LAUSR

Agricultural machinery can improve agricultural productivity and promote agricultural scale operation. However, machinery operations lead to increased dust in farmland and affect the atmospheric environment; thus, they have been increasingly emphasized. In this study, the effects of agricultural machinery operations in wheat cultivation were investigated regarding the emissions of three kinds of particulate matters, namely fine particulate matter (PM2.5), inhalable particulate matter (PM10) and total suspended particulate (TSP), from farmland in Beijing. The results showed that the total dust emission from the traditional tillage mode, including straw crushing, rotary tilling and sowing, was 3.990 g per hectare, which was larger than that of the conservation tillage mode including only no-tillage sowing (0.407 g per hectare). The total dust emission for one hectare of farmland under the two modes was 3.415 g, 0.497 g, 0.407 g and 0.078 g for straw shredding, rotary tillage, no-tillage sowing and conventional sowing, respectively. The values of PM2.5/PM10 and PM2.5/TSP decreased in each tillage section after each agricultural machinery operation, while the values of PM10/TSP were basically unchanged, indicating that particulate matter emissions from farmland due to agricultural machinery operations are mainly PM10 and TSP. The dust concentration generated by agricultural machinery increased with an increase in the speed of the machinery operation, provided that the quality of the operation was guaranteed. This study provides guidance for reducing dust emissions from mechanized operations, improving air quality and decreasing health hazards to operators of agricultural machinery.