氮肥基追比对南疆杂交棉氮素吸收、生物量及产量的影响

探索不同氮肥基追比水平下杂交棉的氮素吸收、干物质积累及产量的变化规律,为南疆杂交棉高产高效栽培技术提供理论依据。以兆丰1号和鲁棉研30号为试验材料,设3个氮肥基追比处理(N1,基肥∶追肥=0∶10;N2,基肥∶追肥=2∶8;N3,基肥∶追肥=4∶6),研究了氮肥基追比对杂交棉氮素吸收、干物质积累及产量的影响。结果显示,随着氮肥追肥比例的减少,植株生物量和氮素吸收量先升后降。其中N1处理不利于棉株干物质积累和氮素的吸收,显著降低了累积速率,使棉花生育期提前、衰老加快;N2处理提高了干物质快速积累速率,延长了快速积累持续时间,增加了开花后生物量积累、氮素吸收量以及花后同化物与氮素向生殖器官中的转运;N3处理由于追肥比例较少,开花后干物质与氮素的积累量以及花铃期干物质与养分向生殖器官中的分配比例减少。本试验条件下,两个杂交棉品种的基肥∶追肥=2∶8处理的棉花干物质及氮素累积最为协调,并能同步增加单株结铃数和铃重,进而实现增产。

Effects of ratios of base and topdressing nitrogen fertilizer on N uptake,biomass and yield of hybrid cotton in southern Xinjiang

In this study, effect of different application ratios of base and topdressing nitrogen fertilizer on the nitrogen uptake, the dry matter accumulation and yield of hybrid cotton was explored to provide a theoretical basis for high-yield and high-effi-cient cultivation techniques of hybrid cotton in southern Xinjiang. Three treatments with different ratios of base fertilizer to top-dressing fertilizer were set up as 0∶10 ( N1 ) , 2∶8 ( N2 ) and 4∶6 ( N3 ) , respectively, and two cultivars of hybrid cotton were used, i. e. Zhaofeng1 and Lumianyan30. The result showed that biomass and the nitrogen accumulation increased firstly and then decreased with the reducing of topdressing nitrogen fertilizer rate. The accumulation of dry matter and the uptake of ni-trogen of N1 treatment was the least and, the growth period was bring forward and the senescence process was accelerated. In N2 treatment the dry matter accumulation was increased quickly, which increased the biomass accumulation and the amounts of nitrogen accumulation after the appearing flower stage and increased the rate of photosynthetic product accumulation of transfer-ring to the reproductive organs. In N3 treatment, the amounts of the dry matter and nitrogen accumulation of after the flowering stage was reduced, which lessened the allocation proportion of the dry matter and nutrient to the reproductive organs during the blooming stage because of the lower fertilizer proportion of topdressing. The dry matter and nitrogen accumulation were the best when the ratio of base and topdressing fertilizer was 2∶8 in southern Xinjiang, and the boll number and boll weight increased. There was no difference between the two different cotton cultivars.