棉花氮经济利用及其高效机理研究

发布时间：2018-12-07 16:56

【摘要】：针对黄河流域棉田施氮量偏高、氮肥运筹不合理等问题,开展了大田和盆栽试验,旨在探讨棉田经济施氮量、合理的氮肥运筹,为氮肥管理提供理论依据。大田试验一以转Bt品种“中棉所79”为材料,设置6个施氮处理(0,90,180,270,360,450 kg N/hm2),探讨施氮量对籽棉产量、氮利用率及棉叶生理特性的影响;氮肥运筹对土壤矿质氮的影响;土壤氮利用相关酶活性对施氮量的响应。大田试验二采用裂区试验,主区设3个种植密度(30000、52500、75000株/hm2),裂区设4个氮水平(0、112.5、225、337.5 kg N/hm2),探讨密度与氮水平对棉花产量、氮肥利用率的互作效应。盆栽试验采用15N示踪技术,在氮施用总量相同条件下(3.5g N/35kg土),设4个处理(氮肥基施与初花期追施比1:1和1:2、蕾期一次性施氮、初花期一次性施氮),探讨氮肥运筹对棉产量、15N回收率的影响。主要结果如下:1.360 kg N/hm2处理籽棉产量高于其他处理,根据氮肥产量效应方程,经济最佳施氮量为299.7 kg/hm2,经济最佳产量3845.5 kg/hm2。不同生育期棉花LAI、功能叶叶绿素含量、GS、GOGAT活性、初花期棉叶净光合速率随施氮量的增加而增加;生育后期棉叶GDH活性、NR活性、MDA含量、SOD活性随施氮量增加而下降。施氮270、360 kg/hm2处理盛铃期LAI较适宜(3.47-3.73),吐絮期棉叶生理活性较高,可为高产提供物质供应。氮积累量、籽棉产量与施氮量间均呈二次曲线关系,氮肥农学利用率(a NUE)和氮内在利用率(i NUE)随施氮量增加显著下降,施氮量180 kg/hm2时氮生理利用率(p NUE)高于其他处理,施氮量270 kg/hm2时氮肥回收率(NRE)高于其他处理。2.大田全生育期表观氮盈余值随施氮总量增加而增加。270 kg N/hm2基追比3:7处理产量优于基追比5:5、7:3处理,而且氮吸收量、a NUE、NRE显著提高,而表观氮盈余值显著降低。3.大田土壤脲酶活性随尿素施用量增加而增加,脱氢酶、蛋白酶活性随尿素施用量(0-360 kg N/hm2)增加而增加,450 kg N/hm2处理土壤脱氢酶、蛋白酶活性下降。4.盆栽条件下,随基肥氮施用量增加,初花期棉株氮吸收来自氮肥(Ndff)的比例显著增大,变幅为25.9%-42.5%。随氮肥追施量的增加,收获期棉株Ndff%显著增加,变幅为26.9%-54.1%。N(1/2)处理棉株籽棉产量最高,但与N(1/1)处理差异不显著。N(1/1)处理和N(1/2)处理棉花收获期单株15N积累量、15N回收率均显著低于蕾期、初花期一次性施氮处理,N(1/1)处理棉花收获期15N回收率低于N(1/2)处理,但无显著差异。棉花收获后N(1/2)处理土壤15N回收率低于N(1/1),但差异不显著。5.密度与氮用量对籽棉产量、氮利用率存在互作效应,中密中氮、高密低氮处理籽棉产量、氮利用率较高。随施氮量增加,a NUE、氮肥偏生产力(NPFP)、i NUE、NRE、p NUE均呈下降趋势。
[Abstract]:Aiming at the problems of high nitrogen application rate and unreasonable nitrogen fertilizer management in cotton fields in the Yellow River Basin, field and pot experiments were carried out in order to explore the economic nitrogen application rate and reasonable nitrogen fertilizer application in cotton fields, and to provide theoretical basis for nitrogen management. In the field experiment 1, 6 treatments (0f90180270360450 kg N/hm2) were used to study the effects of nitrogen application rate on seed cotton yield, nitrogen utilization efficiency and physiological characteristics of cotton leaves, and the effects of nitrogen fertilizer application on soil mineral nitrogen, using the transgenic Bt variety "Zhongmiansuo 79" as the material, and 6 treatments (0 / 90180270360450 kg N/hm2). Response of soil nitrogen utilization related enzyme activity to nitrogen application rate. In field experiment 2, there were three planting densities (30000,52500000 plants / hm2) and four nitrogen levels (0112.5225337.5 kg N/hm2) in the main area. The effects of density and nitrogen level on cotton yield and nitrogen utilization efficiency were studied. Pot experiment was conducted with 15N tracer technique under the condition of the same amount of nitrogen application (3.5g N/35kg soil). Four treatments were set up (the ratio of base application of nitrogen to topdressing at the beginning of flowering was 1:1 and 1: 2, one time application of nitrogen in bud stage, and one time application of nitrogen in early flowering stage). The effects of nitrogen fertilizer application on cotton yield and 15 N recovery were studied. The main results are as follows: the yield of seed cotton treated with 1.360 kg N/hm2 is higher than that of other treatments. According to the effect equation of nitrogen fertilizer yield, the economic optimum nitrogen application rate is 299.7 kg/hm2, and the best economic yield is 3845.5 kg/hm2.. The chlorophyll content, GS,GOGAT activity and net photosynthetic rate of cotton leaves increased with the increase of nitrogen application rate at different growth stages, and the activities of GDH, NR, MDA and SOD decreased with the increase of nitrogen application rate in cotton leaves at different growth stages. Nitrogen application of 270360 kg/hm2 was more suitable for LAI (3.47-3.73) and higher physiological activity of cotton leaves in spitting stage, which could provide material supply for high yield. There was a conic relationship among nitrogen accumulation, yield of seed cotton and nitrogen application rate. The agronomic utilization ratio (a NUE) and intrinsic nitrogen utilization ratio (i NUE) of nitrogen fertilizer decreased significantly with the increase of nitrogen application rate. The physiological utilization rate of (p NUE) was higher than that of other treatments at 180 kg/hm2 nitrogen application rate, and the (NRE) recovery rate of nitrogen fertilizer at 270 kg/hm2 nitrogen application rate was higher than that of other treatments. 2. The apparent nitrogen surplus value increased with the increase of total nitrogen application in the whole growth stage of the field. The yield of the treatment at 3:7 was better than that of the treatment of 5: 5: 7: 3, and the amount of nitrogen absorption, a NUE,NRE, was significantly higher than that of the treatment of 5: 5: 7: 3. However, the apparent nitrogen surplus value decreased significantly by 3. 3%. Soil urease activity increased with the increase of urea application rate, dehydrogenase and protease activity increased with urea application rate (0-360 kg N/hm2). Soil dehydrogenase activity decreased with 450 kg N/hm2 treatment. Under pot condition, the proportion of nitrogen absorbed from (Ndff) in cotton plants increased significantly with the increase of nitrogen application rate at the beginning of flowering, with the range of 25.9- 42.5. With the increase of nitrogen fertilizer topdressing amount, the Ndff% of cotton plant increased significantly at harvest period, the range of variation was 26.9kum and 54.1.N (1 / 2) treatment cotton seed cotton yield was the highest. However, there was no significant difference between N (1 / 1) treatment and N (1 / 1) treatment (. N (1 / 1) and N (1 / 2) treatment. The 15N accumulation and 15N recovery of cotton at harvest stage were significantly lower than those in bud stage. The yield of 15 N in N (1 / 1) treatment was lower than that in N (1 / 2) treatment, but there was no significant difference. The yield of 15N in cotton treated with N (1 / 2) was lower than that of N (1 / 1), but the difference was not significant. Density and nitrogen application rate had interaction effect on seed cotton yield and nitrogen utilization efficiency, medium density medium nitrogen, high density low nitrogen treatment seed cotton yield, nitrogen utilization ratio was higher. The partial productivity of, a NUE, nitrogen fertilizer decreased with the increase of nitrogen application rate.
【学位授予单位】：中国农业科学院
【学位级别】：博士
【学位授予年份】：2015
【分类号】：S562

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