• Energy Research
• 2021-2025close

Increased heat stress is a common feature of global climate change and can cause adverse impacts on crops from germination through maturation and harvest. This review focuses on the impacts of extreme heat (>35 °C) on plants and their physiology and how they affect food and water security. The emphasis is on what can be done to minimize the negative effects of heat stress, which includes the application of various materials and approaches. Nano-farming is highlighted as one promising approach. Heat is often combined with drought, salinity, and other stresses, which together affect the whole agroecosystem, including soil, plants, water, and farm animals, leading to serious implications for food and water resources. Indeed, there is no single remedy or approach that can overcome such grand issues. However, nano-farming can be part of an adaptation strategy. More studies are needed to verify the potential benefits of nanomaterials but also to investigate any negative side-effects, particularly under the intensive application of nanomaterials, and what problems this might create, including potential nanotoxicity.

Aim: United Nations calls for actions to meet future challenges, and industries and governments need to look for new solutions. Coffee is one of the largest industries in the world, and spent coffee grounds (SCG) represents 50% of its waste. Sustainable ways to manage this waste are of interest. Research has shown that SCG is rich in dietary fibres and antioxidants, and we liked to examine if SCG could be used in flavouring muffins. The objectives were to investigate the viability of processing SCG through a comparison of different drying methods, to evaluate how SCG influences properties of baked goods and to investigate consumer acceptance of muffins with SCG. Methods: Three methods for drying SCG were used: oven drying, freeze drying, and vacuum drying. Muffins were baked with 10% milled and sieved SCG related to flour weight, and a control with 2.5% espresso powder. C-cell-, texture- and moisture analyses were conducted along with a sensory analysis. Results: The laboratory measurements showed that SCG powders were comparable to the control regarding textural parameters, except for the slice area parameter. The sensory analysis showed no clear difference in bitterness but a difference in graininess and coffee flavour. The least grainy was the control which also had the strongest coffee flavour. The vacuum dried was the grainiest and the freeze dried had the least coffee flavour. Ranking data showed the control in top and the vacuum dried bottom. Conclusions: SCG has the potential as flavouring coffee muffins but a finetuning in the processing and recipe development is needed to retrieve more coffee flavour without increasing bitterness or graininess.

This study aimed to investigate the effects of a new nitrogen-enriched organic-based fertilizer (NEO) on Italian ryegrass (Lolium multiflorum Lam.) yield and soil fauna feeding activity. Nitrogen is transformed from the air to manure by a plasma process. At the farm level, NEO could improve self-sufficiency and sustainability. The work was carried out under controlled conditions in two pot trials. Five fertilization regimes were used: no fertilizer, different amounts of mineral fertilizer, three NEO types, organic fertilizer (untreated manure), and organic fertilizer + different amounts of N in mineral fertilizer, including 14 treatments in trial one and 11 treatments in trial two. Besides evaluating dry matter yields, we utilized the Bait-lamina test system to assess the feeding activity of soil fauna. The results indicated a clear positive impact of nitrogen (N) on ryegrass yield where all fertilizers increased the yield in correspondence with their N availability regardless of the fertilizer type; whereas the yield was highest with mineral fertilizer up to our maximum level of 235 kg N ha−1 in trial one and 175 kg N ha−1 in trial two. The NEO fertilizers yielded in the same range as mineral fertilizers. The same clear pattern was not observed for soil fauna feeding activity. Instead, a tendency was observed where no fertilization tends to give the highest feeding activity. We saw no correlation between the yield and the soil fauna feeding activity. The feeding activity was highest in depth below 5 cm from the soil surface. Feeding activity also increased over time after fertilization. The NEO fertilizers had no more adverse effects on soil fauna feeding activity than other fertilizers. Other factors than fertilization alone are determining the soil fauna feeding activity.

Cover crops could provide environmental benefits in spring-grain systems through diversification, reduced nitrate leaching, and carbon sequestration. However, few farmers apply the technique, partly as they believe the cover crops will compete with the main crop and cause yield losses. Cover crops can either be sown together with the grain (undersown) or in autumn and establish after grain harvest. The current study uses a mixed-method approach combining field trials, interviews, and literature synthesis. The field trials focused on perennial ryegrass (Lolium perenne L.), Italian ryegrass (Lolium multiflorum Lam.), and meadow fescue (Festuca pratensis L.) that were undersown with 15 kg ha−1 but with different seeding dates in spring wheat and barley. The interviews focused on gathering practical experiences from farmers in Norway and the literature synthesis gathered results from other studies. For carbon sequestration, nine studies were judged relevant for our target climate and included in our synthesis. They showed a median value at 264 kg C ha−1 year−1. In our field trials, 300–900 kg DM ha−1 year−1 was produced, with Italian ryegrass sown at the same date as the grain on top. Our trials showed no significant grain yield reduction due to the use of cover crops. However, our synthesis of the literature showed a 5–10% yield reduction with Italian ryegrass that was sown at the same time as the grain. One- or two-weeks delay in the sowing of Italian ryegrass, or reduced seeding rates, could reduce the problem. The interviews showed that farmers do not prefer undersown species, especially not perennial species, as they have experienced that such species may come up again in the following years and cause a weed problem. We recommend farmers to use cover crops and for undersowing, we recommend Italian ryegrass that is sown one or two weeks after the grain. Perennial ryegrass can also be recommended, as long as the growth is properly terminated.

Mushrooms have always been an important source of food, with high nutritional value and medicinal attributes. With the use of biotechnological applications, mushrooms have gained further attention as a source of healthy food and bioenergy. This review presents different biotechnological applications and explores how these can support global food, energy, and water security. It highlights mushroom’s relevance to meet the sustainable development goals of the UN. This review also discusses mushroom farming and its requirements. The biotechnology review includes sections on how to use mushrooms in producing nanoparticles, bioenergy, and bioactive compounds, as well as how to use mushrooms in bioremediation. The different applications are discussed under the water, energy, and food (WEF) nexus. As far as we know, this is the first report on mushroom biotechnology and its relationships to the WEF nexus. Finally, the review valorizes mushroom biotechnology and suggests different possibilities for mushroom farming integration.

It is urgent that we increase global food production to support population growth. Food production requires significant resources, amongst them water and energy. Therefore, any losses of food or other agricultural products also means a waste of water and energy resources. A significant amount of these losses occurs during the postharvest stage, primarily during processing and storage. This is considered avoidable food waste. The water-energy-waste nexus (WEW), and its relationship to food production, needs to be investigated from a circular bioeconomy lens. Furthermore, alternative uses of the wastes should be investigated. This review focuses on agro-wastes and their management as sources for bioactive compounds, biofertilizers, biomaterials, nanomaterials, pharmaceuticals and medicinal agents, and growth media, e.g., for plant tissue culture. We also investigated the potential contribution of agro-wastes to bioenergy production (bioethanol, biogas, and biofuel). Proper management of agro-wastes may support the mitigation of climate change, produce innovative bio-ingredients and biodegradable materials, and enhance green growth and a circular bioeconomy. We argue that the management of agro-wastes cannot be discussed without referring to the role of water and energy within the food system. Thus, this review focuses on agricultural wastes and their handling, applications, environmental impacts, and potential benefits in the agricultural and medical industries in light of the WEW nexus.