IMPACT OF SOWING MODELS, NITROGEN LEVELS AND BIOFERTILIZATION ON YIELDS AND QUALITY OF SUGAR BEET UNDER SANDY SOIL CONDITIONS

The aim of this research is to study the influence of sowing models (one side of ridges, 60 cm apart, 15 cm between hills and both sides of terraces, 90 cm apart, 20 cm between hills), nitrogen fertilizer levels (70, 90 and 110 kg N/fad.) and biofertilization treatments (treate soil with Cerialin, Rhizobacterin and the mixture of Cerialin and Rhizobacterin) on yield and quality of sugar beet, Karam cultivar under sandy soil conditions. Two field experiment were carried out at Kalabsho Experimental Farm, Dakahlia Governorate, Sugar Crops Research Institute, Agricultural Research Center, Egypt, during 2014/2015 and 2015/2016 seasons. The experiments were carried out in split-split plot design with four replications. The main plots were assigned to sowing models. The sub-plots were occupied with nitrogen fertilizer levels. While, the sub-sub plots were allocated with biofertilization treatments. The obtained results showed that sowing sugar beet in both sides of terraces, 90 cm apart, at 20 cm between hills attained the highest values of yield components, most of root juice quality parameters and yields, followed by sowing in one side of ridges, 60 cm apart, at 15 cm between hills in both seasons. The highest value for each of yield components, most of root juice quality parameters and yields were produced from fertilizing beet plants with 110 kg N/fad in both seasons. However, application of 90 kg N/fad., induced the highest value of sugar yield and the second best value for each of yield components, root juice quality parameters, top and root yields without significant differences between them in most cases in both growing seasons. Application the mixture of Cerialin and Rhizobacterin produced the highest value for each of yield components, most of root juice quality parameters and yields in the two seasons. It can be concluded that sowing sugar beet in both sides of terraces, 90 cm apart, at 20 cm between hills and treat soil with the mixture of Cerialin + Rhizobacterin (225 g/fad., of each) biofertilizers in addition of mineral fertilizing with 90 kg N/fad., to improve productivity and quality of sugar beet under sandy soil conditions.