Preliminary study on abundance and deficiency index of available phosphorus and potassium for alfalfa in Bashang soil

Seventeen soil samples collected from different areas of Bashang region were analyzed for their soil fertility levels in the laboratory. Five samples which had different soil fertility from 17 soil samples were chosen for pot experiments to study on the abundance and deficiency index of available phosphorus and potassium for Medicago sativa. Treatments of the experiments were included well fertilized (added right amount of N, P, K), phosphate deficiency (added right amount of N, K), potassium deficiency (added right amount of N, P) and no fertilized (did not add N, P, K). The results of this study showed when M. sativa was planted in Bashang soil, the indexes of available phosphorus in the soil at serious deficiency, deficiency, no deficiency, abundance and great abundance were 3.5, 3.5-9.8, 9.8-21.4, 21.4-27.7 and 27.7 mg/kg, respectively. The indexes of available potassium in the soil at serious deficiency, deficiency, no deficiency, abundance and great abundance were 2.4, 2.4-15.6, 15.6-63.4, 63.4-101.2 and 101.2 mg/kg, respectively.