Search Results (11)

Temperature is one the most influential environmental factors for the germination and establishment of grass species. The specific objective of this study was to determine the effects of low constant temperature on the time needed to express the full germination capacity of nondormant seedlots. Fifteen accessions, comprising seven of Lolium perenne L., three of Festuca arundinacea Schreb., three of Dactylis glomerata L. and two of Triticum aestivum L., were evaluated at constant temperatures of 5 and 21 °C. As expected, the germination rates were faster at 21 °C than at 5 °C. Indeed, at 5 °C seeds needed up to twenty-one times longer to reach the maximum germination than when tested at 21 °C. The genotypic variability found for the ratio of germination rates between the two temperatures (i.e., germination rate at 5 °C/germination rate at 21 °C) was much more variable than what is found in the literature for perennial cool-season grasses. On the other hand, in most cases, no significant differences were observed in the germinability (the capacity to germinate) response to 5 °C and 21 °C. Within the four species, twelve of the fifteen studied accessions expressed the same germinability at 5 °C and 21 °C, when given enough time. Only three accessions had final germination percentages higher at 21 °C than at 5 °C. Our results suggest that, in general, nondormant seeds at low temperatures germinate as well as nondormant seeds at near-optimal temperatures, provided they have enough time to express their germination capacity. These findings cast doubts on the validity of conclusions drawn in many studies where germination experiments were performed for a period insufficient to obtain full germination at low temperatures. Another major finding in this work concerns the risk of wrongly estimating germinability at low temperatures. Full article

Since two decades, urban agriculture has been booming and a wide range of forms, from urban allotment gardens to rooftop farming under greenhouse, is developing. Various benefits are recognized for urban agriculture integration within the city and a specific consideration is dedicated to ecosystem services. In this article, we have focused on cultural ecosystem services provided by urban micro-farms. The state of the art reveals that urban agriculture delivers cultural ecosystem services that are well perceived and evaluated by users, but there are still few studies on this topic. Based on the analysis of specific literature on cultural ecosystems and micro-farms in parallel to a period of observation and documentary research of five urban micro-farms either on rooftop or at soil level, located in Paris and its surroundings, we proposed a specific methodology. This methodology aimed at quantitative and qualitative evaluation of the cultural ecosystem services provided by urban micro-farms and is based on a framework, which distinguishes exogenous and endogenous cultural ecosystem services. Full article

Our planet suffers from humankind’s impact on natural resources, biogeochemical cycles and ecosystems. Intensive modern agriculture with inappropriate inputs of fertilisers, pesticides and fossil fuel –based energy has increasingly added to human pressure on the environment. As a key element of our natural capital, soils are also under threat, despite being essential to provide food, feed, fibre and fuel for an increasing global population. Moreover, soils play a key role in carbon, water and energy cycles, highlighting their importance for biomass provision and the circular bioeconomy. Evidently, these new and complex challenges cannot be resolved effectively with existing knowledge and experience alone. These challenges require scientific research, interdisciplinary collaboration and networking to find context-specific and tailored solutions addressing societal issues of our time and facilitating the adoption of these solutions. The most effective approaches are based on the involvement of multiple actors from science, policy, economy, civil society and farming that have the same goal, work on the same societal issue, but have complementing backgrounds, expertise and perceptions. The European Joint Programme (EJP) SOIL is a European network of research institutes in the field of soil science and agricultural soil management that will provide science-based advice to practitioners and policymakers, at local, national and European level. The EJP SOIL aims to align and boost research, training and capacity building through joint programming activities co-funded by the European Commission and national research programs. This will reduce current fragmentation and help to find synergies in order to make a leapfrog in research on good agricultural soil management in three main areas: climate change mitigation and adaptation, production capacity in healthy food systems, and environmental sustainability. By joint programming, training and capacity building, EJP SOIL will also take into account the need for effective policy solutions, as well as the socio-economic conditions of all stakeholders in the agricultural value chain. Thus, a key focus of the EJP SOIL is to build and strengthen a framework for an integrated community of research groups working on related aspects of agricultural soil management. As part of this effort, EJP SOIL will co-construct with stakeholders a roadmap for agricultural soil research. To develop a structured roadmap, EJP SOIL works with a version of the knowledge management framework of Dalkir (2005). The EJP version uses four compartments: (i) Knowledge development, (ii) knowledge harmonisation, organisation and storage (iii) knowledge sharing and transfer, and (iv) knowledge application. The four segments are part of a cyclic process to enhance the development and use of knowledge on agricultural soils. Knowledge development comprises assessing new knowledge needs to achieve the expected impacts of EJP SOIL. Therefore, by involving multiple stakeholders, knowledge gaps across Europe will be identified to work towards the adoption of Climate-Smart Sustainable Agricultural Soil Management (CSSASM). Within the knowledge sharing and transfer compartment, the capacity of scientists, advisors, policy makers, farmers and other stakeholders will be strengthened. EJP SOIL will work to support networks and co-creation of new knowledge with stakeholder groups, stimulating innovation in CSSASM. The knowledge harmonization, organization and storage compartment of the knowledge framework ensures linkages with all stakeholders to guarantee data harmonization and standardization. The last compartment, application of knowledge, will be facilitated by creating better guidelines, awareness and capacity for Climate-Smart Sustainable Agricultural Soil Management adoption and by strengthening science-to-policy processes at EU and Member State level. Full article

Urban agriculture is sprouting throughout the world nowadays. New forms of urban agriculture are observed such as rooftop farming. In the case of low-tech rooftop farming projects, based on recycled urban waste, one of the key issues is the type of substrate used, as it determines the functions and ecosystem services delivered by the green roof. Using a five year experimental trial, we quantified the food production potential of Technosols created only with urban wastes (green waste compost, crushed wood, spent mushroom), as well as the soil fertility and the potential contamination of food products. Regarding food production, our cropping system showed promising results across the five years, in relation with the high fertility of the Technosols. This fertility was maintained, as well as the nutrients stocks after five cropping years. Most of the edible crops had trace metals contents below existing norms for toxic trace metals with nevertheless a concern regarding certain some trace metals such as Zn and Cu. There was no trace metal accumulation in the Technosols over time except for Zn. This study confirmed that constructing Technosols only from urban wastes is a suitable and efficient solution to design rooftops for edible production. Full article

Root systems play an important role in crop performance particularly under rain fed conditions. Root architecture is key in determining the ability of crops to extract water at various soil depths. In many rain fed production regions, opportunities to improve yield through changes in management practices are limited. Thus, genetic solutions to improve yield under water limitation are required. We postulate that in drought-prone environments, genotypes with greater yield and yield stability can be developed by breeding for genotypes with favorable root systems. We studied wheat root architecture late in the developmental cycle. Narrow and deep root systems may help wheat to extract more water at depth late in the season and give an advantage to yield and yield stability where crops rely on stored moisture deep in the soil. To improve yield stability in rain fed regions, an effective phenotypic method is needed. However, studying root traits in mature field-grown crops is extremely challenging. A PVC tube method was developed and has been used to identify genotypic differences in root architecture late in crop development. Identification of root traits to improve deep water uptake late in crop development and the development of phenotypic methods to identify genetic sources of such traits will assist breeders to improve yield and yield stability in water-limited environments. Full article

Terminal drought stress is currently a major constraint in many wheat production regions. This is predicted to worsen with future climate change. The stay-green phenotype allows crops to remain green and photosynthesize for longer after anthesis, potentially improving yields in terminal drought environments. Root systems with greater root length density at depth can contribute by increasing access to deep soil moisture late in the season. To study the genetics of root and stay-green traits in wheat, a multi reference parent nested association mapping (NAM) population was developed. Using the “speed breeding” system of rapid generation advance, over 1500 recombinant inbred lines (RIL) were generated in approximately 18 months. Genome-wide association studies (GWAS) using a novel whole-genome NAM method (WG-NAM) identified genetic regions associated with the target traits. High-throughput techniques were developed and used for the NAM lines to (i) phenotype seedling roots in controlled conditions, and (ii) objectively characterize novel stay-green traits for hundreds of genotypes in standard yield plots in the field. NAM lines were phenotyped for yield and stay-green traits at multiple water-stressed and non-stressed environments during 4 seasons. Particular traits were associated with superior adaptation to certain environments. Many lines with adaptive root and stay-green traits exhibited superior yield to the reference parent in relevant target environments and 54 such lines have been provided to commercial Australian wheat breeders for cultivar development. This combination of technologies is increasing understanding of physiological adaptation to water-limited environments in wheat and helping accelerate genetic progress. Full article

The frequency of heat shocks during grain filling of wheat crops across the Australian wheatbelt has significantly increased over the last 30 years. These post-flowering heat events significantly reduce wheat yields with a relatively greater impact on grain size than grain number. A controlled environment study was conducted to assess the impact of post-flowering heat shocks on wheat recombinant inbred lines SB062 and SB003. Plants were submitted to 7-day heat shocks (33/21 °C day/night temperature) at different periods during grain filling. Heat shocks significantly accelerated leaf senescence, with a greater impact on older leaves and for mid post-flowering stresses. Overall, the tolerant line (SB062) could maintain leaf greenness longer than the sensitive line (SB003), especially when submitted to heat stress. Further, heat shocks during early-to-mid grain filling reduced the grain size and weight. While the impact on developing grains was significant in SB003, no significant effect of post-flowering heat was observed on leaf senescence nor on grain size in the tolerant line SB062. Delayed leaf senescence appeared to play a role in maintaining grain size under heat stress. The research findings will assist improving crop models for post-flowering heat effects and developing techniques for screening heat tolerant wheat lines. Increased post-flowering assimilate production through sustained leaf greenness could improve the performance of wheat crops in increasingly warmer environments. Full article

While global food demand is projected to grow by 50–80% by 2050, Australia is expected to continue its significant contribution to global food security. We quantified how recent climatic changes have affected wheat crops in Australia over the last 38 years. Changes in drought, heat and frost stresses affecting a mid-maturing cultivar sown on May 15 were quantified over 1981–2018 using an improved version of the Agricultural Production Systems sIMulator (APSIM). Modifications to APSIM-wheat module included the addition of two calculation subroutines for estimating direct impact of frost events and heat shocks on grain setting and grain filling. National drought-induced yield loss exceeded 40%, significantly increasing by 3.6% per decade (P < 0.1), part of which being compensated for by rising atmospheric CO₂ concentration. The national average impact of hot days (T_max > 26 °C) on grain yield have significantly increased mostly due to a significant trend in the impact on individual grain weight. At the national level, frost damage has reached 14% of wheat yield and has been significantly increasing since 1981. Overall, wheat yield has decreased at a significant rate of 180 kg ha⁻¹ per decade (P < 0.01) with the largest decreasing rate in the South-East and East. As heat and drought are expected to remain predominant yield-limiting factors in the future, adaptation of wheat germplasm to warmer and drier environments appears to be a priority to enhance grain yield in Australia. Full article

Despite recent progress in genetics, genomics, and phenotyping, trait selection is limited by our ability to predict genotype x environment interactions, and to identify impactful traits for target environments. Here, we combined crop modelling, physiology, genetics, and breeding to identify relevant traits to increase wheat yields in the target environments of the Australian wheatbelt, develop high-throughput phenotyping methods for relevant traits, and identify their underlying genetic controls. Better transpiration efficiency (i.e., ‘more crop per drop’) and its components were identified as traits of interest and used as an example to illustrate how integrating modelling, phenotyping, and genetics can be used to improve crop adaptation. We anticipate that such an approach can enhance the efficiency of breeding programmes to increase productivity in target environments in current and future climates. Full article

The dual concern of this article is to present the vision of the church articulated by the renowned generation of Catholic ressourcement thinkers in the mid-twentieth century, and to demonstrate its continued fecundity in the pluralist, multi-cultural context of contemporary western society. It seeks to contribute primarily to ecclesiology, while also providing historical and social commentary with respectful suggestions for its relevance to present-day ecclesiology. The article provides an interpretative framework for understanding ressourcement with reference to its philosophical foundations and the vision of its founders. Its aims are, first, to articulate the role of ressourcement in the modern context and, secondly, to document the genesis and emergence of that movement’s perception of the church’s mandate in the world, based on an essential return to the sources of Christianity. The paper presents the public vision of ressourcement ecclesiology in two parts, drawing principally, though not exclusively, on the work of the two leading intellectual orders of the Catholic Church at the time of its formulation, namely, the Dominicans and the Jesuits of France. In this paper, I limit myself to the French-speaking Jesuits and Dominicans and do not refer to Rahner, Semmelroth, Schillebeeckx or Schoonenberg. Full article

El Niño–Southern Oscillation strongly influences rainfall and temperature patterns in Eastern Australia, with major impacts on frost, heat, and drought stresses, and potential consequences for wheat production. Wheat phenology is a key factor to adapt to the risk of frost, heat, and drought stresses in the Australian wheatbelt. This study explores broad and specific options to adapt wheat cropping systems to El Niño–Southern Oscillation, and more specifically, to the Southern Oscillation Index (SOI) phases ahead of the season (i.e., April forecast) in Eastern Australia, when wheat producers make their most crucial management decisions. Crop model simulations were performed for commercially-grown wheat varieties, as well as for virtual genotypes representing possible combinations of phenology alleles that are currently present in the Australian wheat germplasm pool. Different adaptation strategies were tested at the site level, across Eastern Australia, for a wide range of sowing dates and nitrogen applications over long-term historical weather records (1900–2016). The results highlight that a fixed adaptation system, with genotype maturities, sowing time, and nitrogen application adapted to each location would greatly increase wheat productivity compared to sowing a mid-maturity genotype, mid-season, using current practices for nitrogen applications. Tactical adaptation of both genotype and management to the different SOI phases and to different levels of initial Plant Available Water (‘PAW & SOI adaptation’) resulted in further yield improvement. Site long-term increases in yield and gross margin were up to 1.15 t·ha⁻¹ and AU$ 223.0 ha⁻¹ for fixed adaptation (0.78 t·ha⁻¹ and AU$ 153 ha⁻¹ on average across the whole region), and up to an extra 0.26 t·ha⁻¹ and AU$ 63.9 ha⁻¹ for tactical adaptation. For the whole eastern region, these results correspond to an annual AU$ 440 M increase for the fixed adaptation, and an extra AU$ 188 M for the PAW & SOI tactical adaptation. The benefits of PAW & SOI tactical adaptation could be useful for growers to adjust farm management practices according to pre-sowing seasonal conditions and the seasonal climate forecast. Full article