Under natural environment plants experience different light intensities which can affect photosynthesis and consequently the availability of carbohydrates for daytime growth and their transient storage to supply night growth. We grew a spring barley cultivar, Propino, under three different light intensities under warm days and nights, and evaluated the spatial and diurnal adjustments occurring in the transient carbon stores. Leaves under high light at the end of the day accumulated mainly sucrose (30%) and malate (35%), with lower content of hexoses (5%), starch (15%) and fructans (15%). Under low light, plants presented reduced photosynthesis, with lower metabolite contents at end of day. The malate represented 51% of the total carbon accumulated at end of the day, at the expense of sucrose (12%), other metabolite contributions remaining similar to high light. The percentage of metabolites consumed at night was similar for all light intensities with around 75% of the sucrose and starch being mobilized whilst malate and fructans were only partially mobilized with 56 and 44%, respectively. Altogether, sucrose and malate were the main contributors of the total carbon used at night by barley plants, sucrose being predominant under high light (35% vs. 27%), but malate being the major metabolite used under low light with 40% of the total carbon consumed. Interestingly, light intensity also influenced the location of the C transient stores, the plants under low light prioritizing the accumulation of the metabolites, mostly malate, in the youngest tissues. Therefore, light influences quantitatively, but also qualitatively and spatially the carbon stores in the spring barley cv. Propino, suggesting a tight regulation of the primary metabolism.

Revealing DNA sequence variation within the Lolium perenne genepool is important for genetic analysis and development of breeding applications. We reviewed current literature on plant development to select candidate genes in pathways that control agronomic traits, and identified 503 orthologues in L. perenne. Using targeted resequencing, we constructed a comprehensive catalogue of genomic variation for a L. perenne germplasm collection of 736 genotypes derived from current cultivars, breeding material and wild accessions. To overcome challenges of variant calling in heterogeneous outbreeding species, we used two complementary strategies to explore sequence diversity. First, four variant calling pipelines were integrated with the VariantMetaCaller to reach maximal sensitivity. Additional multiplex amplicon sequencing was used to empirically estimate an appropriate precision threshold. Second, a de novo assembly strategy was used to reconstruct divergent alleles for each gene. The advantage of this approach was illustrated by discovery of 28 novel alleles of LpSDUF247, a polymorphic gene co-segregating with the S-locus of the grass self-incompatibility system. Our approach is applicable to other genetically diverse outbreeding species. The resulting collection of functionally annotated variants can be mined for variants causing phenotypic variation, either through genetic association studies, or by selecting carriers of rare defective alleles for physiological analyses.

Buffer strips between land and waters are widely applied measures in diffuse pollution management, with desired outcomes across other factors. There remains a need for evidence of pollution mitigation and wider habitat and societal benefits across scales. This paper synthesizes a collection of 16 new primary studies and review papers to provide the latest insights into riparian management. We focus on the following areas: (i) diffuse pollution removal efficiency of conventional and saturated buffer strips, (ii) enhancing biodiversity of buffers, (iii) edge-of-field technologies for improving nutrient retention, and (iv) potential reuse of nutrients and biomass from buffers. Although some topics represent emerging areas, for other well-studied topics (e.g., diffuse pollution), it remains that effectiveness of conventional vegetated buffer strips for water quality improvement varies. The collective findings highlight the merits of targeted, designed buffers that support multiple benefits, more efficiently interrupting surface and subsurface contaminant flows while enhancing diversity in surface topography, soil moisture and C, vegetation, and habitat. This synthesis also highlights that despite the significant number of studies on the functioning of riparian buffers, research gaps remain, particularly in relation to (i) the capture and retention of soluble P and N in subsurface flows through buffers, (ii) the utilization of captured nutrients, (iii) the impact of buffer design and management on terrestrial and aquatic habitats and species, and (iv) the effect of buffers (saturated) on greenhouse gas emissions and the potential for pollution swapping. Core Ideas We present an updated synthesis on riparian management incorporating insights from 16 new papers. Topics cover diffuse pollution, biodiversity, new technologies, and biomass reuse. The synthesis shows a move toward designed elements to improve riparian functions.

In spite of many initiatives to set up community or farmer-group-based seed production, there is little empirical evidence about the group functioning in producing and marketing quality seed. This article therefore aims to contribute to better understanding of the process and practice of seed potato cooperatives’ formation and operation in Chencha, Ethiopia. Our study specifically focused on why and how farmer groups organize, produce and market quality seed potato. We collected primary data from two seed potato cooperatives in three phases through interviews, focus group discussions, and field assessment and store inventories on bacterial wilt incidence. We found that the support to the establishing of the two seed potato cooperatives focused more on improving the members’ seed potato production capacity and less on building good governance in the seed chain. The experiences showed the tensions between prescriptive rules, collective action and individual interests which made it very hard to maintain quality seed standards and friendship at the same time. In general, the root of having weak seed cooperatives may not be the lack of intent towards building durable farmer groups. Rather, development practitioners did not take the set-up of strong farmer groups as an evolving process, which continually engages in diagnosis and responds to the emerging social as well as material challenges. The set-up of farmer-group-based seed production, therefore, needs to shift from ‘standard production models’ to an evolving model: an open and flexible model guided by trials, challenges and existing socio-technical and institutional realities.

Severe declines in biodiversity have been well documented for many taxonomic groups due to intensification of agricultural practices. Establishment and appropriate management of arable field margins can improve the diversity and abundance of invertebrate groups; however, there is much less research on field margins within grassland systems. Three grassland field margin treatments (fencing off the existing vegetation “fenced”; fencing with rotavation and natural regeneration “rotavated” and; fencing with rotavation and seeding “seeded”) were compared to a grazed control in the adjacent intensively managed pasture. Invertebrates were sampled using emergence traps to investigate species breeding and overwintering within the margins. Using a manipulation experiment, we tested whether the removal of grazing pressure and nutrient inputs would increase the abundance and richness of breeding invertebrates within grassland field margins. We also tested whether field margin establishment treatments, with their different vegetation communities, would change the abundance and richness of breeding invertebrates in the field margins. Exclusion of grazing and nutrient inputs led to increased abundance and richness in nearly all invertebrate groups that we sampled. However, there were more complex effects of field margin establishment treatment on the abundance and richness of invertebrate taxa. Each of the three establishment treatments supported a distinct invertebrate community. The removal of grazing from grassland field margins provided a greater range of overwintering/ breeding habitat for invertebrates. We demonstrate the capacity of field margin establishment to increase the abundance and richness in nearly all invertebrate groups in study plots that were located on previously more depauperate areas of intensively managed grassland. These results from grassland field margins provide evidence to support practical actions that can inform Greening (Pillar 1) and agri-environment measures (Pillar 2) of the Common Agricultural Policy (CAP). Before implementing specific management regimes, the conservation aims of agri-environment measures should be clarified by defining the target species or taxonomic groups.

Bacterial wilt, caused by Ralstonia solanacearum, is emerging as a major threat to potato production in Ethiopia, reaching epidemic proportions in the Chencha district recently, with a prevalence of 97% of potato fields in 2015. The recent disease outbreak in the district coincided with a significant introduction of seed potatoes. This research was therefore initiated to genetically characterize the pathogen so as to trace its source, identify its relationship with outbreaks in the rest of the country, and make intervention recommendations. Ralstonia solanacearum isolates were sampled both from seed and ware potato fields in Chencha and from seed potato fields in production regions suspected of being potential sources of the pathogen. Multiplex PCR and phylogenetic analysis of partial endoglucanase gene sequences identified all of the isolates as phylotype IIB sequevar 1. VNTR sequence analysis distinguished 11 different haplotypes, nine of which were unique to the Chencha district. However, one of the haplotypes was common to all seed potato producer regions of Ethiopia except for the Shashemene area. The unique and diverse VNTR haplotypes of the pathogen in Chencha indicates that it is well established in the district. When a geographical map of the VNTR haplotypes was superimposed with the main cross-regional seed potato distribution pattern of the country, it became evident that the pathogen was being disseminated via latently infected seed from the Holeta-Jeldu area in the Central Highlands of Ethiopia. Identification of largely uninfected highland districts and multiplication of high-grade seed potato exclusively in those districts should be given priority.

Aims This study explored an effective biological control agent based on lactic acid bacteria culture or culture supernatant, which was effective against fungicide-resistant Zymoseptoria tritici, which causes septoria tritici blotch (STB). Methods and Results Three lactic acid bacteria strains which exhibited broad antifungal activity were investigated for their potential to control Z. tritici. Plate assays, liquid culture growth inhibition assays and STB biocontrol seedling tests were employed. Lactobacillus brevis JJ2P and Lactobacillus reuteri R2 caused significant fungal inhibition as observed by large mycelium clearing on modified MRS agar. Cell-free culture supernatants of Lact. brevis JJ2P and Lact. reuteri R2 showed antifungal activity against Z. tritici, as observed by mycelial radial growth inhibition and liquid culture growth inhibition. Cell-free supernatants of these anti-Z. tritici LAB strains were assessed in vivo for their abilities to inhibit STB development in seedling tests. Lact. brevis JJ2P was capable of inhibiting disease development and significantly reduced the diseased leaf area covered with pycnidia. Conclusions Biological control accomplished by beneficial micro-organisms such as Lact. brevis JJ2P may represent an alternative control strategy for reducing STB. Significance and Impact of the Study Globally, STB is regarded as one of the most important diseases of wheat. Control of Z. tritici is heavily reliant on fungicide application. The recent emergence of resistance or reduced sensitivity to fungicides among Z. tritici populations has urgently called for the development of new control strategies.

With increasing societal demands for food security and environmental sustainability on land, the question arises: to what extent do synergies and trade-offs exist between soil functions and how can they be measured across Europe? To address this challenge, we followed the functional land management approach and assessed five soil functions: primary productivity, water regulation and purification, climate regulation, soil biodiversity and nutrient cycling. Soil, management and climate data were collected from 94 sites covering 13 countries, five climatic zones and two land-use types (arable and grassland). This dataset was analysed using the Soil Navigator, a multicriteria decision support system developed to assess the supply of the five soil functions simultaneously. Most sites scored high for two to three soil functions, demonstrating that managing for multifunctionality in soil is possible but that local constraints and trade-offs do exist. Nutrient cycling, biodiversity and climate regulation were less frequently delivered at high capacity than the other two soil functions. Using correlation and co-occurrence analyses, we also found that synergies and trade-offs between soil functions vary among climatic zones and land-use types. This study provides a new framework for monitoring soil quality at the European scale where both the supply of soil functions and their interactions are considered.

Over the last century an increase in mean soil surface temperature has been observed, and it is predicted to increase further in the future. In order to evaluate the legacy effects of increased temperature on both nitrogen (N) transformation rates in the soil and nitrous oxide (N2O) emissions, an incubation experiment and modelling approaches were combined. Based on previous observations that gross N transformations in soils are affected by long-term elevated-temperature treatments we hypothesized that any associated effects on gaseous N emissions (e.g. N2O) can be confirmed by a change in the relative emission rates from various pathways. Soils were taken from a long-term in situ warming experiment on temperate permanent grassland. In this experiment the soil temperature was elevated by 0 (control), 1, 2 or 3 °C (four replicates per treatment) using IR (infrared) lamps over a period of 6 years. The soil was subsequently incubated under common conditions (20 °C and 50 % humidity) and labelled as NO315NH4 Gly, 15NO3NH4 Gly or NO3NH4 15N-Gly. Soil extractions and N2O emissions were analysed using a 15N tracing model and source-partitioning model. Both total inorganic N (NO3− + NH4+) and NO3− contents were higher in soil subjected to the +2 and +3 °C temperature elevations (pre- and post-incubation). Analyses of N transformations using a 15N tracing model showed that, following incubation, gross organic (but not inorganic) N transformation rates decreased in response to the prior soil warming treatment. This was also reflected in reduced N2O emissions associated with organic N oxidation and denitrification. Furthermore, a newly developed source-partitioning model showed the importance of oxidation of organic N as a source of N2O. In conclusion, long-term soil warming can cause a legacy effect which diminishes organic N turnover and the release of N2O from organic N and denitrification.

Machinery traffic imposes a negative effect on soil structure, leading to soil compaction. Studies to date have primarily focused on the influence of applied wheel loads on soil structure. Few studies have assessed the impact of commercial farm operations on soil structure and crop performance, particularly on field headlands in a temperate maritime climate such as Ireland. A survey was conducted on 41 conventionally managed field sites to investigate the effect of field position (field edge, turning, transition and in-field zones) in relation to machinery operations on soil structure. Soil texture classes ranged from sandy loam to clay loam. All sites used plough-based crop establishment. Soil structural condition was assessed visually using the visual evaluation of soil structure method (VESS) for the topsoil (0−250 mm), and Double Spade below plough depth (250−400 mm). Quantitative soil measurements such as shear strength, bulk density and porosity using soil cores post-harvest, and soil cone penetration resistance were taken at two time points in the crop growth cycle. For most measurements of soil structure, the in-field zone of least machinery traffic produced the best scores (Sq 2.81 & DS 2.48), and the turning zone returned the poorest scores in the 0−250 mm soil layer (Sq 3.31 & DS 2.91). The strongest quantitative scores for the in-field and turning zones, respectively, were for trowel penetration resistance in the upper (2.49 & 3.20) and lower (3.41 & 4.05) soil depth layers and for shear vane (38.17 & 53.59 kPa) for the same zones. The visual assessments and some of the quantitative measurements (0−250 mm soil layer) followed the zone order trend of: turning, field edge, transition and in-field, for increasing machinery traffic. The results show that the visual soil indicators used in this study are more sensitive than quantitative soil measurements such as soil bulk density (ρb) or porosity (TP and MP) at detecting soil structural differences between zones, particularly below plough depth (>250 mm soil depth).