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The pH of grassland soils in Scotland is declining in large areas due to less frequent lime applications. Soil nutrient availability, grassland yield and crop diversity are highly influenced by soil pH values. The consequence of acidic soil on grassland nutritional quality have not yet been comprehensively assessed. Grass-white clover sward samples were collected in 2019-2021 from a long-term pH field experiment, Woodland’s Field in Aberdeen, Scotland. This experiment is part of the larger ACE platform in Aberdeen. This was an 8-course ley-arable crop rotation which included a pH gradient (4.5-7.5 at pH 0.5 increments) superimposed across each crop row resulting in 7 target values. Collected crop samples were separated into grass and clover, and analysed for impact of pH on yield, protein and digestibility. These were analysed in the 1st, 2nd and 3rd year grass-clover ley. White clover growth in the sward was inhibited at pH 4.5≤5.0. Increasing soil pH above 5 increased the clover presence from 0.1-14% to 33-58%, a 800-1650% increase in clover biomass. This significantly increased the nutritional quality of white clover in the sward. This was exhibited through greater percent nitrogen, crude protein content and proportion of more quickly digested fibre fractions. Increasing soil pH from 4.5 to 6.0 increased total sward (grass and clover) biomass yield by 122-282.1%. The positive impact of pH on nutritive qualities of white clover in the sward are likely to increase dry matter intake of grazing animals and therefore liveweight gain and/or milk production. A simple measure to increase human-available products. By not increasing soil pH out of a highly acidic range, there may be sward nutritional quality and overall biomass yield consequences that are easy to remediate.

Barley 'Scald' is an economically damaging fungal disease that is a global problem, causing significant yield and economical losses in the UK barley feed and malting industries. Presently, a limited number of Rhynchosporium resistance genes exist, but selective pressures on the fungi cause the demand for new sources of resistance. Landraces, such as the Scottish Bere barley, hold potential sources of resistance that can be utilised, with farmers providing anecdotal evidence of resistance in field populations of Bere. This study analysed 131 heritage cultivars and landrace lines, including 37 Bere lines, to screen for resistance using both detached leaf assays (DLAs) and field experiments. Results showed that Bere lines produced smaller, but more necrotic, lesions for the majority of isolates in the DLAs, as well as smaller scores when visually assessed in field conditions. Whilst the infection patterns of the lines differed between isolates and experimental conditions, three Bere lines were identified as consistently showing reduced levels of infection (45 A 23, 58 A 36 Eday, and 8-125). Using genome-wide association analysis, we were able to identify a number of genomic regions associated with reduced infection symptoms, four in regions associated with known resistance genes, but another four associated with new regions that contain promising candidate genes. Further analysis of these new regions and candidate genes should be undertaken to identify targets for future disease-resistance breeding.

Silicon in rice has been demonstrated to be involved in resistance to lodging, tolerance to both drought and salinity, and also enhances resistance to pests and diseases. The aim of this study was to determine the range of silicon content in a set of rice (Oryza sativa L.) accessions, and to determine if the natural variation of shoot silicon is linked to the previously identified silicon transporters (Lsi genes). Silicon content was determined in 50 field-grown accessions, representing all sub-populations of rice, with all accessions being genotyped with 700K SNPs. SNPs within 10 kb of the Lsi genes were examined to determine if any were significantly linked with the phenotypic variation. An XRF method of silicon determination compared favourably with digestion and colorimetric analysis. There were significant genotypic differences in shoot silicon ranging from 16.5 – 42.4 mg g-1 of plant dry weight, there was no significant difference between the rice sub-populations. Plants with different alleles for SNPs representing Lsi2 and Lsi3 were significantly different for shoot silicon content. Shoot silicon correlated negatively with grain arsenic in the tropical and temperate japonica sub-population, suggesting that accessions with high shoot silicon have reduced grain arsenic. This study indicates that alleles for Lsi genes are excellent candidate genes for further study to explain the natural variation of shoot silicon in rice.

As the global population grows, demand on food production will also rise. For rice, one limiting factor effecting production could be availability of fresh water, hence adoption of techniques that decrease water usage while maintaining or increasing crop yield are needed. Alternative wetting and drying (AWD) is one of these techniques. AWD is a method by which the level of water within a rice field cycles between being flooded and nonflooded during the growth period of the rice crop. The degree to which AWD affects cultivars differently has not been adequately addressed to date. In this study, 22 rice cultivars, mostly landraces of the aus subpopulation, plus some popular improved indica cultivars from Bangladesh, were tested for their response to AWD across three different field sites in Bangladesh. Grain and shoot elemental concentrations were determined at harvest. Overall, AWD slightly increased grain mass and harvest index compared to plants grown under continually flooded (CF) conditions. Plants grown under AWD had decreased concentrations of nitrogen in their straw compared to plants grown under CF. The concentration of elements in the grain were also affected when plants were grown under AWD compared to CF: Nickel, copper, cadmium and iron increased, but sodium, potassium, calcium, cobalt, phosphorus, molybdenum and arsenic decreased in the grains of plants grown under AWD. However, there was some variation in these patterns across different sites. Analysis of variance revealed no significant cultivar × treatment interaction, or site × cultivar × treatment interaction, for any of the plant mass traits. Of the elements analyzed, only grain cadmium concentrations were significantly affected by treatment × cultivar interactions. These data suggest that there is no genetic adaptation amongst the cultivars screened for response to AWD, except for grain cadmium concentration and imply that breeding specifically for AWD is not needed.

While the impact of arsenic in irrigated agriculture has become a major environmental concern in Bangladesh, to date there is still a limited understanding of arsenic in Bangladeshi paddy soils at a landscape level. A soil survey was conducted across ten different physiographic regions of Bangladesh, which encompassed six types of geomorphology (Bil, Brahmaputra floodplain, Ganges floodplain, Meghna floodplain, Karatoya-Bangali floodplain and Pleistocene terrace). A total of 1209 paddy soils and 235 matched non-paddy soils were collected. The source of irrigation water (groundwater and surface water) was also recorded. The concentrations of arsenic and sixteen other elements were determined in the soil samples. The concentration of arsenic was higher in paddy soils compared to non-paddy soils, with soils irrigated with groundwater being higher in arsenic than those irrigated with surface water. There was a clear difference between the Holocene floodplains and the Pleistocene terraces, with Holocene floodplain soils being higher in arsenic and other elements. The results suggest that arsenic is most likely associated with less well weathered/leached soils, suggesting it is either due to the geological newness of Holocene sediments or differences between the sources of sediments, which gives rise to the arsenic problems in Bangladeshi soils.