Phosphorus accumulation and distribution in different age alfalfa

Phosphorus accumulation and distribution were studied on 2, 3, 4, 5 and 7yearold alfalfa. The results showed that content of phosphorus in aboveground parts decreased during the whole growing seasons except increased little in the late, and decreased as plant ages increased. Content of phosphorus increased as order as leaves, reproductive organs and stems in maturing stage. As the plants growing in a year, phosphorus in aboveground parts increased, while accumulation rates increased firstly and then decreased. Phosphorus in the matured tissues was 64.7% in stems, 23.7% in reproductive organs, and 23.7% in leaves in all ages. For different ages of plants, phosphorus increased in stems and decreased in leaves as ages increased. Percentage of phosphorus in 2yearold reproductive organs was highest, and in 7yearold was lowest.