A laser scraper modification and its effect on performance and operational costs

A field experiment was carried out during the agricultural season of 2004 on a clay soil to evaluate the performance of a modified laser scraper compared to an unmodified scraper. The modification consisted of adding 8 chisel shanks on the main frame of the scraper set at equal distances along the width of the scraper. The objective of the modification is to eliminate firm, un-chiseled, spots that normally appear during leveling with the unmodified laser scraper. In such cases, a chisel plow has to be used to loosen the soil in-between scraper runs to level these spots, which increases the operational costs. Leveling was performed at two slopes; 0% and 0.03%. Results indicate that leveling at 0% slope with the modified laser scraper results in a more homogeneous land surface with no firm, un-chiseled, spots than with the conventional scraper. Comparison of the unmodified laser scraper at the two slopes produced more homogenous leveling at the 0.03% slope. Leveling with the modified scraper at the 0.03% slope resulted in two small areas with higher level than the surrounding ground, which indicates the need for a chisel shank that can go deeper in the soil (more than the 4 cm below cutting blade). The modified laser scraper resulted in better soil physical properties such as higher porosity and lower soil bulk density. Also, it resulted in better soil pulverization at both slopes (0% and 0.03%). Although the modified laser scraper required more power, operational costs decreased by about 32% in comparison with the unmodified scraper for both slopes. In summary, using the modified laser scraper gave more precise leveling at lower cost. Increasing the depth of the chisel shanks helps reduce the chance of leaving firm, un-chiseled soil.