ZINC FERTILIZATION OF SUGARCANE IN ACID AND CALCAREOUS SOILS

Zinc (Zn) is recognized as an essential micronutrient for plant growth. The application of Zn for sugarcane production in Louisiana has not been studied in almost 30 years due to previous research reporting neutral or negative effects on sugarcane yields. In this study, a fertilization experiment was conducted to evaluate the optimum rate of Zn application for sugarcane production in soils low in DTPA-extractable Zn. An acidic Dundee silt loam and a calcareous Jeanerette silty clay loam were chosen for the experiment. The treatments consisted of five rates of soil-applied Zn as granular ZnSO4 (0, 4.4, 8.9, 17.9, and 33.8 kg/ha Zn) and one foliar application rate (1.3 kg/ha Zn). Soil applications of 4.4 and 8.9 kg/ha Zn significantly (P ≤ 0.05) increased cane and sugar yields of LCP 85-384 by an average of more than 23 % above the control for both the acidic Dundee and calcareous Jeanerette soils. The foliar application of 1.3 kg/ha Zn produced significantly greater sugar yields than the control on only the calcareous Jeanerette soil. The results of one year, with two different locations, indicated that Zn application as ZnSO4 can significantly benefit Louisiana sugarcane production in soils testing low in DTPA-extractable Zn