Local Nutrient Research Articles

Transhumance, shielings and soil fertility – land-use legacies in Menstrie Glen, Scotland

ABSTRACT Whilst transhumance has been researched as a livestock and land management system, its legacy on soil- nutrient levels is unknown. This study addresses changes in soil chemistry associated with historical transhumance grazing management with the aim of establishing if soil-nutrient levels can shed new insights into land-use legacies originating from past transhumance in Scotland. The study is focused on one aspect of transhumance, the shielings associated with milking livestock formerly operating in the uplands of the Scottish Midland Valley. A literature review is presented focusing on the history, functioning and geographic distribution of transhumance systems in Scotland set within a global context. This is followed by a detailed examination of two shieling sites in Menstrie Glen in the Ochil Hills. Their relationship to topography is considered, with vegetation survey and chemical analyses for plant macronutrients of soils collected in the vicinity also carried out. Underpinned by theories integrating biogeochemical fluxes and agropastoral activities it is established that there is moderate enrichment of local nutrient levels still evident at the Menstrie Glen shieling sites today. Review of historical and environmental sources suggests that local nutrient levels reflect temporal dynamics of shieling establishment, functioning and abandonment with limited evidence to suggest this was driven by population pressure and adaptation to Little Ice Age climate change. The analyses lead to insights about wider ecological impacts of different forms of land use in the face of climate change and population pressure, carrying implications for land use in Scotland and the challenges facing extant transhumance systems in countries where both these issues are pressing today.

Organ-specific responses during acclimation of mycorrhizal and non-mycorrhizal tomato plants to a mild water stress reveal differential local and systemic hormonal and nutritional adjustments

Main conclusionTomato plant acclimation to a mild water stress implied tissue-specific hormonal and nutrient adjustments, being the root one of the main modulators of this response.Phytohormones are key regulators of plant acclimation to water stress. However, it is not yet clear if these hormonal responses follow specific patterns depending on the plant tissue. In this study, we evaluated the organ-specific physiological and hormonal responses to a 14 day-long mild water stress in tomato plants (Solanum lycopersicum cv. Moneymaker) in the presence or absence of the arbuscular mycorrhizal fungus Rhizoglomus irregulare, a frequently used microorganism in agriculture. Several physiological, production, and nutritional parameters were evaluated throughout the experiments. Additionally, endogenous hormone levels in roots, leaves, and fruits at different developmental stages were quantified by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS). Water deficit drastically reduced shoot growth, while it did not affect fruit production. In contrast, fruit production was enhanced by mycorrhization regardless of the water treatment. The main tissue affected by water stress was the root system, where huge rearrangements in different nutrients and stress-related and growth hormones took place. Abscisic acid content increased in every tissue and fruit developmental stage, suggesting a systemic response to drought. On the other hand, jasmonate and cytokinin levels were generally reduced upon water stress, although this response was dependent on the tissue and the hormonal form. Finally, mycorrhization improved plant nutritional status content of certain macro and microelements, specially at the roots and ripe fruits, while it affected jasmonate response in the roots. Altogether, our results suggest a complex response to drought that consists in systemic and local combined hormonal and nutrient responses.

The riparian reactive interface: a climate-sensitive gatekeeper of global nutrient cycles

Riparian zones are critical interfaces to freshwater systems, acting as gateways for the conveyance and modification of macronutrient fluxes from land to rivers and oceans. In this paper, we propose that certain riparian conditions and processes (conceptually ‘Riparian Reactive Interfaces’) may be susceptible to environmental change with consequences of accelerating local nutrient cycling cascading to global impacts on the cycles of carbon (C), nitrogen (N), and phosphorus (P). However, we argue that this concept is insufficiently understood and that research has not yet established robust baseline data to predict and measure change at the key riparian ecosystem interface. We suggest one contributing factor as lack of interdisciplinary study of abiotic and biotic processes linking C, N, and P dynamics and another being emphasis on riparian ecology and restoration that limits frameworks for handling and scaling topography–soil–water–climate physical and biogeochemical observations from plot to large catchment scales. Scientific effort is required now to evaluate riparian current and future controls on global nutrient cycles through multi-nutrient (and controlling element) studies, grounded in landscape frameworks for dynamic riparian behaviour variation, facilitating scaling to catchment predictions.

Comparison of water use efficiency of sand-binding species along revegetation chronosequence in an alpine desert

Afforestation is an effective measure for ecological restoration in the desert ecosystem. The long-term water use efficiency (WUE) of leaves is an important indicator for evaluating the water adaptation strategy of sand-fixing species. However, the WUE of typical sand-fixing plants in the alpine desert and its responses to local climatic, micro-geomorphology, environmental conditions and nutrient limitations are still unclear. In this study, sand-fixing vegetation community along a revegetation chronosequence (Hippophae rhammoides planted on dunes in 1987, 2008, and 2015, respectively. H. rhammoides with the longest recovery period were defined as mature plantations, and the shortest recovery period were defined as juveniles.) at the alpine desert at the eastern shore of the Qinghai Lake were used as the research plots. Stable carbon isotope was used to evaluate species WUE. The results showed that: (1) the δ13C values of H. rhammoides showed a decreasing trend as plants grew. The seasonal δ13C variation was mainly affected by average relative humidity (MRH). (2) The δ13C in the dunes revegetated in 2008 and 2015 were significantly higher than that in 1987 at the windward slope (P < 0.05). The values of δ13C had various responses to the available soil water under the influence of topography, and soil water content was the key factor for the WUE of individuals in communities. There was a significant negative correlation between the ratio of carbon and nitrogen content in H. rhammoides leaves and WUE. The research indicated that mature plantations had adopted a more stable water use pattern than the juveniles, which provide an effective insight for ecological restoration in fragile ecological regions.

Challenges and opportunities for nutrient circularity: an innovation platform approach

AbstractTo reduce nutrient losses from the food system, it is necessary to improve biomass management and foster change. Such a change is often hindered by a lack of stakeholder interaction. Therefore, a qualitative case study and a practical application of the innovation platform approach in the Dutch-German border region Rhine-Waal were carried out to determine challenges and opportunities in the agro-food-waste system towards circular nutrient management in a nutrient-saturated and intensive animal production-dominated localized area. Twenty-one actors participated in a half-day workshop. A bottom-up approach was chosen as it increases trust between stakeholders and supports the acceptance of research processes. This study identified opportunities and challenges perceived by stakeholders participating in the innovation platform approach to facilitate a transition towards local circular nutrient management. We observed that challenges and opportunities exist at three levels: the individual actor’s level, the system level and the interconnection of the system with its wider environment. With a variety of stakeholders from animal and crop production to the food processing industry being present in the study area, the current demand and supply of biomass is very diverse. This diversity has been identified as a distinct opportunity for the establishment of a biomass exchange network in the area. However, information on demand and supply of nutrients between actors is currently scattered and information sharing hindered by the lack of direct monetary benefits. The lessons learned using the innovation platform approach are a first step towards improving nutrient circularity at a localized scale in nutrient-saturated areas.

Coupled biological and hydrological processes shape spatial food-web structures in riverine metacommunities

IntroductionUnderstanding how species are distributed in space and how they interact with each other is central for scientific and conservation purposes. Species' distributions and interactions result from a complex interplay of local trophic dynamics, dispersal processes, resource availability, and abiotic factors governed by the landscape matrix, which also determines the spatial connectivity for organisms' dispersal and resource fluxes. River networks not only exhibit universal spatial structures, but their dendritic landscape structure is tightly linked to species and metacommunity processes therein.MethodsHere, using a mechanistic model of spatially connected food webs integrating both essential biological and hydrological aspects, we investigate how food-web properties vary in space, and how these patterns are influenced by key model parameters. We then contrast our predictions with a suite of null models, where different aspects (such as spatial structure or trophic interactions) of the spatial food-web model are alternatively relaxed.ResultsWe find that species richness is highest in areas where local nutrient load is maximal (lowland headwaters, according to our default assumption). Overall, species richness is positively associated with link density, modularity and omnivory, and negatively related to connectance, nestedness, and niche overlap. However, for metrics such as connectance and omnivory, stochasticity of trophic interactions is a much stronger predictor than spatial variables such as distance to outlet and drainage area. Remarkably, relationships between species richness and food-web metrics do not generally hold in null models, and are hence the outcome of coupled biological and physical (i.e., hydrological) processes characteristic to river networks.DiscussionOur model generates realistic patterns of species richness and food-web properties, shows that no universal food-web patterns emerge as a result of the riverine landscape structure, and paves the way for future applications aimed at disentangling metacommunity dynamics in river networks.

Inclusive diets within planetary boundaries

Inclusive diets within planetary boundaries

The role of ecosystem services in the design of agroecological transitions in Spain

We can pursue a more resilient and sustainable future if both agriculture and the food system evolve driven by a new model based on agroecology. By applying ecological principles, agroecological farming adapts to local resources, closes biomass and nutrient cycles, and enhances soil biological activity, as well as soil conservation and regeneration. We explore new approaches based on the conceptualization of archetypes to identify which areas comply better with an agroecological transition that entails rebalancing of provisioning, regulating and cultural ecosystem services.In this spirit we apply map algebra to assess the improvement of ecosystem services in Spain guided by regional planning which is fully aware of the food chain and ensures resource management respectful of ecological processes.We put forward three major strategies: prioritize agricultural de-intensification policies in areas with both insufficient provisioning and poor regulating ecosystem services, (3,3 million ha); provide public support for an agroecological transition intertwined with the re-localization of food systems in peri-urban and rural areas well suited for provisioning ecosystem services, so as to reinforce their functions regarding soil retention and groundwater quality regulating services (13,6 million ha); and promote peri-urban areas with potential either as agroecological living labs or as ecological living labs, the latter corresponding to areas not suitable for food production adhering to ecosystem regeneration processes.

Rhizosphere engineering for sustainable crop production: entropy-based insights.

There is a growing interest in exploring interactions at root-soil interface in natural and agricultural ecosystems, but an entropy-based understanding of these dynamic rhizosphere processes is lacking. We have developed a new conceptual model of rhizosphere regulation by localized nutrient supply using thermodynamic entropy. Increased nutrient-use efficiency is achieved by rhizosphere management based on self-organization and minimized entropy via equilibrium attractors comprising (i) optimized root strategies for nutrient acquisition and (ii) improved information exchange related to root-soil-microbe interactions. The cascading effects through different hierarchical levels amplify the underlying processes in plant-soil system. We propose a strategy for manipulating rhizosphere dynamics and improving nutrient-use efficiency by localized nutrient supply with minimization of entropy to underpin sustainable food/feed/fiber production.

Using food residues (potato peels) as an alternative to potato dextrose agar in the growth of edible food fungi

Due to the great importance of edible fungi, their rapid life cycle, and the possibility of their production throughout the year, their cultivation has become a vital resource that many countries depend on in their pursuit of economic growth and food security. The present study aimed to devise a local nutrient media for primary mycelium growth of nine species of fungi belonging to Pleurotus eryngii , Pleurotus floridanus , Pleurotus ostreatus (white strain) , Agaricus heterocystis , Agaricus bispous (brown strain ), Agaricus bispous (white strain), Lentinula edodesstrain No. 1, Lentinula edodes strain No. 2, Flammulina velutipe (yellow strain) using culture mycelium inoculation for reproduction and production of edible fungi. Different natural materials used for this purpose involved potato peels in a concentration ranging from 5 to 20 g/ L and compared with the commercial medium Potato Dextrose Agar at a rate of 39 g/Land according to the manufacturer's instructions. The study also focused on the effect of physical factors such as temperature and pH on the growth rate of fungal mycelium. The results showed that the media prepared from potato peels at 5 g/L and 10 g/L concentrations achieved the best growth rate for the studied fungi compared to Peptone Dextrose Agar (PDA). The increase in the growth rate of fungi on media prepared from potato peels was attributed to the effect of nutrients for the prepared medium because it contained effective and necessary compounds for the growth in addition to their ease of absorption and consumption to be ready for food for agricultural fungi. The effect on the growth and production of edible fungi or any other type of fungi has not previously been studied and compared to the commercial medium PDA.

Long-term concentration of tropical forest nutrient hotspots is generated by a central-place apex predator

Apex predators typically affect the distribution of key soil and vegetation nutrients through the heterogeneous deposition of prey carcasses and excreta, leading to a nutrient concentration in a hotspot. The exact role of central-place foragers, such as tropical raptors, in nutrient deposition and cycling, is not yet known. We investigated whether harpy eagles (Harpia harpyja) in Amazonian Forests—a typically low soil fertility ecosystem—affect soil nutrient profiles and the phytochemistry around their nest-trees through cumulative deposition of prey carcasses and excreta. Nest-trees occurred at densities of 1.5–5.0/100 km2, and each nest received ~ 102.3 kg of undressed carcasses each year. Effects of nests were surprisingly negative over local soil nutrient profiles, with soils underneath nest-trees showing reductions in nutrients compared with controls. Conversely, canopy tree leaves around nests showed significant 99%, 154% and 50% increases in nitrogen, phosphorus and potassium, respectively. Harpy eagles have experienced a 41% decline in their range, and many raptor species are becoming locally extirpated. These are general examples of disruption in biogeochemical cycles and nutrient heterogeneity caused by population declines in a central-place apex predator. This form of carrion deposition is by no means an exception since several large raptors have similar habits.

Regional estimates of nitrogen budgets for agricultural systems in the East African Community over the last five decades.

The online version contains supplementary material available at 10.1007/s13593-023-00881-0.

Nitrogen fixation responds to soil nitrogen at low but not high light in two invasive understory species

Abstract Light and soil nitrogen availability can be strong controls of plant nitrogen (N) fixation, but data on how understory N‐fixing plants respond to these drivers are limited despite their important role in ecosystem N cycling. Furthermore, ecosystem N cycling can be altered by the introduction of species with nutrient use patterns that differ from natives. We assessed how N fixation of two exotic, understory species responded to varying light and soil N environments. We sampled leaf tissue from Mimosa pudica L., Desmodium triflorum (L.) DC., and a nonfixing reference plant (Axonopus) growing in control and two N fertilization treatments under either N‐fixing or non‐N‐fixing trees, which may alter local soil nutrient cycling, across a range of light conditions. We measured N fixation with 15N isotope dilution, and ensured that N‐fixing neighbour trees were in fact fixing N. All understory plants were wild‐growing species not native to the study location. Desmodium and Mimosa acquired 82.6% and 71.6% of their nitrogen from fixation (%Ndfa) in the control, compared to 66.8% and 58.1% in the +10 g N m−2 year−1 treatment and 73.1% and 64.7% in the +15 g N m−2 year−1 treatment. These subtle %Ndfa differences across fertilization treatments were more apparent at low light availability and disappeared at high light availability. The amount of N fixed by neighbouring trees did not influence %Ndfa in the understory species. Synthesis. Our study shows some differences in N fixation across different nutrient environments at low light for two N‐fixing species, though the changes were small, and both species derived most of their N from fixation. These findings imply that introduced N‐fixing species could exacerbate ecosystem N enrichment, particularly under high soil N conditions.

Phenotypic evolution of agricultural crops

Abstract Food crops are a vital source of nutrition for humans and domestic animals, with an estimated 4 billion metric tons of food produced per year. Crops do not only provide yields, but their traits also play a significant role in regulating the ecosystem processes of croplands, affecting local biotas, water balance, nutrient and carbon cycling. Domestication has led to significant changes in crop traits, making it important to understand the recent evolution of crops and how they differ from wild plants. In this paper I review the evidence on how the ecological traits of herbaceous crops have evolved during and after domestication. Loss of seed dispersal mechanisms, increased plant and organ sizes, high rates of consumption by herbivores and fast decomposition of residues by decomposer microbes in the soil, all have evolved independently in domestication processes of different crops. I also point out types of traits for which we have not identified common responses to domestication, be it because domestication processes of the different crop species are disparate, or because of lack of strong evidence. Those traits include resource acquisition rates of leaves and roots, and whole‐plant growth rates. Then, I discuss research gaps in the field, including how to advance knowledge for those traits that show apparently idiosyncratic responses to domestication. Finally, I emphasize the importance of understanding the interactions of crops with other organisms and the environment to breed crops that deliver yield and other services required from croplands. To this end, I introduce an ideotype for sustainable agriculture, which might inspire the breeding of multipurpose herbaceous crops, in the same way than the ideotypes of the Green Revolution inspired the breeding of elite varieties to foster yields under conventional agriculture. Read the free Plain Language Summary for this article on the Journal blog.

Annual biogeochemical cycling in intertidal sediments of a restored estuary reveals dependence of N, P, C and Si cycles to temperature and water column properties

Estuarine intertidal sediments are important centres for organic matter remineralization and nutrients recycling. Nevertheless, there is limited understanding regarding how these processes occur along the salinity gradient and their seasonality. Here, we report on the seasonal biogeochemical cycles from three types of intertidal sedimentary habitats (freshwater, brackish and marine) located in the Western Scheldt estuary (The Netherlands and Belgium). A full year of solute fluxes, porewater nutrient and sediment pigment concentrations at a monthly resolution revealed clear differences in the biogeochemistry of the three sites, indicating that environmental conditions determined the local nutrient dynamics. Temperature controlled sediment oxygen consumption rates and nutrient fluxes, but also affected pore water nutrient concentrations up to 14 cm deep. Fresh and brackish sediments had a net influx of dissolved inorganic nitrogen (DIN) (−1.62 mmol m−2 d−1 and -2.84 mmol m−2 d−1, respectively), while only the freshwater sediments showed a net influx of phosphate (−0.07 mmol m−2 d−1). We estimated that intertidal sediments remineralized a total of 10,000 t C y−1, with 97% of mineralization occurring in the brackish and marine parts. Overall, sediments removed 11% (1500 t N y−1) and 15% (∼200 t P y−1) of the total nitrogen and phosphorus entering the estuary from riverine input. Moreover, observations revealed the historical improvement of water quality resulting from water treatment policies. This spatiotemporal study of OM remineralization and early diagenesis in estuarine systems highlights the importance of intertidal sediments for estuarine systems. Our observations can be used in models to predict estuarine biogeochemistry or assess climate change scenarios.

Life Cycle Environmental Impact Assessment of Aquaculture Products in the Gaza Strip, Palestine

This study used the life cycle assessment (LCA) approach to evaluate the environmental impacts resulting from aquaculture ponds and associated activities. The assessment focused on eutrophication, acidification, global warming, energy use, and local nutrient emissions. Two farms, Fish Fresh and Al-Bahar, were analyzed to determine the contribution of different components in fish farming systems to various impact categories. Data on fish feed, onsite electricity, feed milling electricity, fuel intensity, water input, and fish production were meticulously collected through a comprehensive questionnaire and insightful interviews conducted over a one-year period in 2020. Furthermore, valuable information was diligently gathered regarding the nitrogen and phosphorus emissions in aquaculture ponds, with a focus on feed inputs. Environmental indicators were evaluated using a functional unit of 1 ton and 1 kg of live fish weight. Results reveled that global warming impacts varied between the two farms, with feed production being the primary contributor, accounting for 74.73% and 76.30% of total emissions, respectively. Acidifying emissions were mainly generated through fish production, accounting for 74.8% and 76.3% of the total for Fish Fresh and Al-Bahar farms, respectively. Eutrophication was primarily driven by fish production, while feed production and transportation operations also made noticeable contributions. The average emissions per kilogram of fresh fish were higher for the Fish Fresh farm compared to Al-Bahar in terms of global warming, acidification, and eutrophication. Energy consumption and water dependence also varied between the farms. These findings emphasize the importance of considering environmental impacts throughout the life cycle of fish farming in the Gaza Strip.

A natural extracellular matrix hydrogel through selective nutrient restriction for hyperinflammatory starvation therapy

<h2>Summary</h2> An adequate nutrient supply is essential for maintaining the function of highly active immune cells; however, in an environment of excessive inflammation, this nutrient supply aggravates inflammation. We propose a "hyperinflammatory starvation therapy" for various diseases caused by excessive metabolism by highly selective restriction of the supply of local nutrients. Here we developed a natural, physiologically triggered, injectable, nano-platelet vesicle-based extracellular matrix hydrogel (NPV-ECM). As a proof of concept, in representative excessive inflammatory disease diabetic wounds, we demonstrated that the NPV-ECM can selectively regulate nutrient transportation based on intermolecular interactions, remodel the local immune microenvironment, limit the state of excess metabolism, promote angiogenesis, and achieve wound healing. Moving into the clinic, we conducted a clinical trial in patients with diabetic foot ulcers to verify the safety and therapeutic effect of the NPV-ECM. This study provides an understanding of the preparation and application of natural ECM biomaterials for hyperinflammatory starvation therapy.

Metabolic determinants of tumour initiation.

Tumours exhibit notable metabolic alterations compared with their corresponding normal tissue counterparts. These metabolic alterations can support anabolic growth, enable survival in hostile environments and regulate gene expression programmes that promote malignant progression. Whether these metabolic changes are selected for during malignant transformation or can themselves be drivers of tumour initiation is unclear. However, intriguingly, many of the major bottlenecks for tumour initiation - control of cell fate, survival and proliferation - are all amenable to metabolic regulation. In this article, we review evidence demonstrating a critical role for metabolic pathways in processes that support the earliest stages of tumour development. We discuss how cell-intrinsic factors, such as the cell of origin or transforming oncogene, and cell-extrinsic factors, such as local nutrient availability, promote or restrain tumour initiation. Deeper insight into how metabolic pathways control tumour initiation will improve our ability to design metabolic interventions to limit tumour incidence.

Photosynthetic characteristics, soil nutrients, and their interspecific competitions in an apple–soybean alley cropping system subjected to different drip fertilizer regimes on the Loess Plateau, China

Imprecise irrigation hinders the sustainable development of the fruit tree–crop intercropping system in the Loess Gully Area of China. Drip fertigation was applied for two years as part of an apple–soybean intercropping system to optimize local water and nutrient management patterns. The effects of different drip irrigation and fertilizer levels on photosynthetic characteristics, soil nutrients, and their interspecific competitions were studied. The treatments were four irrigation levels, namely 60% (W1), 70% (W2), 80% (W3), and 90% (W4) of field capacity (Fc), and three nitrogen fertilization levels, namely 59 (F1), 92 (F2), and 124 kg∙ha–1 (F3). The control (CK) was a rain-fed (neither irrigation nor fertilizer) crop. The net photosynthetic rate (Pn), transpiration rate (Tr), and soybean yield (GY) increased at first, but then decreased as irrigation and fertilizer application levels rose. The partial factor productivity (PFP) decreased as fertilization increased, but the soil available nitrogen content showed the opposite trend. The soil nutrients, and soybean Pn and Tr were positively correlated with distance from the apple tree row. The interspecific competition intensity for light and soil water decreased from 2018 to 2019, while root and soil nitrate nitrogen (NN) increased. The interspecific competition correlation between the aboveground and belowground parts was weak and varied between the two intercropping years. A principal component analysis showed that treatment W3F2 had the highest comprehensive score. Thus, a combination of irrigation at 80% Fc and 92 kg∙ha–1 nitrogen fertilizer application is optimal for the system. A multiple regression analysis indicated a water input range of 4624.49–4795.75 m3·ha−1·a−1 combined with 84.10–107.27 kg·ha−1·a−1 fertilizer application was suitable for optimal irrigation and fertilization management based on the integrated benefits to root length density, GY, Pn, and PFP during the first 4–5 years of the intercropping system.

Local Factors Impact Accuracy of Garlic Tissue Test Diagnosis

The low productivity of garlic in Brazil requires more efficient nutritional management. For this, environmental and fertilization-related factors must be adjusted to a set of local conditions. Our objective was to provide an accurate diagnosis of the nutrient status of garlic crops in southern Brazil. The dataset comprised 1024 observations, 962 as field tests conducted during the 2015–2017 period to train the model, and 61 field observations collected during the 2018–2019 period to validate the model. Machine learning models (MLM) related garlic yield to managerial, edaphic, plant, and climatic features. Compositional data analysis (CoDa) methods allowed classification of nutrients in the order of limitation to yield where MLM detected nutrient imbalance. Tissue analysis alone returned an accuracy of 0.750 in regression and 0.891 in classification about the yield cutoff of 11 ton ha−1. Adding all features documented in the dataset, accuracy reached 0.855 in regression and 0.912 in classification. Local diagnosis based on MLM and CoDa and accounting for local features differed from regional diagnosis across features. Local nutrient diagnosis may differ from regional diagnosis because several yield-impacting factors are taken into account and benchmark compositions are representative of local conditions.