Evaluation of productivity performance and nutritional value of Medicago sativa in the dry-hot valleys

Different varieties of alfalfa (Medicago sativa) from the dry-hot valley region of the Yunnan Province were used in this study. The variance and grey correlation analyses were performed to evaluate the production performance and nutritional composition of M. sativa. The results showed that there was a significant difference (P < 0.05) for the 8 varieties (lines) in the number of first-level branches and moisture. All test materials could be cut eight times per year in 2018 and 2020 and nine times in 2019. Variety No.6 ‘Nanmuxu 701-Tequilla’ had the highest average annual hay yield of 29 589.96 kg·ha⁻¹, which was significantly higher than that of Variety No.5 ‘Siriver’ and No.8 ‘Deqin’ (P < 0.05). The order of yield of the 8 alfalfa varieties (lines) from highest to lowest across four quarters is as follows: third quarter > second quarter > fourth quarter > first quarter in 2018. The content of crude fiber, crude fat, crude ash, calcium, and nitrogen-free extract of all the test materials was not significant. ‘Deqin’ had the highest crude protein (21.43%), crude ash (10.16%), total phosphorus content (0.25%), and lowest crude fiber content (18.36%). The result of the grey correlation analysis showed that M. sativa ‘Reyin-41’ ‘Deqin’ ‘Multi-leaf’, and ‘WL525HQ’ had better general performance and a higher value for promotion in this region.