Grassy and Herbaceous Interrow Cover Crops in European Vineyards: A Review of Their Short-Term Effects on Water Management and Regulating Ecosystem Services

Abstract

Interrow management in vineyards significantly contributes to sustainable viticulture, particularly in water-scarce European regions. Grassy and herbaceous cover crops have been proven to enhance multiple regulating ecosystem services, including soil conservation, carbon sequestration, and improved water infiltration. However, the potential for water competition with vines necessitates region-specific approaches. This review aims to analyze the effects of different cover crop types and interrow tillage methods on water management and regulating ecosystem services, focusing on main European vineyard areas. The research involved a two-stage literature review by Google Scholar and Scopus, resulting in the identification of 67 relevant scientific publications, with 11 offering experimental data from European contexts. Selected studies were evaluated based on climate conditions, soil properties, slope characteristics, and interrow treatments. Findings highlight that the appropriate selection of cover crop species, sowing and mowing timing, and mulching practices can optimize vineyard resilience under climate stress. Practical recommendations are offered to help winegrowers adopt cost-effective and environmentally adaptive strategies, especially on sloped or shallow soils, where partial cover cropping is often the most beneficial for both yield and ecological balance. Cover crops and mulching reduce erosion, enhance vineyard soil moisture, relieve water stress consequences, and, as a result, these cover cropping techniques can improve yield and nutritional values of grapes (e.g., Brix, pH, K concentration), but effects vary; careful, site-specific, long-term management is essential for best results.

1. Introduction

Grapevine (Vitis vinifera L.) is an important fruit crop worldwide, which has a remarkable past in our history since Neolithic times [1]. In 2024, the International Organization of Vine and Wine reported that the world’s total vineyard surface area was estimated at 7.1 million hectares. In this summary, the main grape-producing countries are in the European Union, especially in the Mediterranean region, where the largest producers are France, Spain, and Italy. Furthermore, the same study showed that worldwide wine production was estimated at 225.8 million hectoliters, and the global wine export value was EUR 35.9 billion in 2024, the highest ever recorded [2].

Within the world’s total grape production, in 2021, organic farming covered more than 510 thousand hectares and was practiced in 191 countries. For those 3.7 million farmers who managed their lands organically [3], the assortment of plant protection options is limited, and renewable innovative practices are needed to maintain areas that have strong resilience against extreme climatic changes, pests, etc.

In that sense, achieving effective wine production is essential to maintaining consistent viticulture with healthy vineyards. Appropriate grapevine growing and the required wine quality are influenced by complex factors such as climate and soil properties (e.g., soil water retention capacity, erosion, etc.) [4,5,6], topographical features (e.g., slope exposure, etc.) [6], plant protection [7], weeding [8], and irrigation [8], among others. The importance of cover cropping has come to the fore over the past thirty years in Europe, primarily as a strategy to mitigate soil erosion caused by surface runoff [9]. Numerous studies confirm that adopting appropriate interrow tillage methods can be beneficial—especially in regions with extreme climatic conditions—as it is often the most effective and widely adopted approach to reduce runoff and soil erosion [10,11,12]. An increasing number of studies have demonstrated that cover cropping provides significant benefits to vineyards, such as enhancing nutrient cycling and improving the microbiological characteristics of the soil. In contrast, repeated tillage tends to accelerate the mineralization of organic matter, potentially depleting soil organic reserves [13,14]. According to these studies, in addition to the benefits mentioned above, interrow covering could increase both yield and wine quality [15,16]. As a result, some arguments and counterarguments highlight the potential of cover crops in vineyards. One of the main questions is whether or not to cover the surface of interrows and rows. If the answer is yes, what is the best sustainable and economical way to cover these surfaces?

A recent meta-analysis that compiled 70 datasets comparing different interrow management strategies—including tillage and various forms of green cover—found that green cover increased soil water content by an average of 15% in non-irrigated vineyards. In sub-humid climates, green cover was associated with 35–73% higher soil water content compared to semi-arid regions [17].

In vineyards, it is essential to avoid two extremes: excessive water availability and severe water scarcity [18]. The wild grapevine is a heliophilous liana that was widespread mainly along riverbanks and in alluvial and colluvial forests [19]. In general, the grapevine plants are isohydric [20], so during dry periods, stomata are closed to maintain a constant and high water potential in leaves [21]. However, water deficit can significantly restrict leaf growth [22].

On the other hand, a large amount of water can lead to the deterioration of plant health and yield quality.

Excessive water availability in the root zone during the first half of the growing season promotes overgrowth of the canopy, which can lead to photosynthetic inefficiency [23]. This condition is associated with poor grape maturation and an increased risk of fungal infections [18]. In contrast, an increased water supply during the post-véraison period can improve berry composition. However, excessive water uptake at this stage increases the risk of berry cracking [24,25].

This article aims to collect scientific results focusing on the impact of different types of interrow tillage and cover cropping systems on water management and ecosystem services. Lazcano et al. [26], in their review, researched and defined the importance of using cover crops in vineyards with regard to water management; however, they emphasized the need to investigate the effects of different types of coverage. Thus, as a continuation, our main topic is water management in cover-cropped areas, especially in European vineyards, focusing in detail on the types of plant species used. Furthermore, we extended the inquiry to include ecosystem services. In addition, we aim to provide insights into effectively developing cover cropping techniques.

2. Methodology for Data Collection

Data collection for this review was conducted in two main periods. The first period of literature gathering (November 2022–March 2023) was limited to Google Scholar. The second period of data collection (January 2024–March 2025) was carried out with the same keywords and criteria but in Scopus only. The aim of using Google Scholar, as a database with the broadest forward citation [27], was to find records in a comprehensive and open access database, and the database change was driven by increased indexing, the greater number of peer-reviewed results, and a higher proportion of full-text resources in the Scopus database. Another decision criterion in the second data collection period was that Scopus has a slight advantage over other similar search engines (e.g., Web of Science Core Collection) in terms of forward citation coverage [28].

The keywords we searched were a combination of ‘vineyard’ or ‘viticulture’ and ‘inter row’, ‘sward’, ‘mulch’, ‘cover crop’, ‘grazing’ or ‘grassing’, ‘slope’ or ‘sloping’, ‘weed cover’ or ‘weed vegetation’, and ‘ecosystem service’ in general (in the case of Google Scholar) and within the fields of the article title, abstract, and keywords (in the case of Scopus). In order to obtain the most relevant articles, we added more search criteria.

We focused on experimental results that have been completed in viticulture; therefore, we dismissed articles that were outside these criteria. To obtain experimental data from approximately similar climatic conditions, we added a geographical filter, so we focused on European articles.

Moreover, to receive the most recent scientific articles, we added a time limit. Firstly, we searched the literature from 2015. However, this search resulted in few articles closely related to our topic. Thus, we expanded the time limit from 2005 until the date of the search, because the number of sources increased significantly from this period onwards (

Table 1. Number of publications in the Scopus database by keywords and by time periods (date of literature search: 27 March 2025).

Keyword Combinations A		2020–2025	2015–2019	2010–2014	2005–2009	2000–2004	–1999	Year of 1st Record
		Number of Documents
‘vineyard’ or ‘viticulture’	‘inter row’	166	97	41	34	10	3	1997
	‘sward’	7	3	7	6	2	2	1990
	‘mulch’	57	27	24	17	7	11	1985
	‘cover crop’	200	137	102	41	23	17	1984
	‘grazing’ or ‘grassing’	48	25	14	9	7	17	1980
	‘slope’ or ‘sloping’	241	183	129	79	33	69	1960
	‘weed cover’ or ‘weed vegetation’	10	8	0	2	4	1	1998
	‘ecosystem service’	168	90	28	7	0	0	2007
‘ecosystem service’		33,836	18,279	8679	2111	381	109	1984
‘regulating ecosystem service’		243	173	35	4	0	0	2006

^A research fields: article title, abstract, and keywords.

). According to the number of records in different time periods, we can declare that considerable scientific research was conducted in the field of mulching, grassing, or the use of cover crops from the 1980s, but the focus on ecosystem services has increased mainly since the 2010s, and in the case of vineyards/viticulture, the first record for the ecosystem services search combination was found in 2007. In addition, it should be noted that the assessment of ecosystem service capacity would be most effective in the context of long-term works, but unfortunately, the available references have examined these effects only over a 1–4-year time horizon.

After the collecting and filtering of these records, the two collecting methods extracted 67 articles. We studied these documents and selected only those which contained the most information about the climate, average annual precipitation, soil properties, experimental period, slope angle, and interrow’s soil management. As a result, 11 articles emerged, and they are presented in the Section 6.

3. The History and Potential of Ecosystem Services

Ecosystem services have always been of vital and great importance in the history of humankind, from primitive humans to the present day. Perhaps we just called it something else, or maybe we did not turn it into measurable or evaluable data, but these services have always been essential parts of our subsistence.

The first significant mentions of ecosystem services date back to the 1970s, when some publications started to promote ecosystem functions as services to increase public interest in biodiversity protection [29,30,31]. The mainstreaming of ecosystem services occurred in the 1990s [32,33], and 1997 was the year when the first definitions of ecosystem services appeared. One of these was a book titled Nature’s Services: Societal Dependence on Natural Ecosystems, edited by Gretchen Daily [34], and the other was an article titled The Value of the World’s Ecosystem Services and Natural Capital, published in Nature [35]. Both of these works served as triggers that led to serious consideration of ecosystem services, the establishment of a journal on this topic (Ecosystem Services, Elsevier), and an ongoing process to define what ecosystem services are, why they are important for human beings, how they can be measured, and how we can conserve or promote their development. According to these papers, we can define ecosystem services as “the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life” [34] or “the benefits human populations derive, directly or indirectly, from ecosystem functions” [35].

The Millennium Ecosystem Assessment was launched in 2001 [36], and since then, the literature on ecosystem services has steadily grown, bringing the topic to the forefront, including its political dimensions [37]. Of course, there are many earlier sources on ecosystem services, but there was a gap between ecology and economics, and between the domains of nature conservation and economic development [38]. Ecosystem services have huge impacts on our environment; therefore, they need to be divided according to their effects. Scotland’s Nature Agency has determined four main sections:

• Provisioning (renewable and nonrenewable energy, materials, water supply, natural medicines, food and drink);
• Regulating (clean air, carbon storage, flood management, erosion control, water purification, disease and natural pest control, pollination);
• Cultural (physical health and mental wellbeing, tourism, knowledge and learning, recreation, sense of place, inspiration, spiritual and religious connections);
• Supporting (healthy soils, photosynthesis, nutrient cycling, space for wildlife) [39].

In addition to the above categorization system, there are also widespread cases where the supporting category is not separately identified but merged with others [40].

This article focuses on regulating ecosystem services, as these are among the most critical for supporting crop production. According to the USDA Climate Hubs, regulating services are the benefits derived from the regulation of ecosystem processes. A key illustration of the interaction between agriculture and ecosystem services is found in sloped landscapes. Agricultural activities may lead to the degradation of regulating services across various landscape positions, albeit with differing levels of impact. When such losses occur in ecologically critical areas, the resulting decline in regulatory capacity places substantial stress on regions with high demand for these services. In contrast, land-use disturbances in non-critical zones—even if extensive—tend to exert a relatively minor effect on the overall provision of regulatory functions [41].

4. Types of Covering

The covering material can be mulch, which can be either organic (e.g., compost, manure, peat) or inorganic (e.g., plastic-based materials, glass, paper, special foam) [42]. Organic materials can come from various plant origins, such as pine needles, plant stalks, straw bales, turf, etc. Inorganic materials typically include paper or plastic [43]. Some research has shown that combining plastic cover with herbicide application is significantly more effective against weeds than using herbicide alone [44].

In the case of cover crops, the soil surface is covered by permanent vegetation. The crop-independent classification of cover crops includes five types according to how long they remain in the area:

• Perennial/permanent covers: This method is commonly used, especially in humid climates. Permanent cover provides several benefits, such as reducing plant vigor, improving the microclimate and crop quality, preventing erosion, and allowing continuous access to the rows. The crop species can include perennial legumes (e.g., Lotus corniculatus, Trifolium fragiferum, Trifolium repens) or perennial grasses (e.g., Bromus carinatus, Dactylis glomerata, Elymus glaucus, Festuca arundinacea, Festuca idahoensis, Festuca ovina, Festuca rubra, Hordeum brachyantherum, Lolium perenne, Poa secunda) [45].
• Temporary covers: This type of covering is common in warmer, drier climates, as it helps reduce erosion, improve soil bearing capacity, and increase infiltration and fertility. The species used for covering can vary, influenced by the method of row maintenance, the dominant cover species, and other factors [45].
• Annual winter covers with tillage: The main benefits of this cover type are increasing soil fertility and reducing soil erosion. Suitable species include grasses (e.g., Avena sativa, Hordeum vulgare, Lolium multiflorum, Secale cereale, Triticum aestivum), legumes (e.g., Pisum sativum, Trifolium alexandrinum, Vicia faba, Vicia sativa, Vicia villosa, Vicia benghalensis), cruciferous vegetables (e.g., Brassica nigra, Brassica rapa, Raphanus sativus), and forbs (e.g., Brassica spp., Phacelia tanacetifolia) [45].
• Annual winter cover without tillage: This is a good practice for conserving soil throughout the year without competing with vines. It is crucial to select suitable plant species for the autumn and winter seasons. Appropriate species include legumes (e.g., Medicago polymorpha, Trifolium hirtum, T. incarnatum, T. subterraneum) and grasses (e.g., Bromus hordeaceus, Vulpia myuros var. hirsuta) [45].
• Summer covers with tillage: This method is rarely used due to the high competition with vines. Its primary purpose is to promote significant biomass production under high-fertility conditions. The selection of suitable species is limited and includes (e.g., Fagopyrum esculentum, Sorghum sudanense, Sorghum bicolor × Sorghum sudanense, Vigna unguiculata) [45].

The positive effect of legumes as a supplement has not been demonstrated in grape cultivation, but in maize (Zea mays), legumes have been shown to increase the yield of the primary crop by more than 30%. In contrast, grass-dominated cover crops tend to have a neutral or even negative effect on yield [46].

Overall, it is essential to assess the specific conditions of the niche where we plan to sow any kind of cover crop mixture. Several factors must be considered, including the slope of the area, the rate of erosion, regional rainfall, the availability of irrigation, and the type of cultivated plant. In sloped vineyards, farmers need to focus on reducing erosion and soil disturbance, increasing nitrogen levels and organic matter, attracting beneficial pests and organisms, and selecting moderately drought-tolerant plants, especially if there is no irrigation system. Low-growing legumes are often the most suitable option for sloped vineyards, as they meet these requirements. Additionally, grass mixtures such as Bromus hordeaceus and Lolium multiflorum can also be effective choices [47].

After the small grain harvest in late summer, particularly in regions with moderate rainfall, farmers should select cover crop species that protect the soil during winter, supply nitrogen, help control weeds, and conserve moisture. Suitable options include Vicia villosa, Trifolium incarnatum, Pisum sativum ssp. arvense, and Secale cereale. If the grain harvest takes place in late spring or early summer, Vicia dasycarpa can be an appropriate choice [47].

5. The Impact of Cover Cropping on Regulating Ecosystem Services

5.1. Soil and Carbon Storage, Improved Nutrient Cycling

Several studies confirm that interrow cover cropping helps in many ways, e.g., promoting soil conservation [48], improving soil characteristics by decreasing crusting and erosion [12,45,49,50,51,52,53,54,55,56,57], enhancing soil fertility [49,50,51,58], and increasing water-holding capacity [45,48,49,54,59,60,61,62], particularly during the winter months. One study showed that ground cover can limit surface runoff by increasing the infiltration of precipitation during the winter period. Moreover, it positively influences water competition, as the crop’s water uptake occurs earlier compared to vines under bare soil conditions [49]. Ground cover also protects water quality by inhibiting nitrogen leaching into groundwater [47]. These positive effects of soil coverage are not a new scientific result, since, from ancient times, cover crops have been used in China, India, Northern Europe, and North America to reduce erosion, add nitrogen, and improve soil water penetration. However, cover cropping was forgotten for decades in the 1940s and 1950s when conventional agriculture came to the fore [45].

Cover cropping also increases soil biodiversity [55,63]. In a meta-analysis that included datasets from various countries, such as Australia, South Africa, Brazil, Chile, the United States, Turkey, Ukraine, Hungary, Switzerland, Italy, France, Spain, and Portugal, researchers investigated the impact of interrow management on biodiversity and ecosystem services. They found that extensive vegetation management (e.g., maintaining ground cover organically or with other low-intensity methods) increased these services by 20% compared to intensive management practices (e.g., soil tillage or herbicide use to remove vegetation) [55]. At the same time, ground cover also reduces labor and energy inputs [47,64]. Compared to intensive or conventional tillage systems, conservation tillage is significantly more economical. For example, three or more tillage operations can often be reduced to one or two, resulting in labor and fuel cost reductions of 50% or more [47]. All of these factors contribute to sustainable soil management methods (i.e., regenerative agriculture) and ecosystem services. As we know, cover cropping is essential for regenerative agriculture [65,66].

Abad et al. [67,68] selected and reviewed 272 publications on this topic from 1999 to 2018. They found that cover crops typically do not compete significantly with vines for nutrients, except for nitrogen when grass cover crops are used. In contrast, legume cover crops tend to increase soil nitrogen content, although this nitrogen becomes available to plants over a longer period. Furthermore, using cover crops between the rows can decrease the acidity of the must and reduce the enlargement of berry skin, total phenols, and anthocyanins [69].

Vineyards are among the most vulnerable agricultural areas affected by soil erosion processes [70], especially in Mediterranean regions [71]. Bare soils, however, exhibit even worse erosion rates [72]. In these regions, it is especially important to focus on soil and nutrient conservation and minimize soil runoff through appropriate cultivation methods. These methods, regardless of soil type, can reduce soil runoff by 50–75% [51]. During this period of climate change, it is essential to focus on nature-based solutions to maintain sustainable agricultural systems [48]. Under poor conditions, yields can also be positively influenced by using cover crops. Over the long term, coverage can increase yields by up to 10% in one year, and up to 25% after five years, particularly in soils with low organic matter content and low nitrogen fertilizer inputs [73]. Furthermore, it is crucial to create suitable conditions for vines to reduce water stress, which can negatively affect wine quality [59,74,75]. This benefit is especially evident in younger vines [75].

Overall, some researchers have considered the cover cropping method as a way to mitigate the negative consequences of intensive agriculture and provide ecosystem services such as carbon sequestration and climate change regulation, soil protection, and water purification [5,57,58,76]. Abad et al. [67,68] demonstrated that cover crops positively impact soil organic carbon levels, thereby contributing to the reduction of atmospheric greenhouse gases [56]. Payen et al. [77] have arrived at the same conclusion. The authors evaluated 50 studies from short-term (i.e., <6 years) to medium-term (i.e., 6–10 years) and long-term (i.e., >10 years) experiments, the results of which also confirmed that the cover cropping method is capable of increasing soil organic carbon stocks.

Ingels et al. [45], in their study, outlined several potential disadvantages when farmers select inappropriate agricultural methods or cover crop species. In particular, winter annual grasses can lead to nutrient competition—primarily for nitrogen—which may reduce the vine’s leaf canopy due to delayed nitrogen availability, as observed with species such as Lolium arundinaceum and L. perenne [45]. In contrast, legumes are capable of fixing atmospheric nitrogen into forms that are available to grapevines, with accumulation ranging from 18 to 90 kg of nitrogen per acre (44–222 kg N ha⁻¹). Grass cover crops, on the other hand, typically have a higher carbon content than legumes, produce greater biomass, and effectively prevent soil erosion due to their dense root systems [78].

In a separate study, researchers compared seven different types of cover crop mixtures: three blends of cool-season grasses (Schedonorus arundinaceus, Lolium perenne, and Festuca rubra in various compositions), two cool-season grass–legume mixtures (S. arundinaceus, L. perenne, F. rubra, and Trifolium repens in various compositions), naturally occurring resident vegetation, and tilled soil. Among these, S. arundinaceus exhibited the most stable botanical composition, whereas the other mixtures were quickly invaded by competing plant species [79].

Moreover, cover cropping may enhance populations of rodents such as meadow voles (Microtus spp.) and pocket gophers (Thomomys bottae), which can cause significant damage, particularly in young vineyards. After interrow cover crop vegetation matures, flower thrips may also migrate to the grapevines. Finally, spring frosts can pose a greater threat in vineyards with vegetated alleys, as the plant cover reduces solar radiation reaching the soil surface during the day, subsequently lowering air temperature [45].

Additionally, some studies, such as that of Guzmán et al. [80], could not clearly demonstrate the positive effect of cover crops on soil and maximum above-ground biomass production due to large standard deviation values between bare soil and dense cover cropping. Vineyards with low (above-ground biomass) cover crops could generate relevant average biomass production compared to similar areas, even in dry Mediterranean conditions [81].

5.2. Accumulation of Substances

Copper (Cu) is the primary active ingredient used to control fungal diseases in vineyards, leading to significantly elevated Cu concentrations in vineyard soils, often exceeding reference limits. Lolium perenne exhibits tolerance to high Cu levels, making it a suitable candidate for phytoremediation. Its use can help mitigate Cu mobility and prevent its transfer to other components of the ecosystem or the food chain [82]. Certainly, a mixture of cover crops can provide more value for farmers than using only one species [83].

The main factors to be taken into account are the climatic conditions of the area, soil characteristics, average annual rainfall or irrigation possibilities, and the farmer’s ability to use different farming methods. We cannot ignore the importance of cover crop species, which can be the best ally for grape growers. In addition, farmers can achieve more positive effects by rebalancing soil ions and displacing Na⁺. Additional organic matter delivers carbon and contributes to soil structure [84]. Other advice, such as decompacting soil (e.g., once per year to avoid compaction), planting grass in the wintertime, and similar practices, can also help maintain a healthy vineyard [85].

5.3. Water Management

Water conservation is as paramount as soil conservation. Cover cropping can be a long-term solution for farmers who struggle with water runoff [61], which can be reduced by as much as 27% in the rainiest areas (with rainfall higher than 700 mm), while also alleviating water stress [59]. Furthermore, it facilitates the redistribution of grapevine roots not only horizontally but also vertically [86,87], thereby enabling vines to access water from deeper soil layers—up to 4 m in depth [69].

Water availability remains one of the most crucial challenges in global agriculture [88], particularly in viticulture [89]. The extent and timing of water deficits when cover crops are used can reduce vine vigor. This, in turn, may improve sunlight exposure to grape clusters [90], potentially influencing grape quality traits such as Brix, pH, and potassium concentration [91]. Therefore, some researchers argue that an efficient irrigation system coupled with optimal irrigation timing may be the most effective approach during drought periods [91,92]. For instance, withholding water before véraison followed by unrestricted irrigation thereafter has been shown to improve berry composition significantly [93]. Nonetheless, insufficient water availability markedly inhibits leaf growth [22], especially when water deficits occur before flowering [94]. Conversely, an excessive water supply during the first half of the growing season can lead to fungal infections [18] and cracked berries after véraison [24,25]. It is important to note, however, that continuous irrigation throughout the growing season does not necessarily lead to the highest yields or best nutritional quality of grapes [91].

However, water may not be available or expendable (due to legislative restrictions on water use) in every region for irrigation [89]. Moreover, water is not a renewable resource; due to global climate change, water is an increasingly relevant issue, as 90% of global water consumption is for irrigation, and 40% of crops are produced in irrigated areas. Döll and Siebert also show the irrigation requirements in the 2020s through the Global Irrigation Model (GIM). According to the model, irrigation requirement increased in most regions between the 1990s and the 2020s, so water management will need to change in the long term [95].

5.4. Vine Production and Quality

Vine quality is not clearly proven to be affected by cover cropping [79]. Another aspect concerns the interaction between yield and cover cropping, which may be the most important consideration for producers. In some research, where different cover cropping strategies (0%—as bare soil with herbicide application, 30%, 60%, and 100% cover crop) were tested, yield decreased as the interrow soil coverage increased, especially in shallow soil cases [96].

Perhaps the most questionable topic regarding cover cropping is water competition, which has a negative effect on vine production and quality [5]. Some researchers could not find significant evidence of cover cropping’s effectiveness in reducing water runoff and conserving water in dry areas [59], while others considered it harmful [85,97,98,99]. As cover cropping generates more maintenance work, it can be more expensive and time-consuming than bare surface with soil tillage [100].

5.5. Plant Protection

Cover cropping management in the alleys also helps farmers, as some research shows that well-chosen species of cover crops can enhance biodiversity for pest control [7,55,101,102,103] and are effective in weed control by enhancing agrobiodiversity [45] and suppressing weeds [104,105], reducing weed seedling presence due to allelopathic effects or physical consequences of shading [83]. Moreover, cover crops can be an effective way to suppress plant-parasitic nematodes [45,101,106,107], such as Tagetes spp., which can be a valuable tool not only against nematodes but also against some pathogens, such as Alternaria solani [108]. In some studies, Sinapis alba monoculture coverage decreased the abundance of Illinoia liriodendri compared to Triticum aestivum in vineyards [109].

The weed-suppressing effect of some cover crops is significant due to their allelopathic properties [88]. Brassicaceae (e.g., kale), Eruca spp. (e.g., arugula), and Sinapis spp. (e.g., mustard) release toxic isothiocyanates after decomposition [110]. Sorghum spp. contains a compound called sorgoleone, which can also reduce weed growth [111]. Festuca arundinacea, especially in combination with woody plants, is also capable of demonstrating allelopathic effects [112]. It is necessary to note that the number of research works from grapevine is limited, but the results described for other crops can potentially be used in vineyards.

5.6. Biodiversity

Cover crops can enhance biodiversity by providing habitat, forage resources, overwintering sites, and reproduction shelters, especially for pollinators and other beneficial animals (e.g., arthropods, birds). In this case, they also ensure the availability of pollen and nectar, even when these resources are scarce (e.g., during late fall and spring) [113]. Additionally, cover crop residues offer similarly positive benefits by providing nutrients and physical protection for underground micro-arthropods [114].

6. Detailed Results of Key Studies on the Ecosystem Services Provided by Soil Cover

Because of the large number of variables that interact, it is impossible to provide a precise manual that suits every farmer’s vineyard. We need to consider all aspects of different cultivation methods, which are influenced by the intensity of agricultural management, the various species used as cover crops, the timing of cover crop removal, and the height of the cover crops. Last but not least, the typical conditions of each vineyard must also be taken into account [80].

Gulick et al. [115] investigated irrigated vineyards in California (USA), where interrow plots were covered with bromegrass (Bromus mollis) using two different methods: (1) bromegrass used as winter cover, treated with herbicide and mulched in summer; and (2) bromegrass followed by resident vegetation as a summer cover crop. Additionally, there were soil-tilled control plots that received herbicide treatment throughout the year. According to the results, there were no significant differences in water amounts between cover-cropped and non-cover-cropped plots; however, total water usage and water infiltration into the soil were higher in the cover-cropped plots. These findings are consistent with observations from European vineyards.

Némethy et al. (2004) [116] investigated mulch and cultivation techniques, including the following:

• Winter rye (Secale cereale), mowed and used as mulch
• Winter rye mixed with shredded vine prunings used as mulch
• Permanent native vegetation, mowed five to eight times
• Cover crop consisting of Digitaria ciliaris
• Straw mulch
• Control (tillage with machinery)

In these six replications, they examined soil moisture at a depth of 0–60 cm in the interrow soils. The results showed that any type of ground cover techniques resulted in higher soil moisture than the uncovered control, and the cover of Digitaria ciliaris was the most effective in terms of moisture retention. Moreover, the height of the cover crop plants can also be a determining factor, as an intermediate height (12–15 cm) of the stubble maximized soil moisture, but a taller (above 20–23 cm) cover crop resulted in a large amount of soil moisture.

In contrast, some trials highlight the disadvantages or risks of improper interrow cropping. Tesic et al. [97] compared two climatically distinct (‘Dry’ and ‘Humid’) irrigated Chardonnay vineyards over four seasons. They used three types of cultivation methods:

• Continuous tilling without cover cropping,
• Partial cover: permanent resident cover crop in interrows; however, the 100-cm-wide strip under the vines was tilled,
• Full coverage: no tilled strips under the vines.

The complete coverage methods in the tests negatively affected both vineyards regarding soil moisture at a depth of 30 cm in the interrows, as well as the petiole nitrogen and magnesium levels, which were significantly lower in the full cover cropping events. In the case of complete cover cropping in ‘Dry’ vineyards, veraison was delayed by four days, and shoot length, along with leaf layer number, decreased with increased floor coverage. Lastly, the complete cover showed lower yield, cluster number, and berry weight in the third and fourth seasons [97].

Some cases show that ground cover vegetation may not have an impact on yield [75]. Marques et al. [50] compared three different cultivation methods of interrows: continuous tilling, interrow covering with Brachypodium distachyon, and interrow covering with Secale cereale. The highest yield after harvesting was observed in the tilling method case. However, Marques et al. [50] emphasized that long-term tillage in hillside vineyards is unsustainable due to excessive soil loss (1059 g m⁻² year⁻¹), compared to losses of only 70 and 62 g m⁻² year⁻¹ in plots with B. distachyon and S. cereale cover, respectively.

Nevertheless, the age of the vineyard is a critical factor when introducing interrow cover crops, as young vines may exhibit reduced growth and yield. In this study, grapevines less than two years old, cultivated in a semi-arid region, showed unacceptable growth suppression—especially during bloom and pruning—when interrows were sown with grasses such as Bouteloua dactyloides, Festuca rubra, and Lotus corniculatus. In contrast, Capsella bursa-pastoris did not negatively affect vine growth [117].

Lopes [60] compared three Portuguese experimental results from their research team. The interrow cultivation methods in Alenquer were as follows: (1) soil tillage between rows; (2) permanent resident ground cover vegetation between rows; (3) permanent sown cover crop between rows, with a mixture of 60% grasses (Lolium perenne ‘Nui’, L. multiflorum ‘Bartíssi-mo’, Festuca ovina ‘Ridu’, F. rubra ssp. rubra ‘Echo’) and 40% legumes (Trifolium incarnatum ‘Red’, T. repens ‘Huie’, and T. subterraneum ‘Claire’). Herbicides were applied in the rows [69]. In Estremoz, a drip irrigation system was used, with the methods being as follows: (1) soil tillage between rows; (2) permanent resident cover crop vegetation between rows [118]. Last but not least, in Nelas, the methods were interrow soil management (permanent resident cover crop vs. soil tillage) and undervine floor management (mulch vs. herbicide) [119]. In all three experiments, water competition was more intense in the spring, but later, after flowering, it disappeared. Overall, the covered interrows showed higher water storage in deeper soil layers [60].

Bidoccu et al. [53] also investigated the connection between soil moisture and soil coverage in vineyards. The trial treatments were conventional tillage, cover crops (including permanent and seasonal grass cover and spontaneous vegetation), and bare soil with herbicide treatments. Based on the results, there were no significant differences between the cover crops and conventional tillage methods during the experimental period, while there were large annual variations in runoff. These experiments showed similar results to those of Monteiro et al. [69], whose trials revealed no significant differences. However, cover cropping in the alleys effectively reduced soil water content in the spring season.

Ben-Salem et al. [54] compared spontaneous vegetation and spontaneous vegetation cover plus common sainfoin (Onobrychis viciifolia) plantation. In this trial, the topsoil water content of the corridors and the rows was also measured. According to the results, the topsoil water content was higher in the covered interrows and corridors than in the rows. Furthermore, the common sainfoin cover had 40% more topsoil water content on average.

Muscas et al. [120] carried out an experiment with four replications: natural covering, annual self-reseeding legume mixture, grass mixture, and soil tillage. In this shorter-term experiment, the covered interrow management showed lower yield compared to soil tillage. Cover crop mixtures also had an adverse effect on grape production. A legume mixture reduced cluster weight, and a grass mixture reduced both cluster weight and the number of clusters per vine. However, in the authors’ previous and longer-term (5 years) experiment, the grass mixture had not shown a similar decrease in yield [8]. Overall, the results suggest that appropriately selected interrow species can improve berry quality and moderate vine vigor. Grass cover, in particular, enhanced sugar content, anthocyanin concentration, and polyphenol levels, unlike the legume mixture, which had a less favorable effect [120].

Darouich et al. [121] compared different cultivation methods in Italy (rainfed soil tillage and grass cover) and in Portugal (drip irrigated). These areas have different climatic conditions. While the Italian vineyard soils have a large water-holding capacity and the climate is humid, the Portuguese orchard’s soil is sandy and has a small water-holding capacity within a dry, subhumid climate. During their experiment, soil moisture increased in both the rows and interrows in the case of grass cover compared to bare soil, thus preventing water stress for the grapevines. Moreover, the results also support claims promoting cover cropping, as it reduces the infiltration of surface water and groundwater, thereby decreasing soil erosion and increasing soil water availability. In the long term, cover cropping can support water and soil conservation efforts and reduce water stress.

Liebhard et al. [56] sampled 78 vineyards in four countries (Austria, France, Romania, and Spain) and defined site pairs of vineyards that are close enough to each other to have similar geological and hydrological conditions. Moreover, the soil cultivation method of one of the site pairs had low intensity (typically permanent ground cover with mulch, no chemical usage), while the other was tilled with high intensity (typically tilling interrows with herbicide usage). According to the results, where the total carbon storage increased, the bulk density, percolation stability, and, to a lesser extent, hydraulic conductivity and available soil water were also affected. The percolation stability was particularly low in high-intensity vineyards. In Romania, where the intensively tilled interrows changed yearly, the physical soil parameters were much poorer than in Austria, where high-intensity management involved alternating tillage and covering interrows every 2–4 years, showing only slight degradation (macroaggregate stability), in contrast to permanent green cover management. In contrast, water storage capacity was lower in low-intensity management cases in general, despite their significantly higher potential to store water.

Table 2. Detailed presentation of the listed studies.

Location	Climate	Average Annual Precipitation	Soil Properties	Experimental Period	Slope Angle	Soil Management	Reference
California	N/D	irrigated	fine sandy loam	1989–1990	N/D	perennial cover crop winter cover crop	[115]
Hungary	N/D	N/D	sandy	N/D	N/D	winter rye, mowed and used as mulch winter rye mixed with shredded vine prunings used as mulch permanent native vegetation, mowed five to eight times cover crop consisting of Digitaria sp. straw mulch soil tillage with machinery	[116]
Central Portugal	mediterranean	N/D	sandy clay loam	3 years	7%	N/D	[69]
N/D	hot-dry mild semi-humid	N/D	N/D	4 seasons	N/D	N/D	[97]
Portugal, France	mediterranean	487–866 mm	loamy sand clay sandy clay loam clay loam	3–4 years	4.5–12%	N/D	[12]
Portugal	N/D	N/D	sandy clay loam silty clay loam	1 season (3–4 years after cover crop establishment)	N/D	resident cover crop vegetation soil tillage	[60]
North-West Italy	sublitoranean	905 mm (2000–2014)	silty clay loam silt loam	2 years	average 15%	N/D	[53]
Carignano (Italy)	mediterranean	560 mm + drip irrigated 3 timer per year (700 m3 ha−1 year−1)	sand 51.0%, clay 24.9%, silt 24.1%	3 years	N/D	natural covering annual self-reseeding legume mixture grass mixture soil tillage	[120]
Spain	continental mediterranean	446 mm (2009–2017)	sandy loam loam silt loam loamy sand	15 months	average 9.8%	spontaneous spontaneous vegetation with plantation Onobrychis viciifolia	[54]
Italy	sublitoranean	965 mm	clay to clay-loam	2016–2019	average 15%	conventional tillage-controlled grass cover	[121]
Portugal	dry sub-humid	669 mm	sandy loam	2018–2020	N/D	spontaneous grass with soil tillage + drip irrigated	[121]
Austria	N/D	600 mm	loamy sand silt loam	2015–2016	N/D	permanent vegetation, mulched alternating tillage, mechanical	[56]
France	N/D	610 mm	clay loam to sandy loam loamy sand	2015–2016	N/D	permanent vegetation, mulched permanent vegetation, chemical alternating tillage, chemical soil tillage, mechanical/chemical	[56]
Romania	N/D	660 mm	silty clay clay loam to sandy loam	2015–2016	N/D	permanent veg., mulched alternating tillage, mechanical soil tillage, mechanical	[56]
Spain	N/D	600 mm	clay loam to silty clay loam silty clay	2015–2016	N/D	permanent vegetation, mulched temporal, mechanical/chemical soil tillage, mechanical	[56]

N/D: Not Determined.

contains all the collected results of the experiments.

The literature reviewed presents varied results, indicating that the effectiveness of interrow vegetation management is highly dependent on regional conditions such as climate, slope gradient and aspect, soil characteristics, and spontaneous vegetation.

7. Conclusions

The collected results show that the usage of grassy and herbaceous cover can modify the native vegetation in the interrows and influence the fauna in the vineyards. It should be noted that any change in the cultivation method has both advantages and disadvantages, such as the use of cover cropping in the interrows. Overall, vine growers have many options for cultivating their vineyards. Some recommendations suggest combined methods, which have been shown to produce the best outcomes for the vines and their immediate environment.

A combination of plant cover, such as covering the alleys with crops and also covering the intermediate surfaces with external organic amendments (e.g., compost) or crop residues (e.g., pruning debris), could be an effective method for carbon sequestration and biomass production [81]. Moreover, mowed crop residues covering the soil surface can reduce evaporative losses from the soil by 10–30% [85]. Adding legumes into the cover crop mix can reduce grasses’ nitrogen demand [45] and increase yield [46].

Furthermore, farmers need to choose the cover crop species wisely. Spontaneous cover crop vegetation should be prioritized, as this can ensure the greatest positive effects, such as pest control [103,122]. In addition, Shedonorus arundinaceus can effectively prevent soil erosion due to its high persistence and low growth rate, requiring fewer mowings [79]. A combination of leguminous cover crops is an effective alternative method to ensure soil nitrate availability for vines [64]. However, there are also drawbacks; for example, clover has been shown to enhance weed seedling growth, unlike grains such as rye and wheat [123].

During drier periods, low-intensity management and the use of cover crops are more effective in reducing water loss to deeper soil layers than high-intensity management [56]. However, tillage performed immediately before rainfall can temporarily improve soil water absorption by enhancing water infiltration and reducing runoff [53].

Of course, farmers need to adapt the above experiences to their own vineyard, as soil characteristics are also crucial, in addition to what has already been mentioned. This is particularly important in areas with poor, eroded, or shallow soils, where covering the entire interrow area could reduce the yield. In such cases, partial coverage (approximately 30%) can optimize both yield and ecosystem services [96]. Furthermore, the slope angle and its position can be more important than interrow management. Higher points in the interrows showed higher soil water content than the lowest points [124]. Magdić et al. [125] explained a similar effect due to the higher clay content.

Examining the issue of cover cropping reveals how it has evolved over the years. Earlier studies also showed its overall positive effects, just as is the case nowadays, but the question of water competition between the interrow crop and the vine was more prominent and discussed [126,127,128]. More recent studies have a more positive tone and highlight the positive effects of cover cropping on soil moisture, erosion, and yield [129]. The use of cover cropping in organic farming can also be of significant importance, particularly in cases where vinegrowers have limited available methods in plant protection and nutrient management. In such circumstances, leguminous species emerge as the optimal choice, given their capacity for vigorous weed competition and nitrogen production [130].

The cited sources indicate that cover crops can improve the composition and abundance of plant communities, the area’s water balance, the yield level, as well as several environmental and biological factors. However, their effectiveness depends on the species used and management practices.

It is recommended that research institutes and agricultural organizations formulate regional guidelines for cover crops, with the aim of assisting farmers in selecting the most suitable cover crop for the agroecological conditions of the area and their farming technology, thereby facilitating optimal solutions.