Effect of plowing depths and type of transmission system on the performance of agricultural tractors under clay soil condition

  The study was conducted at the Experimental Farm of the University of Gedarif during summer season of 2016 at a soil moisture content of 7.24% and bulk density of 1.4 g/cm3. Three types of tractors with different transmission systems were used in this study, the transmission systems were conventional, powershift and combination of conventional and powershift. The tested parameters were drawbar power, fuel consumption, wheel slip and field capacity.  To evaluate the tested parameters, three different depths were used, namely, 15, 20 and 25 cm. A completely randomized block design with four replications was used to execute the experiment. The statistical analysis indicated that there was no significant difference (p ≥0.05) between the tractors in drawbar power for the plowing depths of 15 and 20 cm, while there was a significant difference (p ≥0.05) between conventional and the other two tractors for the depth of 25cm; it produced the least power

Soil Moisture Content as a Determining Factor for Machinery Selection

By applying the soil moisture content (SMC) prediction model to the weather data for the period from 1981-1993, the suitable workdays were obtained. Testing these results from the Rahad Scheme data records showed high significance. The correlation coefficient was found to be 0.99. show the effect of timeliness cost, a utilization factor (Ut) was determined by dividing the available working days by the total days. The utilization factor is then adjusted using a range of reliability from 30-80% depending on spare part availability and skilled labour. Further analysis were made to demonstrate the effect of workable days on the selection of implement width and cost using good, bad and average rainy seasons and different levels of reliabilities. It was found that the machine width was by the rainfall frequency