In Ghana, studies on the use of organic materials to increase soil productivity have focused on crop-residue management, use of green and animal manures, and legume cover cropping. Few studies have assessed the use of human waste for agriculture, even though this is widely practiced by farmers in the northern part of the country. This study was carried out to investigate the stakeholders in the use of faecal sludge (FS) for crop production in Tamale and Bolgatanga municipalities in the guinea savanna agroecological zone of Ghana. The aim was to determine the driving factors, constraints and potentials for this practice. Field survey and focus group discussions were carried out among 90 farmers who use FS, and officials of the Municipal Sanitation Unit were interviewed. Sixty-four percent of farmers interviewed used FS as a cost-effective way to improve soil fertility and increase yields of maize and sorghum. Sludge is discharged by spreading it on the soil surface, or it is stored and dried in pits during the dry season and incorporated into the soil at the onset of the rainy season. The high temperatures of the savanna climate and this long period of drying allow sludge to be handled easily. Although this treatment is perceived to reduce the number of pathogens in dried sludge, 22% of farmers complained of itching feet and foot rot after working with FS, which is done without wearing protective foot covering. This constraint is coupled with the foul smell, transport problem and public mockery associated with the use of human waste for agriculture. In spite of these problems, there is competition for FS among farmers, due to benefits derived from its use. Further investigation is required to ascertain the causes of itching feet and foot rot, and there is a need for education on proper handling and appropriate hygiene practices when working with FS. Information regarding optimal FS application rates is also required.

An understanding of the nexus of organic fertilizer use decisions that smallholder farmers take is essential to designing relevant policy to support adoption in sub-Saharan Africa. In this paper, we applied exploratory factor analysis (EFA) on observed farmer decisions to identify a set of common management approaches that farmers in the northeastern part of Ghana adopt in using organic fertilizer. After identification, seemingly unrelated regression (SUR) analysis was applied to relate each approach to farmer characteristics that influence uptake decisions. The EFA identified four approaches, labeled as Augmentary Compost Use Approach, Urban Human Waste Organic Fertilizer Approach, Integrated Livestock Manure Approach and Mineral Fertilizer Cost Constraint Organic Approach. Each of the first three approaches involves a set of strategic farmer decisions which could be supported to increase organic fertilizer use. The SUR analysis showed that the uptake of each approach is affected by different subsets of farmer characteristics. However, participation in organic fertilizer management training positively influences the adoption of all four approaches. Thus, we recommend free training of smallholder farmers as a core element of any policy package to support organic fertilizer adoption.

As climate change and agriculture burden water resources globally, there is a need for more efficient water use including irrigation with recycled water in greenhouses. While research has proven that properly treated recycled water can be safe for use, many growers still express concern. Underlying most studies on growers' perceptions is the assumption that they understand recycled water the same way scholars and policy makers do—as municipally treated wastewater. We question this assumption and explore whether the ways in which growers conceptualize recycled water is associated with the ways they perceive its usability. Our findings reveal that growers define recycled water in four different ways—captured water, treated water, recirculation and in a general sense as ‘reuse’. These definitions do appear to suggest trends in the way recycled water is perceived by growers. While these definitions do not significantly affect growers' willingness to use, other factors such as prior experience using recycled water appear to be significant.

Much of the global population lacks access to basic public sanitation, energy and fertilizers. Micro-scale anaerobic digestion presents an opportunity for low-cost decentralized waste management that creates valuable co-products of renewable energy and organic fertilizer. However, field-based assessments of system performance and clearly articulated guidelines for digestate management and field application are needed. Feedstocks and effluent from seven digesters in Kampala, Uganda were monitored for standard wastewater and fertilizer metrics including indicator organisms (Escherichia coli and fecal coliform), chemical oxygen demand (COD), biological oxygen demand (BOD5), total Kjeldahl nitrogen (TKN), total phosphorous (TP), heavy metals, pH, temperature and total solids (TS) over 2 yr. Results reveal that digester effluent does not meet standards for wastewater discharge or international safety standards for field application. Data indicate that digestate could be a suitable source of fertilizer (TKN = 1467 mg L−1, TP = 214 mg L−1) but poses issues for water quality if not managed properly (TS = 26,091 mg L−1, COD = 3471 mg L−1 and BOD5 = 246 mg L−1). While effluent from the digester contained pathogen indicator organisms (fecal coliform = 8.13 × 105 CFU/100 ml, E. coli = 3.27 × 105 CFU/100 ml), they were lower than the influent concentrations, and lower than reported concentrations in drainage canals. All digestate samples contained little to no heavy metals suggesting effective source separation. Data suggest that micro-scale biogas systems have potential to improve waste handling and meet standards associated with fertilizer application with proper post-digestion treatment.