Input Ratio Research Articles

Effects of Fertilizer Application Strategy Adjustments on Nitrogen and Phosphorus Loss from Typical Crop Systems in Taihu Lake Region

The intensity of crop farming fertilizer input is generally high in the Taihu Lake Region, with chemical fertilizer as the main form. Due to inappropriate fertilizer application, nitrogen and phosphorus loss have occurred, causing serious agricultural non-point source pollution. The Ministry of Agriculture and Rural Affairs of China has launched the "zero-growth action for chemical fertilizer use" and "replacement action with organic fertilizer" ("two actions" for short) campaigns since 2015. Local agricultural sectors adjusted fertilizer application strategies of crop farming to respond to the call of two actions. However, the current research is still focusing on reducing the total amount of fertilizer application and increasing the area of organic fertilizer application, which is mainly based on grain crops. The study of agricultural environment problems is still lacking, especially in vegetable, orchard, and tea systems. Therefore, a study was carried out in the typical agricultural area of Suzhou City Wuzhong District from 2019 to 2021. Based on the data of the amount of nitrogen and phosphorus removal by harvest crops and soil nitrogen and phosphorus residual in paddy, vegetable, orchard, and tea systems, the loss was estimated. The responses of nitrogen and phosphorus loss from typical crop systems to fertilizer application strategy adjustments were studied through analysis of different factors. The results showed that fertilizer application rate was the key to control nitrogen and phosphorus loss. Additionally, the suitable replacement ratio of organic fertilizer could further reduce the loss risk. It should be noted that the urgent demand for nutrients in crop growth should be considered to determine the timing of organic fertilizer application, and agricultural machinery should be used to assist organic fertilizer application to reduce labor output if possible. Fertilizer efficiency was the core of environmental friendliness and economic benefits of crop farming. Hence, improving fertilizer efficiency should be the guidance of fertilizer application strategy adjustment. Our suggestions on the adjustment of fertilizer application strategy in different crop systems in the study area are as follows:attention should be paid to the nitrogen, phosphorus, and potassium input ratio in paddy systems to further reduce nitrogen and phosphorus loss. Planting structure adjustment should be emphasized in vegetable systems to promote fertilizer efficiency. The strategy to satisfy both tea and orchard growth from a composite system perspective would help to build crop systems that meet the needs of green agricultural development.

Budidaya Hidroponik Pakcoy (Brassica Rapa L) dan Ikan Nila dengan Sistem Aquaponik (Studi Kasus Desa Losari Nganjuk)

Aquaponics is a combined system of fish farming techniques and hydroponic plant cultivation. Fish manure and feed residues are very dependent on the supply of nutrients in the aquaponic system of red tilapia (Oreochromis niloticus) aquaculture. The level of production of vegetable crops in a certain area is also influenced by the total nutrient input ratio of feed to domestic fish per day. The aquaponic system utilizes optimum water supply for each commodity by utilizing a recirculation system. The type of fish used is fish that live in freshwater, a type of tilapia. Fish farming includes the maintenance of fish, which pays attention to the growth and development of fish. Hydroponics itself is a way of farming without using soil as a medium but using water which contains controlled nutrients containing the essential elements needed for plant growth. The location of this research was conducted in Losari Village, Kec. Gondang, Kab. sleepy. It aims to increase the demand for vegetables, limited land and space, efficiency in land use, and decoration. In addition, this cultivation system allows for increased production of cultivated products with limited land and water sources, and creates its own beauty. (9 pt).

A Study on the Change of Wire Feeding Speed in GTA Welding (Ⅰ) - Changes in the Modes of Metal Transfer -

GTA welding (GTAW) is a representative welding technique employed for pipe root gap welding. Although this technique allows the control of the current and wire feeding speed as independent variables, it is difficult to determine these variables to ensure appropriate quality. In the pipe root gap welding task, the parameters of automated welding applications are difficult to determine due to gap and misalignment. Accordingly, this study was conducted to examine changes in the modes of metal transfer according to the welding current and wire feeding speed. In the various processes of GTAW, changes in volume transfer form yield certain advantages and disadvantages, necessitating appropriate tuning procedures to maintain a desired quality. Changes in heat input ratio (HIR), which relates to the welding heat input (HI) and wire feeding speed, were observed to predict modes of metal transfer. According to changes in welding current and wire feeding speed, metal transfer was expressed as an index, and a regression equation was formulated to predict the modes of metal transfer through said index.

A Study on the Change of Wire Feeding Speed in GTA Welding (Ⅱ) - Development of Weld Bead Shape Prediction Model -

Throughout the GTA welding (GTAW) process, bead width (Bw), bead height (Bh), penetration depth (Dp), and metal transfer modes change in accordance with welding current and wire feeding speed. Various processes employing GTAW include text marking welding systems that have bead width and bead height as the main management items, and some such processes require sufficiently complete penetration. It is judged that there will also be a metal transfer type advantageous for welding the first layer of the pipe root gap. Accordingly, a bead shape prediction model in GTAW has been proposed according to changes in welding current and wire feeding speed, wherein the bead shape change and metal transfer change interval are presented for the heat input ratio (HIR) change.

Root litter quality drives the dynamic of native mineral-associated organic carbon in a temperate agricultural soil.

Understanding the fate and residence time of organic matter added to soils, and its effect on native soil organic carbon (SOC) mineralisation is key for developing efficient SOC sequestration strategies. Here, the effect of litter quality, particularly the carbon-to-nitrogen (C:N) ratio, on the dynamics of particulate (POC) and mineral-associated organic carbon (MAOC) were studied. In a two-year incubation experiment, root litter samples of the C4-grass Miscanthus with four different C:N ratios ranging from 50 to 124 were added to a loamy agricultural topsoil. In an additional treatment, ammonium nitrate was added to the C:N 124 litter to match the C:N 50 litter input ratio. Soils were size-fractionated after 6, 12 and 24 months and δ13C was measured to determine the proportion of new and native POC and MAOC. Litter quality was further assessed by mid-infrared spectroscopy and compound peak analysis. Litter quality strongly affected SOC dynamics, with total SOC losses of 42.5 ± 3.0% in the C:N 50 treatment and 48.9 ± 3.0% in the C:N 124 treatment after 24 months. Largest treatment effects occurred in mineralisation of native MAOC, which was strongly primed by litter addition. The N amendment in the C:N 124 treatment did not alleviate this potential N mining flux. Litter quality plays a major role in overall SOC dynamics, and priming for N mining from the MAOC pool could be a dominant mechanism. However, adding N did not compensate for poor litter quality, highlighting the role of litter quality beyond stoichiometric imbalances.

#3056 IMPACT OF ALBUMIN BINDING FUNCTION ON PHARMACOKINETICS AND PHARMACODYNAMICS OF FUROSEMIDE

Abstract Background and Aims Albumin binding of furosemide forms the basis for its transport to the kidney and subsequent tubular secretion, which is a prerequisite for the effect of furosemide. Accordingly, high albumin concentrations should result in higher efficacy of furosemide. However, study results on the combination of furosemide in conjunction with albumin and on the efficacy of furosemide in hypoalbuminemia did not confirm this hypothesis. The aim of this study was to determine the efficacy of furosemide not only in relation to concentration, but also to take albumin function into account. Method In a prospective and non-interventional clinical observational trial, blood and urine samples from 50 intensive care patients receiving continuous intravenous furosemide therapy were evaluated. Albumin binding capacity (ABiC) determination allowed conclusions to be drawn about the binding site-specific loading state of albumin by quantifying the unbound fraction of the fluorescent marker dansylsarcosine. In addition, assessment of the total concentration of furosemide in plasma and urine as well as the concentration of free furosemide fraction in plasma was performed by HPLC-MS. The efficacy of furosemide was evaluated by the ratio of urine excretion to fluid intake. Results In patients with an ABiC ≥ 60% free furosemide fraction was significantly lower compared to patients with a lower ABiC (p < 0.001), urinary furosemide concentration was higher (p = 0.136), and a significantly higher proportion of infused furosemide was excreted renally (p = 0.010). ABiC was positively correlated (r = 0.908, p = 0.017) with the increase in urine excretion to fluid input ratio after initiation of furosemide therapy. Conclusion ABiC could serve as a marker for individual response to furosemide and could be used to generate patient-specific therapeutic regimens. In view of the relatively low number of patients in this study, the relationship between furosemide efficacy and albumin function should be investigated in larger studies in the future.

The Impact of Digital Enterprise Agglomeration on Carbon Intensity: A Study Based on the Extended Spatial STIRPAT Model

The digital economy has broken the physical space limit, reshaped factor input ratios, and accelerated factor mobility, which drives carbon reduction and social sustainability. Digital enterprise agglomeration is becoming the new tendency and a significant spatial feature for digital economy development. This work aimed to study the impact of digital enterprise agglomeration on carbon intensity. This study first proposed an extended spatial stochastic IPAT (STIRPAT) theoretical framework and regarded digital enterprise agglomeration as a technology factor. Secondly, by building a dataset with 7,902,050 digital enterprises and using the distance-based Duranton and Overman index, this study evaluated the digital enterprise agglomeration of 278 cities from 2007 to 2017 in China. Thirdly, by matching micro digital enterprise data and macro city data, this study employed spatial Durbin, mediating, and moderating effects models to test the impact and mechanism of digital enterprise agglomeration on carbon intensity. There are four main findings: (1) There is a negative “U-shaped” correlation between digital enterprise agglomeration and local and neighboring cities’ carbon intensities, and the impact of neighboring digital enterprise agglomeration on local carbon intensity is more significant than the effect of regional digital enterprise agglomeration on local carbon intensity. (2) The impact of digital enterprise agglomeration on carbon intensity shows great differences under spatial, resource, industrial, and financial heterogeneity. (3) Digital enterprise agglomeration indirectly impacts carbon intensity in two ways: the green technology innovation effect and the industry structure rationalization effect. (4) Human capital enhances the role of digital enterprise agglomeration in reducing carbon intensity, whereas government intervention weakens the effect of digital enterprise agglomeration in decreasing carbon intensity. This paper suggests that digital enterprise agglomeration strategies should be dynamically adjusted based on local digital economy development and resource conditions.

Output–Input Ratio Maximization for Online Social Networks: Algorithms and Analyses

In the last few decades, profit maximization (PM), which is mainly considered for maximizing net profits, i.e., the difference between gain and cost, has been a prominent issue for online social networks (OSNs). However, the output-to-input ratio, which is an important metric in economics, is also worth studying for OSNs. In this article, we present a novel problem that considers the PM problem from the ratio of gain and cost, known as output-to-input ratio maximization (OIRM). Unfortunately, it is neither submodular nor supermodular. The hill-climbing greedy algorithm for solving this problem is a <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>1-e^-(1-c_g)</tex> </formula> approximation algorithm, where c_g is the curvature of the monotone submodular set function g. To speed up the hill-climbing greedy algorithm, we propose the threshold decrease algorithm and prove that its approximation ratio is <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>1-e^-(1-c_g)^2-ε</tex> </formula> . In addition, based on the relationship between classical net PM and OIRM, the algorithms for solving PM can also solve OIRM. Finally, we evaluate the performance of our algorithms using massive experiments on real datasets. To the best of our knowledge, this is the first time to study the OIRM in viral marketing.

Evaluation of Mechanized Field Operations Energies for Production of Sugar Cane Crop: Kenana Sugar Company as Case Study

Mechanization application in agriculture is important for timeliness of field operations and improvement of products quality. This study was conducted in a sugar company to evaluate the mechanization energy requirements for production of sugar cane crop. Mechanization index (MI), mechanization ratio (MR), mechanization productivity (MEP), specific mechanization energy (SME), total mechanization energy and mechanization energy use efficiency (MEU) were estimated. Data for the study was collected from field visits, agricultural engineers working in the company and also from the available information in literatures and other related resources. Results showed that the highest share of mechanized energy consumption belongs to land preparation operation (44%) followed by harvesting operation (30%), while the lowest was for the weeding and fertilization (5%). The highest share of mechanization energy expenses was found to be 72% diesel fuel. The total mechanization energy, overall mechanization index, specific mechanization energy, mechanization energy input ratio, mechanization energy use efficiency and mechanization energy productivity were 17176.3 MJha-1, 97.8%, 0.18 MJkg-1, 0.20, 6.6, 5.6 kgMJ-1. Although the mechanization index of all field operations was more than 90%, but the mechanization energy input ratio was still low, while the mechanization productivity energy was high.

Experimental investigation on effect of external circulation system on preheating characteristics of pulverized coal

To explore whether self-preheating combustion systems ran steadily after loop seal failed, we comparatively investigated the influence of primary air ratio (λp) and extra heat input ratio (Cehi) on self-preheating of pulverized coal preheated in a 30 kW self-preheating burner with or without an external circulation (EC) system. For temperature distribution, lack of EC system greatly raised the temperature in the middle-lower part of the riser, and this temperature was more than 150 °C higher than that with the EC system. Moreover, extra heat input extended this influence throughout the riser. As λp and Cehi increased, the temperature in different positions always rose. For coal gas component and fuel component release, lack of EC system improved fuel composition conversion rates but reduced combustible gas yields. These two indexes increased simultaneously as λp and Cehi elevated properly, and there was an optimal λp with the EC system. Lack of EC system was inconducive to reducing particle size, improving specific surface area, promoting micro-pore generation on the surface and reducing graphitization extent, meaning the macrostructure and microstructure tended to be deteriorated in this condition. Nevertheless, the microstructure in this condition may be improved with extra heat input, and was even better than that with the EC system. The macrostructure and microstructure were improved as λp and Cehi increased properly, and there was an optimal λp with the EC system. The combustion reactivity of coal char was mainly influenced by the macrostructure, followed by the microstructure. Hence, absence of EC system tended to deteriorate it, and it was improved as λp and Cehi increased properly.

Design of a Flexible Hinged Piezoelectric Viscous Slip Actuator with Retraction Suppression

In order to solve the displacement regression phenomenon of piezoelectric viscous-slip actuators, this paper proposes a lever-type flexible hinge mechanism that uses two sets of piezoelectric stacks to move the slider in both directions and efficiently suppress the displacement regression phenomenon. First, the overall dimensional parameters of the drive are designed, the device is modeled using 3D software, and the driving principle is analyzed. Then a theoretical model is built based on the lever amplification principle to derive the relevant expressions for the piezoelectric viscous slip actuator under sawtooth wave type voltage signals. The piezoelectric stack is simulated and analyzed with COMSOL Multiphysics to obtain the modal and stress-displacement clouds of the flexible hinges. Finally, a prototype was built for experimental testing, and the slider in the device was able to achieve smooth motion and effectively suppress the displacement regression phenomenon. The input voltage of piezo stack A is 100 V, the input voltage of piezo stack D is 150 V, the input frequency is 212 Hz, the maximum output displacement of single-step drive is 46.6 μm, and the amplification ratio of flexible hinge input to output is 2.59. The piezoelectric viscous-slip actuator was verified to be able to achieve effective drive and suppress back-off.

CI-452766-1 ABRUPT TORQUE TRANSFER OCCURS FREQUENTLY DURING CONDUCTION SYSTEM PACING INSERTION IN AN EX-VIVO MODEL

A fundamental challenge in conduction system pacing [CSP] is determining appropriate lead deployment. With either fixed core or stylet driven leads, the input number of turns may not match resultant rotations achieved by the helix. To date, no validated ex-vivo experimental model has been developed to enable quantitative assessment of the ratio of input turns to helix rotation. To develop a model system to quantitatively describe CSP lead tip to tissue response curves. Sixty-four fresh (<48h) ex-vivo ovine right ventricular septa were excised. Four different leads (1 fixed core (A), 3 stylet-driven (B,C,D)) were driven into the septal myocardium using support via a custom-engineered jig allowing control of input rotation and measurement of helix rotation. Leads were inserted using 15 turns applied proximally on the lead, with resultant helix rotation and tissue-interface characteristics observed at each 90° increment via high resolution photography. Output (helix) rotation vs input rotation response curves [RRC] were assessed using automated segmented linear regression. RRC linear models were statistically analysed using slope (to characterise input vs output response) and breakpoints (to characterise abrupt torque transfer [AAT]). A total of 3840 observations of ¼ turn at the proximal CSP lead were recorded. 16 repeated RRCs were created for each lead type. Mean input vs output slope across leads was 0.46 [95%CI 0.39, 0.52] implying muted output rotations compared to input rotations. Mean number of abrupt torque transfer events [ATT] during each 15 turn insertion (measured by linear break-points in RRC) was 7.2 [95%CI 6.6, 7.7]. In 57.8% (37/64) of lead insertions, there were uncontrolled abrupt torque transfer events [uATT] where the output response at the lead tip was more than the input rotation. An ex-vivo model system was created to examine the torque transfer relationship for CSP leads. Using a robust sample size, this model showed the relationship between input turns yields an overall muted response at the lead tip. However, during insertion, abrupt torque transfer events are common, with uncontrolled abrupt torque transfer events occurring during more than half the insertions. These findings are of clinical significance to CSP implanters to be aware of the potential abrupt torque transfer events, particularly when they are uncontrolled. These data suggest new lead designs may be required to increase the efficiency and safety of CSP.Tabled 1Slope and breakpoint analysis of rotation relationship curves.Lead TypeLead TypeMean RRC Slope [95%CI]Mean # ATT events per insertion [95%CI]Mean # uATT events per insertion [Range]Solid CoreLead A0.28 [0.15, 0.55]7.31 [6.08, 8.54]0.5 [0 to 3]Stylet DrivenLead B0.48 [0.37, 0.71]6.81 [5.57, 8.05]0.69 [ 0 to 3]Stylet DrivenLead C0.66 [0.55, 0.88]7.56 [6.50, 8.62]1.31 [ 0 to 6]Stylet DrivenLead D0.45 [0.35, 0.64]7.18 [6.11, 8.26]0.86 [ 0 to 2]ALL0.46 [0.39, 0.52]7.22 [6.08, 8.35]0.84 [0 to 6]Table 1: Slope and breakpoint analysis of rotation response curves shows that the output rotations delivered to the helix are substantially less than the input rotations. Abrupt torque transfer events occur when sudden changes in the rotations delivered at the helix are observed, and occur frequenty during 15 rotation insertion of physiological pacing leads. Uncontrolled abrupt torque transmission at the helix occurs when the helix rotation exceeds the immediate input rotation, indicating a sudden release of torque build-up from the lead. RRC = Rotation Response Curve. ATT = Abrupt Torque Transfer event where sudden change in slope of RRC. uATT = Uncontrolled Abrupt Torque Transfer Events where Helix rotation > input rotation. Open table in a new tab

Induced innovation and spillover effects of US and Canadian research expenditures in Canadian agriculture

AbstractThis study examines the induced innovation hypothesis (IIH) from 1958 to 2015 for two Canadian agriculture regions: Central Canada (the provinces of Ontario and Quebec) and Western Canada (the provinces of Alberta, Saskatchewan and Manitoba). There is broadly consistent support for the IIH for Canadian agriculture, especially for Western Canadian agriculture. In addition, there is support for the notion that US, as well as Canadian, research expenditures are important to explain changes in the input ratio in Canadian agriculture in the long run. This indicates the existence of spillover effects from US agricultural research expenditures to Canadian agriculture.

Multi-Block Copolymer Membranes Consisting of Sulfonated Poly(p-phenylene) and Naphthalene Containing Poly(arylene Ether Ketone) for Proton Exchange Membrane Water Electrolysis

Glassy hydrocarbon-based membranes are being researched as a replacement for perfluorosulfonic acid (PFSA) membranes in proton exchange membrane water electrolysis (PEMWE). Here, naphthalene containing Poly(arylene Ether Ketone) was introduced into the Poly(p-phenylene)-based multi-block copolymers through Ni(0)-catalyzed coupling reaction to enhance π-π interactions of the naphthalene units. It is discovered that there is an optimum input ratio of the hydrophilic monomer and NBP oligomer for the multi-block copolymers with high ion exchange capacity (IEC) and polymerization yield. With the optimum input ratio, the naphthalene containing copolymer exhibits good hydrogen gas barrier property, chemical stability, and mechanical toughness, even with its high IEC value over 2.4 meq g-1. The membrane shows 3.6 times higher proton selectivity to hydrogen gas than Nafion 212. The PEMWE single cells using the membrane performed better (5.5 A cm-2) than Nafion 212 (4.75 A cm-2) at 1.9 V and 80 °C. These findings suggest that naphthalene containing copolymer membranes are a promising replacement for PFSA membranes in PEMWE.

A Study on Socio-economic Status of Tomato Growers in Solan District of Himachal Pradesh

Tomato is one of the most consumed and produced horticulture crops in the world. It is more economical than food grains due to their higher production per unit area in less time as they provide a good source of income to farmers. The present study has been conducted to study the socio-economic status of tomato growers in the Solan district of Himachal Pradesh. The multi-stage sampling technique and pre-tested interview schedule were used for data collection for the study. A sample was collected from eight villages in Solan district to make a total sample size of 80 tomato growers in the study area for the agricultural year 2021-2022. Mean, percentage, frequency, and standard deviation were used to find out the socio-economic status of tomato growers. The result revealed that majority i.e., 80 per cent of tomato growers belonged to middle aged group and 33.75 per cent had primary school education. About 76.25 per cent of tomato growers had joint family with 3 to 7 family members. 77.5 per cent of tomato growers had 0.5 to 3.17 bigha under tomato cultivation with 11 to 42 years of farming experience. The gross income of tomato growers was Rs. 60,000 per bigha and net income was Rs. 38,353 per bigha. The output input ratio worked out to be 1.77. The majority i.e., 55 per cent of tomato growers had medium level of socio-economic class. This study suggests the appointment of more extension personnel at grass root level. This study will be helpful in developing suitable and effective extension programmes to increase tomato production.

Modeling of dielectric resonator antenna array for retina photoreceptors

The retina encompasses several cone and rod photoreceptors at fovea region i.e., 90 million cells of rod photoreceptors and 4.5million cells of cone photoreceptors. The overall photoreceptors determine the vision of every human. An electromagnetic dielectric resonator antenna has been presented for retina photoreceptors in order to model them at fovea and its peripheral retina with the respected angular spectrum. Three coloring primary system of human eye (R, G, B) can be realized based on the model. Three miscellaneous models i.e., simple, graphene coated, and interdigital models have been presented in this paper. The nonlinear property of interdigital structures is one of the best advantages to use for creating the capacitor. The capacitance property helps improving the upper band of visible spectrum. The absorption of light for graphene as an energy harvesting material and its conversion into electrochemical signals is making it one of the best models. The mentioned three electromagnetic models of human photoreceptors have been expressed as a receiver antenna. The proposed electromagnetic models based on dielectric resonator antenna (DRA) are being analyzed for cones and rods photoreceptors of retina in the human eye by Finite Integral Method (FIM) utilized by CST MWS. The results show that the models are so fine for vision spectrum due to its localized near field enhancement property. The results indicate fine parameters of S11 (return loss below -10 dB) with invaluable resonants in a wide range of frequencies from 405 THz to 790 THz (vision spectrum), appropriate S21 (insertion loss 3-dB bandwidth), very good field distribution of electric and magnetic fields for flowing the power and electrochemical signals. Finally, mfERG clinical and experimental results validate the numeric results by the normalized output to input ratio of these models and it points out that these models can stimulate the electrochemical signals in photoreceptor cells for the best suiting of realizing the new retinal implants.

Research on Profit Allocation of Agricultural Products Co-Delivery Based on Modified Interval Shapley Value

Most of the domestic wholesale markets have many operating entities, and the level of organization and scale is not high; therefore, at this stage, building a shared business platform and carrying out common distribution is an important way to improve the overall efficiency of the wholesale market distribution operations and the level of the intensive utilization of key resources such as vehicles. Carrying out common distribution requires the formation of a good synergy mechanism among the participating subjects, in which the design of a scientific and reasonable benefit distribution scheme, especially in balancing the relationship between government resources and social resources, is particularly important. As the benefit distribution of cooperation is affected by the dynamic changes of the resource input ratio, the distribution operation scale, the risk taking, and other factors, this paper establishes a multi-weight interval Shapley value method benefit distribution model, which reflects the effect of the key parameter variables. Through the empirical analysis of Beijing’s wholesale markets for agricultural products, the results show that the revised benefit distribution is more in line with the interest demands among multiple subjects and is positively correlated with the contribution degree among the participating subjects, which can better mobilize the cooperation enthusiasm of the participating enterprises and provide a new methodological path to solve the problem of common distribution in wholesale markets. The distribution model constructed in this paper further enriches the relevant research content in the field of common distribution and is of reference value for the benefit distribution problem that requires comprehensive consideration of the dynamic change in the multiple parameters affecting the relationship.

Effects of nitrogen and phosphorus imbalance input on rhizosphere and bulk soil bacterial community of Suaeda salsa in the Yellow River Delta

IntroductionThe effects of nitrogen (N) and phosphorus (P) addition on soil microbial diversity have been widely studied, however, the response of bacterial community to N and P imbalance input remains unclear.MethodsUsing a high-throughput Illumina Miseq sequencing platform, N and P imbalance addition experiment was conducted to characterize the rhizosphere and bulk soil bacterial community of Suaeda salsa (S. salsa) in the Yellow River Delta.ResultsThe results showed that the rhizosphere soil bacterial community α-diversity was significantly higher than bulk soil. The rhizosphere soil Bacteroidetes and Actinobacteria were higher and lower than bulk soil, respectively. N and P imbalance input had small effects on the composition and α -bacterial diversity of the rhizosphere soil, while significantly increasing the bulk soil bacterial diversity and remarkably changing the community composition. Differences in the response of rhizosphere and bulk soil bacterial community to N and P imbalance input were caused by soil organic matter (SOM) content. The N and P imbalance input increased the relative abundance of bulk soil Eutrophic bacteria and decreased the relative abundance of the predicted oligotrophic bacteria (Acidobacteria,Chorolflexi). Rhizosphere and bulk soil bacterial community α-diversity was significantly correlated with SOM, salt, total carbon (TC) and total N (TN) content, with SOM and salt having the greatest effect on bulk soil bacterial community composition.DiscussionThere may be a threshold N-P input ratio between 15:1 and 45:1. This threshold is the optimal ratio for increasing the diversity of bacterial community.

Width of vegetated buffer strips to protect aquatic life from pesticide effects

Vegetated buffer strips (VBS) are an effective measure to retain pesticide inputs during rain events. Numerous studies have examined the retention effects of VBS on pesticides. However, no study has addressed on a large scale with event-related peak concentrations how wide the VBS should be to avoid ecological impacts on aquatic life. Here, we investigated for 115 lowland stream sections in Germany the relevance of environmental and physico-chemical parameters to determine the in-stream pesticide concentration and their ecological risks. Based on peak concentrations related to rain events with precipitation amount resulting in VBS relevant surface runoff for 30 of the 115 investigated stream sections (25 to 70 mm/d), we demonstrated that the average width of VBS was the main parameter (R² = 0.38) reducing the pesticide input ratio, indicating a relevant proportion of surface runoff contributing to the total in-stream pesticide concentrations. Additionally, dry ditches within agricultural fields increased pesticide input (R² = 0.31). Generally, substances classified as slightly mobile were better retained by VBS than mobile substances. Other factors including slope, land use and vegetation cover of VBS had only a minor influence. We assessed the ecological risk of in-stream pesticide concentrations by quantifying exceedances of regulatory- (RAC) and field-validated acceptable concentrations (ACfield). We then translated this ecological risk into protective VBS width by calculating the quotient of in-stream concentration and threshold (RQ). We estimate that a VBS width of 18 m is sufficient to meet the RQACfield protection goal for 95% of streams. The presence of dry ditches increased the protective VBS width to 32 m. In current agricultural practice, however, 26% of the water stretches investigated do not comply with the prescribed 5 m VBS. An extension of the VBS area to 18 m would demand 3.8% of agricultural land within the catchments. A 50% reduction in pesticide use, as required by the European green deal, would still result in 39% (RAC) and 68% (ACfield) of event-related samples being exceeded. Consequently, we see the extension of the VBS width as the most efficient mearsure to sustainably reduce pesticide concentrations in small streams.

Optimizing Straw Management to Enhance Carbon and Nitrogen Efficiency and Economic Benefit of Wheat-Maize Double Cropping System

The optimization of annual straw management can improve the yield, income, and carbon and nitrogen efficiency of wheat-maize double cropping systems. Based on a long-term positioning trial started in 2012, five straw management methods were considered, C100 (100% return), C75 (75% return+25% harvest), C50 (50% return+50% harvest), C25 (25% return+75% harvest), and C0 (100% harvest). We analyzed the effects of farmland carbon and nitrogen inputs and their ratios on crop yield, carbon and nitrogen use efficiency, and economic benefits in wheat and maize anniversaries with different straw managements. The results showed that: ① the amount of straw returning to the field resulted in a significant difference in carbon and nitrogen input. The annual carbon and nitrogen inputs from crop residues decreased by 1.76 t·hm-2 and 34.28 kg·hm-2, respectively, with a 25% reduction in straw returning. The C/N ratios under the C100-C0 treatment were 18.62, 17.03, 15.64, 12.54, and 9.61, respectively. ② Grain yield first increased and then decreased with the decrease in the C/N input ratio, and the effect of straw management on wheat yield was greater than that on maize. Compared with that under C100 and C0, the average grain yield of wheat and maize under the C50 treatment increased by 13.34%-13.67% and 16.10%-17.71%, respectively, and the total grain yield of wheat and maize increased by 14.98% and 15.68%. ③ The annual grain yield and carbon agronomy efficiency were the best with the C/N input ratio of 15.64 (in the C50 treatment), which were 15.71% and 0.29 kg·kg-1, respectively. The carbon production efficiency continued to increase with the decrease in the C/N input ratio, and there was a significant negative correlation between them. The nitrogen production efficiency increased first and then decreased with the decrease in the C/N input ratio. The nitrogen production efficiency of the C50 treatment was the highest (0.64 kg·kg-1), which was significantly higher than that of C100 by 32.63%. ④ The C50 treatment had the highest economic income and net income, which were 46200 yuan·hm-2 and 33400 yuan·hm-2, respectively. Compared with that of C100, the economic income of grain and straw feed increased by 5600 yuan·hm-2 and 3200 yuan·hm-2, respectively. In conclusion, the optimal C/N input ratio can be achieved by optimized straw management; 50% straw returning and 50% harvest in a wheat-maize double-cropping intensive production system can promote carbon agricultural efficiency and nitrogen production efficiency and obtain the maximum grain yield and economic benefits.