Agronomic Biofortification of Fodder Maize (Zea mays L.) with Zn for Improving Herbage Productivity and Its Quality

Zinc (Zn) deficiency in soils not only reduces the productivity of forage crops, but also results in inadequate dietary zinc intake for livestock. The objective of this study was to evaluate the impact of different rates and methods of applying ZnSO4 to both soil and foliage on the yield and quality of fodder maize grown in a sandy loam soil testing low in DTPA-extractable Zn. A 2-year field experiment was conducted with six treatments including control, foliar application of 0.3% ZnSO4 at 30 days after sowing (DAS) (F1), foliar application of 0.3% ZnSO4 at 30 and 40 DAS (F2), soil application of 16 kg ha−1 ZnSO4 (S16) and a combination of both soil and foliar ZnSO4 application (S16 + F1 and S16 + F2). Increase in green herbage yield by 25%, dry matter yield by 47% and Zn content by 79% was observed under S16 + F2 treatment over the control. Zinc application improved N, K, Cu and crude protein content of herbage significantly over the control. Thus, the study shows that significant improvement in growth parameters, herbage yield and quality of maize can be achieved with soil Zn application + two foliar sprays of ZnSO4 at 30 and 40 DAS, thereby ensuring availability of improved fodder Zn to the livestock.