In modern agriculture, weed problems are predicted to worsen and become more complicated as a result of increasing invasiveness, herbicide resistance, and emphasis on high-input methods. Weeds cause huge economic yield losses that range from US$100 million to US$26 billion globally. The knowledge of weed science has offered success in the past through effective, reasonably priced, and secure technologies; specifically, synthetic herbicides to effectively control weeds in agroecosystems. Weed science is accepted and adopted by many universities with teaching, research, and/or extension programs in agriculture. Globally, approximately 7% of all the universities offering agricultural education have dedicated weed science departments focusing on weed biology, ecology, and management. Some universities also offer weed science degree programs or at least certain courses in their degrees related to associated disciplines, such as plant protection, agronomy, and ecology. Although substantial advances have been made in weed science, such as a separate weed science discipline, specialized journals, and specific weed science societies and conferences worldwide, many constraints (e.g., lack of trained weed scientists) and barriers to adoption of new weed science technologies remain. Slow modernization in weed science research and low funding has slowed the progress of this discipline. New curricula in the weed science discipline should focus on the role of biochemistry, evolutionary biology, molecular biology, and genetics in weed science research.

Modern agriculture needs proper solutions to face the current trend of pesticides and fertilizers reduction. One of the available leverages to support this transition is the use of bioproducts that are more environmentally friendly and less hazardous for human health. Among them, blue biotechnology and more precisely seaweed and microalgae gain interest every year in the scientific community. In agriculture, seaweeds (Macroalgae) have been used in the production of plant biostimulants while microalgae still remain unexploited. Microalgae are widely described as renewable sources of biofuels, bioingredients and biologically active compounds, such as polyunsaturated fatty acids (PUFAs), carotenoids, phycobiliproteins, sterols, vitamins and polysaccharides, which attract considerable interest in both scientific and industrial communities. They affect agricultural crops for enhancement of plant growth, seedling growth. They can also improve nutrient incorporation, fruit setting, resistance properties against pests and diseases, improving stress management (drought, salinity and temperature). The present review aimed at the interest of blue biotechnology in agronomy, with a specific focus on microalgae, their biological activities and their possible application in agriculture as a potentially sustainable alternative for enhanced crop performance, nutrient uptake and resilience to environmental stress. This review does not only present a comprehensive study of microalgae as plant biostimulants but also as biofertilizers, with a particular emphasis on future challenges these solutions will have to deal with, microalgae being able to synthesize secondary metabolites with potential biopesticidal action.

This research explains what happened to agricultural soil fertility during the “Campanha do Trigo” (Wheat Campaign) in Portugal, which began in 1929. It is commonly understood that the excessive expansion of wheat crops during the fascist “Estado Novo” (New State) regime led to the degradation of soils in the southern half of Portugal. This relationship, however, has never been questioned before. This article extends the narrative back into the last half of the nineteenth century in search of the origin of processes that gradually intensified throughout the country. In short, expansion of the cultivated area in association with the inadequate intensification of crop rotations over about 80 years, from the 1870s onward, including in non-wheat areas, strongly accentuated soil erosion and made organic fertilization progressively less effective. These transformations were only partially offset by chemical fertilization. Nitrogen and phosphorus were the key factors in this historical process. Focusing on the cultivation system and soil dynamics allows the successive integration of various kinds of historical evidence and sources. From an environmental question—why did agricultural soil degrade?—this article explores soil degradation over time and space, and assesses its social and biophysical impacts. At the same time, it addresses the history of agriculture in Portugal and its disciplinary foundations.

Recirculation of nitrogen (N) from crop residue and green-manure biomass resources may reduce the need to add new reactive N to maintain crop yield and quality. The aim of this study was to determine how different strategies for recycling residual and green-manure biomass influence yield and N concentration of the edible parts of food crops in a stockless organic cropping system. For this purpose, three biomass distribution treatments were investigated in a field experiment, based on a cropping system designed to produce both high-quality food crops and biomass resources from crop residues, cover crops and a green-manure ley. The three treatments, applied at the cropping system level, were: (1) incorporating the aboveground biomass resources in situ (IS); (2) harvesting, ensiling and redistributing the same biomass resources to the non-legume crops (biomass redistribution, BR); and (3) harvesting, ensiling and using the biomass resources as substrate for production of bio-methane via anaerobic digestion (AD) followed by distribution of the digestate as bio-fertilizer to the non-legume crops. The redistribution of ensiled (BR) and digested (AD) biomass did not increase the yield of the edible parts in winter rye (Secale cereal L.), white cabbage (Brassica oleracea L.) or red beet (Beta vulgaris L.) compared with leaving the biomass on the ground at harvest (IS). The BR treatment increased the yield of lentil intercropped with oat, compared with IS treatment in one of the two studied years. The total biomass yield of the cover crop following winter rye was significantly higher in the BR treatment than in IS in both years. The legume proportion in the green-manure ley was significantly higher in the AD and BR treatments as compared with IS in one of the experimental years. This study showed that strategic biomass redistribution has the potential to enhance biomass productivity while maintaining food crop yields, thereby enhancing whole system productivity. Biomass redistribution systems both with and without biogas digestion offer a new strategy for the development of multifunctional arable cropping systems that rely on internal nutrient cycling.

Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 μg Se/d respectively, dietary Se intakes in the UK have declined from >60 μg Se/d in the 1970s to 35 μg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se.

Numerous factors influence the chemical quality of medicinal plants from crop establishment to extraction of raw material. The most important ones are described using the example of Hypericum perforatum. Optimization of these factors contributes to the objective of producing a high-quality drug, and a method consisting of three scientific approaches (technological, agronomical, plant breeding) is presented. All data concerning the plant (biology, physiology and environmental impacts) and the active components and by-products (pathway, localization and stability) are useful to adapt and to develop management sequences. Although plant breeding appears to be the principal way of improvement, and gives good results in terms of resistance to pathogens, active component content and yield; the agronomical and the technological approaches are also very important. The technological approach after harvesting is especially important to avoid degradation of the active components and to induce, in some cases, the transformation of by-products to those molecules sought. This integrated method (plant breeding and agronomical and chemical approaches) requires research on different levels of organization from molecule to field, and includes all processing systems from farmers to chemists.

Introduction. Still practically unknown in the mid-1990s in Europe, pitahaya (Hylocereus spp.) is now a full member of the ‘small exotic fruits’ category in shops. Nevertheless, these species are not very well known. The aims of our work were first to evaluate thoroughly the literature currently available on Hylocereus and secondly to supplement this review by agronomic works not yet published. Knowledge of Hylocereus. The study includes a presentation of the origin, botany, morphology and floral biology of the principal species cultivated within the Hylocereus genus and suggests a key for determination. Cultivation techniques. The agronomical practices used in Hylocereus orchards are broached: multiplication, cultivation practices (supports, density, pruning, mineral nutrition, irrigation, etc.), pollination and harvest. Pests and diseases are cited too. Physico-chemical composition of fruits. This work draws up a review of different studies regarding pitahaya composition, micronutrients and pigments. Post-harvest and processing. The life of the fruit after harvest (conservation and storage life) is approached as well as the various possibilities of processing. European market. The European market is analyzed for the various cultivated species of Hylocereus (imported quantity, market segment, origin of production, etc.) and its evolution prospects are evoked. Conclusion. Our review highlights the fact that the interest shown in these pitahayas is recent and, for these reasons, more detailed knowledge on these species is required (agronomic, genetic and technological).