Preliminary study on sweet sorghum growing on Qinghai Plateau

Sweet sorghum (Sorghum bicolor) was growed on Qinghai Plateau and the preliminary results indicated that the plant density showed a significant effect on plant height, stalk diameter and unit yield, but its effect on growth period and single plant yield were not significant. The highest yield was 101 448 kg/hm2 when plant density was 120 000 plants/hm2. The irrigation times did not significantly affect the growth period, plant height, stalk diameter, single plant yield and unit yield, which suggested that sweet sorghum had strong drought tolerance and drought resistance. Plastic film mulching showed significant positive effect on growth period, plant height and unit yield. The sugar content under plastic film mulching was 15.93% to 16.67% and increased by 29.19% to 47.98% compared with control. In field demonstration trial, the yield was 73 362 kg/hm2 (density was 90 000 plants/hm2) and the ratio of input and output was 1∶1.78. It could be concluded that sweet sorghum was satisfied as forage and silage in the research area.