Distribution Of Nutrients Research Articles

The Impact of Canopy on Nutrient Fluxes through Rainfall Partitioning in a Mixed Broadleaf and Coniferous Forest

Rainfall constitutes the primary input in the nutrient flux within forest ecosystems. The forest canopy modulates this flux by partitioning rainfall and selectively absorbing or adding nutrients. In mixed forests, variation in tree species composition regulates rainwater chemical composition, potentially leading to spatial heterogeneity in nutrient distribution and influencing nutrient cycling processes. This study examined the partitioning of rainfall into throughfall and stemflow, as well as their associated nutrient concentrations and fluxes, in a mixed broadleaf and coniferous forest on Changbai Mountain in Northeast China. We observed a rising trend in nutrient contents from rainfall to throughfall and then stemflow. The nutrient contents of stemflow varied largely with tree species due to the differences in canopy structure and bark morphological characteristics. The nutrient input contributed by throughfall and stemflow was 92.30 kg ha−1 during the observation period, and most elements underwent passive leaching through washout except for F− and Na+. We note that the nutrient fluxes in stemflow differed among tree species, with Pinus koraiensis (PK) delivering more acid group anions and Quercus mongolica (QM) providing more cations. Our research provides new insights into nutrient cycling within mixed forest canopies, sparking a transformative advancement in forest management and protection strategies through hydrochemistry-driven solutions.

Vertical and Horizontal Variability of Chlorophyll-a and Its Relationship with Environmental Parameters in the Waters of Sangihe and Talaud Islands, North Sulawesi, Indonesia

The chlorophyll-a is an important biological parameter that could act as a proxy to indicate the abundance of phytoplankton and the primary productivity of an aquatic ecosystem. This paper investigates the vertical and horizontal variability of chlorophyll-a in the waters of Sangihe and Talaud Islands, Indonesia, and its correlation with water environmental parameters. In this study, the distribution of chlorophyll-a, temperature, salinity, and nutrients (NO3 and PO4) from the surface to a depth of 200 m (photic zone) was measured at 29 research stations. The results showed that the distribution of chlorophyll-a in the waters of the Sangihe-Talaud Islands was varied vertically and horizontally. The waters around the Sangihe Islands generally exhibited a higher chlorophyll-a distribution and shallower Deep Chlorophyll Maxima compared to the water around the Talaud Islands. The concentration of chlorophyll-a varied between 0.0017 and 1.2155 mg.m-3, with most of the water column in Sangihe-Talaud considered oligotrophic, although some stations or depths were mesotrophic or slightly eutrophic. The maximum chlorophyll-a concentration was found in the sub-surface layer at depths between 46 and 101 m. The low N:P ratio (<16) and N:Si ratio (<1) indicate that the water columns of Sangihe-Talaud, up to a depth of 200m, were N-limited. Based on the GAM analysis, chlorophyll-a concentration in Sangihe-Talaud waters was primarily regulated by temperature, salinity, and the N:P ratio, with weak influence from phosphate and the N:Si ratio. The analysis also suggests that primary productivity in Sangihe-Talaud is sensitive to temperature changes, indicating its vulnerability to future warming events.

Common mycorrhizal network: the predominant socialist and capitalist responses of possible plant-plant and plant-microbe interactions for sustainable agriculture.

Plants engage in a variety of interactions, including sharing nutrients through common mycorrhizal networks (CMNs), which are facilitated by arbuscular mycorrhizal fungi (AMF). These networks can promote the establishment, growth, and distribution of limited nutrients that are important for plant growth, which in turn benefits the entire network of plants. Interactions between plants and microbes in the rhizosphere are complex and can either be socialist or capitalist in nature, and the knowledge of these interactions is equally important for the progress of sustainable agricultural practice. In the socialist network, resources are distributed more evenly, providing benefits for all connected plants, such as symbiosis. For example, direct or indirect transfer of nutrients to plants, direct stimulation of growth through phytohormones, antagonism toward pathogenic microorganisms, and mitigation of stresses. For the capitalist network, AMF would be privately controlled for the profit of certain groups of plants, hence increasing competition between connected plants. Such plant interactions invading by microbes act as saprophytic and cause necrotrophy in the colonizing plants. In the first case, an excess of the nutritional resources may be donated to the receiver plants by direct transfer. In the second case, an unequal distribution of resources occurs, which certainly favor individual groups and increases competition between interactions. This largely depends on which of these responses is predominant ("socialist" or "capitalist") at the moment plants are connected. Therefore, some plant species might benefit from CMNs more than others, depending on the fungal species and plant species involved in the association. Nevertheless, benefits and disadvantages from the interactions between the connected plants are hard to distinguish in nature once most of the plants are colonized simultaneously by multiple fungal species, each with its own cost-benefits. Classifying plant-microbe interactions based on their habitat specificity, such as their presence on leaf surfaces (phyllospheric), within plant tissues (endophytic), on root surfaces (rhizospheric), or as surface-dwelling organisms (epiphytic), helps to highlight the dense and intricate connections between plants and microbes that occur both above and below ground. In these complex relationships, microbes often engage in mutualistic interactions where both parties derive mutual benefits, exemplifying the socialistic or capitalistic nature of these interactions. This review discusses the ubiquity, functioning, and management interventions of different types of plant-plant and plant-microbe interactions in CMNs, and how they promote plant growth and address environmental challenges for sustainable agriculture.

Hydrochar fractionation and composition in batch and continuous hydrothermal liquefaction

Understanding differences in hydrochar characteristics in batch and continuous hydrothermal liquefaction (HTL) is crucial in determining suitable valorisation routes for this byproduct, given its high nutrient load and carbon sequestration potential.This study thoroughly characterised hydrochar from batch and continuous HTL at 300, 325 and 350 °C, elucidating their main differences and shedding light on the operational parameters causing them. For this purpose, a bench-scale continuous HTL unit with in-line solids separation was commissioned. It was possible to differentiate primary and secondary char and infer their formation mechanism.The results showed that batch hydrochar yields were higher (24–26%) than continuous (primary and secondary) char yields (15–19%). In both reactions, higher temperatures led to chars with lower carbon and nitrogen contents. The ash content of batch hydrochars was lower than that of continuous primary chars, revealing that the in-line char separator effectively removed inorganic impurities at reaction conditions and produced a cleaner biocrude. The nutrient distribution in the HTL products showed batch biocrudes were more contaminated by Na, K and Fe, while in the continuous biocrudes, only Fe was detected. Moreover, less carbon migrated to the solids from continuous HTL, indicating that removing inorganics may reduce secondary char formation.Batch hydrochars showed a higher presence of oxygenated and nitrogenated compounds, while the continuous primary chars had a higher share of alkanes and alkenes.These differences may imply that batch reactions may not serve as indicators, in terms of hydrochar characteristics, for HTL upscaling to industrial plants.

Distribution and biogeochemical perspectives of nutrients in the Eastern Equatorial Indian Ocean

The seasonal reversal of ocean circulation associated with seasonal change in the direction of prevailing winds and the occurrence of several anomalous events in the Eastern Equatorial Indian Ocean (EEIO) make this region dynamic and complex in terms of its biogeochemical characteristics. Two multidisciplinary cruises were conducted to measure nutrients and associated physicochemical parameters across the water column (up to 1000 m) of the EEIO during boreal summer and winter monsoons to understand the distribution of nutrients and their spatio-temporal variability from a biogeochemical perspective. The seasonality in the thermohaline structure of the region is indistinct except for surface salinity drop during summer monsoon due to more precipitation on-site and in adjoining areas. Low concentrations of chlorophyll at the surface and in the deep chlorophyll maxima represent the oligotrophic nature of this region. Surface water was found nutrient-depleted (0.03–0.4 µM Nitrate, 0.02–0.13 µM Phosphate). The maxima of vertical profiles of nitrate and phosphate were recorded at a shallower depth (150–200 m) when compared to its maxima in usual oceanic conditions, but a silicate maximum was recorded in deeper water. In the surface and upper mixed layer paucity of nutrients resulted in low N:P and N:Si ratios. Therefore, nitrogen limitation is evident. The overall ratio of N:P yielded a mean value of 15.33 and matched with the representative literature value for the Indian Ocean. The minimum oxygen values (<50 µM) in the deep water (150–200 m) indicated a hypoxic condition. No signature of denitrification and a moderate nitrate deficit were observed in deep waters. The negative values of Nitrate anomaly (N-tracer) at 50–100 m depth were attributed to a Watermass influenced by denitrification. The prevailing oligotrophic condition caused limited synthesis of organic matter and subsequently little decomposition in deep water. The maxima in the apparent oxygen utilization (AOU) profile are confined to 150 to 200 m depth and represent the most active zone for regeneration that is limited to shallow depth. Regenerated nutrients reached maxima at shallower depth and primarily control material cycling in this region. Supply of nitrate to the surface water based on the preformed values of prevailing water mass was primarily by Bay of Bengal water. According to the findings of this study, preformed nitrate concentrations between 100 and 200 metres below the surface were found very low, indicating that Indonesian Through Flow (ITF) has little impact on the distribution of nutrients in this area.

Effect of hydrothermal carbonization on pyrolysis behavior, nutrients and metal species distribution in municipal sludge

In this study, the effect of hydrothermal carbonation (HTC) on the pyrolysis behavior and the distribution of nutrients and metal species of waste-activated sludge (WAS) was investigated. Results showed that the pyrolysis activation energy range of WAS decreased from 11 to 57 kJ/mol to 10–36 kJ/mol when the hydrothermal carbonization was at 160 °C. As indicated by thermodynamic parameters, the hydrothermal carbonization process reduces the pyrolysis reaction activity of the hydrochar. The results of the chemical analysis indicate that hydrothermal carbonization significantly enhances the release of phosphorus and nitrogen, with maximum recovery at a temperature of 200 °C. The standard measurement and testing protocol revealed that hydrothermal carbonization increased the content of non-apatite inorganic P fraction in hydrochar and enhanced the availability of P. Heavy metal analysis shows that hydrothermal carbonization can strengthen the stability of heavy metals in WAS.

Geographic Information System (GIS) Application in Soil Fertility Management: A Review

As the global population expected to reach 10 billion by 2050 and arable land decreases, innovative soil management strategies are required to maximize agricultural productivity while preserving natural resources. GIS, as a powerful technology, offers a comprehensive solution by enabling the collection, storage, analysis, and visualization of spatial data for agricultural purposes. By integrating GIS with sensors, communication technologies, and data analytics, precision agriculture is possible, allowing for efficient use of agricultural inputs and reduced environmental impact. GIS technology facilitates the simulation and modeling of biological ecosystems, providing valuable insights for sustainable soil management. It has diverse applications in agriculture, ranging from soil nutrient mapping to yield estimations and runoff detection. GIS works by overlaying various layers of information onto digital maps, allowing for the identification of relationships and patterns that are crucial for optimizing soil fertility. Detailed maps created through GIS highlight the distribution of soil nutrients, pH levels, and moisture content, enabling informed decision-making on fertilizer use, irrigation techniques, and land management practices. By harnessing the power of GIS, farmers and land managers can make data-driven decisions that maximize agricultural productivity, conserve resources, and protect soil health for future generations. The integration of GIS with other technologies further enhances its effectiveness in soil fertility management. Overall, GIS is a valuable tool for understanding and managing soil fertility, contributing to sustainable agriculture and food security.

Impact of reclamation projects on water quality in jinmeng bay, China

Since 2015, green tides have recurred annually in Jinmeng Bay (JMB), China. Reclamation projects have been considered an important anthropogenic perturbation in JMB for green tides. A coupled hydrodynamic and water quality model was used to simulate hydrodynamic and transport processes for different artificial structure scenarios. Numerical results prove that reclamation projects exert a significant impact on the water environment in JMB, and nutrient distributions are mainly influenced by Conch Island, which decreases pollutant dilution and diffusion in coastal waters. Moreover, the average residence time increases by about 35% after the construction of the two artificial islands. Areas with long residence time coincide with the major sources of the green tide blooms, which declares that the weak water exchange capacity affected by artificial islands is responsible for the water quality degradation. The increased nutrient levels and hydraulic residence time also suggest the high possibility of green algal blooms in JMB.

Factors influencing the intensity of cross-front transport: An example from the offshore transport around the Shandong Peninsula, China

Cross-front transport is a vital process in the offshore transport of terrestrial materials. The factors influencing cross-front transport are multifaceted and exhibit regional variability. As important factors regulating material transport patterns in the shelf seas of eastern China, the East Asian Winter Monsoon (EAWM) and Kuroshio current (including its branches) vary on multiple time scales, yet their role in controlling offshore transport is not fully understood. In this paper, cross-front offshore transport in the North Yellow Sea is chosen to investigate the aforementioned issue using numerical simulation. By excluding other potential processes for offshore transport, frontal instability is identified as the primary mechanism for offshore transport, which is triggered by winter storms (bursts of the EAWM); hence, the intensity of offshore transport is highly associated with the strength of winter storms on synoptic scales. However, on the inter-annual scale, the intensity of offshore transport is more likely regulated by the strength of the Kuroshio current, and a warming Kuroshio facilitates offshore transport. Although the role of each factor in controlling the intensity of offshore transport is delineated, the interactive effects of the EAWM and Kuroshio current on offshore transport are quite intricate, and how to quantitatively estimate their roles on multiple time scales remains a challenge using modelling. The results obtained from this study can be applied to analyse cross-front transport throughout the eastern China seas and bear significant implications for future studies on pollutant diffusion, nutrient distribution, and sediment transport in the coastal area.

Nutrient characteristics driven by multiple factors in large estuaries during summer: A case study of the Yangtze River Estuary

Nutrients directly control the level of primary productivity and are crucial for the stability of marine ecosystems. Focusing on the survey results in August 2020 of the Yangtze River Estuary, this study elucidated the distribution characteristics and controlling factors of three nutrients: NO3-N, PO4-P, SiO3-Si. The results showed that the concentrations of NO3-N, PO4-P, SiO3-Si in the study area were generally higher near the shore than far shore, with average concentrations of 11.40, 0.70, and 23.73 μmol/L, respectively. The ocean currents drove the distribution of nutrients, and the transport of CDW and YSCC increased the nutrient levels. The resuspension of sediment caused by factors such as terrain and weather may lead to an abnormal increase in nutrients in the bottom waters. The main controlling factors of the three nutrients were different. NO3-N was significantly affected by human activities, PO4-P and SiO3-Si were mainly affected by natural factors.

Elucidation of the dominant factors influencing N2O emission in water-level fluctuation zones in a karst canyon reservoir, southwest China

The water-level fluctuations zones (WLFZs) are crucial transitional interfaces within river-reservoir systems, serving as hotspots for N2O emission. However, the comprehension of response patterns and mechanisms governing N2O emission under hydrological fluctuation remains limited, especially in karstic canyon reservoirs, which introduces significant uncertainty to N2O flux assessments. Soil samples were collected from the WLFZs of the Hongjiadu (HJD) Reservoir along the water flow direction from transition zone (T1 and T2) to lacustrine zone (T3, T4 and T5) at three elevations for each site. These soil columns were used to conduct simulation experiments under various water-filled pore space gradients (WFPSs) to investigate the potential N2O flux pattern and elucidate the underlying mechanism. Our results showed that nutrient distribution and N2O flux pattern differed significantly between two zones, with the highest N2O fluxes in the transition zone sites and lacustrine zone sites were found at 75 % and 95 % WFPS, respectively. Soil nutrient loss in lower elevation areas is influenced by prolonged impoundment durations. The higher N2O fluxes in the lacustrine zone can be attributed to increased nutrient levels resulting from anthropogenic activities. Furthermore, correlation analysis revealed that soil bulk density significantly impacted N2O fluxes across all sites, while NO3−and SOC facilitated N2O emissions in T1-T2 and T4-T5, respectively. It was evident that N2O production primarily contributed to nitrification in the transition zone and was constrained by the mineralization process, whereas denitrification dominated in the lacustrine zone. Notably, the annual N2O efflux from WLFZs accounted for 27 % of that from the water-air interface in HJD Reservoir, indicating a considerably lower contribution than anticipated. Nevertheless, this study highlights the significance of WLFZs as a vital potential source of N2O emission, particularly under the influence of anthropogenic activities and high WFPS gradient.

Distribution and Ecological Risk Assessment of Nutrients and Heavy Metals in the Coastal Zone of Yantai, China

As urbanization accelerates, a growing influx of pollutants enters the sea through land runoff, posing a threat to coastal ecosystems. In this study, we systematically determined the concentrations of nutrients and heavy metals in the water and sediments of coastal areas (Yantai, China) and assessed their sources and ecological risks. The results showed that inland rivers transported large amounts of NO3− and PO43− into coast water, which caused severe eutrophication. Regarding heavy metals, copper dominated in seawater, whereas plumbum and arsenic were dominant in sediment, which was sourced from aerosol deposition and mariculture. Zinc, chromium, copper, mercury, and cadmium contributed slightly to pollution, with low enrichment factors, mainly from natural sources. Further analysis showed that zinc, mercury, copper, and arsenic were significantly affected by the grain size composition in sediment. Ecological risk assessment indicated that the coastal zone of Yantai City is in a state of light heavy-metal pollution.

32 Amazing Grazing webinar and workshop series improves producers understanding of pasture ecology

Abstract Grassland stewards are seeking a better understanding of the complex interactions occurring in their pastures. Information is readily available to assist producers but each farm provides its own unique challenges and opportunities. A diverse scope of knowledge and skills are required to build resilient grazing systems. To address this need Amazing Grazing conducted a webinar series (April 2023) followed by on-farm workshops in July/August 2023. Webinars were held on consecutive Wednesday evenings with 237 average number of registered attendees and 78 average number of actual participants. Topics covered during the first webinar were pasture ecology basics, plant growth principles, livestock forage demand and grazing management principles. The following week covered pasture layout and design, pasture renovation techniques and pasture soil health concepts. The final evening featured topics on electric fence basics, grazing systems for horses and small ruminants and a synopsis. NC Extension Livestock Agents assisted in the sight selection and execution of workshops (n = 8) that were held on working farms. These events provide the opportunity for hands-on instruction to demonstrate the concepts covered in the webinar series. Total workshop registration was 196, with 148 evaluations completed. Participants were 72% farmers, 1% extension agents, 10% Soil and Water Conservation District Employee, 7% NRCS employee and 10% other. The total number of pasture hectares grazed by participants was 3,217 with 1,257 ha as hay. Livestock inventories for attendees were 4,323 beef cattle, 1,366 sheep, 455 goats and 51 horses. Attendees were asked about their pre- and post- workshop knowledge (1 = Very Low; 5 = Very High) of topics presented. Participants indicated a knowledge gain (average pre = 2.78 and post = 3.91) in Concepts of Pastureland Ecology, Adaptive Management, Managing Nutrient Distribution, Pasture Renovation, Temporary Electric Fence, Troubleshooting Electric Fence and Pasture Plant Identification. Workshop impact was determined by asking attendees their post workshop intentions regarding management practices (1 = No, 2 = Maybe, 3 = Yes, 4 = Already Doing). Attendees plan to spending more time walking pasture to determine plant condition, learn more about soil, plant, animal and human interactions, increase use of temporary electric fence and adopt an adaptive management style (average score = 3.91). Continued workshop participation indicates the demand for hands-on education in these areas and that the on-farm format is an effective teaching environment.

Impact of milling on the nutrients and anti-nutrients in browntop millet (Urochloa ramosa) and its milled fractions: evaluation of their flour functionality.

Browntop millet has gained popularity in recent years owing to its nutritional superiority and health benefits. However, the usage of browntop millet flours as ingredients in composite flours and functional foods is constrained due to a lack of information regarding the grain composition and its flour functionality. Therefore, the distribution of nutrients, anti-nutrients in browntop millet milled fractions and their flour functionality was evaluated in comparison to whole grain flour. Bran fraction comprised the highest protein (13.7%) and fat contents (27%) among other fractions. Pearling of dehulled grains considerably reduced phytic acid, saponins and flatulence-causing oligosaccharides in pearled grain flours. Besides, this led to the enrichment of soluble fibre, minerals, phenolics and trypsin inhibitors in bran fraction. Milling also impacted flour functionality. Despite its lower water holding ability, dehulled grain flour exhibited significantly higher oil absorption capacity than whole grain flour due to the removal of fibre-rich hull fraction. Although emulsion (45.2%) and foaming capacities (12.5%) were superior in bran flour, foam stability was greater in pearled grain flours. These findings suggest the potential utilisation of browntop millet milled flours as ingredients in the development of distinct food formulations and as partial substitutes to wheat flour in confectionary and bakery products. © 2024 Society of Chemical Industry.

Microbial mediated carbon and nitrogen cycling in the spatially heterogeneous vadose zone: A modeling study

AbstractSpatially distributed properties of the subsurface result in varying water saturation and preferential flow paths, which lead to heterogeneous solute transport patterns and heterogeneous microbial environments. This, in turn, influences the distribution of nutrients and energy gradients, microbial biomass, and activity thereof. By their very nature, current field sampling techniques do not resolve subsampling scale heterogeneities in microbial biomass and activity, resulting in inaccurate estimates of microbially mediated carbon and nitrogen turnover in the heterogeneous subsurface. Thus, in this study, we undertook a numerical modeling approach to study the impact of spatial heterogeneity on microbially mediated carbon and nitrogen turnover in the vadose zone. We adapted an established biogeochemical process network that captures a variety of respiration pathways, carbon decomposition strategies, and microbial life processes to simulate microbially mediated carbon and nitrogen turnover in variably saturated spatially heterogeneous settings, using an established numerical tool (OGS#BRNS). The fractionation of microbial communities into active and inactive states, as well as immobile and mobile states followed could be linked to the bulk average saturation. Lastly, we identified three reactive systems, distinguished by the rate ratio of aerobic respiration and transfer of oxygen from the air to the water phase, to evaluate the impact of spatial heterogeneity on carbon and nitrogen removal in subsurface heterogeneous domains. Specifically, when this ratio is approximately 1, there is no impact on carbon removal, while when this ratio is very high, then carbon removal decreases as the domain tends to be oxygen limited.

Geotechnologies in the Assessment of Eutrophication in the Barra Bonita Reservoir, São Paulo, Brazil

Objective: The objective of this study was to identify locations with higher eutrophication and, consequently, susceptible to the emergence of macrophytes in the Barra Bonita reservoir, SP. Theoretical background: The presence of macrophytes, such as Eichhornia crassipes, is influenced by ecological succession driven by human activities like introducing exotic species and discharging untreated nutrients. Effective management, including buffer zones, is suggested to reduce eutrophication, though some studies question their effectiveness on a large scale. Method: The analysis of the Normalized Difference Vegetation Index (NDVI) was conducted using remote sensing images obtained from Landsat 8 and 9 satellites. As a criterion for data acquisition, corresponding data for the study region were obtained over a one-year temporal scale with a maximum cloud cover of 0%. Results and conclusion: Analyzing the images, it is observable that the month of June 2023 exhibited areas with a higher vegetation index and, consequently, eutrophication processes. This trend gradually decreased in the months of August, September, and November. Research implications: The analysis of satellite images revealed specific patterns of eutrophication, suggesting a direct correlation between the geographical distribution of nutrients and the potential proliferation of macrophytes. Additionally, comparative studies of nutrient concentrations in tributaries indicate that urban pollution, besides affecting local water quality, contributed to eutrophication in the Barra Bonita reservoir. Originality/value: Through the NDVI, the eutrophication possibility in Barra Bonita’s Reservoir was evidentiated.

Automatic nutrient estimator: distributing nutrient solution in hydroponic plants based on plant growth.

The primary objective is to address the specific needs of plants at different growth stages by delivering precise nutrient concentrations tailored to their developmental requirements. Challenges such as uneven nutrient distribution, fluctuations in pH and electrical conductivity, and inadequate nutrient delivery pose potential hindrances to achieving optimal plant health and yield in hydroponic systems. By overcoming these challenges, the hydroponic farming community aims to enhance the accuracy of nutrient dosing, streamline automation processes, and minimize resource wastage. Hydroponics, a cultivation technique without soil, facilitates the growth of organic vegetation while concurrently minimizing water use and eliminating the necessity for pesticides. In order to achieve effective cultivation of hydroponic plants, it is essential to maintain a controlled environment that encompasses essential factors such as temperature, carbon dioxide (CO2) levels, oxygen availability, and appropriate lighting conditions. Additionally, it is crucial to ensure the provision of vital nutrients to maximize output and productivity. Due to the demanding nature of a hydroponic farmer's schedule, it is necessary to minimize the amount of time dedicated to nutrient management, as well as pH and EC adjustments. In order to determine and deliver the proper amount of vital nutrients, such as nitrogen, phosphorus, and potassium, based on the plant growth stage, we presented an automatic hydroponic nutrient estimator in this system. We noticed that the plant's nutrient consumption varies depending on its stage of growth according to plant psychology. Four peristaltic pumps with the necessary sensors are controlled by an Arduino board in the suggested system. Both filling and draining the water are done using each pump. To identify the plant stage, we apply the Plant Growth Stage Identification algorithm to encompass the seedling, vegetative, flowers, and fruit stages. The experimental results reveal that the Growth Stage Identification algorithm obtains 97.5% accuracy for the first 5 weeks with 1,715 ppm of nutrition ingestion, identifying the vegetative state. The flowering stage is identified with 97.5% accuracy in the 6-9th week with 2,380 ppm of nutrition consumption, and the fruiting location is determined with 99.4% accuracy in the last 10-15th week with 2,730 ppm of nutrition consumption.

Salinity and pH related microbial nitrogen removal in the largest coastal lagoon of Chinese mainland (Pinqing Lagoon)

Coastal lagoon is critical habitat for human and provides a wide range of ecosystem services. These vital habitats are now threatened by waste discharge and eutrophication. Previous studies suggest that the pollution mitigation of coastal lagoon relies on the water exchange with open sea, and the role of microbial processes inside the lagoon is overlooked. This study takes the Pinqing Lagoon which is the largest coastal lagoon in Chinese mainland as example. The distribution of nutrients, microbial activity of nitrogen removal and community structure of denitrifying bacteria in sediment are analyzed. The results showed that the nutrient in sediment represented by DIN (1.65–12.78 mg kg−1), TOM (0.59–8.72 %) and TN (0.14–1.93 mg g−1) are at high levels and are enriched at the terrestrial impacted zone (TZ). The microbial nitrogen removal is active at 0.27–19.76 μmol N kg−1 h−1 in sediment and denitrification is the dominate pathway taking 51.44–98.71 % of total N removal. The composition of the denitrifying microbial community in marine impacted zone (MZ) is close to that of ocean and estuary, but differs considerably with those of TZ and transition zone (TM). The denitrification activity is mainly controlled by salinity and pH, and the denitrifying bacterial community composition related to the nutrient parameters of TN, TOM, etc. Our study suggested that the distribution of nutrients, microbial activity of nitrogen removal and community structure in Lagoon are the combined effects of terrestrial input and exchange with open sea. The microbial processes play important role in the nitrogen removal of coastal lagoon.

Dynamics of plant nutrient signaling through compost

Nutrient signaling is a fundamental aspect of plant growth and development, encompassing intricate pathways that govern nutrient uptake, allocation, and utilization. Plant growth hormones, root exudates, soil microbes intricately coordinate these processes, responding to nutrient availability and environmental cues. These hormones regulate the expression of transporters, enzymes, and ion channels involved in nutrient acquisition and distribution. Furthermore, plant nutrient signaling pathways interface with hormonal pathways, forming a dynamic regulatory network that allows plants to adapt to changing nutrient conditions and stressors. Additionally, these pathways impact secondary metabolism, root architecture, and nutrient homeostasis, influencing crop yield and quality. Complementing nutrient signaling, through compost application enriches soils, enhancing nutrient availability and soil microbial communities, ultimately optimizing nutrient mobilization and uptake. Understanding these mechanisms is vital for sustainable agriculture and improved crop management, promising increased plant growth, yield, and nutrient utilization efficiency.

The Influence of Shallow Groundwater on the Physicochemical Properties of Field Soil, Crop Yield, and Groundwater

The depth of shallow groundwater significantly influences crop growth and yield by altering the physicochemical properties of farmland soil profiles. Concurrently, shallow groundwater is subject to various changes, and it remains unclear how alterations in shallow groundwater depth within field soil impact soil physicochemical properties, crop yields, and the overall dynamics of groundwater transformations. To address these uncertainties, this study utilized a sample plot equipped with a volume lysimeter and implemented four distinct groundwater depths as treatment conditions: G0 (no groundwater depth), G1 (a groundwater depth of 40 cm), G2 (a groundwater depth of 70 cm), G3 (a groundwater depth of 110 cm), and G4 (a groundwater depth of 150 cm). This study was carried out on a weekly basis to monitor fluctuations in ion content in shallow groundwater and soil moisture after the summer maize harvest, and special attention was afforded to non-irrigation conditions. This study also scrutinized the distribution of salt and nutrients in soil profiles and assessed changes in summer maize yield. Very interesting findings were obtained by conducting the study. Firstly, the shallower the groundwater depth, the higher the water and salt content of the soil surface. Small, frequent rainfall events (precipitation ≤ 25 mm) facilitated the effective removal of salt from the soil surface. Despite increased rainfall contributing to salt ion dilution in groundwater, the risk of soil surface salinization increased at the surface level. Secondly, a linear relationship existed between groundwater depth and surface soil moisture and salt content. With every 10 cm increase in groundwater depth, the surface soil moisture and salt content decreased by 0.56% and 0.06 g/kg, respectively. Soil nutrients tended to accumulate in the surface layer, with nutrient content increasing with depth. However, C/N was not notably affected by groundwater depth. Thirdly, Na+ and K+ consistently dominated the soil surface. As soil salinity increased, the prevalence of Cl− and SO42− increased, with the rate of SO42− increase surpassing that of chlorine. HCO3− altered by rainfall served as an indicator of soil alkalization characteristics, while Na+ and K+ in soil, along with Cl− and SO42− derived from groundwater, represented soil salt composition and salinization trends. Ultimately, under the conditions of this study, the most favorable groundwater depth for the growth of summer maize was determined to be 1.1 m. Analyzing the impact of different shallow groundwater depths on the physicochemical properties of farmland soil enhances our understanding of the mechanisms of interaction between groundwater and soil in agricultural ecosystems. This knowledge is instrumental in significantly improving the soil environment, thereby ensuring optimal crop yields.