3-wheel tractor for lowland, upland cultivation developed

A three-wheel tractor that can be used both for lowland and upland cultivation with the operator riding on it is now being developed by agricultural engineers of the Philippine Rice Research Institute (PhilRice).

Led by Arnold S.Juliano, the agricultural engineers used the common power tiller and surplus small four-wheel tractor as their bases in the development of the three-wheel tractor. The surplus four-wheel tractor has been proven effective in dry land cultivation, but it is still supported by the power tiller for harrowing and leveling operations. On the other hand, the power tiller is used only for lowland cultivation.

The three-wheel tractor, with the operator riding on it, performs plowing, harrowing and leveling in lowland and upland fields. Its design was made simpler than the four-wheel tractor, Juliano said. 

Considering its endurance capability in various vehicles, a differential transmission was used for the three-wheel tractor. Instead of using four wheels, the engineers opted for three wheels for easier turning just like the tricycle. In addition, the three wheels made the machine lighter and simpler with lower cost than the four-wheel tractor.

The three-wheel tractor uses a nine-horsepower (hp) gasoline engine to reduce its weight, cost, and fuel consumption compared with the surplus four-wheel tractor.

Under dry land condition, the three-wheel tractor showed good performance with a rotavator attachment during the first pass. However, it was not able to rotavate the soil at the corners of the field during the initial test and, hence, a reverse clutch mechanism was incorporated.

The tractor also performed well during second rotavation even in soft soil condition. After the second pass, the field was already ready for leveling.

The PhilRice engineers evaluated different wheels to determine their appropriateness under various field conditions. They observed that the pneumatic tire for the wheels performed well in dry field condition. However, the front wheel sometimes slipped in wet land condition whenever the mud was quite deep. 

They also found that narrow metal wheels performed well in dry land condition. However, the two rear wheels sank in areas with deep mud. In addition, mud frequently accumulated in the front wheel, resisting the forward motion of the whole machine.

Juliano reported that his team is now incorporating the following improvements to make the three-wheel tractor comparable with the performance of the four-wheel tractor and power tiller:

1. Improvement of the existing harrow with leveler attachment;

2. Increased diameter of the two pneumatic rear wheels and incorporation of metal spikes for better movement in wet fields;

3. Replacement of the narrow front wheel with a power tiller front wheel with lugs and provide wider clearance of the wheel holder;

4. Replacement of manual lifting component with a hydraulic lifting device for easy adjustment of the rotavator, harrow/leveler height; and

5. Increased width of the rotavator to 100 cm to increase its capacity and eliminate side plowing.

Just like the four-wheel tractor and power tiller with trailer, the three-wheel tractor can also be used for hauling. It performed well with a trailer carrying as many as 20 cavans. 

Juliano said they will also test the three-wheel tractor for crop establishment operations as a seeder, transplanter, and weeder. – Sosimo Ma. Pablico