central element of this system should be started.

Headings

• So far, no attention has been paid to the effect of solar panels on the soil

• Based on the general laws in the soil, solar panels can increase the quality of the soil

• Solar panels enable the regeneration of soil biota

Disclosure statement

The authors have no competing interests to declare that are relevant to the content of this article.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Notes on contributors

Helena Dvořáčková

Helena Dvořáčková co-owner of the company pedologie Dvořáček, s.r.o., focuses mainly on the impact of anthropogenic activity and climate change on the microbial component of soil. She received her Ph.D degree at the Mendelian University in Brno, where she dealt with the issue of biohallow and its microbial revival. Currently, he continues to research the impact of human activity on the soil, especially with regard to the microbial component of the soil.

Jan Dvořáček

Jan Dvořáček is the co-owner of the pedology company Dvořáček s.r.o., where he deals with the physical and chemical properties of soil. His professional expertise is in the field of soil classification and the impacts of anthropogenic activity and climate change on soil. He received his Ph.D degree at the Mendel University in Brno, where he devoted himself to the use of biological methods for archaeological research. He is currently studying anthropogenic impacts on soil and mitigating these negative impacts.

Vítězslav Vlček

Vítězslav Vlček, PhD. is a researcher at Mendel University in Brno, Czech Republic. His focus is soil science: soil classification and research of the function and influence of some fractions of soil organic matter on soil quality.