Effects of ⁶⁰Co-γ ray irradiation on the growth and utilization of Chinese milk vetch

To explore the mutagenic effect of ⁶⁰Co-γ rays on Chinese milk vetch and clarify the suitable irradiation dose for its utilization and growth, Chinese milk vetch plants were treated with different ⁶⁰Co-γ-ray irradiation doses 0 (CK), 300, 500, and 700 Gy to observe and compare the nutrient absorption characteristics, germination rate, and field growth conditions. The results showed that radiation treatment improves the N content during the flowering period, and Chinese milk vetch treated with 500 Gy had the highest N content. Under equal N input, compared with CK treatment, the incorporation amounts under 500 Gy treatment can be reduced by 2 063 kg·hm⁻², which is convenient for mechanical flipping operations. Compared with CK treatment, the number of seedlings produced by radiation treatment and many indicators of a tall plant height showed a downward trend. Fresh grass yield and seed yield were significantly reduced under treatment with a high irradiation dose of 700 Gy (P < 0.05). The indicators of 500 Gy treatment were the closest to those of CK treatment, and the difference was relatively small. in summary, irradiation of Chinese milk vetch with 500 Gy ⁶⁰Co-γ rays improved the nitrogen content per unit mass, which was convenient for light and simple overturning and utilization during the flowering period.