Farm Platform Research Articles

Power Supply Control Strategy for Offshore Wind Ship

The electric load of the ship at the bottom berth of the floating offshore wind farm platform is compatible with the power generation of the wind farm generator. The 60Hz ship power and 50Hz wind power adopt frequency conversion, the 50Hz ship power and the 50Hz wind power use the inverter to smoothly switch seamlessly, and the seamless power supply ensures that the ship can be easily and quickly berthed in a short period of time. Based on the inverter power supply control strategy of virtual synchronous generator (VSG) control and grid-connected working mode and autonomous mode of the system small-signal model, the VSG has the characteristics of fast tracking and certain mechanical and electrical inertia compared with the frequency variation of the inverter power supply based on the droop control. Meanwhile, the grid-connected pre-synchronization process and the synchronous generator pull-in synchronization process have similar characteristics, and the frequency and voltage change amplitude are relatively flat. The simulation analysis and experimental results verify the correctness of the control strategy.

The economics of alternative crop production systems in the context of farmer participation in carbon trading markets

ABSTRACT Using scaled up data from an experimental farm platform in Scotland, we examined the relative economics of a conventional and a low-carbon integrated management system for two (otherwise identical) farms. By employing a novel market-based approach, we factored the market costs of greenhouse gas (GHG) emissions on the relative economics of both systems. Specifically, farmers are considered to be awarded emission credits in accordance with Scotland’s agricultural emissions reduction targets. Farmers are then considered to trade their net GHG emissions in an emissions trading scheme, with the integrated system expected to benefit from this arrangement due to its lower emissions. In further sensitivity analyses, we also considered the effect of premium pricing of integrated system crops on the relative economics of both systems. We find that in both the status quo and emissions trading scenarios, the conventional system is significantly more profitable. In the emissions trading scenario, an emissions price roughly three times the reported median prices over the last five years is required for the integrated system’s profitability to break-even with the conventional system. However, even at prevailing emissions prices, a 20% premium pricing of the integrated system crops enables near parity in the profitability of both systems. We conclude that in order to facilitate greater adoption of low-carbon systems, policies may be needed to encourage farmers’ realization of the cost of their externalities, in particular GHG emissions. At the same time, support should be given to a market system that recognizes premium prices for low-carbon system products.

The Feasibility of Integrating the Noble Scallop Mimachlamys nobilis with Existing Fish Monoculture Farms in the South China Sea: A Bioeconomic Assessment from Hong Kong

The environmental implications of integrated multitrophic aquaculture have been well studied in China, but few investigations have empirically explored potential economic benefits. This study investigated the technical and economic feasibility of physically integrating the noble scallop Mimachlamys nobilis (Reeve, 1852) with existing fish monoculture farms in Hong Kong. Scallops were grown for 201 days from June to December in lantern nets hung directly from fish farm platforms at treatment depths of 1, 3.5, and 6 m. Only the 1-m treatment attained the target mean height-at-harvest of 80 mm. Fitted von Bertalanffy growth functions showed significant differences in growth performance between depths. The von Bertalanffy growth function projected that the 3.5- and 6-m treatments would require an additional 26 and 59 days of culture to reach 80 mm. Mortality was significantly lower at 1 m (53% ± 12.5%) compared with those at 3.5 m (70% ± 9.0%) and 6 m (83% ± 4.5%). The slower growth and higher mortality at 3.5 and 6mwere probably due to periodically low oxygen which dropped to 4.96, 3.08, and 1.73 mg L-1 at 1, 3.5, and 6 m, respectively, in midsummer. A bioeconomic assessments of two typical farm sizes was conducted; small (45 m2) and large (315 m2). The initial investment, discounted payback time, and 10-y net present value of the projects was US$5,485.51, 3 y, and US$20,211.33, respectively, for the small farm and US$27,659.03, 2 y, and US$227,406.49, respectively, for the large farm. Sensitivity analysis revealed that the profitability of operations was sensitive to changes in mortality and sales price. This study has confirmed that physically integrating M. nobilis at existing fish farms is technically and economically feasible.

Low Protease Content in Medicago truncatula Cell Cultures Facilitates Recombinant Protein Production.

Medicago truncatula is an established model for studying legume biology. More recently, it has also been exploited as a Molecular Farming platform for the production of recombinant proteins, with the successful expression of fungal and human proteins in plants and cell suspension cultures of this species. One of the challenges that now must be overcome is the degradation of final products during production and downstream processing stages. In the M. truncatula genome, there are more than 400 putative protease-encoding genes, but to date, the proteolytic content of Medicago cell cultures has not been studied. In this report, the proteolytic activities that can potentially hamper the successful production of recombinant proteins in this system are evaluated. The potential proteases responsible for the degradation of target proteins are identified. Interestingly, the number of proteases found in Medicago spent medium is considerably lower than that of the well-established tobacco bright yellow 2 (BY-2) system. Papain-like cysteine proteases are found to be the major contributors to recombinant protein degradation in Medicago. This knowledge is used to engineer a cell line with reduced endogenous protease activity by expressing a selective protease inhibitor, further improving this expression platform.

Impact of Conventional and Integrated Management Systems on the Water-Soluble Vitamin Content in Potatoes, Field Beans, and Cereals.

The reduction of the environmental footprint of crop production without compromising crop yield and their nutritional value is a key goal for improving the sustainability of agriculture. In 2009, the Balruddery Farm Platform was established at The James Hutton Institute as a long-term experimental platform for cross-disciplinary research of crops using two agricultural ecosystems. Crops representative of UK agriculture were grown under conventional and integrated management systems and analyzed for their water-soluble vitamin content. Integrated management, when compared with the conventional system, had only minor effects on water-soluble vitamin content, where significantly higher differences were seen for the conventional management practice on the levels of thiamine in field beans (p < 0.01), Spring barley (p < 0.05), and Winter wheat (p < 0.05), and for nicotinic acid in Spring barley (p < 0.05). However, for all crops, variety and year differences were of greater importance. These results indicate that the integrated management system described in this study does not significantly affect the water-soluble vitamin content of the crops analyzed here.

Roles of instrumented farm-scale trials in trade-off assessments of pasture-based ruminant production systems

For livestock production systems to play a positive role in global food security, the balance between their benefits and disbenefits to society must be appropriately managed. Based on the evidence provided by field-scale randomised controlled trials around the world, this debate has traditionally centred on the concept of economic-environmental trade-offs, of which existence is theoretically assured when resource allocation is perfect on the farm. Recent research conducted on commercial farms indicates, however, that the economic-environmental nexus is not nearly as straightforward in the real world, with environmental performances of enterprises often positively correlated with their economic profitability. Using high-resolution primary data from the North Wyke Farm Platform, an intensively instrumented farm-scale ruminant research facility located in southwest United Kingdom, this paper proposes a novel, information-driven approach to carry out comprehensive assessments of economic-environmental trade-offs inherent within pasture-based cattle and sheep production systems. The results of a data-mining exercise suggest that a potentially systematic interaction exists between ‘soil health’, ecological surroundings and livestock grazing, whereby a higher level of soil organic carbon (SOC) stock is associated with a better animal performance and less nutrient losses into watercourses, and a higher stocking density with greater botanical diversity and elevated SOC. We contend that a combination of farming system-wide trials and environmental instrumentation provides an ideal setting for enrolling scientifically sound and biologically informative metrics for agricultural sustainability, through which agricultural producers could obtain guidance to manage soils, water, pasture and livestock in an economically and environmentally acceptable manner. Priority areas for future farm-scale research to ensure long-term sustainability are also discussed.

Relationship between precipitation and soil water chemistry in an intensively managed clayey soil environment in southwest England: a preliminary study

This study investigated the temporal characteristics of precipitation chemistry, and precipitation-soil water chemistry relationship at an intensively managed farm in the UK. Data investigated were the environment change network (ECN) terrestrial observation data for the Rothamsted research farm platform at North Wyke in Devon. Results showed that temporal variability exists in the precipitation chemistry but did not show that either the soil or the precipitation was chemically impaired. Temporal variations in the precipitation chemistry were attributed to climatic effects and anthropogenic sources as informed by the trends and results of the comparison to the seawater ion ratio. Strong relationships that existed in the investigated chemical variables (except Cl− and PO43−) between the top (above 10 cm) and lower (below 10 cm) soil layers indicated significant mixing of the soil water at this profile. The study indicated significant precipitation-soil water chemistry in the clayey-rich area.

Modelling field scale spatial variation in water run-off, soil moisture, N2O emissions and herbage biomass of a grazed pasture using the SPACSYS model

In this study, we evaluated the ability of the SPACSYS model to simulate water run-off, soil moisture, N2O fluxes and grass growth using data generated from a field of the North Wyke Farm Platform. The field-scale model is adapted via a linked and grid-based approach (grid-to-grid) to account for not only temporal dynamics but also the within-field spatial variation in these key ecosystem indicators. Spatial variability in nutrient and water presence at the field-scale is a key source of uncertainty when quantifying nutrient cycling and water movement in an agricultural system. Results demonstrated that the new spatially distributed version of SPACSYS provided a worthy improvement in accuracy over the standard (single-point) version for biomass productivity. No difference in model prediction performance was observed for water run-off, reflecting the closed-system nature of this variable. Similarly, no difference in model prediction performance was found for N2O fluxes, but here the N2O predictions were noticeably poor in both cases. Further developmental work, informed by this study's findings, is proposed to improve model predictions for N2O. Soil moisture results with the spatially distributed version appeared promising but this promise could not be objectively verified.

Recombinant Plant Engineering for Immunotherapeutic Production.

Purpose of ReviewThe requirement for large quantities of therapeutic proteins has fueled a great interest in the production of recombinant proteins in plant bioreactors. The vaccines and bio-therapeutic protein production in plants hold the promise of significantly lowering the cost of manufacturing life-saving drugs. This review will reflect the current status and challenges that the molecular farming platform faces becoming a strategic solution for the development of low-cost bio-therapeutics for developing countries.Recent FindingsDifferent plant parts have been successfully identified as suitable expression systems for the commercial production of therapeutic proteins for some human and animal diseases ranging from common cold to AIDS. The processed therapeutics from such sources are devoid of any toxic components. The large-scale cultivation of these transgenic plants would be possible anywhere in the world including developing countries, which lack sophisticated drug manufacturing units. A couple of such commercially generated products have already hit the market with success. Newer methods using suitable plant viruses and recombinant gene expression systems have already been devised for producing therapeutic proteins and peptides.SummaryPlants are promising bio-factories for therapeutic protein production because of their several advantages over the other expression systems especially the advanced mechanisms for protein synthesis and post-translational modification which are very much similar to animal cells. Plant biotechnologists are much attracted to the bio-farming because of its flexibility, scalability, low manufacturing cost, as well as the lack of risk of toxic or pathogenic contamination. A number of projects on bio-farming are designed and are at various developmental stages but have not yet become available to the pharmaceutical industry. Therefore, we need further advancement in the optimization of lab protocols for up-scaling the production of such therapeutics at commercial level with a promise to offer their best clinical use.

Distributions of emissions intensity for individual beef cattle reared on pasture-based production systems

Life Cycle Assessment (LCA) of livestock production systems is often based on inventory data for farms typical of a study region. As information on individual animals is often unavailable, livestock data may already be aggregated at the time of inventory analysis, both across individual animals and across seasons. Even though various computational tools exist to consider the effect of genetic and seasonal variabilities in livestock-originated emissions intensity, the degree to which these methods can address the bias suffered by representative animal approaches is not well-understood. Using detailed on-farm data collected on the North Wyke Farm Platform (NWFP) in Devon, UK, this paper proposes a novel approach of life cycle impact assessment that complements the existing LCA methodology. Field data, such as forage quality and animal performance, were measured at high spatial and temporal resolutions and directly transferred into LCA processes. This approach has enabled derivation of emissions intensity for each individual animal and, by extension, its intra-farm distribution, providing a step towards reducing uncertainty related to agricultural production inherent in LCA studies for food. Depending on pasture management strategies, the total emissions intensity estimated by the proposed method was higher than the equivalent value recalculated using a representative animal approach by 0.9–1.7 kg CO2-eq/kg liveweight gain, or up to 10% of system-wide emissions. This finding suggests that emissions intensity values derived by the latter technique may be underestimated due to insufficient consideration given to poorly performing animals, whose emissions becomes exponentially greater as average daily gain decreases. Strategies to mitigate life-cycle environmental impacts of pasture-based beef productions systems are also discussed.

Assessment of soil water, carbon and nitrogen cycling in reseeded grassland on the North Wyke Farm Platform using a process-based model

The North Wyke Farm Platform (NWFP) generates large volumes of temporally-indexed data that provides a valuable test-bed for agricultural mathematical models in temperate grasslands. In our study, we used the primary datasets generated from the NWFP (https://nwfp.rothamsted.ac.uk/) to validate the SPACSYS model in terms of the dynamics of water loss and forage dry matter yield estimated through cutting. The SPACSYS model is capable of simulating soil water, carbon (C) and nitrogen (N) balance in the soil-plant-atmosphere system. The validated model was then used to simulate the responses of soil water, C and N to reseeding grass cultivars with either high sugar (Lolium perenne L. cv. AberMagic) or deep rooting (Festulolium cv. Prior) traits. Simulation results demonstrated that the SPACSYS model could predict reliably soil water, C and N cycling in reseeded grassland. Compared to AberMagic, the Prior grass could fix more C in the second year following reseeding, whereas less C was lost through soil respiration in the first transition year. In comparison to the grass cultivar of the permanent pasture that existed before reseeding, both grasses reduced N losses through runoff and contributed to reducing water loss, especially Prior in relation to the latter. The SPACSYS model could predict these differences as supported by the rich dataset from the NWFP, providing a tool for future predictions on less characterized pasture.

An evaluation of the hysteresis in chemical concentration–discharge (C–Q) relationships from drained, intensively managed grasslands in southwest England

ABSTRACTThis study examined the hysteresis exhibited in concentration–discharge (C–Q) relationships in the runoff from four hydrologically separated fields (catchments) at an intensively managed grassland. The objectives were to examine C–Q relationships constructed from high-resolution time series of flow, temperature, pH, conductivity, nitrate and turbidity, and their implications for hydrological processes. High-resolution datasets from the quality assured records of the Rothamsted Research North Wyke Farm Platform in the UK were examined using a graphical method and cross-correlation statistics. The study found that storm events based C–Q hysteresis reflects the cross-correlation that is generally hidden in time series analysis of large datasets, and that although Q and water quality variables can be effectively influenced by catchment size, the C–Q relationship is less significantly influenced. The dominant C–Q relationships of the water variables in the study area reflect that saturated overland flow was prevalent during the study period in the catchments, while the CCF results indicate coupled transfer of sediments and solute in the area at lag ≥ 0.EDITOR D. KoutsoyiannisASSOCIATE EDITOR M. D. Fidelibus

Molecular identification and distribution of leatherjackets (Diptera: Tipulidae) in U.K. agricultural grassland

Abstract DNA barcoding is useful for the identification of morphologically cryptic invertebrates. An important application is for pest species, for which it is critical to determine the distribution, biology and ecology of damaging life stages in order to target management effectively. Tipula paludosa (Meigen) and Tipula oleracea (Linnaeus) leatherjackets, the larvae of crane flies (Diptera: Tipulidae), are pests of agricultural grassland in Europe and the U.S.A. and are difficult to distinguish morphologically. We used cytochrome c oxidase subunit I (COI) barcoding to identify leatherjackets from 19 permanent grassland fields over 2 sampling seasons on the Rothamsted Research North Wyke Farm Platform, south west UK, to assess species-level distribution and genetic diversity. Most larvae (94%) were found to be T. paludosa, comprising 18 haplotypes that were spread across the sampling site in a panmictic population. However, T. oleracea were found in low abundance (3% of larval samples) and only in the second year of sampling. Other morphologically similar Dipteran larvae (3%) were also found. This dominance of one species suggests that there may be underlying differences in species biology, such as choice of oviposition site and dispersal ability, which is in agreement with other studies and has implications for monitoring and management.

The effect of trophic level on individual amino acid δ15N values in a terrestrial ruminant food web

ABSTRACTBulk collagen δ15N analysis is widely used to investigate past diet and trophic positions, but these values average the δ15N values of the constituent amino acids. Compound–specific isotope analysis of amino acids (AAs) can help elucidate the complex metabolic effects underpinning bulk δ15N values. Although trophic level effects on individual AA δ15N values have been investigated in aquatic and terrestrial invertebrate food webs, most archaeological applications involve terrestrial herbivores, hence a greater understanding of these effects between diet and consumer in this food chain is required. The North Wyke Farm Platform provided baseline nitrogen isotope information for cattle grazing on a Lolium perenne-dominated pasture. Bulk dentine δ15N values show a shift expected for a one trophic level increase, but obscure insight into the underlying metabolic processes that cause this change in value. However, determination of AA δ15N values of hydrolysable plant protein and cattle tooth dentine clarifies the trophic effect on consumer AA δ15N values. The observed trophic shift in the studied system is different from previously studied food webs, with a trophic enrichment factor, based on the δ15N values of glutamate and phenylalanine, of 4.0‰ compared to 7.6‰ commonly used in ecological and archaeological studies. This emphasises the need to understand the trophic shifts in the particular food web being investigated in order to apply isotopic investigations in archaeological contexts.

Spatial variation in soil properties and diffuse losses between and within grassland fields with similar short-term management.

SummaryOne of the major challenges for agriculture is to understand the effects of agricultural practices on soil properties and diffuse pollution, to support practical farm‐scale land management. Three conventionally managed grassland fields with similar short‐term management, but different ploughing histories, were studied on a long‐term research platform: the North Wyke Farm Platform. The aims were to (i) quantify the between‐field and within‐field spatial variation in soil properties by geostatistical analysis, (ii) understand the effects of soil condition (in terms of nitrogen, phosphorus and carbon contents) on the quality of discharge water and (iii) establish robust baseline data before the implementation of various grassland management scenarios. Although the fields sampled had experienced the same land use and similar management for at least 6 years, there were differences in their mean soil properties. They showed different patterns of soil spatial variation and different rates of diffuse nutrient losses to water. The oldest permanent pasture field had the largest soil macronutrient concentrations and the greatest diffuse nutrient losses. We show that management histories affect soil properties and diffuse losses. Potential gains in herbage yield or benefits in water quality might be achieved by characterizing every field or by area‐specific management within fields (a form of precision agriculture for grasslands). Permanent pasture per se cannot be considered a mitigation measure for diffuse pollution. The between‐ and within‐field soil spatial variation emphasizes the importance of baseline characterization and will enable the reliable identification of any effects of future management change on the Farm Platform.Highlights Quantification of soil and water quality in grassland fields with contrasting management histories.Considerable spatial variation in soil properties and diffuse losses between and within fields.Contrasting management histories within and between fields strongly affected soil and water quality.Careful pasture management needed: the oldest pasture transferred the most nutrients from soil to water.

The North Wyke Farm Platform: effect of temperate grassland farming systems on soil moisture contents, runoff and associated water quality dynamics.

SummaryThe North Wyke Farm Platform was established as a United Kingdom national capability for collaborative research, training and knowledge exchange in agro‐environmental sciences. Its remit is to research agricultural productivity and ecosystem responses to different management practices for beef and sheep production in lowland grasslands. A system based on permanent pasture was implemented on three 21‐ha farmlets to obtain baseline data on hydrology, nutrient cycling and productivity for 2 years. Since then two farmlets have been modified by either (i) planned reseeding with grasses that have been bred for enhanced sugar content or deep‐rooting traits or (ii) sowing grass and legume mixtures to reduce nitrogen fertilizer inputs. The quantities of nutrients that enter, cycle within and leave the farmlets were evaluated with data recorded from sensor technologies coupled with more traditional field study methods. We demonstrate the potential of the farm platform approach with a case study in which we investigate the effects of the weather, field topography and farm management activity on surface runoff and associated pollutant or nutrient loss from soil. We have the opportunity to do a full nutrient cycling analysis, taking account of nutrient transformations in soil, and flows to water and losses to air. The NWFP monitoring system is unique in both scale and scope for a managed land‐based capability that brings together several technologies that allow the effect of temperate grassland farming systems on soil moisture levels, runoff and associated water quality dynamics to be studied in detail.Highlights Can meat production systems be developed that are productive yet minimize losses to the environment?The data are from an intensively instrumented capability, which is globally unique and topical.We use sensing technologies and surveys to show the effect of pasture renewal on nutrient losses.Platforms provide evidence of the effect of meteorology, topography and farm activity on nutrient loss.

Historic record of pasture soil water and the influence of the North Atlantic Oscillation in south-west England

The North Wyke Farm Platform for sustainable grassland research in south-west England contains infrastructure measuring soil moisture and field runoff. Its time series of sensor data is used to validate the parsimonious SH2O-NW model for soil water at field-scale. Thirty-four years of daily soil moisture and runoff is simulated, and used to detect long-term trends and produce a risk analysis. The model accounts for wetter periods of soil moisture and the main summer soil deficit and autumn re-wetting; limitations involve short-term, rapid changes in drying and re-wetting. The soil moisture sensor observations however do not reflect field variability. Analysis of more than one field allows an assessment of unexpected sensor anomalies. The paper recommends that soil moisture sensor confidence levels be provided, for comparison against modelled data. The simulations show a historic reduction in the occurrence of summer soil moisture deficits above a third of water capacity, while the winter precipitation and runoff simulation shows a stable long-term trend, matching the direction and magnitude of the North Atlantic Oscillation Index. A large runoff of 400 m3/day from a 1.75 ha pasture has a 0.07% probability, having a return period of once in 4 years during the 34-year period.

Sustainable grassland systems: a modelling perspective based on the North Wyke Farm Platform.

SummaryThe North Wyke Farm Platform (NWFP) provides data from the field‐ to the farm‐scale, enabling the research community to address key issues in sustainable agriculture better and to test models that are capable of simulating soil, plant and animal processes involved in the systems. The tested models can then be used to simulate how agro‐ecosystems will respond to changes in the environment and management. In this study, we used baseline datasets generated from the NWFP to validate the Soil‐Plant‐Atmosphere Continuum System (SPACSYS) model in relation to the dynamics of soil water content, water loss from runoff and forage biomass removal. The validated model, together with future climate scenarios for the 2020s, 2050s and 2080s (from the International Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES): medium (A1B) and large (A1F1) emission scenarios), were used to simulate the long‐term responses of the system with three contrasting treatments on the NWFP. Simulation results demonstrated that the SPACSYS model could estimate reliably the dynamics of soil water content, water loss from runoff and drainage, and cut biomass for a permanent sward. The treatments responded in different ways under the climate change scenarios. More carbon (C) is fixed and respired by the swards treated with an increased use of legumes, whereas less C was lost through soil respiration with the planned reseeding. The deep‐rooting grass in the reseeding treatment reduced N losses through leaching, runoff and gaseous emissions, and water loss from runoff compared with the other two treatments.

Network Security Study Based on Data Farming

With the development of network technology and network size, network security incidents occur more frequently. Exploring the reasons and processes that cause network security incidents can help us analyze the current network situation and formulate appropriate coping strategies. In order to find the causes we apply data farming in the filed of network security, a data farming platform based on simulation software NetLogo and data farming tool OldmcData was established in this paper. By planting data in the area of interest, data mining, visualization and such analytical methods can be applied to find out the reasons and processes behind in the incidents so as to take corresponding measure to improve the security of network.

Mooring Analysis of Offshore Aquaculture Oceanic Farming Platform for Seaweed

Aquaculture activities are performed at close proximity to coastline and near shore. Issues and environmental impact concerns and challenges necessitate offshore aquaculture that required reliable structural integrity and mooring system design for ultimate state limit, fatigue state limit and accidental and progressive state limit against environmental loading and accidental loading. To avoid mooring system failure, selecting an appropriate breaking strength and limit state for mooring system components is necessary. Suitable mooring system has been designed by group of researchers at Universiti Malaysia Terengganu. Valuable information was obtained from Technip and Bureau Veritas. The system has been tested in towing tank in Universiti Teknologi Malaysia. This paper describes mooring system design that account for forces and environmental loadings. The paper describes evaluation of optimum mooring performance in wave and current loadings on mooring components anchor buoy and riser elements that are involved in the mooring system dynamics.