Effects of silage maize varieties and harvest time on silage nutritional composition

To determine the suitable silage maize varieties and harvest time in the Hexi area, 23 silage maize varieties were planted in Minqin County. The whole plant samples of silage maize were collected at 107, 112, 125, 130, and 135 days after sowing to study the nutritional dynamics of different maize varieties at the milk ripening and wax ripening stages. The results showed that the yield difference of the 23 maize varieties was significant at 120 days. The whole plant yields of silage maize of 14 varieties were higher than 57 000 kg·ha⁻¹. The top three varieties were J27, J10, and J67 with yields of 73892.58, 72336.95, and 72 336.95 kg·ha⁻¹, respectively. Silage maize varieties and cutting time significantly affected the dynamic nutritional composition of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and starch (P < 0.05). The amounts of dry matter and starch in all varieties increased significantly with the extension of harvest time (P < 0.05). Based on the comprehensive yield, and dry matter and starch levels, planting J27, J10, and J67 is recommended in Minqin County and the suitable harvest times are 125, 130, and 130 days after sowing, respectively.