施磷水平与冬小麦产量和土壤有效磷含量的关系

  【目的】  研究施磷水平对冬小麦分蘖成穗、产量、磷素吸收利用的影响及其与土壤有效磷含量的关系，明确维持冬小麦持续高产的最佳土壤有效磷含量及施磷量，为冬小麦高效磷肥管理提供理论依据。  【方法】  于2018—2021年在河南科技大学农场进行了连续3年小麦田间试验，试验设P₂O₅ 0、90、180和270 kg/hm2 4个磷水平，分别记为P₀、P₉₀、P₁₈₀、P₂₇₀处理，研究了施磷水平对冬小麦分蘖成穗率、干物质积累与分配、产量、磷素吸收与分配及利用效率的影响，并分析了施磷水平、土壤有效磷含量与产量之间的关系。  【结果】  (1)随着施磷水平的提高，冬小麦单位面积最大分蘖数、有效分蘖数和干物质积累量处理间均呈P₂₇₀>P₁₈₀>P₉₀>P₀，而穗粒数、干物质向籽粒中分配率和产量呈先增加后降低的趋势；P₁₈₀处理的冬小麦产量高达9.8?10.2 t/hm2，比P₉₀处理高17.3%～18.2% (P<0.05)，与P₂₇₀处理相比高出4.2%～11.5%，但差异不显著；(2)随着施磷水平的提高，冬小麦茎、叶、颖壳及穗轴和籽粒的磷含量处理间多呈P₂₇₀>P₁₈₀>P₉₀>P₀；籽粒磷积累量呈先增加后降低的趋势，P₁₈₀水平下籽粒磷积累量最高，为57.0～61.1 g/m2；与P₉₀相比，P₁₈₀处理显著 (P<0.05) 提高了籽粒磷积累量，提高幅度为27.7%～39.0%；冬小麦磷偏生产力和磷农学利用效率均随着施磷水平的提高呈降低的趋势，与P₉₀相比，P₁₈₀、P₂₇₀水平下冬小麦磷偏生产力和农学利用效率分别降低了40.0%～41.1%和35.3%～36.1%、62.1%～64.7%和58.6%～62.8%，且均达到显著水平(P<0.05)；(3)土壤有效磷含量与施磷水平呈线性相关，小麦产量与施磷水平和土壤有效磷含量的关系可用一元二次方程拟合。年施P₂O₅ 194.2～197.4 kg/hm2时最佳土壤有效磷含量25.5～25.8 mg/kg，产量最高为9752～10349 kg/hm2。  【结论】  适宜的施磷量可显著增加冬小麦的有效分蘖数和成穗数，提高茎、叶、颖壳及穗轴的干物质和磷素积累量及向籽粒的转移，增加冬小麦单位面积穗数、穗粒数、千粒重和产量。在供试区域，获得冬小麦最高产量的施P₂O₅ 量为194.2～197.4 kg/hm2，土壤有效磷含量为25.5～25.8 mg/kg。

Relationship of phosphorus application rate,winter wheat yield and soil available phosphorus content

  【Objectives】  We studied the influence of phosphorus (P) application level on tiller-earing, yield, and the absorption and utilization of P in winter wheat.   【Methods】  From 2018 to 2021, a field experiment was conducted in Luoyang, Henan Province. Four P₂O₅ levels (0, 90, 180 and 270 kg/hm2) were setup, recorded as P₀, P₉₀, P₁₈₀ and P₂₇₀ treatments, respectively. The dry matter accumulation, P content in different organs at the main growing stages of wheat, the yield and yield components were recorded. After harvest, 0–20 cm soil samples were collected for the determination of available P.   【Results】  Among the P treatments, the maximum and effective tiller number, and the dry matter accumulation of winter wheat were in order of P₂₇₀>P₁₈₀>P₉₀>P₀, while the grain number per spike, the dry matter allocation rate in grains and yield increased first and then decreased. P₁₈₀ recorded the highest yield (9.8?10.2 t/hm2), which was 17.3%?18.2% higher (P<0.05) than P₉₀, but similar with P₂₇₀. The P concentration of stems, leaves, glume shells, spike shafts and grains of winter wheat were in order of P₂₇₀>P₁₈₀>P₉₀>P₀, while the grain P accumulation reached pick under P₁₈₀ (57.0?61.1 g/m2). Compared with P₉₀, P₁₈₀ significantly (P<0.05) increased grain P accumulation by 27.7%?39.0%. The partial productivity of P and the agronomic utilization efficiency of P in winter wheat showed a decrease trend with the increase of P application levels. Compared with P₉₀, the P partial productivity and P agronomic utilization efficiency of winter wheat at the P₁₈₀ and P₂₇₀ levels decreased by 40.0% to 41.1%, 35.3% to 36.1% and 62.1% to 64.7%, 58.6% to 62.8%, respectively. P application levels had linear relationship with soil available P content, but the relationship of wheat yield with P application levels and soil available P content could be fitted with quadratic equations.  【Conclusions】  Suitable application rate of phosphorus can significantly increase the number of effective tillers and panicles of winter wheat, increase the accumulation of dry matter and phosphorus in stems, leaves, glumes and rachis and their transfer to grains, and increase the number of spikes per unit area, grains per spike, 1000-grain weight and yield of winter wheat. For the highest winter wheat yield in the test area, the P₂O₅ application rate was 194.2?197.4 kg/hm2, and the soil available P was 25.5?25.8 mg/kg.