Abstract: In the study two summer maize varieties（‘Zhengdan 958’,‘Xianyu 335’）were used to study the effects of four densities and two planting patterns（equal row, wide and narrow rows）on straw feeding quality of summer maize, as well as to evaluate straw feeding quality of summer maize under those cultivation conditions. The results indicated that under the planting pattern of equal row the density significantly affected crude fiber, neutral detergent fiber and crude protein; however, under the planting pattern of wide and narrow row, density only significantly influenced crude protein. It was also found that relatively lower fiber content and higher crude protein content appeared in these two summer maize varieties under the planting density of 105 000 plants per hm². In conclusion, compared with the planting pattern of equal row, the planting pattern of wide and narrow row was recommended for high density cultivation because of higher straw crude protein content and lower fiber content under this pattern.

Key words: density, planting patterns, straw, feeding quality