부산대학교 도서관

Nitrogen use efficiency (NUE) in plants is dependent on various factors including nitrogen availability and root morphology. This study investigated changes in root morphological and growth features in response to plant community structures in legume-grass mixed pastures. Three types of legume forage and three gramineous forage were selected, including Bromus. innermis, Onobrychis. viciaefolia, Phleum pretense, Trifolium. pretense, Dactylis glomerata, and Medicago sativa. The effects of different community structures on changes in the land equivalent ratio, crowding, aggressivity, and competition, as well as the NUE, N yield, and root morphologies, were investigated. It was found that mixed seeding combinations increased the forage yield significantly but increasing the number of mixed seeding species did not further affect the herbage yield. Both the root lengths and root specific areas of the forage grass increased with increasing spatial distance, indicating that while the root morphology of the grass was controlled by genetic factors, the phenotypic characteristics of forage grass were changed by the balance between aboveground and underground growth. Root morphology was found to play a significant role in the NUE and the relation between specific root area of legume and LN(WN), specific root length of grass, and LN (WNt) can be expressed by the binomial function model.