Abstract: This study was conducted in order to further clarify the relationships between planting density of different sorghum varieties and soil moisture content,growth and development,biological yield and yield components.In this paper,the sorghum hybrid'tongza 139'selected and bred by the sorghum research institute of Tongliao academy of agricultural sciences was used as the experimental material.Field experiments were conducted to study the effects of different planting densities on soil water content,sorghum growth,yield and its components.The experiment was conducted with a randomized block design,with three densities 75 000 plants/hm2 105 000 plants/hm2 and 135 000 plants/hm2,and three replicates.Data analysis showed that plant height increased and stem diameter decreased with the increase of planting density.The average soil water content of 105 000 plants/hm2 was 12.66%and 8.28%higher than those of 75 000 plants/hm2 and 135 000 plants/hm2,respectively,and the differences were significant.Leaf area index increased significantly with the increase of planting density.When the planting density was between 75 000 and 105 000 plant/hm2,as planting density increased,the grain yield increased accordingly.The panicle weight,grain weight per panicle,1000-grain weight and grain number per panicle all decreased with the increase of planting density.The results showed that when the planting density of‘tongza 139’was 105 000 plants/hm2 and the row spacing of plants was 50 cm×15.87 cm,the soil water and fertilizer conditions could be well balanced,the spatial structure could be rationally constructed and the yield level could be maximized.

Key words: Sorghum;Planting density;Leaf area index;Soil moisture content;Production