The soil was loamy sand having pH 8.2, EC 0.15 dsm-1, Available N 209.6 Kg ha-1, available P 14.0 Kg ha-1, available K 130.6 Kg ha-1 and available manganese 3.25 mg kg ha -1 the design of the experiment is Randomized Block design, the treatments consisted of the four levels of nitrogen(0,40,80,120kg ha-1) and four levels of manganese (0, 2.5, 5.0, and 10 mg kg-1). The levels of nitrogen influences the green foliage, dry matter yield, nutrients content and their uptake by oat crop and increased significantly with N1 @ 40 kg ha-1, N2@ 80 kg ha-1 and N3 @ 120 kg ha-1 levels of nitrogen as compared to control during both the cuttings. The levels of manganese also affected significantly the green foliage, dry matter production and nutrients composition of oat crop in both the cuttings. The maximum green foliage, dry matter production, nutrients content and their uptake by oat crop were maximum at 10 mg kg-1 of Manganese over control. However the Nitrogen @ 120 kg-1 and manganese @ 10 mg kg-1 provided significantly higher green foliage and dry matter yield of oats over rest of the treatments.