Abstract
In an acid Inceptisol of the humid sub-tropics, the effects of four levels (0, 20, 40, and 60 t ha-1) of farmyard manure (FYM) and three levels (0, 70, and 140 kg ha-1) of N continuously applied for three years to golden timothy grass (Setaria sphacelata) showed that the mean dry matter (DM) yield increased up to the highest levels of their application. Residual effects of the application of FYM at 60 t ha-1 was significant on the DM yield in the fourth and fifth years. Nitrogen recovery, percentage of the crude protein content, and the DM yield per unit of applied N decreased with increasing levels of the N input from urea and FYM. Total root biomass increased due to the application of N. However, it decreased due to the application of FYM up to 40 t ha-1. Specific root length and root length density were significantly influenced by the management of nutrients. Farmyard manure and N increased the soil organic C, available P in the 20-60 cm depth of the soil, exchangeable Ca + Mg, and soil pH by reducing exchangeable Al substantially. Available K decreased with the application of FYM up to 40 t ha-1. Application of N decreased the soil pH, organic C in the 0-20 cm, available P in the 0-40 cm, and available K in the 0-60 cm soil profiles.
