Effects of tillage management on quantity and quality yield of sugar beet (Beta vulgaris L.)

In order to investigate the effects of several tillage methods on quantitative and qualitative of sugar beet, a field experiments were carried out based on RCBD design with four treatments and 4 replication in Miandoab Agricultural and Natural Resources Station during three growing seasons (2010-2012). Treatments were moldboard plowing at 15-20 cm depth, moldboard plowing at 25-30 cm depth, chisel plowing at 25-30 cm depth, sub soiling at 35-40 cm depth plus moldboard plowing at 15-20 soil depth with same secondary tillage practices including disk and the use of leveler, if necessary, for all treatments. Quantity and quality characteristics such as root yield, green cover percent, shoot biomass, gross sugar content, white sugar yield, K, Na, alpha-amino nitrogen and molasses sugar content were measured. The results showed that different tillage had significant effect on shoot growth only at the early stages of growth, but had not significant effect at later stages of sugar beet. Effect of different tillage methods was significant on root yield, gross sugar content and yield, white sugar percent and yield. The highest sugar yield (7.63 tons per hectare) belonged to sub soiling at 35-40 cm depth+ moldboard plowing at 15-20 cm depth treatment. There were not observed significant differences between tillage treatments in terms of alpha-amino nitrogen, sodium and potassium. Conclusively, for the preparing the suitable seedbed for sugar beet cultivation, deep tillage be practiced by moldboard at 25-30 cm depth and if there is a hard layer, sub-soiling must be used to increase the yield.