Effect of Nitrogen and Phosphorus Fertilization on Forage Yield and Quality of Annual Ryegrass Grown in Southwest Texas, 1997
Texas has almost one million acres in ryegrass forage production. The goal of this study was to evaluate ryegrass response to several rates of nitrogen and phosphorous fertilization. Dry matter yield response of ryegrass to nitrogen and phosphorus fertilizer applications during the 1996-97 growing season was excellent. The maximum response observed was almost 7000 lbs dry matter per acre. Increases in phosphorous fertilization increased dry matter yield across all nitrogen treatments. A major increase in yield occurred with split applications of nitrogen at the rate of 120 lb/A, provided at least 40 lb/A of P2O5 were also applied. A further increase in yield was obtained with 240 lb/A of nitrogen and 80 lb/A of P2O5. Fertilizer applications above these levels gave no economic increases in yield. The results of this study emphasize the importance of balanced nitrogen and phosphorous fertility, and the effect of good phosphorous fertility on yield and nitrogen use efficiency. TX-35F
