干旱区生态环境知识资源中心

The objective of this study was to determine the short-term response of rangeland to fertilization rangeland (all combinations of 0; 10; 30 and 50 kg ha(-1) nitrogen, with 0 and 10 kg ha-1 of phosphorus) in terms of dry matter production and botanical composition. After three years of fertilization, the botanical composition of the high-N fertilized plots changed completely from a climax to sub-climax vegetation. Wire grass (Elionurus muticus) showed the greatest decrease in frequency (62%) due to N fertilization. Phosphorus fertilization had an insignificant influence on species composition over the three years. The increase (P< 0.01) in production with increased N fertilizer, peaked in the second season, declining afterwards. With N and P fertilizer applied together, the production increased constantly and peaked in the last season. After three years the production increased (Pless than or equal to0.01) with the application of N together with P, compared to the applying of only N. ne higher the amount of fertilizer, the more sensitive to drought the climax grasses became. The results confirm the vulnerability of native grasses in dry areas, due to change in soil fertility.