Research in Agricultural Engineering, 2021 (vol. 67), issue 2
Development of a manually operated organic and inorganic fertiliser applicator for smallholder farmersOriginal Paper
Olayinka Omotosho, Adebayo Oke, Azarel Uthman, Adekunle Atta, Emmanuel Ezaka
Res. Agr. Eng., 2021, 67(2):51-57 | DOI: 10.17221/39/2020-RAE 
This paper reports the design, fabrication and testing of a low-cost PVC-based manual fertiliser applicator (MFA) for the placement of granular and powdery fertilisers (organic and inorganic) at a required soil depth and plant spacing. The MFA consists of a spring-loaded trigger mechanism, a connecting tube and a knapsack plastic tank for the fertiliser storage, holding between 8.0-12.0 kg of fertiliser depending on the fertiliser's characteristics. The MFA was tested using four common fertilisers (NPK, SSP, Urea and organic manure) at different fertiliser moisture contents (3, 4, 5 and 6% w.b.). The results reveals that the MFA performed effectively...
Role of a corona field application in the physicochemical properties of stored strawberriesOriginal Paper
Ali Esehaghbeygi, Arash Hajisadeghian, Masih Nasri Nasrabadi
Res. Agr. Eng., 2021, 67(2):58-64 | DOI: 10.17221/50/2020-RAE
Grey mould disease caused by the fungus Botrytis cinerea Pers is widely distributed on strawberries as the dominant postharvest disease. Therefore, fruits have been treated using a pin-to-plate corona electrical field at a high voltage electric field (HVEF) intensity of 3.61, 4.56, and 5.13 kV.cm-1 for 60 minutes. The result revealed that the corona discharge demolished the B. cinerea growth using 20 kV.cm-1 for 10 min in the Petri dishes. In addition, the treated strawberries at 4.56 kV.cm-1 had an average infection rate of 23.33% compared with non-treated samples rate of 45.33%. The HVEF-treated...
Calculation model of the tractor transport set - Economic and environmental indicatorsOriginal Paper
Karel Kubín, Martin Pexa, Michal Holúbek
Res. Agr. Eng., 2021, 67(2):65-73 | DOI: 10.17221/51/2020-RAE
This contribution presents a calculation method of indicators in agricultural transport. The tractor Zetor Forterra 8641 with a silage trailer was used. Calculations were performed with various weights of transported material: 2.5, 3.6, 5.8, 7.4 and 9.0 tons. The model was created concerning significant parameters of the transport set, engine characteristics and route. It considered splitting of the route into elementary sections, in which important route parameters were regarded as constant. Indicators were defined in every section (fuel consumption, emissions, etc.) and overall values were calculated as a sum. The set with 7.4 t of load reached the...
Thin layer mathematical modelling of white maize in a mobile solar-biomass hybrid dryerOriginal Paper
Joseph Oppong Akowuah, Ato Bart-Plange, Komla Agbeko Dzisi
Res. Agr. Eng., 2021, 67(2):74-83 | DOI: 10.17221/56/2020-RAE
Performance of a tractor mounted solar-biomass hybrid dryer which utilise combined energy of solar and biomass was investigated. Drying behaviour of maize grains in the dryer was also investigated using 10 thin-layer mathematical models. The models were compared based on coefficient of determination (R2) and root mean square error (RMSE) values between experimental and predicted moisture ratios. Moisture content (MC) of grains in the dryer reduced from 19 ± 0.86% to 13 ± 0.4% (w.b.) in 5 h, compared to grains dried in open-sun which reached same MC in 15 hours. This resulted in average drying rate of 1.2 %.h-1...
Optimisation of concurrent Calophyllum oil-resin extraction and separationOriginal Paper
Ika Amalia Kartika, Muriel Cerny, Virginie Vandenbossche, Philippe Evon, Wega Trisunaryanti, Rino Rakhmata Mukti, Hartati, Nancy Dewi Yuliana, Illah Sailah
Res. Agr. Eng., 2021, 67(2):84-91 | DOI: 10.17221/67/2020-RAE
This research optimised the application of a hexane-methanol mixture as a binary solvent for the concurrent oil-resin extraction and separation from Calophyllum seeds on a pilot scale, in a direct stage. The optimum oil and resin yields were determined by optimising the extraction conditions using response surface methodology and a second order polynomial model. The extraction conditions affected the oil and resin yields, with the extraction time as the biggest influencing factor. Optimum oil (65%) and resin (16%) yields were predicted to be obtained at 5.2 h and 433 rpm. The model validation with these extraction conditions showed that the...
Influence of palm kernel variables on the yield and quality of oil expressed using an expellerOriginal Paper
Sunday Louis Ezeoha, Clement Onyeaghala Akubuo
Res. Agr. Eng., 2021, 67(2):92-99 | DOI: 10.17221/99/2020-RAE
The objectives of this study were to establish the impact order of the oil-palm kernel processing variables, namely: kernel moisture content (KMC), kernel heating temperature (KHT), kernel heating duration (KHD), and kernel particle size (KPS) on the palm kernel oil (PKO) yield; to develop an empirical model for the PKO yield as influenced by the KMC, KHT and KHD; to investigate the effect of the KMC, KHT and KHD on the PKO quality; and to specify levels of the kernel variables for the maximum PKO yield with minimum variability. The study was undertaken using oil-palm kernels of unidentified variety from Nsukka, Nigeria. The statistical analysis of...