Using Vinasse as a Source of Potassium Fertilization for Sugar Beet and a Sandy Soil Amendment

Two field experiments were conducted in a sandy soil at Al-Hossein Agricultural Farm located, Cairo-Alexandria Desert Road, Egypt, in 2017/2018 and 2018/2019 seasons, to check the possibility of using cane vinasse as a source of potassium fertilization for sugar beet, and its effect as an amendment on some properties of soil. A randomized complete block design was used. The present work included 13 treatments as follows: - 100% K2O: 48 kg K2O/fed as K2SO4 "48% K2O" (control). - Three treatments represent the sole application of 100% equivalent to 48 kg K2O/fed, in the form of raw (V1), photo-chemically (V2) and biologically (V3) treated vinasse, i.e. 708.0 l/fed, 708.0 l/fed and 817.7 l/fed, respectively. - Nine treatments, using 75, 50 and 25 % of the recommended rate as K2SO4 combined with 25, 50 and 75 %, successively, equivalent to 48 kg K2O/fed from each of V1, V2 and V3. The lowest value of HMF was recorded with V3,and phenolic compounds with V2. The maximum activity of dehydrogenase enzyme was found with adding (50% K2O+50% V3)/fed. Adding (50% K2O+50% V3) significantly increased root yield/fed. The different treatments including V3 markedly increased sugar yield/fed, as compared to that gained with 100% K2O/fed, in both seasons. In the final, the addition of [50% of the recommended rate of K-fertilizer (24 kg K2O) as K2SO4+50% of the biologically treated vinasse (408.85 liters)/fed] could be recommended to get economical root and sugar yields, which means saving 50% of mineral potassium sulphate required for sugar beet crop.