Investigating the Effect of Blade Cutting Angles of a Manual Hoe on Operator’s Heart Rate during Weeding Operations
B. G. Jahun
Department of Agricultural and Bioresource Engineering Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi State Nigeria
D. D. Usman
Department of Agricultural and Bioresource Engineering Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi State Nigeria
J. A. Mustapha
Department of Agricultural and Bioresource Engineering Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi State Nigeria
S. Adamu
Department of Agricultural Engineering, Federal Polytechnic Mubi Adamawa State Nigeria
S. A. Iya
Department of Agricultural and Environmental Engineering, Modibbo Adama University of Technology Yola Nigeria
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Keywords

Blade Angle
Bulk Density
Moisture Content
Heart Rate
Weeding

How to Cite

Jahun, B., Usman, D., Mustapha, J., Adamu, S., & Iya, S. (2022). Investigating the Effect of Blade Cutting Angles of a Manual Hoe on Operator’s Heart Rate during Weeding Operations. JOURNAL OF AGRICULTURAL ENGINEERING AND TECHNOLOGY, 27(1), 15 - 27. Retrieved from http://jaet.com.ng/index.php/Jaet/article/view/216

Abstract

The present findings focus on the assessment of manual hoe blade cutting angles on operator heart rate during weeding operation. Three hoe blades were developed with different blade cutting blade angles (65o, 75o, and 85o) using AutoCAD software and analyzed by 3D modeling. Heart rate (bpm) was measured using a polar heart rate monitor and recorded at rest, during the entire period of work and recovery thereafter for a period of 5 mins. Soil bulk density and moisture content (db) were determined using a standard method from literature. Randomized Complete Block Design (RCBD) was employed to evaluate the effect of hoe blade cutting angle, soil moisture content, soil bulk density and the operator’s height on the heart rate of the operator during weeding operations. Three levels of cutting angles (65o, 75o and 85o), bulk density (1.2, 1.3 and 1.5 g/cm3), moisture content (13, 15 and 18 %) and two different operator’s heights (1.56 and 1.65 m) making a 3 x 3 x 3 x 2 factorial experiment design and analyzed using ANOVA and Tukey’s Studentized Test mean comparison. Results obtained show that mean heart rate increases with an increase in soil moisture content, soil bulk density and operator’s height respectively, but decreases with hoe blade cutting angle. The optimum heart rate of 84.24, 80.35, 72.01 and 74.61 bpm were obtained at 85o blade cutting angle, 15% soil moisture, 1.2 kg/m3 bulk density and 1.56m operator’s height respectively. It was, however, recommended that a study on manual hoe be carried out to ascertain its effects on the weeding index, performance index and cost of operation.

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