不同施氮量对棉花花铃期的生长特性与产量及经济效益的影响

Effects of Different Nitrogen Rates on Growth Characteristic at Flowering-boll Stage,Yield and Economic Benefit of Cotton

为揭示氮素不同供应量下棉花生长后期的营养生长和生殖生长的变化规律,以棉花品种冀丰1982为供试材料,设置5个氮肥用量处理(分别为0(N1)、90(N2)、180(N3)、270(N4)、360 kg/hm^(2)(N5)),研究不同施氮量对棉花花铃期生长特性、产量及经济效益的影响。结果表明,在花铃期,施氮肥的株高显著高于不施氮肥;叶绿素CCI值随施氮量增加呈增加趋势;而果枝数、单株有效铃数、叶绿素荧光参数Fv/Fm和Fv/Fo值随氮肥用量增加均呈先升高后下降趋势,N3处理的果枝数、有效铃数、Fv/Fm和Fv/Fo均为最高。成熟期施氮肥处理单株平均根质量显著高于不施氮肥;棉花单株的茎秆质量和生物量随施氮量增加呈增加趋势,各处理间差异显著,但铃质量、根冠比差异不显著。有效铃数、收获指数、籽棉产量、皮棉产量、衣分、收益和效益随施氮量的增加呈先升高后下降的趋势,施氮量为180 kg/hm^(2)时获得产量最高,为3848.58 kg/hm^(2),该施氮量下有效铃数、衣分、收益和效益也相对较高;氮肥农学效率和氮肥偏生产力随着施氮量增加呈显著的下降。利用回归分析推测,当地适宜的施氮量,氮肥用量与籽棉产量、经济效益均呈二次函数关系。各处理磷钾肥投入一致,当氮肥用量为223.55 kg/hm^(2)时,籽棉产量最高,为3809.53 kg/hm^(2);当氮肥用量为196.66 kg/hm^(2)时,经济效益最高,为19428.3元/hm^(2)。

To reveal the changes in vegetative growth and reproductive growth of cotton responded to the different nitrogen(N)supply at the late growth period,this study took the cotton variety of Jifeng 1982 as the test material,and set five nitrogen application rates(0,90,180,270,360 kg/hm^(2)),represented by N1,N2,N3,N4 and N5.The effects of different nitrogen application rates on growth characteristics,yield and economic benefits of cotton at flowering and boll stage were studied.The results showed that the plant height under nitrogen fertilizer treatments was significantly higher than that under no nitrogen fertilizer at flowering-boll stage.The chlorophyll CCI value increased with the increase of N application rates.However,the number of fruit branches,effective bolls per plant,the values of chlorophyll fluorescence parameters Fv/Fm and Fv/Fo increased firstly and then decreased with the increase of N application rates.The number of fruit branches,effective bolls per plant,Fv/Fm and Fv/Fo values under N3 were the highest.The average root quality under nitrogen fertilizer treatments were significantly higher than that under no nitrogen fertilizer at maturity stage.The stem quality and biomass of cotton per plant presented an increasing trend with the increase of nitrogen rates,and there were significant differences among treatments.However,there were no significantly differences in the value of root-shoot ratio and boll quality.The effective bolls per plant,harvest index,seed cotton yield,lint yield,lint percentage,income and economic benefit increased firstly and then decreased with the increase of N application rates.The highest yield could be obtained at 180 kg/hm^(2)N rate and attainable yield was 3848.58 kg/hm^(2).Under this nitrogen application rate,the effective boll number,lint percentage,income and benefit were also relatively higher.The N agronomic efficiency and N partial factor productivity significantly decreased with the increase of N application rates.Regression analysis was used to estimate the appropriate fertilizer application in the local area.Seed cotton yield and economic benefit represented quadratic function relationship with N application rate.Based on the same phosphorus and potassium fertilizer inputs,when the nitrogen fertilizer was 223.55 kg kg/hm^(2),the seed cotton yield reached the highest value of 3809.53 kg/hm^(2).When the nitrogen fertilizer was 196.66 kg/hm^(2),the economic benefit reached the highest value of 19428.3 yuan/hm^(2).