不同种植密度对高粱生长、产量及养分吸收的影响

为了明确密度与高粱[Sorghum bicolor (L.) Moench]农艺和经济性状以及养分吸收的关系，以‘晋杂23号’高粱为试验作物，采用大田试验方法，试验设4.5万株/hm2、7.5万株/hm2、10.5万株/hm2和13.5万株/hm2 4个种植密度，研究了不同种植密度对高粱生长、产量、产量构成因素以及养分吸收的影响。结果表明，随着密度增加，高粱株高显著增高，茎粗显著变细，单株叶面积和单株干重显著下降。在4.5万株/hm2~7.5万株/hm2范围内，籽粒产量随着密度增加呈显著性增加。密度在4.5万株/hm2~10.5万株/hm2时，单位面积穗数随密度增加呈显著性增加。随着密度增加，穗粒数显著性增加，而千粒重影响不显著。除磷以外，密度对高粱氮和钾吸收总量均无显著影响。密度对籽粒氮吸收量没有显著影响；在10.5万株/hm2~13.5万株/hm2范围内，磷和钾吸收量明显下降。与氮和磷不同，钾主要分配在秸秆中，只有少量钾转运到籽粒中。相关分析表明，种植密度与株高、生物产量、籽粒产量和单位面积穗数呈显著性正相关，而与茎粗、单株叶面积、单株干重、经济系数、穗粒数和千粒重呈显著性负相关。本研究表明，种植密度与高粱主要农艺和经济性状以及养分吸收息息相关，在高粱高产高效栽培中起着非常重要的作用。

Effect of Different Plant Density on Growth, Yield and Nutrient Uptake of Sorghum

In order to determine the relationships between plant density and agronomic and economic properties, and nutrient uptake of sorghum [Sorghum bicolor （L.） Moench]. An experiment with a sorghum variety ＇Jinza No. 23＇ was conducted to investigate the effects of plant density on growth, yield and nutrient uptake of sorghum under field conditions. The experiment design was the randomized complete block with 3 replications. 4 plant densities （45000, 75000, 105000, 135000 plants/hm^2） were employed. The results showed that, plant height of sorghum was significantly increased, and stem diameter was significantly thinned, leaf area and dry matter weight per plant were significantly declined as plant density increased. Grain yield increased with plant density increasing at the ranges of 45000 plants/hm2 to 75000 plants/hm^2. The panicle number per unit area was significantly increased when plant density increased from 45000 plants/hm2 to 105000 plants/hm^2. Grain number per panicle decreased as plant density increased. 1000-grain weight was not influenced by plant density variety. The total amount of N and K uptake were not significantly influenced by plant density except for P. The uptake of. P and K in grain was markedly declined as plant density was increased from 105000 plants/hm2 to 135000 plants/hm2, whereas N uptake in grain was significantly affected by plant density. Unlike N and P, the major portion of K was contained in the vegetative parts and little in the heads. Correlation analysis revealed that the relationships between plant density and plant height, biomass, grain yield and panicle number per unit area were significant and positive correlation. Whereas the relationships between plant density and stem diameter, leaf area and dry weight per plant, economic index, grain number per panicle, and 1000-grain weight were significant and negative correlation. The current study indicates that plant density is closely linked with sorghum main agronomic and economic traits and nutrient uptake. It plays a very important role in the cultivation of high yield and high efficiency in sorghum.