Performance of lugged cage wheel for wetland cultivation

Abstract

Rice is a major food grain crop grown in North-eastern Himalayan region of India with varying level of mechanization. Rice field remains wet and loose for a considerable period of growing season. Land preparation of rice field is one of the critical operations both in terms of timeliness and energy requirement. The losses up to 70%-80% of input power are reported while negotiating wetland terrain by tractors or power tillers, particularly in difficult terrain. This paper described the attempts made to address the issue of wetland traction primarily relevant to mechanization of rice cultivation in North-eastern Himalayan region of India. There is a variety of design of cage wheels used on power tillers with varying levels of performances based on the soil conditions. An innovative lug of split type has been developed, tested and compared with non-split lugs of identical contact area in the sandy loam soils of wetland rice fields of the region. Cage wheel lugs interact with the soil and thrust is generated to move the power tiller forward. The strength of supporting soil and area of contact governs the generated thrust. In general, the pull developed by cage wheel is positively correlated with area of interaction especially in better soil condition. Release of loose soil trapped beneath the cage wheel lugs, so as to bring hard layers of soil in contact with the interacting lug surface, is attempted through split lugs instead of solid lugs (non-split). A set of lugs with split (S) and non-split (NS) having 3 varying sizes (8000, 12000 and 16000 mm2 surface area) were fabricated as per suitability of a typical walking type tractor (power tiller). Each set of lugs were fitted on cage wheel frame at 450 angular spacing for testing its field performance at two levels of soil moisture contents (23% and 36%). During experiments the performance enhancement of split lugs was found better in moist (36%) soil than a relatively dry (23%) soil. Newly designed lug fitted power tiller operation resulted higher (0.052 ha/h) field capacity (about 17% higher than the identical non-split lug). The fuel consumptions of split lugs were found less compared to non-split lugs of all sizes. Split lug cage wheel fitted power tiller operation resulted about 27% less wheel slip associated with about 14% saving of fuel (L/ha) in comparison of non-split lug in moist field.