The researchers wanted to see how adding different amounts of zinc to barnyard millet plants could improve their growth and yield. They tested various levels of zinc fertilizer in the soil and by spraying it on the leaves. The best results came from using a combination of soil test-based NPK fertilizer and 20 kg of ZnSO4 per hectare. This method increased plant height, root length, number of tillers, and grain yield significantly compared to using only NPK fertilizer. Overall, adding zinc to the soil helped the barnyard millet plants grow better and produce more grain and straw.