DESIGN AND DEVELOPMENT OF A LOW COST MOUNTED TYPE SINGLE LEG SUBSOILER

Free movement of air in the soil and good drainage are necessary for good crop yields.Modem tractors and machinery are partly responsible for soil compaction and soil pans.Subsoilers are used to break compacted soil, allowing free passage of air and water. Forconducting this important operation in crop production, suitable Subsoiler does not existin Sri Lanka. However without proper land preparation, higher yield of crop productionby applying other input cannot be expected. Therefore fields should be subsoiled time totime at right angles to the intended direction of ploughing. Sometimes fanners useexpensive, un tested, imported Ploughs for this purpose. The commercial ploughs used inmany developed countries, are beyond the financial capabilities of local paddy farmers.Properly designed subsoilers are usually mounted on the tractor and consist of a strongframe with one or more legs. Each leg has a replaceable point. Working depth isnormally from 30 to SOcmand spacing between passes is from 0.5 to 2m. Subsoiling isbest carried out after the cereal harvest when the soil is dry.Considering the above facts, a low cost suitable Subsoiler for four wheel tractors wasdesigned and constructed after testing first model Subsoiler in the field and implementingnecessary modificationsAn experiment was conducted in the paddy field to compare the performances of thedeveloped Subsoiler. The result shows that the effective field capacity, effective workingwidth, ploughing depth, travel reduction. average operation speed, and Cost ofproduction of Subsoiler were 0.2 ha/hr, O.Sm,0.3m, 60/0, 1.6 km/hr, SOOORsrespectively.The result shows that the overall field performances of designed Subsoiler wassatisfactory.