Comprehensive analysis of performance and nutritional quality of different silage maize varieties in the farming-pastoral ecotone of northern Shaanxi

Given the diversity of silage maize ( Zea mays) varieties in the agro-pastoral ecotone of northern Shaanxi, yield potential and forage quality vary significantly. In this study, field experiments were conducted using seven silage maize varieties—‘Dajingjiu 26’ ‘Dajingjiu 23’ ‘Jingang Silage 50’ ‘Jinling Silage 37’ ‘Ningdan 34’ ‘Beiyu 1522’ and ‘Heyu 9566’—to comprehensively analyze agronomic traits, yield, and nutritional quality using a completely randomized block design. The results showed that: 1) At the harvest stage, the plant height of ‘Dajingjiu 23’ was 0.56%～9.65% higher than that of other varieties. The stem diameter of ‘Heyu 9566’ was significantly greater than that of other varieties by 9.36%～17.79% (P < 0.05), and its whole-plant dry matter accumulation was 11.74%～66.97% higher. 2) The fresh grass yield of ‘Dajingjiu 23’ was 5.21%～21.08% higher than that of other varieties, while its hay yield was significantly greater by 8.30%～23.51% (P < 0.05). The grain yield of ‘Heyu 9566’ was significantly higher than that of other varieties by 25.87%～56.33% (P < 0.05). The leaf and stem specific gravities were 5.18%～29.46% and 6.59%～60.92% lower than other varieties, respectively, whereas the panicle-specific gravity was 5.49%～50.98% higher. 3) The crude protein content of ‘Heyu 9566’ was 1.78%～28.05% higher than that of other varieties, while its acid detergent fiber content was 2.32%～42.68% lower. The starch content of ‘Ningdan 34’ was 18.74%～99.21% higher than that of other varieties, whereas its neutral detergent fiber content was 1.28%～18.84% lower. 4) The top three varieties based on grey correlation analysis were ‘Heyu 9566’ ‘Dajingjiu 23’ and ‘Ningdan 34’ . In conclusion, ‘Heyu 9566’ and ‘Dajingjiu 23’ exhibited superior overall performance and are well-suited for cultivation in this region. This study provides a theoretical basis for selecting and utilizing silage maize varieties in Yulin and the broader agro-pastoral ecotone of northern Shaanxi.