Zinc application enhances sugar yield, productivity and potassium uptake of planted and ratoon sugarcane under sandy soil

Sandy soil can be considered a factor that reduces Zn availability. In this study, the effect of zinc (Zn) application on planted and ratoon cane in sandy soil was investigated. The effect was studied in terms of (i) the short-term dynamics of soil available Zn under incubation, (ii) the cane and sugar yield of planted and ratoon cane and (iii) the nutrient (N, P, K and Zn) concentrations, uptake and Zn use efficiency in planted and ratoon cane. The incubation experiment used a factorial design in a completely randomized block. Factor A was NPK fertilizer application (with and without). Factor B was Zn application rates, i.e. control, Zn4, Zn8, Zn10 and Zn20 (Zn application at 0, 4, 8, 10, 20 kg Zn ha⁻¹). The field experiment used a randomized complete block design. There were 5 treatments i.e. Control (no NPK chemical fertilizer nor zinc application), CF (NPK chemical fertilizer application), Zn4 + CF, Zn8 + CF and Zn10 + CF (ZnSO₄ application at 4, 8, 10 kgZn ha⁻¹ combined with CF). Our results revealed that Zn application increased the soil available Zn content (an incubation experiment). In the field experiment, Zn10 + CF provided the greatest Zn uptake, K uptake, yield and sugar yield in planted and ratoon cane. Zn application provided a P dilution effect in straw but had no effect on the N and K concentrations. Thus, Zn application at the rate of 10 kg ha⁻¹ enhances cane, sugar yield, Zn and K uptake of planted and ratoon cane under sandy soil.