Effects Of Planting Density On Growth, Nutrient Accumulation, Yield And Its Component Factors Of Sorghum

Appropriate planting density is the essential condition to achieve high corps yield due to the reasons that it can adjust the growth of colony and individual plant, contribute to construct a better group structure as well as improve the solar utilization efficiency.In order to explore the effort of planting density on the growth of sorghum, physiological indicators of sorghum, nutrient uptake as well as yield component, this paper is applying different planting density treatments to experimental samples’Jinza No.23’,’Jza No.122’and’Jinza No.34’. For brewed type sorghum among above types-’Jinza No.23’, there are 4 level of plant density applied, including 45000 plants/hm2,75000 plants/hm2, 105000plants/hm2and 135000 plants/hm2. For mechanized type-’Jinza No.122’along with’Jinza No.34’,6 level of plant density applied, including 120000 plants/hm2,135000 plants/hm2,150000 plants/hm2,165000 plants/hm2,180000 plants/hm2 and 195000 plants/hm2. Based on plant density setup as above, this paper further measured the sorghum in terms of plant features, plant total dry weight, leaf area index (LAI), net assimilation rate (NAR), crop growth rate (CGR), leaf area duration(LAD) and nutrient absorption. Moreover with combination of the changing features of production performance parameters’, it conducts density-tolerant property analysis and draws conclusion as below:(1)Due to the different density effects of sorghum colony structure, their height, stem thickness, dry matter accumulation volume are different as well. Whereby, the plant height will rise with the increase of the density, while the stem thickness and, dry matter accumulation volume per plant will decrease with the increase of the density.(2) The colony physiological index is also determined by different density effects of sorghum colony structure. With the increase of planting density, the leaf area index (LAI) of sorghum presents a trend of rise in the beginning and drop in the end; LAD of colony structure will rise with the increase of the density; Colony light transmittance, colony net assimilation ratio, colony growth rate will decline with the increase of the density, but colony net assimilation ratio’s change is not obvious and colony growth rate is only outstanding during the flowering period.(3) In aspect of nutrient absorption,’Jinza No.23’,’Zinza No.122’and ’Jinza, No.34’vary a lot with the change of planting density. For’Jinza No. 23’, the absorption volume for nitrogen, phosphorus, and potassium by sorghum will decline with the increase of planting density; For "Zinza No. 122", the absorption volume presents a trend of rise in the beginning and decline in the end; For’Jinza, No.34’, the absorption volume presents a trend of decline in the beginning while risk in the end. Moreover, when looking into the absorption ratio among nitrogen, phosphorus, and potassium in above three types of sorghum, it is presented from high to low as nitrogen> potassium> phosphate.(4) With the increase of sorghum planting density, the biological yield and ear number per unit of’Jinza No.23’,’Jinza No.122’and’Jinza, No.34’.have increased significantly, while seeds per ear and 1000-seed weight have dropped severely. In addition, within certain destiny scope, the grain yield is rising with the increase of planting density, but once the density exceeds this scope, the yield will drop with the increase of the density. Optimal plant density for brew sorghum’Jinza No.23’production in this environment is 105000 plants/hm. And the appropriate plant density is 165000 plants/hm2 for’Jinza No.122’and’Jinza No.34’It can construct the good population, coordinate population growth and individual growth, and optimize population physiological function, which made both biomass and grain yield to achieve higher level.