Browsing by Author "Hale, Sarah E."

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Biochar Effect on Maize Yield and Soil Characteristics in Five Conservation Farming Sites in Zambia
    (Agronomy, 2013) Cornelissen, Gerard; Martinsen, Vegard; Shitumbanuma, Victor; Alling, Vanja; Breedveld, Gijs D.; Rutherford, David W.; Sparrevik, Magnus; Hale, Sarah E.; Obia, Alfred; Mulder, Jan
    Biochar addition to agricultural soils can improve soil fertility, with the added bonus of climate change mitigation through carbon sequestration. Conservation farming (CF) is precision farming, often combining minimum tillage, crop rotation and residue retention. In the present farmer-led field trials carried out in Zambia, the use of a low dosage biochar combined with CF minimum tillage was tested as a way to increase crop yields. Using CF minimum tillage allows the biochar to be applied to the area where most of the plant roots are present and mirrors the fertilizer application in CF practices. The CF practice used comprised manually hoe-dug planting 10-L sized basins, where 10%–12% of the land was tilled. Pilot trials were performed with maize cob biochar and wood biochar
  • Thumbnail Image
    Item
    Designing and Performance Evaluation of Biochar Production in a Top-Lit Updraft Upscaled Gasifier
    (Journal of Sustainable Bioenergy Systems, 2015) Kisiki Nsamba, Hussein; Hale, Sarah E.; Cornelissen, Gerard; Bachmann, Robert Thomas
    The Original Belonio Rice Husk Gasifier (OBRHG), initially of height of 0.6 m, diameter of 0.15 m and thickness of 0.025 m was tested for biochar production through air gasification of rice husk (RH) and the design was upscaled to height of 1.65 m, diameter of 0.85 m and thickness of 0.16 m. A total of 27 experiments were conducted to monitor the gasifier performance and the system can operate with the centrifugal blower operating at a power input of 155 W and a maximum flow rate of 1450 m3/hr regulated according to the air requirement. Building the UBRHG is simple and inexpensive to fabricate and with the fairly satisfactory performance and ease of construction along with the convenience of operation, the UBRHG with RH as feed would find abundant avenues of applications in a rural setting for biochar production alongside thermal, mechanical and electrical energy delivery.
  • Thumbnail Image
    Item
    The potential of biochar in improving drainage, aeration and maize yields in heavy clay soils
    (PLoS One, 2018) Obia, Alfred; Mulder, Jan; Hale, Sarah E.; Laela Nurida, Neneng; Cornelissen, Gerard
    Heavy clay soils are globally widespread but their poor drainage and poor aeration limit their use for agriculture. This study was designed to test the effect of the amendment of biochar (BC) from woody shrubs on drainage/saturated hydraulic conductivity (Ksat), soil aeration/air capacity, available water capacity and biomass and grain yields of maize. In a field experiment, BC from Gliricidia sepium was applied in planting basins or rip lines at 2.5% and 5% w/w in addition to a control without BC. The maize biomass and grain yields were higher in BC treated plots compared to control (p<0.05) during the 2012 and 2013 seasons. There was no significant difference in the yields between 2.5% and 5% BC treatments (e.g. grain yield were 6.6 and 8.1 t ha-1 in 2012 and 9.3 and 10.3 t ha-1 in 2013 compared to control with 4.2 and 6.7 t ha-1 in 2012 and 2013, respectively). Soil from the same field site was also mixed with a similar woody shrub BC from Eupatorium adenophorum in the laboratory at rates of 2.5%, 5% and 10% BC w/w and a control without BC. The mixtures were then incubated and subjected to two wet-dry cycles for two weeks. Core samples were taken from the incubated soil and tested for bulk density, Ksat and pF measurements. Total porosity and moisture at field capacity and wilting point were 72.3%, 43.7% and 23.7%, respectively, and not affected by BC amendment (p>0.05). In contrast, bulk density decreased linearly by 0.011±0.002 g cm-3 per percent BC added (p<0.001). Ksat and air capacity of the soil were 288 cm day-1 and 30.9%, respectively falling within the generally accepted optimal range.
  • Thumbnail Image
    Item
    Sustainable Technologies for Small-Scale Biochar Production—A Review
    (Journal of Sustainable Bioenergy Systems, 2015) Kisiki Nsamba, Hussein; Hale, Sarah E.; Cornelissen, Gerard; Bachmann, Robert Thomas
    Charcoal has found enormous application in both agriculture (AKA biochar) and other sectors. Despite its potential benefits, small scale technologies relevant for its production remain a chal- lenge. Technologies striking a balance between user friendliness, energy efficiency, ease of adap- tation and limited emissions could easily be integrated into the local community for the sustaina- ble production of biochar answering both technical and socio-economic aspects. These technolo- gies can be customized to recover the produced heat alongside biochar and the producer gas. The purpose of this work is to review the state of the art in small scale technologies, their associated risks and challenges as well as research gaps for future work. Factors affecting biochar production have been discussed and temperature is known to heavily influence the biomass to biochar con- version process. Based on the reviewed work, there is a need to develop and promote sustainable and efficient technologies that can be integrated into biochar production systems. There is also further need to develop portable, economically viable technologies that could be integrated into the biochar production process without compromising the quality of produced biochar. Such tech- nologies at midscale level can be channeled into conventional small scale farmer use in order that the farmers can process their own biochar.
  • Thumbnail Image
    Item
    Sustainable Technologies for Small-Scale Biochar Production—A Review
    (Journal of Sustainable Bioenergy Systems, 2015) Kisiki Nsamba, Hussein; Hale, Sarah E.; Cornelissen, Gerard; Bachmann, Robert Thomas
    Charcoal has found enormous application in both agriculture (AKA biochar) and other sectors. Despite its potential benefits, small scale technologies relevant for its production remain a challenge. Technologies striking a balance between user friendliness, energy efficiency, ease of adaptation and limited emissions could easily be integrated into the local community for the sustainable production of biochar answering both technical and socio-economic aspects. These technologies can be customized to recover the produced heat alongside biochar and the producer gas. The purpose of this work is to review the state of the art in small scale technologies, their associated risks and challenges as well as research gaps for future work. Factors affecting biochar production have been discussed and temperature is known to heavily influence the biomass to biochar conversion process. Based on the reviewed work, there is a need to develop and promote sustainable and efficient technologies that can be integrated into biochar production systems. There is also further need to develop portable, economically viable technologies that could be integrated into the biochar production process without compromising the quality of produced biochar. Such technologies at midscale level can be channeled into conventional small scale farmer use in order that the farmers can process their own biochar.