Assessment of optimum mineral zinc fertilizer rate for quantitative and qualitative production of sugarcane in north-western India

Abstract

Sugarcane crop has tremendous potential to increase the farmers income, however the deficiency of micronutrients especially zinc (Zn) deficiency in Indo-Gangetic plains regions is one of the major constraints in improving the sugarcane productivity and quality of cane juice. Farmers are using Zn fertilizers injudiciously and hence a field experiment was planned to optimize the Zn fertigation rate to obtain higher sugarcane yield, Zn content in cane juice and nutritional quality of juice. The field experiment comprised of 5 levels of Zn i.e. no Zn(Zn-0); Zn@12.5 kg ha−1 (Zn-12.5); Zn@25 kg ha−1 (Zn-25.0); Zn@37.5 kg ha−1 (Zn-37.5) and Zn@50 kg ha−1 (Zn-50.0). Among various treatments, highest cane yield (117.2 t ha−1) was observed with treatment Zn-37.5, which was 18.3 percent higher over no Zn application. The agronomic efficiency (0.49) and Zn concentration in cane juice (3.62 mg l−1) and cane trash (28.3 mg l−1) were also higher in the treatment Zn-37.5. Mineral zinc fertigation also improved the content of total soluble solids (21.5oB) and other minerals viz. Ca, Mg, K, Cu, Fe and Mn and found maximum with treatment Zn-50.0. Hence, recommended NPK fertilizers along with Zn@37.5 kg ha−1 was found best for higher sugarcane yield and improved quality of cane juice under Zn deficient soil.