Comprehensive evaluation of the production performance and nutritional value of 14 silage maize varieties in rainfed areas of Ningxia

To screen for high quality and high yield varieties of silage maize (Zea mays) suitable for planting in rainfed areas of Ningxia, the adaptability of 14 silage maize varieties was evaluated using a randomized block experiment in Xugou Village, Longde County, Ningxia from 2019 to 2020. Principal component analysis (PCA) was used to comprehensively evaluate the agronomic traits, yield, and nutritional components. The results showed that ‘Zhongxing 618’ had the highest plant height (313.2 cm), ‘SN211’ had the largest number of leaves (15 per plant), and ‘Jingang 50’ had a fresh grass yield significantly higher than those of all other varieties (99 822.9 kg·ha⁻¹; P < 0.05). There were three varieties with starch content greater than 30%, namely ‘Yinyu 238’, ‘SN211’, and ‘Wenyu No.3’. The best variety with respect to stem sugar content was ‘Yinyu 238’ (9.14%). The best variety for crude protein content was ‘Bailv 2900’ (11.69%), while ‘Jingang 50’ had the lowest neutral detergent fiber content (39.72%) and the highest relative feeding value (144.92). The top five varieties based on PCA comprehensive evaluation score were ‘SN211’, ‘Ningdan 46’, ‘Zhongxing 618’, ‘Jingang 50’, and ‘Wenyu No.3’, among which ‘Jingang 50’, ‘Ningdan 46’, and ‘Wenyu No.3’ had the best yield and quality. Therefore, by considering together the PCA score, yield, and quality, ‘Jingang 50’, ‘Ningdan 46’, and ‘Wenyu No.3’ were determined to be suitable for planting in rainfed areas of Ningxia.