不同密度和氮素水平对棉花冠层光截获的影响

【 Objective 】 To explore the effects of planting density and nitrogen on the cotton canopy. 【 Method 】 The experiment used Ji Nong Da Cotton No. 36 as the material and adopted a splice zone design. The main zone had 2 planting densities and the secondary zone had 6 nitrogen application rates. For each treatment, the plant height, stem diameter, dry matter accumulation, leaf area and canopy light interception of cotton were measured at the bud formation stage, the initial flowering stage and the full flowering stage. Analyze the effects of planting density and nitrogen on the cotton canopy. 【 Result 】 Increased application of nitrogen fertilizer can significantly increase the plant height, stem diameter, accumulation of vegetative organs, total dry matter and nitrogen accumulation of cotton plants. Increasing the planting density can significantly enhance the plant height, vegetative organs, total dry matter accumulation and nitrogen accumulation of cotton. Increasing nitrogen fertilizer application or increasing planting density can significantly improve the leaf area index of cotton. With the increase of nitrogen application rate, the accumulation of dry matter and nitrogen in the reproductive organs of cotton showed a trend of first increasing and then decreasing, reaching the maximum value when the nitrogen application rate was 225 kg per hectare. Increasing the planting density can enhance the accumulation of dry matter and nitrogen in the reproductive organs of cotton. 【 Result 】 Planting density and nitrogen can regulate the plant height, stem diameter, dry matter and nitrogen accumulation of cotton, and affect the interception of photosynthetically active radiation by the canopy. Appropriate nitrogen application rate and planting density can slow down the senescence of leaves, increase the interception of photosynthetically active radiation by the canopy, promote the transportation of photosynthetic products to reproductive organs, and thereby increase the yield of cotton.