【摘要】 【目的】棉花是喜磷喜钾作物，适宜的施氮量不仅可以保证棉花的营养生长，还会促进磷、钾的吸收。为此我们研究了中熟和中早熟棉花品种的适宜施氮量。【方法】田间试验于2019—2020年在河南安阳开展。试验采用裂区设计，主区设7个施氮量：0、60、120、180、240、300、360 kg/hm~2，依次记为N0、N60、N120、N180、N240、N300、N360；副区为黄河流域两个主栽棉花品种冀棉228 (中熟)和鲁棉研28号(中早熟)。在棉花采收期，测定了棉花地上部生物量、产量及氮、磷、钾含量，计算氮、磷、钾累积量和皮棉生产效率。【结果】与N0相比，中熟品种冀棉228地上部生物量在施氮0～240 kg/hm~2范围内，随施氮量的增加显著增加，施氮量超过240 kg/hm~2后生物量不再显著增加；而中早熟品种鲁棉研28号地上部生物量在施氮量超过180 kg/hm~2后，就不再显著增加。施氮显著增加了冀棉228和鲁棉研28号地上部的氮、磷、钾累积量，冀棉228分别增加了37.5%、23.5%、29.2%，鲁棉研28号分别增加了47.2%、34.0%、35.5%。鲁棉研28号提高的幅度大于冀棉228。棉花氮、磷、钾积累量的增加65.9%～82.4%是由于地上部生物量的增加，17.6%～34.1%是由于地上部氮、磷、钾含量的增加。冀棉228的单株成铃数和鲁棉研28号的单铃重均随着施氮量的增加呈先增加后降低的趋势，通过线性加平台模拟得到的两个品种的最高产量施氮量分别为180和188 kg/hm~2，对应的皮棉产量分别为1661和1538 kg/hm~2。氮、磷、钾皮棉生产效率均随施氮量增加而显著降低。磷素、钾素皮棉生产效率与氮素皮棉生产效率呈正相关。产量收获指数与氮、磷、钾的累积量显著负相关，而与氮、磷、钾收获指数间呈显著正相关，可作为肥料利用效率的间接选择指标。【结论】适宜的施氮量可有效提高棉花地上部生物量和氮、磷、钾含量，二者的增加共同提高了棉铃和地上部的氮磷钾累积量，生物量增加对提高氮磷钾积累量的贡献率为65.9%～82.4%，氮、磷、钾含量增加的贡献率为17.6%～34.1%。氮素皮棉生产效率与磷素、钾素的皮棉生产效率呈正相关。综上，氮素吸收可促进棉花对磷、钾素的吸收，本试验条件下，冀棉228和鲁棉研28号皮棉产量和氮磷钾吸收利用率均较高的施氮量分别为180和188 kg/hm~2。更多还原

【Abstract】 【Objectives】Nitrogen supply is necessary for the rapid and healthy growth of cotton, however lint cotton production is sensitive to excessive N supply. We investigated the appropriate nitrogen(N) application rates for efficient lint cotton production and nutrient absorption, to provide theoretical basis for efficient yield and nutrient management of cotton.【Methods】 A field experiment with split-plot design was conducted in 2019and 2020 in Anyang, Henan Province.The main plot was N application rate: 0, 60, 120, 180, 240, 300, and 360kg/hm~2; the sub-plot was two cotton cultivars, Jimian228(middle maturity) and Lumianyan28(mid-early maturity), which were the main high-yielding cultivars grown in the areas of the Yellow River Valley. The shoot biomass, yield, and above ground N, P and K contents were determined.【Results】The shoot biomass of Jimian228 increased significantly with the increase of N application rates from 0 to 240 kg/hm~2, but was not affected by N application rates which exceeded 240 kg/hm~2. The shoot biomass of Lumianyan28 started decreasing when N application rates exceeded 180 kg/hm~2. N application significantly increased the accumulation of N, P, and K in the shoots of Jimian228 and Lumianyan28. The increment for Jimian228 were37.5%, 23.5%, and 29.2%, where as for Lumianyan28, it was 47.2%, 34.0% and 35.5%, respectively, and Lumianyan28 was higher than in Jimian228. The increase of shoot biomass and NPK concentent contributed65.9%–82.4% and 17.6%–34.1% to the increase of N, P and K accumulation in cotton shoot. The boll number per plant of Jimian228 and single boll weight of Lumianyan28 initially increased and then decreased with increasing N application rates. Simulated with a linear-plateau model, the optimal N application rates for the two cultivars were 180 kg/hm~2 and 188 kg/hm~2, which corresponded with lint yield of 1661 kg/hm~2 and 1538 kg/hm~2,respectively. The lint production efficiency of N, P and K generally decreased significantly with increasing N application rates. The lint production efficiency of P and K showed significantly positive relationship with that of N. The yield harvest index was negatively correlated with the accumulation of N, P and K, but positively correlated with the harvest index of N, P and K, indicating that it can be used as an indirect index of fertilizer use efficiency.【Conclusions】N application increased NPK contents and the dry matter of cotton shoot, both NPK content and dry matter brought about enhanced shoot NPK accumulation, with the contribution rate of65.9%–82.4% by dry matter and 17.6%–34.1% by higher NPK content. The lint cotton production efficiency of N was closely related to that of P and K. Therefore, N application could stimulate the absorption and utilization of P and K. Under conditions similar to the study area, the optimal N application rate for high yield and high use efficiency of nutrient for Jimian 228 and Lumianyan 28 are 180 and 188 kg/hm~2, respectively.更多还原