The Dutch horticultural sector aims to be climate-neutral by 2040. Scientists at Wageningen University & Research have therefore recently built a new demonstration greenhouse ‘Greenhouse 2030’ in an effort to find ways to reduce CO2 emissions as well eliminating the need for crop protection chemicals and optimizing the use of water and nutrients.

Greenhouses helping to reduce greenhouse gas emissions

Scientists at Wageningen University & Research (WUR) in the Netherlands have employed Vaisala carbon dioxide sensors in their research greenhouses for over a decade. Carbon dioxide is an extremely important measurement parameter in plant science, not just because plants need carbon dioxide to grow, but also because environmental emissions contribute to climate change, so enormous threats and opportunities surround this gas. As a world renowned research organisation, the value of the institute’s work is partly dependent on the accuracy and reliability of sensors, so it is important that its researchers do not compromise on sensor quality.

Wageningen has been one of the driving forces in research and technology development for greenhouse horticulture in the Netherlands. The institute’s expertise in the greenhouse cultivation of ornamental, fruit and vegetable crops is unique, and together with growers and technology partners, it has developed new cultivation systems, climate control systems, revolutionary greenhouse cover materials and other innovations. The application of these new technologies has made greenhouse horticulture in the Netherlands a world leader.

The Plant Research Institute operates over 100 greenhouse compartments at its Bleiswijk site, which means that researchers are able to generate a wide variety of environmental conditions. Typical environmental variables include light, water, growing medium, nutrients, (biological) pest/disease control, temperature, humidity and of course carbon dioxide (CO₂); all of which have significant effects on crop yields.

The Dutch horticultural sector aims to be climate-neutral by 2040. The Wageningen researchers have therefore recently built a new demonstration greenhouse ‘Greenhouse 2030’ for the cultivation of vegetables, fruit and flowers in an effort to find ways to reduce CO₂ emissions as well eliminating the need for crop protection chemicals and optimizing the use of water and nutrients. Pests and diseases are preferably tackled biologically, and the energy-efficient greenhouse reuses water and nutrients as much as possible; leading to cleaner cultivation and improved yields.

Carbon Dioxide in Greenhouses
Carbon dioxide is a by-product of many processes in the oil, gas and petrochemical industries, but it is also required by plants to grow through photosynthesis, so Dutch greenhouse operators have collaborated with the country’s industrial sector to utilise this byproduct and thereby contribute in the fight against climate change by lowering the country’s net CO₂ emissions. Globally, many greenhouse operators burn natural gas to generate CO₂, but this also generates heat that may not be needed in the summer months, so the utilisation of an industrial byproduct is significantly preferable.

Carbon dioxide was first delivered to Dutch greenhouses in 2005 via a pipe network established by the company Organic Carbon Dioxide for Assimilation of Plants (OCAP). Commercial greenhouse operators pay for this CO₂ supply, which is largely derived from a bio ethanol plant. A key feature of the Institute’s research is work to optimise the utilisation of CO₂, along with other plant growth variables. For example, the Institute has developed a simulation tool for CO₂ dosing: the “CO₂-viewer.” This programme monitors and displays the effects of a grower’s dosing strategy. For instance, it enables the evaluation of CO₂ dosing around midday compared with dosing in the morning. The computational results of such an evaluation take all relevant greenhouse building characteristics and climate control settings into account.

Monitoring Carbon Dioxide

CO₂ Probe

After around 10 years of operation, the institute is replacing around 150 of the older model probes with a newer model. The calibration of all probes is checked prior to the commencement of every project, utilizing certified reference gases. It is important that calibration data is traceable, so each probe’s calibration certificate is retained and subsequent calibration checks are documented. A portable CO₂ monitor (a Vaisala GM70) with a GMP252 CO₂ probe are also used as a validation tool to check installed probes, even though further calibration is not necessary.

Currently, the Institute’s installed probes provide 4-20 mA signals which feed into ‘climate computers’ that are programmed to manage the greenhouses automatically. This system also raises alarms if CO₂ levels approach dangerous levels for any reason.

CO₂ Sensor Technology
Carbon dioxide absorbs light in the infrared (IR) region at a wavelength of 4.26 μm. This means that when IR radiation is passed through a gas containing CO₂, part of the radiation is absorbed, and this absorbance can be measured. The Vaisala CARBOCAP® carbon dioxide sensor features an innovative micro-machined, electrically tunable Fabry-Perot Interferometer (FPI) filter. In addition to measuring CO₂ absorption, the FPI filter enables a reference measurement at a wavelength where no absorption occurs. When taking the reference measurement, the FPI filter is electrically adjusted to switch the bypass band from the absorption wavelength to a non-absorption wavelength. This reference measurement compensates for any potential changes in the light source intensity, as well as for contamination or dirt accumulation in the optical path. Consequently, the CARBOCAP® sensor is highly stable over time, and by incorporating both measurements in one sensor, this compact technology can be incorporated into small probes, modules, and transmitters.

The CARBOCAP® technology means that the researchers don’t have to worry about calibration drift or sensor failure.

Carbon Dioxide Plant Science Research
Two projects are currently underway evaluating the effects of different CO₂ levels on plant production. One is studying soft fruit and the other tomatoes; however with CO₂ playing such an important role in both plant growth and climate change, the value of accurate measurements of this gas continues to grow. Most of the greenhouses are now connected to the institute’s Ethernet and a wide variety of new sensors are continually being added to the monitoring network; providing an opportunity to utilise new ‘smart’ sensors.

Summary
The accuracy, stability and reliability of the CO₂ sensors at Bleiswijk are clearly vitally important to the success of the Institute’s research, particularly because data from one greenhouse are often compared with data from others.

The CO₂ supply has a cost; it is therefore important that this resource is monitored and supplied effectively so that plant production can be optimized.

Clearly, moves to lower the use of fossil fuels and develop more efficient energy management systems will help to reduce CO₂ emissions from the greenhouse sector. However, the importance of CO₂ utilization is set to grow, given the 2040 climate-neutral target and the world’s need to find new and better ways to capture CO₂ emissions in ways that are both sustainable and economically viable.

#Hortoculture #Environment @VaisalaGroup @_Enviro_News

Monitoring is an essential component of natural flooding management, helping to define appropriate measures, measure their success, keep stakeholders informed, identify mistakes, raise alarms when necessary, inform adaptive management and help guide future research.

Great Fen showing Holme Fen woods top left and new ponds and meres in April

Flooding is a natural process, but it endangers lives and causes heavy economic loss. Furthermore, flood risk is expected to increase with climate change and increased urbanisation, so a heavy responsibility lies with those that allocate funding and formulate flood management strategy. In the following article, Nigel Grimsley from OTT Hydromet explains how the success of such plans (both the design and implementation) depend on the accuracy and reliability of the monitoring data upon which they rely.

Climate projections for Britain suggest that rainfall will increase in winter and decrease in summer, and that individual rainfall events may increase in intensity, especially in winter. This paradigm predicates an increased risk of flooding.

Emphasising the urgent need for action on flood risk, (British) Environment Agency chairwoman Emma Howard Boyd, has said that on current trends, global temperature could rise between 2 deg C and 4 Deg C by 2100 and some communities may even need to move because of the risk of floods. Launching a consultation on the agency’s flood strategy, she said: “We can’t win a war against water by building away climate change with infinitely high flood defences.”

In response, Mike Childs, head of science at Friends of the Earth, said: “Smarter adaptation and resilience building – including natural flood management measures like tree-planting – is undeniably important but the focus must first and foremost be on slashing emissions so that we can avoid the worst consequences of climate chaos in the first place.”

Historically, floodplains have been exploited for agricultural and urban development, which has increased the exposure of people, property and other infrastructure to floods. Flood risk management therefore focused on measures to protect communities and industry in affected areas. However, flood risk is now addressed on a wider catchment scale so that initiatives in one part of a catchment do not have negative effects further downstream. This catchment based approach is embodied within the EU Floods Directive 2007/60/EC, and in recent years, those responsible for flood management have increasingly looked for solutions that employ techniques which work with natural hydrological and morphological processes, features and characteristics to manage the sources and pathways of flood waters. These techniques are known as natural flood management (NFM) and include the restoration, enhancement and alteration of natural features but exclude traditional flood defence engineering that effectively disrupts these natural processes.

NFM seeks to create efficiency and sustainability in the way the environment is managed by recognising that when land and water are managed together at the catchment scale it is possible to generate whole catchment improvements with multiple benefits.

Almost all NFM techniques aim to slow the flow of water and whilst closely connected, can be broadly categorised as infiltration, conveyance and storage.

Infiltration
Land use changes such as set-aside, switching arable to grassland or restricted hillside cropping, can improve infiltration and increase water retention. In addition, direct drilling, ‘no-till’ techniques and cross slope ploughing can have a similar effect. These land use techniques are designed to reduce the soil compaction which increases run-off. Livestock practices such as lower stocking rates and shorter grazing seasons can also help. Field drainage can be designed to increase storage and reduce impermeability, which is also aided by low ground pressure vehicles. The planting of shrubs and trees also helps infiltration and retention by generating a demand for soil moisture, so that soils have a greater capacity to absorb water. Plants also help to bind soil particles, resulting in less erosion – the cause of fertility loss and sedimentation in streams and rivers.

Conveyance
Ditches and moorland grips can be blocked to reduce conveyance, and river profiles can be restored to slow the flow. In the past, peats and bogs have been drained to increase cropping areas, but this damages peatlands and reduces their capacity to retain water and store carbon. The restoration of peatland therefore relies on techniques to restore moisture levels. Pumping and drainage regimes can be modified, and landowners can create strategically positioned hedges, shelter belts and buffer strips to reduce water conveyance.

Storage
Rivers can be reconnected with restored floodplains and river re-profiling, leaky dams, channel works and riparian improvements can all contribute to improved storage capability. In urban areas permeable surfaces and underground storage can be implemented, and washlands and retention ponds can be created in all areas. As mentioned above, the re-wetting of peatland and bogs helps to increase storage capacity.

Many of the effects of NFM might be achieved with the re-introduction of beavers, which build dams that reduce peak flows, create pools and saturate soil above their dams. The dams also help to remove pollutants such as phosphates. Beavers do not eat fish, instead preferring aquatic plants, grasses and shrubs during the summer and woody plants in winter. Beavers are now being introduced in a number of areas in trials to determine their value in the implementation of NFM. One of the key benefits offered by beavers is their ability to quickly repair and rebuild dams that are damaged during extreme weather. However, whilst the potential benefits of beavers are well known, several groups have expressed concern with the prospect of their widespread introduction. For example, farmers and landowners may find increased areas of waterlogged land due to blocked drainage channels. In addition, dams present a threat to migratory fish such as salmon and sea trout.

Beavers are native to Britain and used to be widespread, but they were hunted to extinction during the 17th century. However, other non-native species such as signal crayfish can have a detrimental effect on flood protection because they burrow into river banks causing erosion, bank collapse and sediment pollution. Signal crayfish are bigger, grow faster, reproduce more quickly and tolerate a wider range of conditions than the native white-clawed crayfish. Signal crayfish are also voracious predators, feeding on fish, frogs, invertebrates and plants, and as such can create significant negative ecological effects.

NFM benefits
NFM provides protection for smaller flood events, reduces peak flooding and delays the arrival of the flood peak downstream. However, it does not mitigate the risk from extreme flood events. Effective flood management strategy therefore tends to combine NFM with hard engineering measures. Nevertheless, NFM generally provides a broader spectrum of other benefits.

The creation of new woodlands and wetlands produces biodiverse habitats with greater flood storage capacity. They also enable more species to move between habitats. NFM measures that reduce soil erosion, run-off and sedimentation also help to improve water quality and thereby also improve habitats. In particular, these measures lower nutrient and sediment loading lower in the catchment; two issues which can have dramatic effects on water quality and amenity.

Land use and land management measures help to reduce the loss of topsoil and nutrients. This improves agricultural productivity and lowers the cost of fertilizers. Furthermore, a wide range of grants are available for NFM measures, such as the creation of green spaces and floodplains, to make them more financially attractive to farmers and landowners.

Many NFM measures help in the fight against climate change. For example, wetlands and woodlands are effective at storing carbon and removing carbon dioxide from the atmosphere. Measures that reduce surface run off and soil erosion, such as contour cultivation, can also reduce carbon loss from soil.

Monitoring NFM
Given the wide range of potential NFM benefits outlined above, the number and type of parameters to be monitored are likely to be equally diverse. Baseline data is essential if the impacts of implemented measures are to be assessed, but this may not always be deliverable. For example, it may only be possible to collect one season of data prior to a five year project. However, it may be possible to secure baseline data from other parties. In all instances data should of course be accurate, reliable, relevant and comparable.

Monitoring data should be used to inform the design of NFMs. For example, a detailed understanding of the ecology, geomorphology, hydrology and meteorology of the entire catchment will help to ensure that the correct measures are chosen. These measures should be selected in partnership with all stakeholders, and ongoing monitoring should provide visibility of the effects of NFM measures. Typically stakeholders will include funders, project partners, local communities, landowners, regulators and local authorities.

Since NFM measures are designed to benefit an entire catchment, it is important that monitoring is also catchment-wide. However, this is likely to be a large area so there will be financial implications, particularly for work that is labour-intensive. Consequently, it will be necessary to prioritise monitoring tasks and to deploy remote, automatic technology wherever it is cost-effective.

OTT ecoN Sensor

Clearly, key parameters such as rainfall, groundwater level, river level and surface water quality should be monitored continuously in multiple locations if the benefits of NFM are to be measured effectively. It is fortunate therefore that all of these measurements can be taken continuously 24/7 by instruments that can be left to monitor in remote locations without a requirement for frequent visits to calibrate, service or change power supplies. As a business OTT Hydromet has been focused on the development of this capability for many years, developing sensors that are sufficiently rugged to operate in potentially aggressive environments, data loggers with enormous capacity but with very low power requirement, and advanced communications technologies so that field data can be instantly viewed by all stakeholders.

Recent developments in data management have led to the development of web-enabled data management solutions such as Hydromet Cloud, which, via a website and App, delivers the backend infrastructure to receive, decode, process, display and store measurement data from nearly any remote hydromet monitoring station or sensor via a cloud-based data hosting platform. As a consequence, alarms can be raised automatically, which facilitates integration with hard engineering flood control measures. Hydromet Cloud also provides access to both current and historic measurement data, enabling stakeholders to view the status of an entire catchment on one screen.

Holme Fen – a monitoring lesson from the 1850s

Holme Fen post

Surrounded by prime agricultural land to the south of Peterborough (Cambridgeshire,GB) , the fens originally contained many shallow lakes, of which Whittlesey Mere was the largest, covering around 750 hectares in the summer and around twice that in the winter. Fed by the River Nene, the mere was very shallow and was the last of the ‘great meres’ to be drained and thereby converted to cultivatable land.

Led by William Wells, a group of local landowners funded and arranged the drainage project, which involved the development of a newly invented steam powered centrifugal pump which was capable of raising over 100 tons of water per minute by 2 or 3 feet. A new main drain was constructed to take water to the Wash. Conscious of the likely shrinking effect of drainage on the peaty soil, Wells instigated the burial of a measurement post, which was anchored in the Oxford Clay bedrock and cut off at the soil surface. In 1851 the original timber post was replaced by a cast iron column which is believed to have come from the Crystal Palace in London.

By installing a measurement post, Wells demonstrated remarkable foresight. As the drainage proceeded, the ground level sank considerably; by 1.44 metres in the first 12 years, and by about 3 metres in the first 40 years. Today, around 4 metres of the post is showing above ground, recording the ground subsidence since 1852. The ground level at Holme Post is now 2.75 metres below sea level – the lowest land point in Great Britain.
Several complications have arisen as a result of the drainage. Firstly, there has been a huge impact in local ecology and biodiversity with the loss of a large area of wetland. Also, as the ground level subsided it became less sustainable to pump water up into the main drain.

Holme Fen is now a National Nature Reserve, managed by Natural England, as is the nearby Woodwalton Fen. They are both part of the Great Fen Project, an exciting habitat restoration project, involving several partners, including the local Wildlife Trust, Natural England and the Environment Agency. At Woodwalton, the more frequent extreme weather events that occur because of climate change result in flooding that spills into the reserve. In the past, this was a good example of NFM as the reserve provided a buffer for excess floodwater. However, Great Fen Monitoring and Research Officer Henry Stanier says: “Floodwater increasingly contains high levels of nutrients and silt which can harm the reserve’s ecology, so a holistic, future-proof strategy for the area is necessary.”

Applauding the farsightedness of William Wells, Henry says: “As a conservationist I am often called in to set up monitoring after ecological recovery has begun, rather than during or even before harm has taken place. At the Wildlife Trust, we are therefore following the example provided by Wells, and have a network of monitoring wells in place so that we can monitor the effects of any future changes in land management.

“For example, we are setting up a grant funded project to identify the most appropriate crops for this area; now and in the future, and we are working with OTT to develop a monitoring strategy that will integrate well monitoring with the measurement of nutrients such as phosphate and nitrate in surface waters.”

Summary
Monitoring provides an opportunity to measure the effects of initiatives and mitigation measures. It also enables the identification of trends so that timely measures can be undertaken before challenges become problems, and problems become catastrophes.

Monitoring is an essential component of NFM, helping to define appropriate measures, measure their success, keep stakeholders informed, identify mistakes, raise alarms when necessary, inform adaptive management and help guide future research.

#Environment @OTTHydromet @EnvAgency @friends_earth

Nigel Grimsley from OTT Hydrometry describes relatively new technologies that have overcome traditional barriers to the continuous monitoring of phosphate and nitrate.

The science behind nutrient pollution in rivers is still poorly understood despite the fact that nitrate and phosphate concentrations in Britain’s rivers are mostly unacceptable, although an element of uncertainty exists about what an acceptable level actually is. Key to improving our understanding of the sources and impacts of nutrient pollution is high-resolution monitoring across a broad spectrum of river types.

Background

Green Box Hydro Cycle

Phosphates and nitrates occur naturally in the environment, and are essential nutrients that support the growth of aquatic organisms. However, water resources are under constant pressure from both point and diffuse sources of nutrients. Under certain conditions, such as warm, sunny weather and slow moving water, elevated nutrient concentrations can promote the growth of nuisance phytoplankton causing algal blooms (eurtrophication). These blooms can dramatically affect aquatic ecology in a number of ways. High densities of algal biomass within the water column, or, in extreme cases, blankets of algae on the water surface, prevent light from reaching submerged plants. Also, some algae, and the bacteria that feed on decaying algae, produce toxins. In combination, these two effects can lower dissolved oxygen levels and potentially kill fish and other organisms. In consequence, aquatic ecology is damaged and the water becomes unsuitable for human recreation and more expensive to treat for drinking purposes.

In its State of the Environment report, February 2018, the British Environment Agency said: “Unacceptable levels of phosphorus in over half of English rivers, usually due to sewage effluent and pollution from farm land, chokes wildlife as algal blooms use up their oxygen. Groundwater quality is currently deteriorating. This vital source of drinking water is often heavily polluted with nitrates, mainly from agriculture.”

Good ecological status
The EU Water Framework Directive (WFD) requires Britain to achieve ‘good status’ of all water bodies (including rivers, streams, lakes, estuaries, coastal waters and groundwater) by 2015. However, only 36% of water bodies were classified as ‘good’ or better in 2012. Nutrient water quality standards are set by the Department for Environment, Food & Rural Affairs (DEFRA), so for example, phosphorus water quality standards have been set, and vary according to the alkalinity and height above mean sea level of the river. Interestingly, the standards were initially set in 2009, but in 75% of rivers with clear ecological impacts of nutrient enrichment, the existing standards produced phosphorus classifications of good or even high status, so the phosphorus standards were lowered.

Highlighting the need for better understanding of the relationships between nutrients and ecological status, Dr Mike Bowes from the Centre for Ecology & Hydrology has published research, with others, in which the effects of varying soluble reactive phosphate (SRP) concentrations on periphyton growth rate (mixture of algae and microbes that typically cover submerged surfaces) where determined in 9 different rivers from around Britain. In all of these experiments, significantly increasing SRP concentrations in the river water for sustained periods (usually c. 9 days) did not increase periphyton growth rate or biomass. This indicates that in most rivers, phosphorus concentrations are in excess, and therefore the process of eutrophication (typified by excessive algal blooms and loss of macrophytes – aquatic plants) is not necessarily caused by intermittent increases in SRP.

Clearly, more research is necessary to more fully understand the effects of nutrient enrichment, and the causes of algal blooms.

Upstream challenge
Headwater streams represent more than 70% of the streams and rivers in Britain, however, because of their number, location and the lack of regulatory requirement for continuous monitoring, headwater streams are rarely monitored for nutrient status. Traditional monitoring of upland streams has relied on either manual sampling or the collection of samples from automatic samplers. Nevertheless, research has shown that upland streams are less impaired by nutrient pollution than lowland rivers, but because of their size and limited dilution capacity they are more susceptible to nutrient impairment.

Monitoring technology
Sampling for laboratory analysis can be a costly and time-consuming activity, particularly at upland streams in remote locations with difficult access. In addition, spot sampling reveals nutrient levels at a specific moment in time, and therefore risks missing concentration spikes. Continuous monitoring is therefore generally preferred, but in the past this has been difficult to achieve with the technology available because of its requirement for frequent re-calibration and mains power.

High resolution SRP monitoring has been made possible in almost any location with the launch by OTT Hydromet of the the ‘HydroCycle PO4’ which is a battery-powered wet chemistry analyser for the continuous analysis of SRP. Typically, the HydroCycle PO4 is deployed into the river for monitoring purposes, but recent work by the Environment Agency has deployed it in a flow-through chamber for measuring extracted water.

The HydroCycle PO4 methodology is based on US EPA standard methods, employing pre-mixed, colour coded cartridges for simple reagent replacement in the field. Weighing less than 8kg fully loaded with reagents, it is quick and easy to deploy, even in remote locations. The instrument has an internal data logger with 1 GB capacity, and in combination with telemetry, it provides operators with near real-time access to monitoring data for SRP.

The quality of the instrument’s data is underpinned by QA/QC processing in conjunction with an on-board NIST standard, delivering scientifically defensible results. Engineered to take measurements at high oxygen saturation, and with a large surface area filter for enhanced performance during sediment events, the instrument employs advanced fluidics, that are resistant to the bubbles that can plague wet chemistry sensors.

Environment Agency application
The National Laboratory Service Instrumentation team (NLSI) provides support to all high resolution water quality monitoring activities undertaken across the Agency, underpinning the EA’s statutory responsibilities such as the WFD, the Urban Waste Water Directive and Statutory Surface Water Monitoring Programmes. It also makes a significant contribution to partnership projects such as Demonstration Test Catchments and Catchments Sensitive Farming. Technical Lead Matt Loewenthal says: “We provide the Agency and commercial clients with monitoring systems and associated equipment to meet their precise needs. This includes, of course, nutrient monitoring, which is a major interest for everyone involved with water resources.”

Matt’s team has developed water quality monitoring systems that deliver high resolution remote monitoring with equipment that is quick and easy to deploy. There are two main options. The ‘green box’ is a fully instrumented cabinet that can be installed adjacent to a water resource, drawing water and passing it though a flow-through container with sensors for parameters such as Temperature Dissolved Oxygen, Ammonium, Turbidity, Conductivity pH and Chlorophyll a. Each system is fitted with telemetry so that real-time data is made instantly available to users on the cloud.

Conscious of the need to better understand the role of P in rivers, Matt’s team has integrated a HydroCycle PO4 into its monitoring systems as a development project.
Matt says: “It’s currently the only system that can be integrated with all of our remote monitoring systems. Because it’s portable, and runs on 12 volts, it has been relatively easy to integrate into our modular monitoring and telemetry systems.

“The HydroCycle PO4 measures SRP so if we need to monitor other forms of P, we will use an auto sampler or deploy a mains-powered monitor. However, monitoring SRP is important because this is the form of P that is most readily available to algae and plants.”

Explaining the advantages of high resolution P monitoring, Matt refers to a deployment on the River Dore. “The data shows background levels of 300 µg P/l, rising to 600 µg P/l following heavy rain, indicating high levels of P in run-off.”

Nitrate
Similar to phosphates, excessive nitrate levels can have a significant impact on water quality. In addition, nitrates are highly mobile and can contaminate groundwater, with serious consequences for wells and drinking water treatment. Nitrate concentrations are therefore of major interest to the EA, but traditional monitoring technology has proved inadequate for long-term monitoring because of a frequent recalibration requirement. To address this need, which exists globally, OTT Hydromet developed the SUNA V2, which is an optical nitrate sensor, providing high levels of accuracy and precision in both freshwater and seawater.

The NLSI has evaluated the SUNA V2 in well water and Matt says: “It performed well – we took grab samples for laboratory analysis and the SUNA data matched the lab data perfectly. We are therefore excited about the opportunity this presents to measure nitrate continuously, because this will inform our understanding of nitrate pollution and its sources, as well as the relationship between groundwater and surface water.”

Summary
The new capability for high-resolution monitoring of nutrients such as phosphorus will enable improved understanding of its effects on ecological status, and in turn will inform decisions on what acceptable P concentrations will be for individual rivers. This is vitally important because the cost of removing P from wastewater can be high, so the requirements and discharge limits that are placed on industrial and wastewater companies need to be science based and supported by reliable data. Similarly, nitrate pollution from fertilizer runoff, industrial activities and wastewater discharge, has been difficult to monitor effectively in the past because of the technology limitations. So, as improved monitoring equipment is developed, it will be possible to better understand the sources and effects, and thereby implement effective prevention and mitigation strategies.

@OTTHydrometry @EnvAgency @CEHScienceNews #Water #Environment

Increased atmospheric CO₂ levels and climate change are believed to contribute to extreme weather conditions, which is a major concern for many. And beyond extreme events, global warming is also predicted to affect agriculture.^1,2

While climate change is expected to affect agriculture and reduce crop yields, the complete effects of climate change on agriculture and the resultant human food supplies are yet to be fully understood.^2,3,4

Simulating a Changing Climate
In order to understand how changes in CO₂, temperature and water availability caused by climate change have an impact on crop growth and food availability, Researchers often use controlled growth chambers to grow plants in conditions that mimic the predicted atmospheric conditions at the end of the century. These controlled growth chambers enable precise control of temperature, CO₂ levels, humidity, water availability, light quality and soil quality, allowing Scientists to study how plant growth changes in response to elevated temperatures, elevated CO₂ levels and altered water availability.

However, plant growth / behaviour in the field considerably varies from in growth chambers. Owing to differences in light intensity, light quality, evaporative demand, temperature fluctuations and other abiotic and biotic stress factors, the growth of plants in tiny, controlled growth chambers does not always sufficiently reflect plant growth in the field. Moreover, the less realistic the experimental conditions used during simulation experiments of climate change, the less likely the resultant predictions will reflect reality.⁴

Several attempts have been made over the past 30 years to more closely stimulate climate change growing scenarios including free air CO₂ enrichment, open top chambers, free air temperature increases and temperature gradient tunnels, although all these methods are known to have major disadvantages. For instance, chamber-less CO₂ exposure systems do not enable stringent control of gas concentrations, while other systems suffer from “chamber effects” such as changes in humidity, wind velocity, temperature, soil quality and light quality.^4,5

Spanish Researchers have recently reported temperature gradient greenhouses and growth chamber greenhouses, which are specifically designed to remove some of the disadvantages of simulating the effects of climate change on crop growth in growth chambers. An article reporting their methodology was featured in Plant Science in 2014, describing how the Researchers used temperature gradient greenhouses and growth chamber greenhouses to simulate climate change conditions and study plant responses.⁴

Choosing the Right Growth Chamber
Compared to traditional growth chambers, temperature gradient greenhouses and controlled growth chambers offer increased working area, allowing them to work as greenhouses without the necessity for isolation panels while still allowing precise control of various environmental factors such as temperature, CO₂ concentration and water availability.

Researchers have used these greenhouses to investigate the potential effects of climate change on the growth of grapevine, alfalfa and lettuce.

CO₂ Sensors for Climate Change Research
Researchers investigating the effects of climate change on plant growth using greenhouses or growth chambers will require highly accurate CO₂ measurements.

The Spanish Researchers used Edinburgh Sensors Guardian sensor in their greenhouses to provide accurate and reliable CO₂measurements. As a customer-focused provider of high-quality gas sensing solutions, Edinburgh Sensors has been delivering gas sensors to the research community since the 1980s.^4,6

The Guardian NG from Edinburgh Sensors
The Edinburgh Sensors Guardian NG provides precise CO₂ measurements in research greenhouses simulating climate change scenarios. The sensor provides near-analyser quality continuous measurement of CO₂ concentrations, operates in temperatures of 0-45 °C and relative humidity of 0-95%, and has a CO₂ detection range of 0 to 3000 ppm. These features make Guardian NG suitable for use in greenhouses with conditions meant to simulate climate change scenarios.

In addition, the Guardian NG can be easily installed as a stand-alone product in greenhouses to measure CO₂, or in tandem with CO₂ controllers as done by the Spanish Researchers in their temperature gradient and growth control greenhouses.^4,6

Conclusions
In order to understand the potential effects of climate change on plant growth and crop yields, it is important to simulate climate change scenarios in elevated CO₂ concentrations. For such studies, accurate CO₂ concentration measurements are very important.

References

• http://www.charlotteobserver.com/news/nation-world/article171632462.html (Accessed September 7^th, 2017.)
• Walthall CL, Hatfield J, Backlund P, et al. ‘Climate Change and Agriculture in the United States: Effects and Adaptation.’ USDA Technical Bulletin 1935, 2012. Available from: http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1000&context=ge_at_reports  
• https://www.co2.earth/2100-projections  (Accessed September 7^th, 2017.)
• Morales F, Pascual I, Sánchez-Díaz M, Aguirreolea J, Irigoyen JJ, Goicoechea N Antolín MC, Oyarzun M, Urdiain A, ‘Methodological advances: Using greenhouses to simulate climate change scenarios’ Plant Science 226:30-40, 2014.
• Aguirreolea J, Irigoyen JJ, Perez P, Martinez-Carrasco R, Sánchez-Díaz M, ‘The use of temperature gradient tunnels for studying the combined effect of CO₂, temperature and water availability in N2 fixing alfalfa plants’ Annals of Applied Biology, 146:51-60, 2005.

@Edinst #agriculture

In this article key points that are covered in depth in the IDTtechEX published report “Agricultural Robots and Drones 2017-2027: Technologies, Markets, Players” by Dr Khasha Ghaffarzadeh and Dr Harry Zervos are discussed. 

New robotics is already quietly transforming many aspects of agriculture, and the agrochemicals business is no exception. Here, intelligent and autonomous robots can enable ultraprecision agriculture, potentially changing the nature of the agrochemicals business. In this process, bulk commodity chemical suppliers will be transformed into speciality chemical companies, whilst many will have to reinvent themselves, learning to view data and artificial intelligence (AI) as a strategic part of their overall crop protection offerings.

Computer vision
Computer vision is already commercially used in agriculture. In one use case, simple row-following algorithms are employed, enabling a tractor-pulled implement to automatically adjust its position. This relieves the pressure on the driver to maintain an ultra-accurate driving path when weeding to avoid inadvertent damage to the crops.

The computer vision technology is however already evolving past this primitive stage. Now, implements are being equipped with full computer systems, enabling them to image small areas, to detect the presence of plants, and to distinguish between crop and weed. The system can then instruct the implement to take a site-specific precision action to, for example, eliminate the weed. In the future, the system has the potential to recognize different crop and weed types, enabling it to take further targeted precision action.

This technology is already commercial, although at a small scale and only for specific crops. The implements are still very much custom built, assembled and ruggedized for agriculture by the start-ups themselves. This situation will continue until the market is proven, forcing the developers to be both hardware and software specialists. Furthermore, the implements are not yet fully reliable and easy to operate, and the upfront machine costs are high, leading the developers to favour a robotic-as-a-service business model.

Nonetheless, the direction of travel is clear: data will increasingly take on a more prominent (strategic) role in agriculture. This is because the latest image processing techniques, based on deep learning, feed on large datasets to train themselves. Indeed, a time-consuming challenge in applying deep learning techniques to agriculture is in assembling large-scale sets of tagged data as training fodder for the algorithms. The industry needs its equivalents of image databases used for facial recognition and developed with the help of internet images and crowd-sourced manual labelling.

In not too distant a future, a series of image processing algorithms will emerge, each focused on some set of crop or weed type. In time, these capabilities will inevitably expand, allowing the algorithms to become applicable to a wider set of circumstances. In parallel, and in tandem with more accumulated data (not just images but other indicators such NDVA too), algorithms will offer more insight into the status of different plants, laying the foundation of ultra-precision farming on an individual plant basis.

Agriculture is a challenging environment for image processing. Seasons, light, and soil conditions change, whilst the plant themselves transform shape as they progress through their different stages of growth. Nonetheless, the accuracy threshold that the algorithms in agriculture must meet are lower than those found in many other applications such as autonomous general driving. This is because an erroneous recognition will, at worse, result in elimination of a few healthy crops, and not in fatalities. This, of course, matters economically but is a not safety critical issue and is thus not a showstopper.

This lower threshold is important because achieving higher levels of accuracy becomes increasingly challenging. This is because after an initial substantial gain in accuracy improvement the algorithms enter the diminishing returns phase where lots more data will be needed for small accuracy gains. Consequently, algorithms can be commercially rolled out in agriculture far sooner, and based on orders of magnitude lower data sizes and with less accuracy, than in many other applications.

Navigational autonomy
Agriculture is already a leading adapter of autonomous mobility technology. Here, the autosteer and autoguide technology, based on outdoor RTK GPS localization, are already well-established. The technology is however already moving towards full level-5 autonomy. The initial versions are likely to retain the cab, enabling the farmer/driver to stay in charge, ready to intervene, during critical tasks such as harvesting. Unmanned cable versions will also emerge when technology reliability is proven and when users begin to define staying in charge as remote fleet supervision.

The evolution towards full unmanned autonomy has major implications. As we have discussed in previous articles, it may give rise to fleets of small, slow, lightweight agricultural robots (agrobots). These fleets today have limited autonomous navigational capability and suffer from limited productivity, both in individual and fleet forms. This will however ultimately change as designs/components become standardized and as the cost of autonomous mobility hardware inevitably goes down a steep learning curve.

Agrobots of the future
Now the silhouette of the agrobots of the future may be seen: small intelligent autonomous mobile robots taking precise action on an individual plant basis. These robots can be connected to the cloud to share learning and data, and to receive updates en mass. These robots can be modular, enabling the introduction of different sensor/actuator units as required. These robots will never be individually as productive as today’s powerful farm vehicles, but can be in fleet form if hardware costs are lowered and the fleet size-to-supervisor ratio is increased.

What this may mean for the agrochemicals business is also emerging. First, data and AI will become an indispensable part of the general field of crop protection, of which agrochemical supply will become only a subset, albeit still a major one. This will mandate a major rethinking of the chemical companies’ business model and skillsets. Second, non-selective blockbuster agrochemicals (together with engineered herbicide resistant seeds) may lose their total dominance. This is because the robots will apply a custom action for each plant, potentially requiring many specialized selective chemicals.

These will not happen overnight. The current approach is highly productive, particularly over large areas, and off-patent generic chemicals will further drive costs down. The robots are low-lying today, constricting them to short crops. Achieving precision spraying using high boys will be a mechanical and control engineering challenge. But these changes will come, diffusing into general use step by step and plant by plant. True, this is a long term game, but playing it cannot be kicked into the long grass for long.

@IDTechEx #Robotics #Agriculture #PAuto

Extreme weather, believed to result from climate change and increased atmospheric CO₂ levels, is a concern for many. And beyond extreme events, global warming is also expected to impact agriculture.(Charlotte Observer, 7 Sept 2017)

Although it is expected that climate change will significantly affect agriculture and cause decreases in crop yields, the full effects of climate change on agriculture and human food supplies are not yet understood. (1, 2 & 3 below)

Simulating a Changing Climate
To fully understand the effects that changes in temperature, CO₂, and water availability caused by climate change may have on crop growth and food availability, scientists often employ controlled growth chambers to grow plants in conditions that simulate the expected atmospheric conditions at the end of the century. Growth chambers enable precise control of CO₂ levels, temperature, water availability, humidity, soil quality and light quality, enabling researchers to study how plant growth changes in elevated CO₂ levels, elevated temperatures, and altered water availability.

However, plant behavior in the field often differs significantly from in growth chambers. Due to differences in light quality, light intensity, temperature fluctuations, evaporative demand, and other biotic and abiotic stress factors, the growth of plants in small, controlled growth chambers doesn’t always adequately reflect plant growth in the field and the less realistic the experimental conditions used during climate change simulation experiments, the less likely the resultant predictions will reflect reality.³

Over the past 30 years, there have been several attempts to more closely simulate climate change growing scenarios including open top chambers, free air CO₂ enrichment, temperature gradient tunnels and free air temperature increases, though each of these methods has significant drawbacks.

For example, chamber-less CO₂ exposure systems do not allow rigorous control of gas concentrations, while other systems suffer from “chamber effects” included changes in wind velocity, humidity, temperature, light quality and soil quality.^3,4

Recently, researchers in Spain have reported growth chamber greenhouses and temperature gradient greenhouses, designed to remove some of the disadvantages of simulating the effects of climate change on crop growth in growth chambers. A paper reporting their methodology was published in Plant Science in 2014 and describes how they used growth chamber greenhouses and temperature gradient greenhouses to simulate climate change scenarios and investigate plant responses.³

Choosing the Right Growth Chamber
Growth chamber and temperature gradient greenhouses offer increased working area compared with traditional growth chambers, enabling them to work as greenhouses without the need for isolation panels, while still enabling precise control of CO₂ concentration, temperature, water availability, and other environmental factors.

Such greenhouses have been used to study the potential effects of climate change on the growth of lettuce, alfalfa, and grapevine.

CO2 Sensors for Climate Change Research
For researchers to study the effects of climate change on plant growth using growth chambers or greenhouses, highly accurate CO2 measurements are required.

The Spanish team used the Edinburgh Sensors Guardian sensor in their greenhouses to provide precise, reliable CO2 measurements. Edinburg Sensors is a customer-focused provider of high-quality gas sensing solutions that have been providing gas sensors to the research community since the 1980s.^3,5

The Guardian NG from Edinburgh Sensors provides accurate CO₂ measurements in research greenhouses mimicking climate change scenarios. The Edinburgh Sensors Guardian NG provides near-analyzer quality continuous measurement of CO₂ concentrations. The CO₂ detection range is 0-3000 ppm, and the sensor can operate in 0-95% relative humidity and temperatures of 0-45 °C, making it ideal for use in greenhouses with conditions intended to mimic climate change scenarios.

Furthermore, the Guardian NG is easy to install as a stand-alone product in greenhouses to measure CO₂, or in combination with CO₂ controllers as done by the Spanish team in their growth control and temperature gradient greenhouses.^4,6 Conclusions Simulating climate change scenarios in with elevated CO₂ concentrations is essential for understanding the potential effects of climate change on plant growth and crop yields. Accurate CO₂ concentration measurements are essential for such studies, and the Edinburgh Sensors Guardian NG is an excellent option for researchers building research greenhouses for climate change simulation.

References

1. Walthall CL, Hatfield J, Backlund P, et al. ‘Climate Change and Agriculture in the United States: Effects and Adaptation.’ USDA Technical Bulletin 1935, 2012. Available from: http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1000&context=ge_at_reports
2. https://www.co2.earth/2100-projections Accessed September 7th, 2017.
3. Morales F, Pascual I, Sánchez-Díaz M, Aguirreolea J, Irigoyen JJ, Goicoechea N Antolín MC, Oyarzun M, Urdiain A, ‘Methodological advances: Using greenhouses to simulate climate change scenarios’ Plant Science 226:30-40, 2014.
4. Aguirreolea J, Irigoyen JJ, Perez P, Martinez-Carrasco R, Sánchez-Díaz M, ‘The use of temperature gradient tunnels for studying the combined effect of CO2, temperature and water availability in N2 fixing alfalfa plants’ Annals of Applied Biology, 146:51-60, 2005.
5. https://edinburghsensors.com/products/gas-monitors/guardian-ng/ Accessed September 7th, 2017.

@Edinst #PAuto #Food