Modern Agroecosystems Research Articles

TEHNOLOGII ȘI SOLUȚII CONSTRUCTIVE PRIVIND MANAGEMENTUL INTERVALULUI DINTRE RÂNDURILE DE VIȚĂ DE VIE ȘI POMI FRUCTIFERI

The management of inter-row space of vineyards and fruit trees has emerged as an essential approach in sustainable agriculture, optimizing resource use and improving ecosystem services. This paper reviews a range of innovative technologies and solutions aimed at revolutionizing line management practices. Modern sensing and monitoring systems provide real-time data on soil moisture, nutrient levels, and plant health, facilitating precision row-to-row management. Furthermore, techniques for grassing the space between rows of vines and fruit trees are important for space management, ensuring good air circulation and facilitating agricultural activities such as maintenance and harvesting. In addition, the advent of inter-row seeding machines simplified the implementation of cover crops. These machines use advanced seed delivery mechanisms, precisely distributing the cover seed into the spaces between the rows. This not only encourages soil health and erosion prevention but also mitigates weed competition, increasing the overall resilience of the agroecosystem. The purpose of this review is to discuss the combination of state-of-the-art technologies such as 3D LIDAR technology, intelligent systems used for inter-row management of vines and fruit trees, and inter-row solar panel systems, all these examples have revolutionized inter-row management in vineyards and orchards. This holistic approach optimizes resource allocation, improves soil health, and encourages sustainable agricultural practices, paving the way for greener and more resilient inter-row spaces in modern agroecosystems.

No evidence for competition over floral resources between winter-active parasitoids and pollinators in agroecosystems

Warming temperate winters are resulting in increased insect winter activity. With modern agroecosystems largely homogenous, characterised by low floral diversity, competitive interactions may arise between flower-visiting species, with potential implications for the ecosystem services they provide (e.g. biological control and pollination). Flower strips may be implemented during winter months to support flower-visiting insects and enhance ecosystem service provision. Employing field trials conducted in Brittany, France between 2019 and 2021 and laboratory cage experiments, the current study examined the impact of winter flower strips on aphid biological control performed by parasitoid wasps and the potential for competitive interactions between winter-active parasitoids and pollinators. Results revealed that parasitism rate was not enhanced by the presence of winter flower strips. This lack of effect was not the consequence of pollinator presence, and the current study found no effect of pollinator abundance on parasitism rate. Flower strips may thus be implemented during winter months to support nectar-feeding insects when floral resources are scarce, with no evidence of exploitative competition between pollinators and parasitoids, nor a detrimental impact on biological control provision.

Interaction networks reveal highly antagonistic endophytic bacteria in native maize seeds from traditional milpa agroecosystems.

Milpas are traditional Mesoamerican agroecosystems maintained with ancestral practices. Maize landraces are grown in polyculture, creating highly productive and diverse ecosystems. Recent studies suggest that milpas maintain beneficial plant-microbe interactions that are probably absent in modern agroecosystems; however, direct comparisons of the microbiome of plants between traditional and modern agroecosystems are still needed. Here, we studied seed-endophytic bacterial communities from native maize landraces from milpas and hybrid varieties. First, we quantified the abundance of culturable endophytic microbes; next, we assessed pairwise antagonistic interaction networks between bacterial isolates; finally, we compared bacterial community structure by 16S rRNA amplicon sequencing. We found that seeds from native maize landraces harbour a higher endophytic microbial load, including more bacterial strains with antagonistic activity against soil-borne bacteria, and overall harbour more diverse bacterial communities than the hybrid varieties. Noteworthy, most of the seed-endophytic strains with antagonistic activity corresponded to Burkholderia spp. that were only found in native maize seeds, through both culture-dependent and independent strategies. Altogether, our results support that crop modernization alters the functions and structure of plant-associated microbes; we propose native maize from milpas could serve as a model for understanding plant-microbe interactions and the effect of modernization.

Ecological Risks of Using Nitrogen Fertilizers

The article shows that the mass use of industrial nitrogen fertilizers has doubled the nitrogen flows in its global biogeochemical cycle, while transforming it into an agrogeochemical one, with many environmental consequences. Th e article discusses the ecological risks associated with the use of nitrogen fertilizers, such as the accumulation of nitrates in groundwater, vegetable products, in the atmosphere. It is shown that it is necessary to reduce nitrogen losses during the cultivation of agricultural crops, while ensuring its suffi cient resources to ensure food security. Methods of ecological risk management in modern agroecosystems are proposed.

Partitioning of arthropod species diversity in temperate meadows, wildflower areas and pastures

To counteract the rapidly ongoing species decline in modern agroecosystems, most European countries have developed and adopted agri-environment schemes. The efficiency of these schemes, however, ranges from successful to nearly ineffective. To estimate the efficiency of the Swiss agri-environment scheme in particular, we investigated the contribution of extensively managed pastures and meadows and wildflower areas to beetle, heteropteran bug and spider diversity. Extensively managed meadows were shown to contribute most to landscape-scale richness (highest species richness for beetles and bugs), followed by wildflower areas (bugs). Meadows harboured approximately twice as many beetle species unique to this habitat type than wildflower areas and pastures. Bug species unique to a specific habitat type were similar between meadows and wildflower areas, but much lower (approximately 30%) in pastures. To increase beetle species richness, extensively managed meadows should be represented more often in the landscape because meadows harboured the highest number of species and most uniquely found species. To increase species richness of true bugs, both meadows and wildflower areas should be represented more often in the landscape because they harboured more species and more uniquely found species compared to pastures. Across arthropod taxa and habitat types, β diversity was more important for γ diversity than α diversity, indicating that distinctiveness, rather than within-site diversity, was key in determining the contribution of sites to γ (landscape) diversity. This substantiates the argument that increasing the number of sites is efficient to increase landscape species richness. The turnover component of β diversity was far more important than the nestedness component for all arthropod taxa and habitat types and accounted for 79.0% to 95.4% of total β diversity. In conclusion, extensively managed meadows and wildflower areas should be particularly promoted by the Swiss agri-environment scheme, as they contributed more to landscape species richness and species uniqueness than pastures.

Spatial configuration and landscape context of wildflower areas determine their benefits to pollinator α- and β-diversity

Wildflower areas have become a staple tool within agro-environmental schemes (AES) to counteract pollinator declines. While their role in providing food resources to resident flower-visiting insects is unambiguous, the conservation effectiveness in a landscape context is less clear. Particularly, how multiple vs. single wildflower area utilization differs between simple and complex landscapes is understudied. We examined colonisation and community dynamics of wild bees and hoverflies in 33 newly established wildflower areas across a gradient of landscape complexity (amount of semi-natural habitat) and connectivity (presence of additional wildflower areas) for seven weeks during three consecutive years (one year during and two after establishment). We recorded more than 25% of the wild bee and hoverfly species of Hesse in an area of approx. 10 ha, substantiating the general benefit of wildflower areas to pollinators. While alpha-diversity increased with landscape complexity in isolated wildflower areas, the opposite pattern was observed for connected areas. The low alpha-diversity in complex landscapes indicated a dilution effect between connected sites. The inverse relationship between alpha and beta diversity among wildflower areas within landscapes suggests interspecific trade-offs between local resource conditions and landscape context. Accordingly, the establishment of multiple wildflower areas within AES is advisable to increase connectivity of suitable habitats in simple landscapes. Moreover, adjusting local conditions (plant diversity) to landscape context likely optimizes conservation effectiveness in modern agroecosystems.

Do trends in Bangladeshi rice yields support Conway’s hypotheses about the consequences of modern agroecosystems?

Gordon Conway postulated that in comparison to traditional agroecosystems, crop yields from modern agroecosystems are: (1) higher; (2) less sustainable; and (3) more variable, particularly in the early adoption stages. The existing literature predates more recent developments and does not employ long-term time series data to identify time phases using any econometric tests for structural breaks. This paper fills this gap by investigating the applicability of Conway’s hypotheses to Bangladeshi rice yields over sixty years examining trends, their sustainability, and their variability. We find mixed support for Conway’s hypotheses. Rice yields rose substantially following the Green Revolution. Overall, higher yields have been sustained. However, they have now virtually plateaued, and various factors (including environmental and ecological) have increased the risk of these yields becoming unsustainable. Until recently, absolute variations in Bangladesh’s rice yields were found to be higher than before the Green Revolution. This supports Conway’s third hypothesis. However, the relative variability of Bangladesh’s rice yields has consistently fallen since the Green Revolution. We highlight the trio of general factors determining rice yields and underscored the need for holistic analysis. Non-economists often overlook economic factors while economists often do not pay adequate attention to eco-environmental factors.

Benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on landscape structural complexity

Wildflower areas are a popular agri-environment scheme to counteract the biodiversity loss in agro-ecosystems. While benefits for flower-visiting and predatory insects during the vegetation period were frequently shown, few studies addressed the suitability of wildflower areas as overwintering habitats. Here, we studied the significance of wildflower areas as overwintering habitats and whether their benefits vary with landscape context, i.e. the proportions of permanent semi-natural habitats such as hedges. We selected ten landscapes that encompassed independent gradients of proportions of permanent semi-natural habitats (e.g. hedgerows, ditches) and transient wildflower areas. The centres of the landscapes were pairs of wildflower areas and arable fields on which we sampled overwintering ground-dwelling arthropods by emergence traps. In total, we recorded 2838 overwintering individuals from 115 species of rove and carabid beetles as well as spiders. Abundance of rove beetle larvae, as well as species richness of adult rove beetles and spiders was significantly higher in wildflower areas than in arable fields. With respect to landscape context, abundance and species richness of adult rove beetles showed a hump-shaped relationship with the proportion of permanent semi-natural habitats. The abundance of adult carabid beetles showed a hump-shaped relationship with the proportion of transient wildflower areas, while the abundance of carabid beetle larvae showed a hump-shaped pattern with permanent semi-natural habitats. For the first time we showed that, similar to the vegetation period, benefits of wildflower areas as overwintering habitats for ground-dwelling arthropods depend on both local habitat characteristics as well as landscape context. Benefits of wildflower areas for overwintering were highest in simple landscapes with an intermediate proportion of either permanent semi-natural habitats or transient wildflower areas. Our results suggest that in order to sustainably maintain the functional guild of ground-dwelling arthropods, agricultural landscapes should provide both sown wildflower areas and permanent semi-natural habitats. Our results also support the general claim that semi-natural habitats should at least contribute 10–15% to agricultural landscapes in order to maintain the characteristic biodiversity in modern agro-ecosystems.

Insecticide exposure affects intergenerational patterns of DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata.

Insecticide use is pervasive as a selective force in modern agroecosystems. Insect herbivores exposed to these insecticides have been able to rapidly evolve resistance to them, but how they are able to do so is poorly understood. One possible but largely unexplored explanation is that exposure to sublethal doses of insecticides may alter epigenetic patterns that are heritable. For instance, epigenetic mechanisms, such as DNA methylation that modifies gene expression without changing the underlying genetic code, may facilitate the emergence of resistant phenotypes in complex ways. We assessed the effects of sublethal insecticide exposure, with the neonicotinoid imidacloprid, on DNA methylation in the Colorado potato beetle, Leptinotarsa decemlineata, examining both global changes in DNA methylation and specific changes found within genes and transposable elements. We found that exposure to insecticide led to decreases in global DNA methylation for parent and F2 generations and that many of the sites of changes in methylation are found within genes associated with insecticide resistance, such as cytochrome P450s, or within transposable elements. Exposure to sublethal doses of insecticide caused heritable changes in DNA methylation in an agricultural insect herbivore. Therefore, epigenetics may play a role in insecticide resistance, highlighting a fundamental mechanism of evolution while informing how we might better coexist with insect species in agroecosystems.

Distribution of adventive species Solidago canadensis, Phalacroloma annuum, Ambrosia artemisiifolia, Heracleum sosnowskyi in phytocenoses of Volyn’ Polissya (Ukraine)

Biological pollution of natural phytocenoses by adventive plant species poses is a serious threat to endemic species and species with narrower ecological amplitude in ecosystems around the world. This study presents the results of a study of the composition and distribution of adventive plant species in natural, semi-natural and anthropogenic transformed phytocenoses of Volyn’ Polissya, Ukraine. To clarify the effect of drainage melioration on non-native flora species distribution, a botanical study was carried out during the 2003–2019 vegetation seasons on the territory of four drainage systems. The adventive flora of this unique region of Europe was studied in detail for the first time. In total, 279 non-native plant species were found. They belong to 110 genera and 32 families. The results of studying the systematic, bioecological, range-distributional and phytogenetic structure of adventive species found within agricultural lands and adjacent territories are presented. It was found that 161 species are associated with agricultural production. Of these, 90 species were found directly within the agricultural land, another 71 species were found growing in the adjacent territories. It was found that a significant increase in the number of adventive species on the territory of Volyn’ Polissya is associated with drainage melioration carried out in the 1960–1990s, significant changes in the structure and forms of agro-industrial production, and climatic changes in recent decades. The expansion of agricultural land in this area over the past 50–60 years has led to an increase in the number of adventive species by more than 60%. On the territory of drainage systems used for agricultural activities, more than 40% of the total species composition of the adventive flora of Volyn’ Polissya is represented. The majority of these species originate from arid and sub arid regions of the planet. The transformer plants, Solidago canadensis L. and Phalacroloma annuum (L.) Dumort pose a potential threat to phytocenoses of the described region, as well as the whole of Europe. Of particular interest are the species that in the future may pose a serious threat to natural phyto-diversity and have negative practical consequences for the structure of agricultural landscapes. These are Ambrosia artemisiifolia L. and Heracleum sosnowskyi Manden. In general, modern agro ecosystems are characterized by instability and low ability to resist non-native species. The strongly weedy character of cultivated fields and the presence of abandoned uncultivated lands have caused the rapid spread of adventive vegetation. In order to further optimize the structure of agrolandscapes, it is advisable to monitor and regulate not only expansionary invasive species, which is especially important for preventing biological pollution, but also species whose status has not yet been determined.

A ley-farming system for marginal lands based upon a self-regenerating perennial pasture legume

Annual-based farming systems represent some of the most highly disturbed terrestrial ecosystems on the planet. They are also highly exposed to climate variability. Many wheatbelt systems of southern Australia rotate annual crops with annual pastures, where the productivity of both is reliant upon seasonal rainfall. Perennial plants, in contrast, are less reliant upon both consistent rainfall and annual establishment, so one approach to decrease exposure to climate variability and disturbance in agriculture is to increase the proportion of the farm sown to perennial species. Perennial pasture or forage species offer immediate possibilities for transformation of agricultural ecosystems as they offer high protein feed to animals, often when green feed is most limiting, and concomitantly restore soil fertility. However, there are no perennial forage legumes adapted to acid and infertile soils in low-rainfall regions of the developed world, either in temperate or Mediterranean climates. Here, we review the recent research efforts to domesticate a perennial legume for these regions. Reasons for the lack of success are provided by a comparison of the attributes of the legumes evaluated in recent research programs and the limitations of these legumes as assessed by reviews and publications. This manuscript outlines an alternative approach to domestication of perennial forage legumes for acid soils and introduces new concepts in ley farming in an Australian context that might support the development of more sustainable agro-ecosystems. It highlights situations where very hard-seeded annual legumes have been successfully included in modern intensive cropping systems, and where perennial legumes may underpin ley-farming systems on infertile soils that normally produce low crop yields. Both innovations require the legume and their nodule bacteria to be sown only once in decades and address concerns about the sustainability of modern agro-ecosystems.

Soil as a Biological System and Its New Category—Health

It is proposed that soil should be considered a biological system with the following notions: “soil ecosystem” or “ecosystem of soil.” A new, integral characteristic of the soil ecosystem—soil health—is addressed. Parameters and methods essential to define soil health and characterize this new category are provided. Natural soil ecosystems and agroecosystems are discussed and compared. Conventional and organic land use systems are addressed in relation to agroecosystems. The need to determine and assess the health of soil ecosystems with respect to the land-use type is highlighted. Activities and methods required to preserve and protect the health of soil ecosystems, the significance of “activity suppression” in soil ecosystems, and means to diagnose soil health and to use therapy in modern agroecosystems are discussed.

SOLATINA: A Latin-American Society for Bee Research to Foster the Interactions Between Scientists and Coordinate Large-Scale Research Programs

Bees (members of the super family Apoidea) are the main pollinators in modern agro-ecosystems, where they have a critical positive effect on yield improvement for about 75% of world's crops (Klein ...

Soil microbiome of cultural plants under different agrotechnologies

The results of research of soil microbiome of plants: Capsicum annuum, Vitis vinifera, Rubus idaeus L., Petroselinum crispum cultivated in open and closed ground are presented. The biological activity of the soil under the condition of using different agrotechnologies is investigated. The taxonomic structure of microbial community has been determined by biochemical markers. The screening of conditionally pathogenic and pathogenic microorganisms of soil microbiome that have multiple antibiotic resistances is performed. It is established that modern agroecosystems are the source of the spread of pathogenic and opportunistic antibiotic resistant microorganisms. In total, 64 isolates were selected and tested. Antibiotic resistance anaerobic microbiota were isolated from the closed ground where raspberry was cultivated: Clostridium perfringens (resistant to erythromycin, clindamycin, tetracycline, rifampicin, amoxicillin, moderately sensitive to metronidazole and vancomycin sensitive), Clostridium oedematiens (moderately susceptible to amoxicillin and vancomycin), Clostridium difficile (only sensitive to metranidazole). A significant number of aerobic microorganisms with multiple antibiotic resistances were isolated from the closed ground where raspberry is cultivated: Enterobacter cloacae, Enterococcus faecalis, Hafnia alvei, Bacillus megaterium, Bacillus mycoides, and Pseudomonas aeruginosa. The following bacteria were isolated from the agroecosystem of parsley: Bacillus mycoides, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Salmonella enterica, Enterococcus faecalis. It has been established that the most spread antibiotic resistant aerobic and anaerobic microbiota in closed ground agroecosystems of raspberry and parsley. Consequently, agroecosystems are the source of the spread of pathogenic and opportunistic microorganisms with multiple antibiotic resistance and endangering human health.

Prospects for the inter-branch optimization of modern agroecosystems

The article substantiates the necessity of increasing soil fertility as the basis of an ecologically sustainable agrarian system. Based on the results of stationary experiments and theoretical studies, the efficiency factors of photosynthetically active radiation for different soil-climatic conditions are presented. Theoretical studies were carried out based on the results of stationary experiments of scientific and research institutions of the National Academy of Agrarian Sciences, laid down in different soil and climatic conditions with the aim of determining the doses of traditional and alternative organic and mineral fertilizers that ensure the reproduction of soil fertility and high productivity of crops. Among the problems of managing agrarian production systems, the special attention is paid to the lack of integrated production development plans. The stages of solving this problem are proposed on the basis of optimizing the ratio of crop and live-stock sectors using the information-analytical system. The possibilities for improving land use applying the «AIS.AGRO» complex are demonstrated using the example of an agricultural enterprise located in the northern part of the Poltava region. The structure of the agrolandscape and land use there is typical for the left-bank Forest-Steppe of Ukraine. The dominant soil is typical low-humus black soil with mean content of available phosphorus and potassium. Three variants of a business model, namely retrospective, modern and perspective (productivity of crop production at the level of 50 hundredweight fodder units per hectare, livestock - 1 basic cattle unit per hectare) were simulated. The increase in the total productivity of one hectare up to 52.9 hundredweight fodder units per hectare in the perspective model compared with the current model (32.3 hundredweight fodder units per hectare) is shown. At the same time, the need for mineral fertilizers to achieve a deficit-free balance of nutrients only increases by 8.6%. That is due to the increase in recirculation of nutrients from 51 to 60%, as well as the increase in the use of biological nitrogen from 23 to 65 kg per 1 hectare of arable land

Global climate changes and conceptual foundations of sustainable development of agroecosystems

The risks of degradation processes and adaptive measures to mitigate their impact on the agroecosystems productivity were considered. The basic principles of agroecosystems sustainable development in Ukraine, where the nature acquired the typical characteristics of the built environment, were justified. Their implementation will provide not only the stability of agricultural production sector, but also the optimal conditions for the entire biodiversity. Basic principles of plant cultivation of the adaptive agroecosystems for natural resources conservation and energy costs were given. The measures for transformation of modern agroecosystems in adaptive, sustainable and stable ones were analyzed. The main autecological strategy of exogenous induction the plant adaptive responses under adverse factors influence of the transformed environment were allocated. Physiological and biochemical changes that determine plant resistance to the oxide stress effect are the objective tests for early diagnosis of stability of created forms and varieties, their selection in the laboratory conditions and for biochemical monitoring of transformed agrocenoses. Ecologically safe and effective me thods of the adaptive capacity of plants regulation in a complex influence of climatic factors conditions were proposed. The results of the use of a hydrogen peroxide at physiological concentrations solution (1·10–6–1·10–2 М) to protect the winter wheat plants in the field of steppe and forest-steppe ecotypes were shown. The hydrogen peroxide treatment of plants had a positive effect on the 1000 grains weight and increased the yield by 15–18%. It was shown that the use of hydrogen peroxide by the scheme contributed to activation of endogenous defense mechanisms, optimization of metabolic processes of winter wheat plants under conditions that are actually formed during ontogeny.

Soil health-ecosystem health: From problem identification to diagnosis and treatment

The need for the general use of the category 'soil ecosystem' (SE) as objectively more comprehensive and more specific than the laconic term 'soil' is discussed and supported by arguments. Agroecosystem soils in organic and intensive farming are compared. Soil health (SH) as a new, basic property of SE is commented upon. Methods for determining SH and its characteristic parameters are specified. The need to assess the health of SEs depending on their type and utilization is emphasized. The topics covered include soil health maintenance and protection options, natural and induced suppressiveness of SEs, and potential routes to diagnosis and treatment of soils in modern agroecosystems.

Energy Balance in Modern Agroecosystems; Why and How?

Energy Balance in Modern Agroecosystems; Why and How?

Agroecology: Principles for the Conversion and Redesign of Farming Systems

Modern agroecosystems require systemic change, but new redesigned farming systems will not emerge from simply implementing a set of practices (rotations, composting, cover cropping, etc.) but rather from the application of already well defined agroecological principles. These principles can be applied using various practices and strategies, each having different effects on productivity, stability and resiliency of the target farming system. By breaking the monoculture nature of farming systems, agroecological diversification aims at mimicking ecological processes leading to optimal nutrient cycling and organic matter turnover, soil biological activation, closed energy flows, water and soil conservation and balanced pest-natural enemy populations. All these processes are key maintaining the agroecosystem’s health, productivity and its self-sustaining capacity. By enhancing functional biodiversity, a major goal of the conversion process is achieved: strengthening the weak ecological functions in the agroecosystem, allowing farmers to gradually eliminate inputs altogether by relying instead on ecological processes and interactions.

Developing smarter host mixtures to control plant disease

Adaptation of plant pathogens to disease control measures (both chemical and genetic) is facilitated by the genetic uniformity underlying modern agroecosystems. One path to sustainable disease control lies in increasing genetic diversity at the field scale by using genetically diverse host mixtures. In this study, a robust population dynamics approach was used to model how host mixtures could improve disease control. It was found that when pathogens exhibit host specialization, the overall disease severity decreases with the number of components in the mixture; this finding makes it possible to determine an optimal number of components to use. In a simple case, where two host varieties are exposed to two host‐specialized pathogen species or strains, quantitative criteria for optimal mixing ratios are determined. Using these model outcomes, ways to optimize the use of host mixtures to decrease disease in agroecosystems are proposed.