Effects of planting density and variety on biomass and nutrient quality of green maize

The effects of planting density and variety on biomass and nutrient quality of green maize were studied in order to provide a theoretical basis for the promotion of high-quality green forage resources for cattle and sheep. In 2019, the green maize varieties “Dongdan 13” (H₁), “Zhengda 12” (H₂), “Keyu 188” (H₃), “Hengyuan Y4038” (H₄), and “Pudan 6” (H₅) were selected as test materials and grown at planting densities of 4.50 × 10⁴ (D₁), 5.25 × 10⁴ (D₂), 6.00 × 10⁴ (D₃), 6.75 × 10⁴ (D₄) and 7.55 × 10⁴ (D₅) plants·hm⁻². The results showed that planting density had significant effects on the yields of fresh grass and hay (P < 0.01) and on the ash content (P < 0.05). The contents of ether extract, ash, neutral detergent fiber, acidic detergent fiber, starch, calcium, phosphorus, and total digestible nutrients, and the in vitro dry matter digestibility at 48 h were significantly affected by the varieties (P < 0.01), and the contents of dry matter and water soluble carbohydrates were significantly affected (P < 0.05). After comprehensive evaluation of biomass and nutrient quality indexes of each treatment with grey correlation degree, the three best varieties and their densities were H₁D₅ > H₂D₄ > H₃D₅ . In conclusion, the three green maize varieties (and their densities) with the best performance in Huanxian region were “Dongdan 13” (7.50 × 10⁴ plants·hm⁻²), “Zhengda 12” (6.75 × 10⁴ plants·hm⁻²) and “Keyu 188” (7.50 × 10⁴ plants·hm⁻²); these varieties could be popularized in this region.