Innovations in market crop waste compost production: Use of black soldier fly larvae and biochar

Purpose Compost production technology and use are known among Ghanaians farmers. However, the long composting period averaging three months has had adverse effect on adoption. The black soldier fly (Hermetia illucens) larvae (BSFL) feed voraciously and breaks down organic wastes fast. Addition of rice husk biochar (RHB) neutralises acidity and aerates the compost. Combined application of BSFL and RHB to feedstocks could therefore reduce composting period and improve compost quality. Method Two studies were conducted with market crop waste (MCW) as feedstock. Firstly, feedstocks at two particle sizes (x 10 mm), with and without BSFL were evaluated to determine degradability, chemical content of the degraded residue and to select appropriate feedstock size ideal for composting. Secondly, the selected feedstocks size of between 5 mm and 10 mm were inoculated with or without BSFL and RHB of 0%, 5% 10% and 15% added. Composting trials were conducted in barrels inclined at 30o to facilitate drainage. Physicochemical and biological parameters of feedstock were monitored until maturity. Results Degradability of MCW by BSFL was feedstock specific rather than feedstock size. Inoculation of BSFL and biochar addition reduced composting period from 76 to 45 days. Biochar addition at 15% increased P availability to 1882 mg kg-1 but reduced total N to 10.5 g kg-1. E coli levels decreased in the BSFL-biochar composts to acceptable limits. Conclusion Composting MCW with BSFL and biochar reduced composting period and improved compost quality

Sustainable P-enriched biochar-compost production: harnessing the prospects of maize stover and groundnut husk in Ghana’s Guinea Savanna

Farmers in resource-poor areas of the Guinea Savanna zone of Ghana often face declining soil fertility due to the continuous removal of nutrient-rich harvested produce from their fields. This study focuses on the Lawra Municipality in the Guinea Savanna zone of Ghana, where low soil fertility, specifically, limits phosphorus (P) bioavailability and hinders crop production. The objective of this research is to formulate P-enhanced biochar-compost from maize stover (MS) and groundnut husk, which abound in the area, to close the nutrient loop. MS was co-composted with groundnut husk biochar at varying rates of 0, 10, 20, 30, and 40% by volume. To facilitate decomposition using the windrow system, the composting heaps were inoculated with decomposing cow dung, and the moisture content was kept at 60% throughout the monitoring period. The addition of biochar shortened the lag phase of composting. However, rates above 20% resulted in reduced degradation of MS. Biochar incorporation enriched the available phosphorus content in the final compost from 286.7 mg kg−1 in the non-biochar-compost to 320, 370, 546, and 840.0 mg kg−1 in the 10, 20, 30, and 40% biochar-compost, respectively

Advances in research on the use of biochar in soil for remediation: a review

Purpose: Soil contamination mainly from human activities remains a major environmental problem in the contemporary world. Significant work has been undertaken to position biochar as a readily-available material useful for the management of contaminants in various environmental media notably soil. Here, we review the increasing research on the use of biochar in soil for the remediation of some organic and inorganic contaminants.  Materials and methods: Bibliometric analysis was carried out within the past 10 years to determine the increasing trend in research related to biochar in soil for contaminant remediation. Five exemplar contaminants were reviewed in both laboratory and field-based studies. These included two inorganic (i.e., As and Pb) and three organic classes (i.e., sulfamethoxazole, atrazine, and PAHs). The contaminants were selected based on bibliometric data and as representatives of their various contaminant classes. For example, As and Pb are potentially toxic elements (anionic and cationic, respectively), while sulfamethoxazole, atrazine, and PAHs represent antibiotics, herbicides, and hydrocarbons, respectively.  Results and discussion: The interaction between biochar and contaminants in soil is largely driven by biochar precursor material and pyrolysis temperature as well as some characteristics of the contaminants such as octanol-water partition coefficient (KOW) and polarity. The structural and chemical characteristics of biochar in turn determine the major sorption mechanisms and define biochar’s suitability for contaminant sorption. Based on the reviewed literature, a soil treatment plan is suggested to guide the application of biochar in various soil types (paddy soils, brownfield, and mine soils) at different pH levels (4–5.5) and contaminant concentrations ( 50 mg kg−1).  Conclusions: Research on biochar has grown over the years with significant focus on its properties, and how these affect biochar’s ability to immobilize organic and inorganic contaminants in soil. Few of these studies have been field-based. More studies with greater focus on field-based soil remediation are therefore required to fully understand the behavior of biochar under natural circumstances. Other recommendations are made aimed at stimulating future research in areas where significant knowledge gaps exist

Integrating Biochar and Inorganic Fertilizer Improves Productivity and Profitability of Irrigated Rice in Ghana, West Africa

The efficiency of mineral fertilizer use in most soils in Sub-saharan Africa is low. Prominent among the reasons for this is low soil carbon stock. In this study, we hypothesized that in the short term, combined use of biochar and inorganic fertilizer in irrigated rice (Oryza sativa var KRC Baika) cropping systems will increase soil organic carbon storage, N recovery and agronomic efficiency of N use (above world average of 55% and 20 kg grain·kg−1·N respectively) and improved economic returns compared to the sole use of inorganic fertilizer. A two-year (4‒cropping cycles) field trial was, thus, conducted on a Vertisol. The experiments were designed as split–plot with two (0 and 10 t·ha−1) biochar and four (0, 45, 90, 120 kg·ha−1·N) nitrogen application rates. Additionally, the effect of biochar on the chemical properties of the soil was investigated using standard protocols. Biochar application improved the soil organic carbon storage in the topsoil. There were significant interactions between the application of biochar and nitrogen fertilizer on yield parameters. Introducing biochar significantly increased root volume and nutrient (N, P and K) uptake, resulting in increased grain and straw yield. Grain yields under biochar amended plots were higher than sole fertilizer amended plots in 14 out of 16 instances (cropping cycles × N rates). The increase in grain yield was between 12 to 29% across N rates. Biochar amendment also enhanced agronomic N use and apparent N recovery efficiencies in 3 out of the 4 cropping cycles. Gross margin indicated that biochar application under irrigated rice cropping systems is economically feasible in all cropping cycles and N rates. However, the value cost ratio of biochar application was higher than for sole inorganic fertilizer in three out of the four cropping cycles (each cropping cycle has three N rates). The soil organic carbon storage of biochar amended soil increased by 17% under unfertilized condition and by 32% under fertilized condition. To enable the promotion and efficient use of the biochar technology in enhancing productivity and profitability in irrigated rice, extension officers and farmers will need to be trained on how to char the rice husk to reduce emissions prior to upscaling the technology to farmers

Efficacy of Histick Soy in soybean nodulation in two Alfisols of Ghana

IntroductionSoybean is an important legume whose nitrogen-fixing ability may be exploited to improve the fertility status of soils. In Ghana, where most of the soils are poor in fertility, cultivation of soybean presents an inexpensive way for resource-poor farmers to earn appreciable income and improve the fertility of arable land at the same time. However, the yield and N-fixing response of soybean to inoculation in most soils with poor fertility in Ghana are not well-researched.MethodA screen house study on the efficacy of Histick Soy (an inoculum manufactured by a German chemical company) on improving the nodulation of soybean in P-deficient soils comprising two Plinthustalfs, Ny1 and Ny2, with a history and no history, respectively, of soybean cultivation and a Kandiustalf with no history of soybean cultivation was evaluated in Ghana. Sterile riverbed sand was included as a check. Soybean seeds were inoculated with Histick Soy at three different rates, namely, zero, half, and recommended rate, and grown in a screen house to ascertain the efficacy of the inoculant in nodulating soybean. Nitrogen was applied at 0 and 10 kg/ha, K was applied at 60 kg/ha, and P was applied at 0, 30, and 60 kg/ha. These treatments were completely randomized with four replicates at a moisture content equivalent to 80% field capacity and grown till flowering. At flowering, the number of nodules per plant was counted. A parallel experiment was carried out to physiological maturity where 100-seed weight per pot was determined.Results and discussionResults obtained revealed that plants from the uninoculated seeds in the riverbed sand and the Kandiustalf did not nodulate. In the case of Ny2, the number of nodules at harvesting was statistically similar for half and full recommended application rate of the inoculant. The uninoculated Ny2 with 4.4 average nodules per pot did not increase at half recommended application rate. At the recommended rate, nodule numbers increased 2.3-fold to 10.3. The Ny1 showed no response to inoculation. Treatments, which received the application of 60 and 30 kg P2O5/ha triggered higher responses to inoculation in low and high Bradyrhizobia populations, respectively, in the Plinthustalfs

Use of Biochar-Compost for Phosphorus Availability to Maize in a Concretionary Ferric Lixisol in Northern GHANA

A pot experiment was conducted to investigate the effect of biochar-compost on availability of P for maize cultivation in a concretionary Lixisol of northern Ghana and residual soil characteristics thereof. Sawdust biochar was co-composted with kitchen waste and cow dung in various proportions. Four biochar-composts were selected based on their superior carbon and available P content, lower pH, and electrical conductivity (EC). These were amended to attain the standard phosphorus requirement (SPR) and half the SPR of the Lixisol. Triple superphosphate and (NH4)2 SO4 were, respectively, applied as inorganic fertilizer to meet the SPR and the average total nitrogen of the selected biochar-compost treatments. A control without any soil amendment was included. Maize was grown to tasseling (eight weeks) and shoot dry matter and P uptake determined. A 2.71 to 3.71-fold increase in P uptake led to a 1.51 to 2.33-fold increase in shoot dry matter in biochar-compost-amended soils over the control. Residual soil C, pH, and total and available P in the biochar-compost-amended soils were enhanced. Biochar-composts at half the SPR level produced maize with higher shoot dry matter than the equivalent inorganic amendment at full SPR

Effects of co-composting of faecal sludge and agricultural wastes on tomato transplant and growth

Purpose: Faecal sludge (FS) has been co-composted with many organic solid wastes globally. Agricultural wastes, such as oil palm empty fruit bunches (EFB) and cocoa pod husks (CPH), have received very little research attention as far as combining with FS is concerned. This study aimed at co-composting these wastes at different ratios to produce safe compost for use as soilless medium for raising tomato transplants. Methods: Dewatered FS (DFS) was mixed with shredded EFB and CPH at five different ratios: 1DFS:1EFB, 1DFS:1CPH, and DFS:EFB:CPH in ratios of 1:1:1, 2:1:1, and 2:2:1 and composted for 3 months. Select physicochemical parameters and pathogens were monitored every fortnightly and 3 weeks, respectively. Results: Maximum temperatures obtained ranged 46.8–54.5 °C. Though these temperatures were lower than sanitizing temperatures prescribed by USEPA, no E. coli was found in any of the piles at the end of composting. The ratio 2DFS:2EFB:1CPH was found to be the safest formulation and hence was used to grow tomato under greenhouse conditions. Tomato seeds were sown in three different growing media: 100% FS-based compost, 100% rice husk biochar, and 50% FS-based compost–50% rice husk biochar mix. Conclusion: Results showed that FS-based compost was a suitable growing medium for tomato. Further studies into the optimal rate and frequency of application of compost teas on tomato are recommended

Feeding practices and malnutrition at the Princess Marie Louise Children’s hospital, Accra: what has changed after 80 years?

BACKGROUND: Sub-optimal feeding practices are associated with malnutrition. In 1933, Dr Cecily Williams, while working at Princess Marie Louise Children’s Hospital (PML) in Accra described Kwashiorkor as the disease of children “deposed” from breast feeding who were being fed plain fermented maize diets. Presently, it is not clear how this has changed after 80 years. METHODS: We conducted an unmatched case–control study at PML in 2013 in order to determine faulty feeding practices associated with malnutrition. PML is a 74 bed children’s hospital and the largest centre for treating children with malnutrition in Ghana. Under-fives with Moderate or Severe Acute Malnutrition (SAM or MAM) were selected as cases while the controls were children without SAM or MAM. RESULTS: A total of 182 malnourished and 189 well-nourished under-fives and their mothers were studied. Faulty feeding practices including early weaning, shorter duration of exclusive breastfeeding, mixed feeding, bottle feeding and limited consumption of fruits were found. Though the use of “iced kenkey” a maize-based diet was limited, over one-third of malnourished children (39.1 %) were still being weaned with plain unfortified fermented maize gruel both of which Dr Williams associated with Kwashiorkor. Well-nourished children were more likely to receive solid food (38.0 %), fortified maize gruel (29.2 %), and Cerelac® (24 %) a processed cereal-based complementary food. A child’s refusal to breastfeed was the most common reason for stopping breastfeeding among malnourished children. CONCLUSIONS: More effective nutrition education and new complementary feeding diets that are wholesome yet appeal to a new generation of mothers are needed. The patho-physiology of feeding problems needs further study

Changing Patterns of Disease and Mortality at the Children's Hospital, Accra: Are Infections Rising?

The Millennium Development Goals (MDGs) have led to reductions in child mortality world-wide. This has, invariably, led to the changes in the epidemiology of diseases associated with child mortality. Although facility based data do not capture all deaths, they provide an opportunity to confirm diagnoses and insight into these changes which are relevant for further disease control.To identify changes in the disease pattern of children who died at the Princess Marie Louise Children's Hospital (PML) in Ghana from 2003-2013.A cross sectional review of mortality data was carried out at PML. The age, sex, duration of admission and diagnosis of consecutive patients who died at the hospital between 2003 and 2013 were reviewed. This information was entered into an Access database and analysed using Stata 11.0 software.Altogether, 1314 deaths (3.6%) occurred out of a total of 37,012 admissions. The majority of the deaths, 1187 (90.3%), occurred in children under the age of 5 years. While deaths caused by malaria, malnutrition, HIV infection and diarrhoea decreased, deaths caused by pneumonia were rising. Suspected septicaemia and meningitis showed a fluctuating trend with only a modest decrease between 2012 and 2013. The ten leading causes of mortality among under-fives were malnutrition, 363 (30.6%); septicaemia, 301 (25.4%); pneumonia, 218 (18.4%); HIV infection, 183 (15.4%); malaria, 155 (13.1%); anaemia, 135 (11.4%); gastroenteritis/dehydration, 110 (9.3%); meningitis, 58 (4.9%); tuberculosis, 34 (2.9%) and hypoglycaemia, 27 (2.3%). For children aged 5-9 years, the leading causes of mortality were malaria, 42 (42.9%); HIV infection, 27 (27.6%); anaemia, 14 (14.3%); septicaemia, 12 (12.2%); meningitis, 10 (10.2%); malnutrition, 9 (9.2%); tuberculosis, 5 (5.1%); pneumonia, 4 (4.1%); encephalopathy, 3 (3.1%); typhoid fever, 3 (3.1%) and lymphoma, 3 (3.1%). In the adolescent age group, malaria, 8 (27.6%); anaemia, 6 (20.7%); HIV infection, 5 (17.2%); sickle cell disease, 3 (10.3%) and meningitis, 3 (10.3%) were most common.There has been a decline in the under-five mortality at PML over the years; however, deaths caused by pneumonia appear to be rising. This highlights the need for better diagnostic services, wider HIV screening and clinical audits to improve outcomes in order to achieve further reductions in child mortality and maintain the gains