Performance Evaluation of a Maize Stalk Chopping Device Based on Field Tests

Abstract

HighlightsThe performance of the stalk chopping device is investigated based on field test.The painting method is used to distinguish the different sections of stalks chopped. The broken types of maize stalks are obtained after the stalks being harvested.The percentage of stalk broken is highest of 61.9% at the mid-lower section of maize Xianda 205 stalk. ABSTRACT.Maize stalk is a considerable biomass resource in China. The degree to which stalks are chopped has a substantial impact on subsequent operations in the field. Field tests were conducted to investigate the effects of chopping on different sections of the stalks for different maize varieties, working speeds of the combine harvester and moisture contents of the stalks. Prior to the tests, the stalks were divided into four sections from bottom to top and painted with four colors to identify the different sections of the stalks being chopped. The results showed that the percentage of the qualified length of stalk chopped (PQLSC) gradually decreased and the percentage of the stalk broken (PSB) initially increased and then decreased from the lower to the upper sections of maize stalk under the same rotational speed of blades. When the moisture content of the stalk was held constant, a larger stalk diameter resulted in a higher PQLSC and PSB. The PQLSC was lowest (30.2%) for the lower section of the stalk, and the PSB was highest (48.3%) when the working speed of the harvester was 1.0 m s-1. The PQLSC was highest (37.4%) and the PSB was lowest (40.9%) when the working speed of the harvester was 1.5 m s-1. For the same section of the maize variety Xianda 205 stalks, an increased moisture content of the stalk resulted in a simultaneous increase in the PQLSC and the PSB. The PQLSC was lowest (27.4%) for the lower section of the stalks, and the PSB was highest (51.4%) when the rotational speed of the blades was 807 rpm. The PQLSC was highest (34.1%) for the lower sections of the stalks, and the PSB was lowest (44.8%) when the rotational speed of the blades was 915 rpm. This research provides a reference for the selection of a suitable working speed of the harvester and the rotational speed of the blades for a harvester, which can achieve the smallest particles. Keywords: Chopping, Device, Field test, Maize, Stalk.