Oyster mushrooms can be cultivated with great spatial efficiency, on nutrient-poor plant materials, without light and under diverse climatic conditions. Their production therefore has a great potential for improving food security, especially in impoverished and overpopulated areas. However, the pasteurization or sterilization of mushroom substrates uses a lot of energy and water. This study investigates the impact of different pasteurization and sterilization techniques on the growth and yield of oyster mushrooms, and evaluates their water and energy usage. The efficacy of heat-based methods, including hot water, hot air, and pressurized steam, as well as a chemical method utilizing hydrated lime (Ca(OH)2) were assessed. The results show that sterilizing mushroom substrates through autoclaving can significantly increase the dry yields, up to 50% compared to pasteurization methods. However, pasteurization methods also achieved excellent results compared to untreated substrates, with good harvests and low pest occurrence. The mushroom water content was significantly higher in pasteurization methods where the substrate is submerged in water. In terms of fresh yield, hot water pasteurization was as good as autoclaving and significantly better than the other pasteurization methods. Hot air pasteurization has, on balance, a better water and energy efficiency than autoclave sterilization (about 75 % less energy) or hot water pasteurization (about 85 % less water). When performed at an air temperature of 75° C, which was found to be sufficient for successful mushroom cultivation, as little as 1068 kJ was needed to pasteurize one kg of dry substrate (e.g. maize straw). While hydrated lime pasteurization could use as little as 270 kJ per kg of dry substrate, it is very wasteful of water, as is hot water pasteurization and could lead to nutrient leaking. The success of mushroom cultivation, especially with hot air pasteurization, could also be influenced by the duration of substrate soaking before treatment. The study provides slight evidence, although inconclusive, for a positive effect of prolonged soaking periods on yield. Lastly, the study discusses the applicability of different disinfection techniques at varying production scales and for different mushroom species, focusing on African countries, where comparably small mushroom economies are growing rapidly, but often through the use of unsustainable pasteurization technology.

This study explores the viability of cultivating oyster mushrooms on cereal and legume straw of poor feed quality, investigating oyster mushroom productivity, and the implications for mass-, nitrogen- and carbon flows within the agricultural system. Four types of straw (wheat, maize, faba bean, and soy bean) were utilized as substrates for mushroom cultivation. Fresh yields varied widely, from 114% biological efficiency on maize straw to 58% on wheat straw, while dry yields ranged from 9.2% biomass conversion rate on maize straw to 3.8% on wheat straw. The protein content of mushrooms varied between 16.8% on wheat straw and 23.2% on faba bean straw, correlating with the nitrogen content of the straw. Furthermore, results revealed significant variations in carbon emissions, ranging from an estimated 3.5 kg (on wheat straw) to 2.6 kg (on soy straw) emitted per kg of dry mushroom produced. These findings underscore the importance of substrate selection in mushroom cultivation, with implications for agricultural resource management and food production. Depending on the focus, different substrates may be considered as optimal. While maize straw produced most mushrooms in this study, soy bean straw emitted the least carbon in relation to yield, faba bean straw produced mushrooms with higher protein content, and wheat straw retained the most nitrogen in the spent mushroom substrate.

This special issue presents the outcomes from “ Designing sustainable and circular agricultural systems for the year 2100 ,” the joint scientific workshop of ISOFAR, the Thünen-Institute, and INRA-Morocco, which was held from November 14 to 16, 2019 in Marrakesh, Morocco. Nineteen scientists from a broad array of background and nationalities came together with the understanding that food security globally is at risk, especially in the post-2050 timeframe. Current concepts, strategies, measures, and scientific efforts carried out by governments, NGOs, businesses, and societies do not deliver satisfying solutions for how to sustainably produce enough healthy and affordable food to support the global population. With the economic and social impact of the Covid-19 pandemic in 2020, it became even more evident that food security is a challenge. This workshop took an innovative approach to addressing the challenges of future agriculture by considering sustainable, circular agricultural systems. Participants presented research results on algae-based food, edible insects, mushrooms, novel concepts for nutrient management, bioreactor-based farming, sustainable food culture, as well as sensor- and remote-controlled automatic food production. This special issue presents the papers contributed to the workshop and the results of the discussions.

The scientific roots of organic systems are anchored in the four principles of IFOAM – Organics International: ecology, health, fairness, and care. Scientific skills are needed for the continuous improvement of organic food, systems, and culture. The Forum invited researchers to share their work in the following five themes, with a special focus on interdisciplinary research.

The population in Africa will increase four- to fivefold by the year 2100.•Land for food production will then decrease to about 500 to 600 m2 per person.•A combination of land-based and landless food production can help.•A research model for a sustainable and circular food chain has been developed.

Edible mushrooms are cultivated mainly on ligno-cellulosic plant materials, thereby turning agricultural wastes to high-quality products. In this review, several ways in which mushroom cultivation could help in the transition towards a circular agricultural economy are discussed, including food, feed, and compost production. The production processes of different mushroom species are also described and an overview of the global mushroom market and its history are given. Resource use efficiency could be maximized by using spent mushroom substrate as feed for invertebrates, such as insects or earthworms, which produce high-quality compost and can serve as food or feed for other livestock. In the context of an increasing world population, as well as limited resources and agricultural land, mushroom cultivation could fulfill the need for protein-rich food and for the recycling of nutrient-poor agricultural wastes.

For feeding the world in 2100, the global agriculture, the entire food chain, as well as the behavior of all consumers must be change fundamentally. Essential resources needed to intensify agriculture and use barren land, such as phosphorus, water, and fossil fuels, are becoming increasingly scarce and expensive. An ecological form of agriculture that uses these resources more responsibly requires more land for the same yields. Therefore, new concepts for food and feed production have to be developed, in which nutrients are recycled beyond these areas. A possible starting point could be bioreactors, since these are enormously efficient and enable resource-efficient land use. Wastewater treatment as a means of nutrient recycling will be one of the most important tasks in the future. Hereby, not only the heterotrophic bioreactors currently used for this purpose but also autotrophic photobioreactors show great potential, especially if these two reactor types would be combined. Because of the ability to use inorganic nitrogen and phosphorus for their growth as well as the ability to produce a wide range of metabolites, microalgae offer an integrated approach. This review provides an overview of the potential of microalgae as components of a sustainable, circular agricultural system for feed and food production.

Even optimistic assumptions about population growth, agricultural productivity, and potentially available cropland produce a grim image for the future food security and sovereignty of many developing countries, in particular in sub-Saharan Africa. Here, we review literature and datasets on the current and future state of food security, with focus on Africa, and propose a plan of ten interconnected actions to create sustainable, circular, and local food systems to feed a global population between 11.2 and 16.6 billion people in 2100. In particular, we focus on “action number 10”: landless food systems in combination with land-based food production, using modern “organic agricultural strategies.” The concept shall be applicable to the needs and conditions in low-income countries with high population densities and small-scale farming systems, as expected in sub-Saharan Africa in 2100. We designed the concept “LandLessFood” with research recommendations for a circular bioreactor-based system of “calorie food and feed.” Our aim is to “replace one hectare of cropland with one square meter of bioreactor space.” Released cropland can and has to be used for “quality food” production to have enough, healthy, and affordable food for everyone on the earth in the year 2100.

Die Bevolkerung in Afrika wird sich bis zum Jahr 2100 vervier- bis verfunffachen.•Land fur Lebensmittelproduktion wird dann auf ungefahr 500 bis 600 m2pro Person zuruckgehen.•Eine Kombination von landgebundener und landloser Lebensmittelproduktion kann helfen.•Ein Forschungsmodell fur eine nachhaltige und zirkulare Lebensmittelkette wurde entwickelt.

Four hundred fifty-eight meter square is the available cropland per person throughout Africa, if the population will increase 4 to 5 times towards 4.3 to 5.9 billion people in 2100, the maximum estimation of the UN 2019 (95% confidence interval). This space is not enough for food sovereignty, if the low African yields remain. Even with the global average yields, nearly 3 times higher than African yields, will not allow food sovereignty. Hunger, wars, diseases, and mass migration can be the consequences already long time before 2100. Nevertheless, food sovereignty is possible, but not in the way as it is done up to today by governments and development projects. In the future, intensification of (yields) and/or expansion (grassland, forest: LULUCF) of agriculture will not be able to produce enough, nutritious, and affordable food for everyone. But clever combining of land-based and landless food production can be a solution for a local, sustainable, and circular food security. Maize and soybeans are best for WFP minimum diets and have the best yields. Using insects and earthworms as protein source can deliver enough and nutritious protein, and local photoreactors can produce oil/and/or starch for food energy. Later can be large industrial and very small household scaled. This “out-of-the-box” system approach needs research and development. Every good research needs good questions and a concept with some simple calculations to assess the strengths, weaknesses, opportunities, and threats. Socio-economic aspects are often not considered enough in technical focused and far ahead R&D.

On smallholder farms in Ethiopia, livestock manure and organic residues are traditionally removed from fields for construction, feed, and fuel purposes, while the remainder stays in the field as feed or fertilizer. Burning and removing organic matter without replacing it leads to valuable losses of on-farm nutrients and soil carbon, which could otherwise be used to fertilize crops. Instead, resources need to be used efficiently by reducing and recycling organic residues and forming a closed production system. Competition between applications can be eliminated by bio-methanation using a biodigester. There, organic residues are transformed to biogas utilized for light and cooking and bioslurry, a nutritious organic fertilizer and source of organic matter. Through capturing nutrients in agricultural by-products, nutrients become available to the food system again. Literature review has been supplemented with empirical evidence from a study carried out in the central Ethiopian Highlands on 47 smallholder farms, to provide a baseline for further improvements on the management of biogas technology. The study identifies a series of inadequate handling practices and thus a significant potential to optimize the farming system around a biodigester. It is recommended to include forage legumes in the farm system to enhance on-farm available nutrients that can be recycled through a biodigester. It is further necessary to involve the private sector in biodigester programs, to improve local availability of materials, which are suitable to the local culture and traditions. Space for knowledge exchange between farmers and advisors like demonstration farms can further improve bioslurry management. Although challenges remain, the integration of a biodigester should be encouraged as it fulfills the production of energy and a nutritious and economic fertilizer without additional resources, resulting in a win-win situation for the farmer.

Sustainable rangeland management is crucial for conservation and improvement of global grassland ecosystems, livestock performance and grassland-linked livelihoods. This applies in particular for Sub-Saharan African countries like Namibia with its rangeland-based low external input livestock husbandry. In the local savannas, productivity and resource distribution is spatially heterogeneous and temporally variable, which calls for adaptive and responsive grazing strategies to meet the needs of livestock and vegetation. The adjustment of stocking rate (SR; kilogramme livestock per hectare per year) and stocking density (SD; kilogramme livestock per hectare during a specific grazing event) is considered as a key success factor but very different rates and densities have been recommended in the past by practitioners, scientific evidence is lacking. On an Organic Namibian beef cattle and sheep farm were these recommendations assessed in order to investigate the responses of savanna rangelands to varying grazing intensities. Since 2014, forage biomass production and composition under three different grazing regimes have been assessed: (1) the routine management (here Holistic Management) as control and in comparison to this (2) an increased SR or (3) increased SD. Destructive biomass sampling was done each May in 2014, 2015, 2016 and 2017, respectively. The results showed that the increased SR or SD can be beneficial for average fodder production, but not significantly. However, the negative standing dead biomass accumulation was significantly reduced.

Agriculture in tropical countries has to adapt not only to climate change and resource depletion but also to population growth – especially in Africa, where around 80 % of the growth until 2100 is predicted to happen. The medium estimate of the United Nations predicts an increase from currently 1.2 to 4.4 billion people by the end of the century – but no strategic plans exist beyond the year 2050. Since Africa is a continent with large deserts, arid and semi-arid areas, only about 400 m2 of agricultural land will be available per person according to these predictions. In the LandLessFood project, we are trying to design an agricultural system, based on the principles of circular economy, in which it is possible to feed everyone on this little space, focusing on Nigeria as an example. The main idea is the combination of “landless” food systems such as microalgae production and mushroom cultivation, with organic, “land-based” food production. Microalgae are very spatially efficient, can be produced independent of fertile soils, could be used as a pathway of nutrient recycling in the sewage system and can produce large amounts of oils or starch, to fulfil the energy-need of the population. Land-based food production should be used to fulfil the need for “quality food” (vitamins, nutrients, minerals) of the population. Mushroom cultivation is a form of “selective composting” in which food is produced. While mushrooms themselves are an excellent meat-substitute, spent mushroom substrate can be used as animal feed, ideally for invertebrates, such as earthworms, which are good chicken, pig and fish feed.

Au Bénin, les femmes rurales sont au cœur des systèmes de production agricole où elles jouent des rôles primordiaux. Néanmoins, à l'heure de s'exprimer, elles sont reléguées au second rang et deviennent des invisibles et des sans voix. Ceci revient au fait que si la femme doit parler, étant la propriété privée d'un homme, cet homme devient la courroie de transmission entre ses idées et ses interlocuteurs. Or, l'analyse des comportements discursifs ou des pratiques langagières est un créneau assez révélateur des relations entre différentes couches sociales. Cette étude prend pour base les pratiques langagières des femmes agricultrices produisant le coton biologique, les analyse et révèle les mécanismes rhétoriques et linguistiques utilisés afin d'analyser l'impact de la conversion à l'agriculture biologique en général et surtout le coton biologique sur les discours des femmes. Introduit dans les années 90 comme alternative au coton conventionnel qui était la principale culture d'exportation mais inhibitrice des efforts des femmes, le coton biologique a commencé par faire émerger les femmes au point d'induire un changement remarquable dans leurs discours qui entre temps ne pouvaient qu'être portés par des hommes. Cette recherche, menée dans une perspective sociolinguistique, s'inscrit dans une démarche méthodologique pluridisciplinaire où plusieurs cadres théoriques ont été exploités pour atteindre les objectifs fixés. Elle part de la méthode de collecte de données proposée par Franco Ferraroti (1981; 1990) pour se construire sur le schéma de Teun A. van Dijk. Ce schéma se focalise sur les inégalités sociales et l'exercice du pouvoir en général et comment ces inégalités et réalités s'expriment au quotidien à travers l'usage du langage. Nous avons donc analysé les discours des femmes converties à l'agriculture biologique dans les zones de Kandi, Sinendé, Glazoué et Djidja pour mettre en évidence les avancées notables qui s'y remarquent à travers la force des mots qu'elles emploient et comment elles tendent vers une certaine acquisition du pouvoir, comment elles exhibent un certain prestige qui ne pouvait se manifester avant. Même si cette acquisition de pouvoir pourrait être jugée de relative et éphémère, il est à remarquer qu'il faudrait la valoriser afin de la maintenir avec des efforts constants à divers niveaux pour un changement durable dans les luttes des femmes ; ceci permettra d'atteindre un niveau encore plus élevé et une évolution discursive permettant de déconstruire les mentalités sur le rôle et la place des femmes dans les prises de décision les concernant en milieu rural. Les études en agriculture écologique et biologique montrent très peu d'intérêt aux questions langagières en général et celles des femmes en particulier en considérant à tort ou à raison les travaux linguistiques comme non adéquates en agriculture. Toutefois, la langue se trouve au cœur de toute discipline et c'est qui nous motive lorsque nous nous intéressons au discours de femmes qui s'investissent dans ce mode de production. De la Vulnérabilité au Prestige? L'agriculture écologique et biologique, un outil de négociation et d'exercice du pouvoir des femmes

Soil quality improvement provides an environment for plant nutrient uptake that impacts the development and yield of crop. Thus, this study evaluated the effect of applied poultry composted organic manure (PCOM) on selected soil physical attributes and soil organic carbon content (SOC) under two tomato (UC82B and -1 BESKE) varieties planted in succession. Three rates 0, 10 and 20 t ha of compost were applied to two tomato varieties. The experiment was arranged in a 2x3 factorial experiment fitted into a randomized complete block design with three replicates. The soil physical parameters considered were bulk density, aggregate stability, total porosity and SOC. It was observed that application of PCOM increased SOC, total porosity, aggregate stability and decreased the bulk -1 density in the cropped tomato area. The SOC was highest in 10t ha of PCOM. -1 Application of 10 t ha compost is adequate to improve carbon content and soil physical properties for a fragile soil. 175 Influence of Composted Poultry Manure on Organic Carbon and Selected Soil Properties under Tomato Cultivation 1 2 Wahab A.A. *, Dada O.A. , 4 4 Aina O. , Agbanna K , 3 and Hamza A. Kwara State University, Malete, Kwara State Federal University, Ndufu-Alike Ikwo, Ebonyi State, Nigeria University of Ibadan, Ibadan, Nigeria Kogi State University, Ayingba, Kogi State Corresponding author: *loukinse@gmail.com

Peppermint (Mentha piperita L.) is one of the most economical aromatic and medicinal crops useful in pharmaceutical and agro-allied industries globally. In view of the potential threat Plant-Parasitic Nematodes (PPN) pose to the crop, a + study was conducted to appraise the effects of Arati-OBD organic fertilizer in the control of associated phytonematodes in a field in Abeokuta. Responses of Free-Living Nematodes (FLN) to the organic fertilizer were also recorded. The -1 -1 -1 fertilizer was applied at 0 tha , 5 tha or 10 tha , laid out in Randomized Complete Block Design with three replications. Five core soil samples were collected randomly from the rhizosphere at depth of 0-30 cm, once every month for the period of three months per plot. Soil samples per plot were bulked to form a composite sample from which 250 g sub-samples were obtained and assayed for nematode presence, type and numbers of each found. Results indicated that 11 genera of PPN were found in the organic peppermint tested. They included Helicotylenchus, Rotylenchus, Rotylenchulus, Meloidogyne, Longidorus, Aphelenchus, Radopholus, Tylenchulus, Ditylenchus, Hoplolaimus, Pratylenchus and some free-living nematodes. These nematodes varied significantly (P<0.05) + -1 -1 across treatments. Application of Arati-OBD at 5 tha and 10 tha significantly (P<0.05) suppressed PPN compared with untreated (control) plots. Ditylenchus, Tylenchulus, Meloidogyne, Radopholus and Aphelenchus decreased by up to 100% (total control), Helicotylenchus by 73 50% and Rotylenchus by 60 33% in the treated plots while the FLN increased by as much as 18 47% in the soil following -1 application 5 – 10 tha .

There have been persistent increases in the cost fish feeds and organic fish feeds are practically non-existent in Nigeria. This study was conducted to investigate the effects of replacement of soybean meal (SBM) with dried pig feces (DPF) and poultry droppings (PD) on growth performance, nutrient utilization and carcass composition of Oreochromis niloticus fingerlings. O. niloticus weighing 5.29 ± 0.02g and standard length 5.35 ± 0.07cm were fed seven iso-nitrogenous diets containing 40% crude protein in which the SBM protein was replaced with DPF and PD meals each at 0% (control diet, D7), 15% (Diets DPF1and PD4), 30% (Diets DPF2 and PD5) and 45% (Diets DPF3 and PD6) levels for 12 weeks in 3 plastic aquaria measuring 52x33x33 cm (Length x Breadth x Height). Each treatment was in triplicate. At the end of the feeding trial, data obtained were analyzed statistically using one-way analysis of variance; and means were separated using Duncan's multiple range test, DMRT. Water quality parameters measured during the study period were within the range for tilapia production, except for dissolved oxygen. Weight gain of 11.0 ± 0.27g was highest in fish fed PD5, while PD4 had the lowest (6.99 ± 0.27 g);and was significantly different (p<0.05) from other diets. Feed conversion ratio of 1.79 in fish fed PD5 was not significantly different (p>0.05) from 1.81 and 1.83 recorded for fish fed D7 and PD6 respectively. Apparent net protein utilization was highest (62.57%) in fish fed PD5 and lowest (35.85%) with a significant differences (p<0.05) in fish fed diet PD4. Apparent protein digestibility was highest in fish fed PD5 (91.86%) and lowest in fish fed PD4 (78.98%). Percentage survival was similar (100%) in fish fed DPF3 and PD6 (93.33%) but was significantly higher (p<0.05) than values obtained in fish fed D7, DPF1, DPF2, PD4 and PD5 with an equal value of 90% respectively. This study revealed that poultry droppings could replace 30% of soybean meal in practical diets of O. niloticus without any adverse effects on growth and with concomitant reduction in aquaculture feed costs.