Integrative Effect of Foliar and Soil Nutrition in Reducing Mineral Nitrogen Fertilizer and Enhancing Sugar Beet (Beta vulgaris L.) Yield and Quality by Applying Calcium Nanofertilizer

TWO-FIELD experiment was conducted at the experimental farm of Delta Sugar Company at ElHamoul area (latitude: 31.28 and longitude: 31.15) in North of Egypt, Kafr El-Sheikh Governorate, Egypt during 2020/21 and 2021/22 winter seasons to investigate the integrative effect of foliar and soil nutrition for partially reducing mineral nitrogen (N) fertilizer applied and enhancing sugar beet yield and quality. The experiments were carried out in strip plot design, where the vertical plots were devoted to soil application of fertilizers, while the horizontal plots were assigned to foliar fertilization treatments. Following are the three soil fertilization treatments: a) mineral N was topdressed at a rate of 100 kg/fed, b) mineral N was top-dressed at a rate of 30 kg/fed + green foliar as a commercial fertilizer compound was drenched at a rate of 10 L/fed, and c) mineral N was top-dressed at a rate of 50 kg/fed + green foliar compound was drenched at a rate of 20 L/fed. Four foliar fertilization treatments where treatments were applied in this investigation as follows: a) control (plants sprayed with tap water), b) malty green at a rate of 5 L/fed, c) nano-calcium at a rate of 2.5 L/fed, and d) malty green at a rate of 2.5 L/fed + nano calcium at a rate of 1.25 L/fed. The obtained results indicated that spraying sugar beet plants with malty green (2.5 L/fed) + nano calcium (2.5 L/fed) treatment considerably improved of all the traits studied compared with sugar beet plants treated with tap water (control) in both seasons. The RY trait depicted a significant positive correlation with NAR, CGR and SY (p = 0.05) in 2020/21 season; however, in the 2021/22 season, RY showed a significant positive correlation with all the previously mentioned traits as RGR, NAR, RL, RFW, sucrose percentage, purity percentage, and SY under four foliar and three soil fertilization treatments in both seasons. In conclusion, fertilizing sugar beet plants with 50 kg N/fed + green foliar (20 L/fed) as a soil drenching integrated with foliar spraying of malty green (2.5 L/fed.) + nano calcium (2.5 L/fed.) was found by a promising agronomic practice for maximizing growth, root, sugar yields, and sugar quality of sugar beet cultivar under the study area.