Effect of some soil amendments on yield and quality traits of sugar beet (Beta vulgaris L.) under water stress in sandy soil

TO STUDY the ability of soil amendments treatments for improving sugar beet quality and yield with reduce quantities of mineral nitrogen fertilizer under water stress. Two field experiments were carried out at Wadi El-Natrun, El-Beheira Governorate, Egypt, during 2014/2015 and 2015/2016 growing seasons. Compost and bentonite as soil amendments solely or mixed and two nitrogen rates (216 and 288 kg N/ha) under water stresses (100, 75 and 50% of irrigation water requirements, IWR) using a drip irrigation system were applied. The obtained results showed that increasing water stress up to 50% of water requirement significantly decreased sugar lost in molasses, root and sugar yields. While, it increased sucrose % and sugar extractable. Decrease nitrogen fertilizer from 100% to 75% of recommended rate (288 kg N/ha) significantly decreased root and sugar yields, however, increased sucrose % and sugar extractable. Application of 12 ton/ha compost or bentonite as well as mixed 6 ton/ha of each of them led to a significant increase in all studied traits. Compost followed by bentonite was the best treatments. The maximum values of root and sugar yields were produced from the interaction between irrigation without water stress and fertilization by 216 or 288 kg N/ha and application of 12 ton/ha compost in the second season.