Philip Haygarth

• Lancaster University

Phosphorus is closely linked to other nutrient cycles, notably carbon and nitrogen, therefore, to understand potential risks to food production models are required that simulate integrated nutrient cycling over long timescales. The soil-plant system model N14CP meets these requirements and simulates both semi-natural and agricultural environments....

Brazil is the world's largest sugarcane producer. This crop leaves huge amounts of straw behind which have to be managed with innovative approaches. In this study, a field experiment was carried out over six successive years of sugarcane harvests to evaluate the effect of straw maintenance on the field on changes in soil phosphorus (P) fractions. F...

Phosphorus is a critical nutrient in sustaining food production. In agricultural systems, application of P fertilizers has significantly increased since the green revolution to become common practice globally, contributing to increased productivity. However, excess use of P fertilizer does not only pose a cost to farmers, but costs for society in t...

The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruz...

Tropical grasses grown as cover crops can mobilize phosphorus (P) in soil and have been suggested as a tool to increase soil P cycling and bioavailability. The objective of this study was to evaluate the effect of tropical grasses on soil P dynamics, lability, desorption kinetics and bioavailability to soybean, specifically to test the hypothesis t...

Background Phosphorus (P) fertilizer is usually applied in excess of plant requirement and accumulates in soils due to its strong adsorption, rapid precipitation and immobilisation into unavailable forms including organic moieties. As soils are complex and diverse chemical, biochemical and biological systems, strategies to access recalcitrant soil...

Aims Intercropping can improve plant yields and soil phosphorus (P) use efficiency. This study compares inter- and intra-species intercropping, and determines whether P uptake and shoot biomass accumulation in intercrops are affected by soil P availability. Methods Four barley cultivars (Hordeum vulgare L.) and three legume species (Trifolium subt...

Background The dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (Po) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical t...

The article “Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities”, written by Timothy S George et al., was originally published with incorrect affiliation information for one of the co-authors, E. Klumpp.

River discharge and nutrient measurements are subject to aleatory and epistemic uncertainties. In this study we present a novel method for estimating these uncertainties in co‐located discharge and phosphorus (P) measurements. The ‘voting point’ based method constrains the derived stage‐discharge rating curve both on the fit to available gaugings a...

Citrate and phytase root exudates contribute to improved phosphorus (P) acquisition efficiency in Nicotiana tabacum (tobacco) when both exudates are produced in a P deficient soil. To test the importance of root intermingling in the interaction of citrate and phytase exudates, Nicotiana tabacum plant-lines with constitutive expression of heterologo...

There is a need to model and predict the transfer of phosphorus (P) from land to water, but this is challenging because of the large number of complex physical and biogeochemical processes involved. This study presents, for the first time, a ‘limits of acceptability’ approach of the Generalized Likelihood Uncertainty Estimation (GLUE) framework to...

Soil organic phosphorus has broad agronomic and ecological significance, but remains a neglected topic of research. This opinion paper reflects a collaborative discussion between three generations of scientists who have collectively studied soil organic phosphorus for almost 50 years. We discuss personal reflections on our involvement in the field,...

Phosphorus losses from land to water will be impacted by climate change and land management for food production, with detrimental impacts on aquatic ecosystems. Here we use a unique combination of methods to evaluate the impact of projected climate change on future phosphorus transfers, and to assess what scale of agricultural change would be neede...

Excess nutrients in surface waters, such as phosphorus (P) from agriculture, result in poor water quality, with adverse effects on ecological health and costs for remediation. However, understanding and prediction of P transfers in catchments have been limited by inadequate data and over-parameterised models with high uncertainty. We show that, wit...

In order to improve the efficiency of nutrient use whilst also meeting projected changes in the demand for food within China, new nutrient management frameworks comprised of policy, practice and the means of delivering change are required. These frameworks should be underpinned by systemic analyses of the stocks and flows of nutrients within agricu...

Phytase enzymes from bacteria, fungus and plant root exudates are known to hydrolyse organic phosphorus (Po) to bioavailable inorganic orthophosphate in soil. Exploiting such biochemical functions in agricultural systems, offers the potential for alternative sustainable phosphorus sources. Phytase adsorption to soil particles and phytate metal comp...

Zymographic methods for the 2D distribution of phosphatase activity in soils have markedly advanced our understanding of root-soil-microbiota interactions. Robust quantitative approaches for 2D assays, which use 4-methylubelliferyl phosphate (4-MUP), are needed to advance a mechanistic understanding of enzyme behaviour and distribution in soils. We...

Climate projections for the future indicate that the United Kingdom will experience hotter, drier summers and warmer, wetter winters, bringing longer dry periods followed by rewetting. This will result in changes in phosphorus (P) mobilization patterns that will influence the transfer of P from land to water. We tested the hypothesis that changes i...

Excess nutrients in surface waters, such as phosphorus (P) from agriculture, result in poor water quality, with adverse effects on ecological health and costs for remediation. However, understanding and prediction of P transfers in catchments have been limited by inadequate data and over-parameterised models with high uncertainty. We show that, wit...

Background and Aims Plant acquisition of endogenous forms of soil phosphorus (P) could reduce external P requirements in agricultural systems. This study investigated the interaction of citrate and phytase exudation in controlling the accumulation of P and depletion of soil organic P by transgenic Nicotiana tabacum plants. Methods N. tabacum plant...

This paper evaluates the existing policy frameworks for mitigation of diffuse water pollution from agriculture (DWPA) in England and China. With reference to a conceptual model of the process of policy transfer or international lesson drawing, and possible constraints to this, it assesses whether and how China can draw lessons to improve current po...

The essential role of phosphorus (P) for agriculture and its impact on water quality has received decades of research attention. However, the benefits of sustainable P use and management for society due to its downstream impacts on multiple ecosystem services are rarely acknowledged. We propose a conceptual framework—the "phosphorus-ecosystem servi...

Soil organic phosphorus contributes to the nutrition of tropical trees, but is not accounted for in standard soil phosphorus tests. Plants and microbes can release organic anions to solubilize organic phosphorus from soil surfaces, and synthesize phosphatases to release inorganic phosphate from the solubilized compounds. We developed a procedure to...

We developed a parsimonious topography-based hydrologic model coupled with a soil biogeochemistry submodel in order to improve understanding and prediction of soluble reactive phosphorus (SRP) transfer in agricultural headwater catchments. The model structure aims to capture the dominant hydrological and biogeochemical processes identified from mul...

Root exudation of phytase could improve the ability of plants to access organic forms of soil phosphorus (P), thereby minimizing fertilizer requirements and improving P use efficiency in agroecosystems. After 75 days growth in a high available P soil, shoot biomass and P accumulation, soil pH, and rhizosphere P depletion were investigated in Nicoti...

There are high aspirations for environmental water quality targets in the UK, but requirements for significant growth in agricultural production to meet both food security objectives and provide viable livelihoods for farmers make these hard to achieve. Significant water quality challenges are related to nutrients, pesticides, pharmaceuticals, path...

In China intensification of agriculture has been achieved at a cost to the environment. The extension service is the leading public resource to address this but remains focused by a historic national ethos for food security, production and economic growth, whilst its administrative structure is hierarchical, slow to change and lacking in relevant f...

We describe the development of a manual of methods for mitigating diffuse water pollution from agriculture and its important influence on policy and practice in England and Wales. The objective of the 'User Manual' was to provide policy makers and those implementing policies with information about the cost, effectiveness and applicability of potent...

Mass transport, such as movement of phosphorus in soils and solutes in rivers, is a natural phenomenon and its study plays an important role in science and engineering. It is found that there are numerous practical diffusion phenomena that do not obey the classical advection-diffusion equation (ADE). Such diffusion is called abnormal or superdiffus...

link to official article... http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2693.html Global food production depends on phosphorus. Phosphorus is broadly applied as fertilizer, but excess phosphorus contributes to eutrophication of surface water bodies and coastal ecosystems. Here we present an analysis of phosphorus fluxes in three larg...

We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, he...

The mobility and resupply of inorganic phosphorus (P) from the solid phase were studied in 32 soils from the UK. The combined use of diffusive gradients in thin films (DGT), diffusive equilibration in thin films (DET) and the ‘DGT-induced fluxes in sediments’ model (DIFS) were adapted to explore the basic principles of solid-to-solution P desorptio...

We developed a parsimonious topography-based hydrologic model coupled with a soil biogeochemistry sub-model in order to improve understanding and prediction of Soluble Reactive Phosphorus (SRP) transfer in agricultural headwater catchments. The model structure aims to capture the dominant hydrological and biogeochemical processes identified from mu...

This paper reflects the ‘big picture’ of the global phosphorus cycle taking a particular focus on the continuum of the transfers between agriculture, soil, water and river catchments. The paper will pinpoint our current understanding of phosphorus biogeochemistry and the mechanisms of its transfer from soil to water with a consideration of travel t...

Introduction Plant systems with the ability to utilise sparingly available and organic forms of soil phosphorus (P) have the potential to improve the efficiency and sustainability of nutrient use in food production systems (Stutter et al. 2012). In the absence of bioavailable inorganic P, plants respond to P deficiency through a variety of biochemi...

Introduction For many plant species the exudation of organic anions and phosphatases by roots represents an important mechanism for the acquisition of soil phosphorus (P) (Richardson et al. 2011). However, the benefits of citrate and phytase exudation have been shown to be limited in soils due to interactions with soil (George et al. 2005) or the d...

Phosphorus (P) contributes to eutrophication of surface waters and buffer strips may be implemented to reduce its transfer from agricultural sources to watercourses. This study was conducted to test the hypothesis that soil type and slope influence the retention of dissolved organic P and inorganic orthophosphate in agricultural runoff in 2-m-wide...

This article explores the nature of calls for risk-based policy present in expert discourse from a cultural theory perspective. Semi-structured interviews with professionals engaged in the research and management of livestock disease control provide the data for a reading proposing that the real basis of policy relating to socio-technical hazards i...

There is an emerging and urgent need for new approaches for the management of environmental challenges such as flood hazard in the broad context of sustainability. This requires a new way of working which bridges disciplines and organisations, and that breaks down science-culture boundaries. With this, there is growing recognition that the appropri...

Recent advances in monitoring technology have enabled high frequency, in-situ measurements of total phosphorus and total reactive phosphorus to be undertaken with high precision, whilst turbidity can provide an excellent surrogate for suspended sediment. Despite these measurements being fundamental to understanding the mechanisms and flow paths tha...

Increasing pressures on the hydrological cycle from our changing planet have led to calls for a refocus of research in the sciences of hydrology and water resources. Opportunities for new and innovative research into these areas are being facilitated by advances in the use of cyberinfrastructure, such as the development of digital catchment observa...

De-icers containing propylene glycol and potassium acetate are a major source of organic pollution in airport surface waters. Direct discharges of these pollutants into receiving waters, even at very low concentrations, can result in detrimental environmental impacts and may breech regulatory requirements. The airport operator is responsible for de...

Data on the distribution of phosphorus (P) species in soils with differing land uses and properties are essential to understanding environmental P availability and how fertiliser inputs, cropping and grazing affect accumulation of soil inorganic P (Pi) and organic P (Po) forms. We examined thirty-two temperate soils (with soil organic C concentrati...

The mobility and resupply of inorganic phosphorus (P) from the solid phase was studied in 32 representative soils from the UK. The objective was to identify the background soil properties driving the variation of soil inorganic P desorption kinetics across different soil types. Diffusive gradients in thin films (DGT), diffusive equilibration in thi...

This article explores the nature of calls for risk-based policy present in expert discourse from a cultural theory perspective. Semi-structured interviews with professionals engaged in the research and management of livestock disease control provide the data for a reading proposing that the real basis of policy relating to socio-technical hazards i...

Phosphorus is known to be an important contributor to eutrophication of aquatic systems,11. Elser, J. J., Bracken, M. E. S., Cleland, E. E., Gruner, D. S., Harpole, W. S., Hillebrand, H., Ngai, J. T., Seabloom, E. W., Shurin, J. B., and Smith, J. E. (2007). Global analysis of nitrogen and phosphorus limitation of primary producers in freshwater, ma...

This paper uses high-frequency bankside measure-ments from three catchments selected as part of the UK government-funded Demonstration Test Catchments (DTC) project. We compare the hydrological and hydrochemical patterns during the water year 2011–2012 from the Wylye tributary of the River Avon with mixed land use, the Black-water tributary of the...

Here we introduce an organic P consortium who has recently been funded to test the hypothesis that: cropping systems selected to express favourable root exudate properties will facilitate sustainable agricultural production through improved access to soil organic phosphorus (Po). Specifically, we will use exemplar plant mixtures to investigate the...

Despite the volume of environmental data available at local, national and global scales, the likely impacts of land management and climate change, as well as their interactions and the management options available to protect against natural disasters like flooding can remain obscure. Interpreting the complexity of findings presents a broad range of...

Models that estimate P-loss from agricultural land to surface waters are important tools used by soil scientists, catchment scientists and land managers, to help identify high-risk areas and determine measures that can reduce such losses. A widely used method for predicting P-loss from agricultural land is the ‘Phosphorus Index’ (PI) tool, develope...

Organic phosphorus (P) in grazed pastures/grasslands could sustain production systems that historically relied on inorganic P fertiliser. Interactions between inorganic P, plants and soils have been studied extensively. However, less is known about the transformation of organic P to inorganic orthophosphate. This paper investigates what is known ab...

The EVO Pilot (EVOp) was an ambitious two year project to test the value of new cloud technologies for connecting and integrating fragmented data, models, and tools to deliver new holistic approaches to environmental challenges. The need for such an approach has become increasingly clear as we seek to improve food, water and energy security. These...

Headwater streams are an important feature of the landscape, with their diversity in structure and associated ecological function providing a potential natural buffer against downstream nutrient export. Phytobenthic communities, dominated in many headwaters by diatoms, must respond to physical and chemical parameters that can vary in magnitude with...

Whilst a large body of plot and field-scale research exists on the sources, behaviour and mitigation of diffuse water pollution from agriculture, putting this evidence into a practical, context at large spatial scales to inform policy remains challenging. Understanding the behaviour of pollutants (nutrients, sediment, microbes and pesticides) and t...

Cattle in-stream activity is potentially an important contributor to water pollution from agriculture. Here we present research on the physical movements of cattle within a stream on suspended solid concentrations (SSC). This study used camera surveillance to monitor the in-stream activity of dairy cattle in an unfenced reach over a four-month peri...

The Demonstration Test Catchments (DTC) project is a UK Government funded initiative to test the effectiveness of on-farm mitigation measures designed to reduce agricultural pollution without compromising farm productivity. Three distinct catchments in England have been chosen to test the efficacy of mitigation measures on working farms in small tr...

This study tests the hypothesis that microbial biomass phosphorus (P) makes a significant contribution to P solubility in riparian buffer strip soils. In 36 soils collected from buffer strips within three UK soil associations, water-extractable inorganic P solubility was most strongly related to NaHCO3 extractable inorganic P. However, within indiv...

The manuscript by Ulrich et al. (2013) describes and discusses key large scale international policy and communication issues associated with the development of appropriate responses to improving the utilisation of global phosphorus (P) resources. In particular the paper outlines the need for an integrated and holistic-multidisciplinary approach to...

Phosphorus is essential to all life. A critical component of fertilizers, Phosphorus currently has no known substitute in agriculture. Without it, crops cannot grow. With too much of it, waterways are polluted. Across the globe, social, political, and economic pressures are influencing the biogeochemical cycle of phosphorus. A better understanding...

This chapter analyzes case studies concerning phosphorus sustainability. It looks into theargument of the maximization of appropriate local efforts with regards to phosphorus sustainability. It demonstrates that phosphorus budgets, inputs and outputs, provide a useful indicator of long-term sustainability. It looks into the behavior of water bodies...

We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species...

To meet our environmental management responsibilities, there is a need to estimate the likely effect of current and future soil and land management policies on water quality and choose the most effective strategies given catchment characteristics, climate and economic drivers. Efficient management of diffuse phosphorus (P) delivery from agricultura...

Introduction Sources of nitrogen and phosphorus to soil-plant systems Chemical and biological processes of nutrient cycling, transformations and bioavailability Processes of nitrogen and phosphorus losses from soils Nitrogen and phosphorus use in agricultural systems Future soil nutrient cycles and environmental change References

Temperate productive grasslands are often located in areas of high rainfall prone to flooding, but even here moderate summer droughts occur with regularity causing significant yield reductions. Grasslands capable of resisting both water excess and deficit are required. Alternative breeding technologies are employed to combine as Festulolium cultiva...

Highlights ► This paper prefaces 12 state-of-the-science contributions relating to water quality policy and management in agricultural catchments. ► The contributions relate to examples in the European Union on uncertainty, scale and economic perspectives. ► Policy uptake, biophysical and confounding influences on mitigation measures, policy partic...

The pathway that delivers mobilized phosphorus (P) from source to surface water is conceptually complex. Firstly P mobilization itself, either through mechanical disturbance of the soil, or through chemical dissolution or weathering is difficult to measure in situ, secondly the annual flow weighted mean concentration of P is a difficult metric to g...

The Pilot Environmental Virtual Observatory, EVO, a proof of concept project to develop new cloud-based applications for accessing, interrogating, modelling and visualising environmental data, by developing local and national scale exemplars, EVO has demonstrated how cloud technologies can make environmental monitoring and decision making more effi...

1. Phosphorus (P) transfer from agricultural land to freshwater systems has been studied across many scales and environmental compartments that range from understanding biogeochemical processes in soils and fields, to assessment of localised in‐stream biotic and ecological impacts. 2. This study tackles the challenges of scale when moving from soil...

Decision making for zoonotic disease management should be based on many forms of appropriate data and sources of evidence. However, the criteria and timing for policy response and the resulting management decisions are often altered when a disease outbreak occurs and captures full media attention. In the case of waterborne disease, such as the robu...

Soils are important sources of sediment and phosphorus in rural catchments, necessitating the development of mathematical models for impact assessment. In this paper, multiple empirical models are tested on an event basis at four nested locations in an intensively managed grassland headwater catchment while accounting for parameter and data uncerta...

Our environment is a complex system of interactions between natural process and anthropogenic activities that disrupt them. It is crucial to manage the balance for continued food production whilst maintaining the quality of the environment. The challenges we face include managing the impact of agricultural land use on aquatic quality and biodiversi...

Public participation in the development of flood risk management and river basin management plans are explicit components of both the Water Framework and Floods Directives. At the local level, involving communities in land and water management has been found to (i) aid better environmental decision making, (ii) enhance social, economic and environm...

Meeting the demands of good water quality such as those of the EU Water Framework Directive is a complicated, wicked problem. On the one hand the directive forces us to consider the catchment as a single functioning unit, a water body where ecological status can be assessed and classified. On the other hand, catchments are most obviously perturbed...

Empirical monitoring studies of catchment-scale Escherichia coli burden to land from agriculture are scarce. This is not surprising given the complexity associated with the temporal and spatial heterogeneity in the excretion of livestock faecal deposits and variability in microbial content of faeces. However, such information is needed to appreciat...

Diffuse pollution remains a major threat to surface waters due to eutrophication caused by phosphorus (P) transfer from agricultural land. Vegetated buffer strips (VBSs) are increasingly used to mitigate diffuse P losses from agricultural land, having been shown to reduce particulate P transfer. However, retention of dissolved P (DP) has been lower...