Yield gaps, nutrient use efficiencies and response to fertilisers by maize across heterogeneous smallholder farms of western Kenya

The need to promote fertiliser use by African smallholder farmers to counteract the current decline in per capita food production is widely recognised. But soil heterogeneity results in variable responses of crops to fertilisers within single farms. We used existing databases on maize production under farmer (F-M) and researcher management (R-M) to analyse the effect of soil heterogeneity on the different components of nutrient use efficiency by maize growing on smallholder farms in western Kenya: nutrient availability, capture and conversion efficiencies and crop biomass partitioning. Subsequently, we used the simple model QUEFTS to calculate nutrient recovery efficiencies from the R-M plots and to calculate attainable yields with and without fertilisers based on measured soil properties across heterogeneous farms. The yield gap of maize between F-M and R-M varied from 0.5 to 3 t grain ha-1 season-1 across field types and localities. Poor fields under R-M yielded better than F-M, even without fertilisers. Such differences, of up to 1.1 t ha-1 greater yields under R-M conditions are attributable to improved agronomic management and germplasm. The relative response of maize to N-P-K fertilisers tended to decrease with increasing soil quality (soil C and extractable P), from a maximum of 4.4-fold to -0.5- fold relative to the control. Soil heterogeneity affected resource use efficiencies mainly through effects on the efficiency of resource capture. Apparent recovery efficiencies varied between 0 and 70% for N, 0 and 15% for P, and 0 to 52% for K. Resource conversion efficiencies were less variable across fields and localities, with average values of 97 kg DM kg-1 N, 558 kg DM kg-1 P and 111 kg DM kg-1 K taken up. Using measured soil chemical properties QUEFTS over-estimated observed yields under F-M, indicating that variable crop performance within and across farms cannot be ascribed solely to soil nutrient availability. For the R-M plots QUEFTS predicted positive crop responses to application of 30 kg P ha-1 and 30 kg P ha-1 + 90 kg N ha-1 for a wide range of soil qualities, indicating that there is room to improve current crop productivity through fertiliser use. To ensure their efficient use in sub-Saharan Africa mineral fertilisers should be: (1) targeted to specific niches of soil fertility within heterogeneous farms; and (2) go hand-in-hand with the implementation of agronomic measures to improve their capture and utilisation

Beyond Speculative Robot Ethics

In this article we develop a dialogue model for robot technology experts and designated users to discuss visions on the future of robotics in long-term care. Our vision assessment study aims for more distinguished and more informed visions on future robots. Surprisingly, our experiment also lead to some promising co-designed robot concepts in which jointly articulated moral guidelines are embedded. With our model we think to have designed an interesting response on a recent call for a less speculative ethics of technology by encouraging discussions about the quality of positive and negative visions on the future of robotics.

Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

The flows and balances of N, P and K were studied in 20 farms in the Campo Ma'an area in Cameroon between March and August 2002 to assess the nutrient dynamics in smallholder farms. Data were collected through farmer interviews, field measurements and estimates from transfer functions. Nutrient input from mineral (IN1), animal feed (IN2a) and inorganic amendments (IN2b) was absent. Major outputs were through crop (OUT1a) and animal (OUT1b) products sold. Partial budgets for farmer managed flows were negative: -65 kg N, -5.5 kg P and -30.8 kg K ha-1 year-1. For inflows not managed by farmers, deep capture (IN6) was the major source: 16.6, 1.4 and 6.6 kg ha -1 year-1 of N, P and K, respectively. Atmospheric deposition (IN3) was estimated at 4.3 kg N, 1.0 kg P and 3.9 kg K ha -1 year-1, and biological nitrogen fixation (IN4) at 6.9 kg N ha-1 year-1. Major losses were leaching (OUT 3a): 26.4 kg N, and 0.88 kg K ha-1 year-1. Gaseous losses from the soil (OUT 4a) were estimated at 6.34 kg N, and human faeces (OUT 6) were estimated at 4 kg N, 0.64 kg P and 4.8 kg K ha-1 year-1. The highest losses were from burning (OUT 4c), i.e. 47.8 kg N, 1.8 kg P and 14.3 kg K ha-1 year-1. Partial budgets of environmentally controlled flows were negative only for N -4.8 kg N, +2.4 kg P and +9.6 kg K ha-1 year-1. The overall farm budgets were negative, with annual losses of 69 kg N, 3 kg P and 21 kg K ha-1. Only cocoa had a positive nutrient balance: +9.3 kg N, +1.4 kg P and +7.6 kg K ha-1 year-1. Nutrients reaching the household waste (1.9 kg N, 2.8 kg P and 18.8 kg K ha-1 year-1), animal manure (4.9 kg N, 0.4 kg P and 1.6 kg K), and human faeces (4 kg N, 0.64 kg P and 4.8 kg K ha -1 year-1) were not recycled. Five alternative management scenarios were envisaged to improve the nutrient balances. Recycling animal manure, household waste and human faeces will bring the balance at -62.6 kg N, 0 kg P and +1 kg K ha-1 year-1. If, additionally, burning could be avoided, positive nutrient balances could be expecte

Distancing Measures and Challenges Discussed by COVID-19 Outbreak Teams of Dutch Nursing Homes:The COVID-19 MINUTES Study

The most severe COVID-19 infections and highest mortality rates are seen among long-term care residents. To reduce the risk of infection, physical distancing is important. This study investigates what physical distancing measures were discussed by COVID-19 outbreak teams of Dutch long-term care organizations and what challenges they encountered. The COVID-19 MINUTES study is a qualitative multi-center study (n = 41) that collected minutes of COVID-19 outbreak teams from March 2020 to October 2021. Textual units about distancing measures were selected and analyzed using manifest content analysis for the first wave: early March-early May 2020; the intermediate period of 2020: mid-May-mid-September 2020; and the second wave: late September 2020-mid-June 2021. During all periods, COVID-19 outbreak teams often discussed distancing visitors from residents. Moreover, during the first wave they often discussed isolation measures, during the intermediate period they often discussed distancing staff and volunteers from residents, and during both the intermediate period and the second wave they often discussed distancing among residents. During all periods, less often admission measures were discussed. Challenges persisted and included unrest among and conflicts between visitors and staff, visitors violating measures, resident non-adherence to measures, and staffing issues. The discussed distancing measures and corresponding challenges may guide local long-term care and (inter)national policymakers during the further course of the COVID-19 pandemic, outbreaks of other infectious diseases, and long-term care innovations

Assessment as the site of power:A Bourdieusian interrogation of service user and carer involvement in the assessments of social work students

The centrality of service user and carer involvement in social work education in England is now well established, both in policy and practice. However, research evidence suggests their involvement in student assessments is underdeveloped and under researched. This study focused on the positioning of service users and carers in relation to other stakeholders involved in the assessments of social work students in England. Using narrative research methodology, 21 participants, including service users, carers, social work students, social work employers and social work educators, were offered a semi-structured individual interview. Participants’ narratives revealed different power relations among those involved in social work students’ assessments and a lack of confidence among service users and carers in making failed assessment recommendations. The paper concludes by arguing the case for social work educators and service user organisations to provide joint training to support service users and carers in their role as assessors of social work students

Redefining Case Study

Abstract: In this paper the authors propose a more precise and encompass-ing definition of case study than is usually found. They support their defini-tion by clarifying that case study is neither a method nor a methodology nor a research design as suggested by others. They use a case study prototype of their own design to propose common properties of case study and demon-strate how these properties support their definition. Next, they present sev-eral living myths about case study and refute them in relation to their definition. Finally, they discuss the interplay between the terms case study and unit of analysis to further delineate their definition of case study. The target audiences for this paper include case study researchers, research de-sign and methods instructors, and graduate students interested in case study research