In order to sustainably increase crop yields to feed the growing world population, and considering the challenges we are facing today due to climate change, we need to carefully manage our soil resources. Promoting measures to manage soils better whilst reducing costs will also help farming businesses remain competitive and profitable. Instead of burning fossil fuels to drag more steel through the ground, this research will harness the power and properties of plant roots to engineer soil for optimised crop growth. Roots can bio-engineer soil because they can bind soil particles together, providing resistance against soil erosion by water. Roots can also improve soil infiltration and hence prevent runoff. Roots also absorb and release nutrients into the soil, allowing soils to improve their nutrient status and to reduce environmental side effects. Last but not least, roots break up the soil and create pore spaces when they decay. These macro-pores aerate the soil and make its structure more crumbly. So roots can act as a surrogate for machinery and hence reduce the number of tillage operations. Cover crops are a way for UK growers to address the current Greening Rules that require them to: maintain minimum soil cover, minimise land management to limit erosion and maintain organic matter levels. They are fast growing species, planted between two cash crops, which have the ability to boost soil health and reduce the negative impact of agro-management on the environment. They are usually planted immediately after harvest and left to grow all winter; they cover and protect the soil surface against erosion and die off or are destroyed in early spring to make way for the cash crop. There has been an increasing interest in research to support the application of cover crops. However, current estimates indicate that only 8% of all arable land used for spring cropping in the UK adopts winter cover crops in the rotation. This is because robust science that provides evidence of the multiple benefits of cover crops is lacking. Past research has successfully linked agronomic productivity to above ground plant traits. More recent studies also investigated root traits and demonstrated their important effect on several single soil functions such as aggregate stability and water availability. No study has looked at the effects of root properties of cover crops to synergistically enhance multiple soil functions and no study has provided a robust methodology to combine complementary root traits in plant communities and to model their effects on multiple soil functions. The main aim of this study is therefore to develop a novel framework to select and combine complementary root traits in cover crops that prevent soil resource losses and improve crop growth conditions. To develop the model, root screening will be performed with ten common cover crops (oat, rye, ryegrass, Festulolium, buckwheat, mustard, fodder radish, phacelia, Lucerne and vetch) grown in big soil monoliths, filled with real soil, under laboratory conditions. The plants will be grown in different environments prone to soil degradation. A series of root properties (e.g. rooting depth, root hair density) will be carefully determined, and we will use a DNA technique, qPCR, to determine the proportions of root biomass of each species within a plant community. The key deliverable of this research will be a novel model that will allow the design of combinations of plant species with complementary root traits that prevent soil erosion, mitigate runoff and improve soil structure and nutrient status for optimised crop growth.

Our research is designed to help UK farmers control soil pests which damage crop production cheaply and effectively at the same time as reducing dependence on conventional pesticides which might harm the environment. The most damaging of these soil pests are microscopic nematode worms. There are different species of nematodes: some attack potato plants whilst others can infect a range of plants, including carrots and soft fruit. The most prevalent economically important species of nematode, and so the one that has the highest economic impact on UK farmers, infects the roots of potato plants and is consequently termed potato cyst nematode (PCN). There are disproportional impacts on our potato industry because of a higher incidence of PCN in the UK than in most of Europe. EU legislation has resulted in the recent loss of two major chemicals used to control nematode pests, termed nematicides, in response to the environmental concerns their use raised and plans to amend the legislation regulating pesticide use still further are likely to remove the three remaining nematicides, possibly quite suddenly. This is causing major concern to the British potato industry because it is doubtful if new pesticides, which are effective but also meet appropriate environmental safety standards, can be developed in time to replace the pesticides being phased out. One alternative control method that could be adopted in the limited timeframe available to UK potato growers is a strategy known as biofumigation, which suppresses pests by incorporating mustards and other types of plants into soil. Potato Council Ltd (which safeguards the interests of the UK potato growing industry) and the Horticultural Development Company (which promotes the UK horticultural sector), in conjunction with potato businesses, have now committed to support research to understand exactly how biofumigation works and how the potential of this technique can be exploited most effectively under field conditions. Our preliminary work has characterised a number of different plant species that produce natural chemicals which detrimentally affect PCN. We have shown that biofumigation can be used to stop the eggs of PCN from hatching into worms which subsequently attack potato plants. We have identified different types of mustard plant that could be used in biofumigation because of the range of natural anti-nematode chemicals they produce. However, inconsistencies in the effectiveness of these plants and a lack of detailed data on how best to deploy biofumigation under a range of agronomic situations prevent the widespread uptake of this sustainable pest control technique. This project will address this knowledge gap by elucidating the fundamental biochemical and metabolic processes underpinning effective biofumigation. It will characterise the profiles of the active chemical compounds, called glucosinolates, of different biofumigant mustards and determine how these vary with plant development stage and environmental factors. It will identify novel active compounds potentially effective against pests but not, as yet, evaluated in biofumigant field trials. We will analyse the effects of biofumigant plants on a range of pests both in glasshouse studies and in multiple field trials. We will use a novel plant growth technique that makes soil appear transparent allowing us to observe the effects of biofumigation on some of the nematode species for the first time. It must be shown that biofumigation does not adversely affect UK soils before the approach can be endorsed by the Potato Council, DEFRA, EU or certifiers of organic produce. We will therefore analyse the impact of biofumigant crops on beneficial organisms in the soil when deployed in the field. Outputs of the research will allow optimal deployment of biofumigation strategies for maximum efficiency over a range of field conditions, providing a sustainable pest control option for both conventional and organic farmers.

Nitrogen fertiliser is essential to sustain wheat yields but is also an important determinant of grain quality. This is because nitrogen is required for the synthesis of grain proteins, with the gluten proteins forming the major grain protein fraction. About 40% of the wheat produced in the UK is used for food production, particularly for making bread and other baked products. Wheat is also widely used as a functional ingredient in many processed foods, while bread wheat and imported durum wheats are used to make noodles and pasta, respectively. The gluten proteins are essential for these uses, providing visco-elastic properties to dough. Consequently, the content and quality of the grain proteins affect the processing quality, with a minimum of 13% being specified for the Chorleywood Breadmaking Process (CBP) which is used for over 80% of the "factory produced" bread in the UK. The requirement of nitrogen to produce wheat for bread making is also above the optimum required for yield, and farmers may apply up to 50 kg N/Ha above the yield optimum to achieve 13% protein (2.28% N). This is costly with nitrogen fertiliser contributing significantly to crop production, and may also contribute to a greater "nitrogen footprint" in the farmed environment. It may be possible to reduce the requirement for breadmaking wheats, to a limited extent, by optimising the efficiency of nitrogen uptake and use within the wheat plant. However, this will only have limited benefits and a more viable long-term solution is to develop new types of wheat and processing systems which will allow the use of lower protein contents for bread making. We will therefore identify types of wheat which have good and stable breadmaking quality at low grain protein. Genetic analyses of the trait will provide molecular markers to assist wheat breeders while studies of underpinning mechanisms will allow new selection procedures to be used to identify germplasm and select for quality in breeding programmes. We will also work with millers and bakers to establish optimum conditions for processing of wheats with lower protein contents.

Our project is designed to facilitate the practical development of plant defence activators, such as cis-jasmone, as novel crop protection treatments for use against aphids. Earlier research has shown that cis-jasmone treatment can significantly reduce aphid infestations in the field and that treated plants become repellent to aphids while also becoming more attractive to natural enemies of pests. Plant defence activators have the advantage of having a non-toxic mode of action. They work by switching on (inducing) defence in plants and could provide new, environmentally friendly crop protection options. Farmers urgently need new options as conventional pesticide use is increasingly restricted by changes in legislation and compromised by evolution of resistance. Plant defence activators are: * environmentally friendly * work with not against natural enemies of pests * provide new interventions farmers can use against pests * form part of integrated pest management (IPM) * can be used against insecticide resistant pests Here, we will make the next steps towards commercialisation of plant defence activator treatments. We have discussed with Agrii, a leading UK agronomy company, the research that would be needed. Wheat is their preferred crop for initial trials due to the large area it is grown in and also because our earlier field trials have already shown cis-jasmone can reduce aphid populations in wheat. Agrii have other potential plant defence activators (AGRII101, AGRII202) they would like to test alongside cis-jasmone in order to compare performance. Our project will therefore conduct field trials comparing different plant defence activator treatments with each other as well as with untreated control plots and plots treated with a standard pyrethroid insecticide. We will test the performance of plant activators with different wheat varieties because different varieties can have different capacity for inducing defence. Having tested efficacy under realistic conditions we will then explore with regulatory authorities how to obtain regulatory approval for for plant activators. The benefits listed above mean a strong case can be made for regulatory approval and we will include dialogue with regulators as a project objective.

Wheat yellow rust caused by the fungus Puccinia striiformis f. sp tritici is a substantial threat to wheat production worldwide and recently re-emerged as a major constraint on UK agriculture. Its importance to global food security is reflected by the significant contribution of wheat to the calorific and protein intake of human kind (approximately 20%). The devastating impact of this disease gives a deep sense of urgency to breeders, farmers and end users to improve surveillance. To address this, we recently developed a novel approach called "field pathogenomics" for pathogen population surveillance. This method, based on new gene sequencing technology, allows us to acquire data directly from field samples of rust-infected wheat. By implementing this approach we found that the yellow rust population across the UK underwent a major shift in recent years. Genetic analyses revealed four distinct lineages that correlated to the phenotypic groups determined through traditional pathology-based virulence assays. The overall aim of this project is to apply gene-sequencing technology to the surveillance of yellow rust and undertake comprehensive global population genetic analyses of this important plant pathogen. Currently, the assessment of genotypic diversity is not included within UK national surveillance activities for wheat rust. Our new approach enables the integration of high-resolution genotypic data into pathogen surveillance activities that is vital to improve our understanding of the genetic sub-structure within a population. The proposed research aims to: (1) Analyze the threat of potential exotic incursions of wheat yellow rust to the UK by mapping the global population structure, (2) exploit the rust genotype data (Obj. 1) to confirm outbreaks on particular wheat varieties and look for associations between pathogen genotypes and host pedigrees, (3) generate information on whether genotypic diversity shifts over time at a locality and whether early appearing rust genotypes are predictive of late season genotypes and (4) develop appropriate open-source tools to ensure all data generated herein is released into the public domain as soon as possible and in a format that is suitable for breeders, pathologists and the wider demographic. This project aims to equip the UK with the latest genomic tools, facilitate more efficient varietal development by breeders, and help reduce the environmental and economic costs associated with fungicide applications, all of which will have a positive impact on the overall competitiveness and sustainability of the UK arable industry. This will be achieved through collaboration with 13 rust pathology laboratories across 6 continents and industrial support from 6 breeding, agronomy and chemical companies and the HGCA.