Physical workload during selected farm operations

An investigation was conducted to determine the physical workload on agricultural workers during selected farm operations in paddy fields in Thailand. Four male and four female agricultural workers were randomly selected. Four common farm operations, i.e. ploughing, planting, weeding and harvesting, were selected. The physical responses in terms of heart rate, oxygen consumption and pulmonary ventilation were determined as a function of physical work capacity on a laboratory bicycle ergometer. During different field operations, heart rate, oxygen consumption and pulmonary ventilation were recorded and energy expenditure, oxygen pulse and relative cost were estimated. The postural discomfort was also assessed during different farm operations. It was observed that the physical workload for ploughing, planting, wedding and harvesting operations, expressed in percent of physical work capacity, was 44, 41, 33 and 44%, respectively. Ploughing was found to be the heaviest work and other operations were moderate. Postural discomfort was higher for ploughing than for other operations.