Abstract
Response of grazing behaviour and nutritional component of pasture plant to topdressing of N and P_2O_5 fertilizer were examined using yearling race horse grazing sward. Nitrogenous and phosphorus fertilizer were treated 0, 2, 4 and 6 kg per 10 a respectively in each experimental sward. Results obtained were summarized as follows : 1) Just after the topdressing, horses were grazed down only none or low level fertilized plot and not grazed high level fertilized plot at all. 2) After several days horses grazed on more and more high level fertilized plot. 3) Under the continious set grazing not only sward canopy maintained lower but also maintained nutritional component of pasture plant constantly, even in high level topdressed plot.
