International Journal of Research and Innovation in Applied Science (IJRIAS) |Volume VIII, Issue II, February 2023|ISSN 2454-6194
Evaluation of Grain Losses as Affected by Combine Forward Speed
R.Bawatharani and D.N.Jayatissa
Department of Agricultural Engineering, Faculty of Agriculture, Eastern University, SRI LANKA
Received: 09 February 2023; Accepted: 14 February 2023; Published: 17 March 2023
Abstract: Header losses were evaluated at forward speeds 4.24, 2.95 and 2.04 km/h in combine A and 3.81, 2.73 and 1.9 km/h in combine B. Header grain losses initially decreased with an increasing forward speed from 2.04 km/h to 2.95 km/h but increased with an increase of the speed from 2.95 to 4.24 km/h in combine A. Header grain losses were also increased due to the increase of the speed from 2.73 to 3.81 km/h from combine B. Forward speed of 2.95 km/h in combine A and 2.73 km/h in combine B resulted in lower header losses of 38.7 and 45.8 kg/ha, respectively. The increasing forward speed of combine A from 2.01 to 4.24 km/h increased the effective field capacity from 0.245 to 0.38 ha/h. Similarly, in combine B forward speeds from 1.9 to 3.81 km/h increased effective field capacity from 0.175 to 0.197 ha/h. Increasing forward speed in combine A from 2.01 to 4.24 km/h decreased the field efficiency from 60.9% to 49.3%, whereas, increasing forward speed from 1.9 to 3.81 km/h decreased the field efficiency from 50.8% to 30.6% in combine B.
Keywords: Combine harvester, forward speed, field capacity, field efficiency, header loss
I. Introduction
Harvesting and threshing operations are known as crucial and influential processes on quantity, quality and production cost of paddy. Manual harvesting of paddy is such a troublesome, time consuming and costly operation that it needs about 100-150 man hour labour to harvest one hectare of paddy field (Nadeem, 1983).
Some paddy producing countries in Asia have seriously attempted to introduce compatible technologies for current circumstances and pass from this crisis (Bora and Hansen, 2007). Therefore, in order to overcome the labour shortage, majority of the farmers in the paddy growing areas have sought after combine harvesters to take over the task, which are playing a more important role in harvesting paddy and many types of harvesters are widely used in these days.
However, there are many factors that control the performance of combine harvesters, which can be divided into machine and plant factors. Machine variables include combine forward speed, peripheral speeds of combine devices, and feeding rate. During the past few years, farmers have drawn to purchase substantial number of combine harvesters and it is estimated they will consider utilizing more machinery due to increasing trend of wages for upcoming years. Therefore, it is required to conduct technical investigations on the viewpoint of grain losses and performance of the combine harvesters at local conditions.
The data presented by many other researchers indicated that forward speed plays an important role during the harvest process in determining the proportion of harvest losses as it has negative impact on the process of harvest because losses proportionate with the speed of the harvester due to its impact on the operating units and feeding rate (Al-Kazaz 1990; Al-Tahhan et al., 1990; Chen et al., 2012; Mohammed and Al-Kazaz 2000; Ramadan 2010; Randal and Mark, 2002). Therefore, this study aimed to evaluate grain losses from two widely used combines in terms of different forward speeds and to assess their field performances.
II. Materials and Methods
A. Study Area and Test Field
The 450 m x 20 m field was planted with BG 94-1, paddy variety in Batticaloa, Sri Lanka. The experiment was conducted with two different brands of combine harvesters of Japanese (A) and Chinese (B) origin. Both combines were crawler type with 2m cutting width. All the field trials were conducted according to RNAM test code (RNAM Test Codes, 1995). The reel angular velocity of 30 rpm was used in both types of combines. Each combine harvester was operated at 3 different levels of gear positions namely 1st gear (high), 2nd gear (low) and 2nd gear (high) at an engine speed of 3000 rpm which resulted in different forward speeds as sub plot factors. Combine forward speeds obtained at these gear positions in each combine harvester are given below (Table 1).