The Effect of Nitrogenous Fertilizer on the Rate of Growth of Italian Ryegrass

The rate of growth of Italian ryegrass in the spring was measured by recording dry‐matter yield at weekly intervals over periods of 6 weeks. There were 3 levels of applied N: 25, 75 and 125 lb/ac. Yield increased fairly slowly in the first 2 weeks and level of applied N had little effect. In the final 4 weeks the grass grew at a faster and fairly constant rate, which was very much affected by the level of N. Grass receiving 25 lb N produced 2900 lb of dry matter/ac in 6 weeks, 75 lb N 4400 Ib, and 125 Ib N 4700 lb. By the end of the first week, % N and % nitrate‐N were higher at the 75 lb than at the 25 lb N level and by the end of the second week they were higher at the 125 lb than at the 75 lb N level. The effect of weather factors and the question of predictability of yield are discussed.