Effect of different planting densities on bio mass yield and quality for various varieties of silage maize

A field experiment was conducted to investigate the effects of planting density on biomass yield, agronomic characters and nutritional quality. Six silage maize varietieswrer studied to provid a basis for optimizing silage maize production technology based on selecting suitable planting density to obtain high biological yield, good nutritional quality, and the best comprehensive properties of silage maize varieties. The results showed that the biological yield was increased with the increase of planting density, high and medium density had greater biological yield from 8.1% to 43.0% and 5.0% to 19.9%, respectively, than that of low density for the 6 silage maize varieties. In particular, Gansu silage 2 and Hokuno silage 368 demonstrated better resuilts in the increase of biological yield. Harvest day of silage maize was delayed, stem diameter and stay green were decreased with the increase in planting density. Compared to low density, high density increased harvest day by 3.2% to 10.6%, decreased stem diameter and stay green from 6.0% to 22.8% and 2.7% to 3.9%, respectively. The effect of planting density on crude fat was significant, and the crude fat content was decreased with the increase in density. The crude fat content at high density was from 6.8% to 13.5% lower than that of low density. However, the content of neutral detergent fiber and acid detergent fiber was increased with the increase of density, high density had greater neutral detergent fiber and acid detergent fiber by 5.0% to 8.5% and 5.9% to 16.2%, respectively, than that of the low density plantings. Overall, integrated biological yield, agronomic traits, quality traits, the suitable silage maize in the Zhangye area was Gansu silage 2, Wu Ke 107, and Hokuno silage 368. The appropriate planting density for Gansu silage 2 and Hokuno silage 368 was 7.5 × 10⁴ plants·ha^–1, and the appropriate planting density of Wu Ke silage 107 was 9 × 10⁴ plants·ha^–1.