العوامل المؤثرة على كفاءة استهلاك الوقود فى الجرارات الزراعية فى مصر

By approaching the 21 Century , Agricultural Engineering becomes one of the moat important technology for Egyptian agriculture. The large expansion of such technology, is associated with more scarcity of the conventional energy source, particularly petrol fuel , which, currently is the only source of energy for the main agricultural operating power , the tractor . Therefore , this study objective was to determine the magnitude and direction of the response of the main factors affecting the fuel consumption efficiency for agricultural tractors in Egypt . The study analysis depended upon a field survey data of a sample size of 269 tractors By using the proper verification procedures, the total observations reached 241 tractors. The factors affecting filet consumption rate , estimated as Liters per operating hour, are the tractors horse power, tractor condition and loading rate of the tractor . The horse power is given from the questionnaire data, tractor condition is introduced in the function in two forms. The first, is as a dummy variable (old or new tractor) The second, is as a quantitative variable, which is estimated as a ratio between the current actual operating life to the proposed useful life. The loading rate, that reflects the intensity of work of a given tractor, is usually estimated through certain technical test that is done in a special oration . However, the study simulated its concept, by giving relative score to farm operations conducted by the tractor, according to the intensity of operating work required for each operation, and weighted by the operating hours consumed for each corresponding operation. The highest score of such scale is given to' plowing operation' and the lowest score is given to' field planning operation' The loading rate is estimated as percentage (ratio) of the aggregate sum of the farm operation scores weighted by tractor-operating hours for each farm operation over the score of flowing operation multiplied by the total operating hours ',he estimated multiple regression linear function showed that an increase in the horse power of the tractor by 10HP will increase fuel consumption rate by 5% Therefore, using a tractor with 90 HP to conduct a given operation will consume 25% more fuel than a tractor with only 50 HP 10% increase in loading factor increases the fuel consumption rate by 1% Each 10./r, increase in the tractor's operating life increases the filet consumption by 6%. Therefore, the study recommends to use such estimated model to adjust and to assess the Said performance of the fuel consumption of the agricultural tractor. It also recommends to reach an economic consistency between the loading factor and the horse power for the management of the tractors operation in Egypt .