Separating autotrophic respiration due to roots from soil heterotrophic respiration in an agroforestry parkland system in Saponé, Burkina Faso

Soil respiration is the largest component of ecosystem respiration but little is known about it and its components in parkland systems. We therefore conducted an experiment to estimate the amount of CO2 respired and to partition it into soil, tree root and crop root contributions in parkland systems in Burkina Faso. Three factors effects were estimated: pruning, species and presence of tree canopy. Pruning showed no significant effect on soil respiration. The soil respiration was significantly higher under Parkia biglobosa (1.54 g CO2 m-2 h-1 against 0.93 in the open area) than under Vitellaria paradoxa (0.98 g CO2 m-2 h-1 against 0.52 in the open area). The autotrophic respiration associated with the P. biglobosa system due to sorghum roots was 0.37 g CO2 m-2 h-1 and due to tree roots was 0.61. For the V. paradoxa system, the figures were 0.13 g CO2 m-2 h-1 for sorghum roots and 0.46 for tree roots. We observed higher CO2 emissions from under trees crowns than in open areas owing to higher tree-root respiratory activities, and higher water and organic matter contents. However, further studies are needed to discover if these low values of soil CO2 fluxes from parklands translate into higher amounts of carbon fixed than emitted taking into consideration the seasonal variations.Keywords: Carbon balance, CO2 flux, carbon-sink, carbon-source

Landscape-based nutrient application in wheat and teff mixed farming systems of Ethiopia: farmer and extension agent demand driven approach

Introduction: Adapting fertilizer use is crucial if smallholder agroecosystems are to attain the sustainable development goals of zero hunger and agroecosystem resilience. Poor soil health and nutrient variability characterize the smallholder farming systems. However, the current research at the field scale does not account for nutrient variability across landscape positions, posing significant challenges for targeted nutrient management interventions. The purpose of this research was to create a demand-driven and co-development approach for diagnosing farmer nutrient management practices and determining landscape-specific (hillslope, mid-slope, and foot slope) fertilizer applications for teff and wheat. Method: A landscape segmentation approach was aimed to address gaps in farm-scale nutrient management research as well as the limitations of blanket recommendations to meet local nutrient requirements. This approach incorporates the concept of interconnected socio-technical systems as well as the concepts and procedures of co-development. A smart mobile app was used by extension agents to generate crop-specific decision rules at the landscape scale and forward the specific fertilizer applications to target farmers through SMS messages or print formats. Results and discussion: The findings reveal that farmers apply more fertilizer to hillslopes and less to mid- and foot slopes. However, landscape-specific fertilizer application guided by crop-specific decision rules via mobile applications resulted in much higher yield improvements, 23% and 56% at foot slopes and 21% and 6.5% at mid slopes for wheat and teff, respectively. The optimized net benefit per hectare increase over the current extension recommendation was $176 and$333 at foot slopes and $159 and$64 at mid slopes for wheat and teff (average of $90 and$107 for wheat and teff), respectively. The results of the net benefit-to-cost ratio (BCR) demonstrated that applying landscape-targeted fertilizer resulted in an optimum return on investment ($10.0 net profit per$1.0 investment) while also enhancing nutrient use efficiency across the three landscape positions. Farmers are now cognizant of the need to reduce fertilizer rates on hillslopes while increasing them on parcels at mid- and foot-slope landscapes, which have higher responses and profits. As a result, applying digital advisory to optimize landscape-targeted fertilizer management gives agronomic, economic, and environmental benefits. The outcomes results of the innovation also contribute to overcoming site-specific yield gaps and low nutrient use efficiency, they have the potential to be scaled if complementing innovations and scaling factors are integrated

Validated fertilizer use at landscape scale: demand driven approach in sorghum, wheat and teff mixed farming systems in Ethiopia: A Technical Report

Soil nutrient management is very critical to maximize crop yield and to maintain soil health for a sustainable productivity. Decline in soil fertility and soil quality, among other factors, are major constraints to the agricultural productivity and disfunction of environmental services (Bahr, 2015). In Ethiopia, soil nutrient mining and very less replenishment of organic and inorganic resources are the recurrent problems that resulted in soil nutrient depletion. Besides, severe topsoil erosion associated with steep slope cultivation made the country one of the highest nutrient depletion rates in Africa with 41, 6 and 26 kg ha-1yr-1 of nitrogen, phosphorus and potassium, respectively (Stoorvogel and Smaling, 1990). Soil nutrient balance assessments in central Ethiopia showed that nutrient losses even worsen and reached an amount of 122 kg N, 13 kg P and 82 kg K ha-1 per year-(Haileslassie et al., 2005). In addition to the poor nutrient and organic matter status, aluminum toxicity and phosphorous fixation are other constraints in Ethiopian soils apparent in pH less than 5.5 which enhances nutrient limitations and toxicity (Agegnehu and Amede, 2017; Agegnehu et al., 2006). The state of nutrient depletion entails context specific nutrient management and fertilizer applications

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its ‘Minimal Information for Studies of Extracellular Vesicles’, which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly