Performance Evaluation of Single-Axle Tractors During Secondary Tillage Operation in Ultisol Soil Series of Nigeria
Agricultural Mechanization is still at a low ebb when compared with what obtains in developed countries. This study aims at contributing to the information buildup required by agricultural planners and potential intervening aid agencies/organizations by way of field testing two categories of two-wheel tractors during secondary tillage operations on a 1,200 m2 field consisting of soil identified as that belonging to the ultisol soil series of Nigeria. Two models of single-axle tractors (HONDA GX 120 and YANMAR GE 50) with rated engine power of 2.9 kW (4.0 Hp) and 5.2 kW (7.0 Hp) respectively were tested on a field which undergone primary tillage operation during the previous two weeks. The field had developed various level of vegetative regrowth by the time the secondary tillage operation was carried out. The HONDA GX 120 and YANMAR GE 50 single-axle tractors belong to categories I and II respectively as a result of the rated power of their engines. The field was divided into twenty (24) plots of 50 m2 each with various levels of weed infestation determined with the use of a 1.0 m x 1.0 m lay-down frame and a laboratory weighing balance. Eight(8) of the plots had weed infestation within the range of 830-1,450 kg/ha; another group of eight(8) plots had their weed infestation level falling within the range of 1451-2070 kg/ha while the last group of eight(8) plots had weed infestation level within the range of 2071-2690 kg/ha. The category I tractor was tested in four(4) out of the eight(8) plots in each of the three(3) levels of weed infestation while the category II tractor was tested on the remaining four(4) plots. In essence four replicates of a factorial experiment were on the field for three (3) levels of weed infestation and two categories of single -axle tractor. Data on fuel consumption, lubricant consumption and effective field capacity were collected and subjected to analysis of variance (ANOVA). From the ANOVA results, it was concluded that: 1).the level of weed infestation and rated engine power significantly affect fuel consumption;average fuel consumption increased with increase in rated engine power and level of weed infestation. 2)With the exception of fields with low level of weed infestation (i.e. 830-1450 kg/ha),lubricant consumption was significantly affected by both the rated engine power and level of weed infestation. 3) Effective field capacity was not significantly affected by neitherthe rated engine power nor level of weed infestation although there is significant interaction between them.This result implies that single-axle tractors will not perform at their best during secondary tillage operation when the level of weed infestation in the field is very high; the use of single-axle tractors with small rated engine power should be confined to small field while those with high rated engine power should be used on large fields in order to achieve best results.
Keywords - Single-axle tractors, weed infestation, secondary tillage, effective field capacity, fuel consumption, lubricant consumption, ultisol soil series