缓释肥对紫色土油菜生长和养分吸收利用的影响

分析缓释专用配方肥与当地常用肥对油菜生物量、氮磷钾养分吸收利用及其在土壤中累积的影响，为油菜节肥高效生产提供依据。通过大田试验，以油菜品种三峡油5号为试验材料，设置6种施肥处理：以不施肥（F₀）和常规施肥(F_c)为对照处理，缓释专用配方肥设置4种施肥水平(F₃₇₅: 375 kg·hm^-2，F₅₂₅: 525 kg·hm^-2，F₆₇₅: 675 kg·hm^-2，F₈₂₅: 825 kg·hm^-2)。结果表明，不同施用量的缓释专用肥料对油菜产量、单株有效角果数以F₆₇₅处理最大，F₈₂₅处理次之，F₃₇₅处理最小，其分别较F_c 处理增产43.54%、36.82%、13.88%；施用缓释专用配方肥油菜氮养分损失率从F_c处理的78.30%降低至53.97% ~ 73.66%；磷养分损失率从F_c处理的56.65%降低至20.53% ~ 46.13%；施用缓释专用肥料油菜收获期根区土壤全氮、全磷与全钾含量从F_c处理的0.651 0 g·kg^-1、0.404 4 g·kg^-1与20.74 g·kg^-1上升至0.661 7 ~0.691 4 g·kg^-1、0.407 2~0.496 0 g·kg^-1与28.96~29.50 g·kg^-1。施肥大幅增加油菜生物量，缓释专用配方肥的施用不仅利于提升肥料利用率，同时使得根区土壤养分含量变化较小，结合农业可持续发展，实际生产应该施用缓释专用肥。

Effects of Slow-release Fertilizers on Growth and Nutrient Uptake and Utilization of Canola Grown on Purple Soil

A fertilization field experiment on Brassica napus L., Sanxiayou 5 in cultivar was conducted. The experiment aimed to study effects of special slow-release fertilizer and conventional fertilizer on biomass and nutrients (nitrogen, phosphorus and potassium) uptake and utilization of canola, and nutrient accumulation in soil. The field fertilization experiment on canola (Sanxiayou 5) was designed to have six fertilization treatments, i.e. F₀ (no fertilizers), F_c (conventional fertilizer), F₃₇₅ (special slow-release fertilizer at 375 kg·hm^-2), F₅₂₅ (special slow-release fertilizer at 525 kg·hm^-2), F₆₇₅ (special slow-release fertilizer at 675 kg·hm^-2) and F₈₂₅ (special slow-release fertilizer at 825 kg·hm^-2). Results show that application of slow-release fertilizer improved yield and effective number of pods per plant of canola, exhibiting an order of Treatment F₆₇₅ > Treatment F₈₂₅ > Treatment F₃₇₅ in the effect. Compared with Treatment F_c, Treatment F₆₇₅, Treatment F₈₂₅ and Treatment F375 increased yield of the crop by 43.54%, 36.82% and 13.88%, respectively. Besides, the application reduced N nutrient loss rate from 78.30% (in Treatment Fc) to 53.97%(in Treatment F375) -73.66% (in Treatment F825), and P nutrient loss rate from 56.65% (in Treatment F_c) to 20.53% (in Treatment F₃₇₅) - 46.13% (in Treatment F₈₂₅). Total N, total P and total K in the rhizosphere soil applied with slow-release special fertilizers increased from 0.651 0 g·kg^-1, 0.404 4 g·kg^-1 and 20.74 g·kg^-1 (in Treatment F_c) to 0.661 7-0.691 4g·kg^-1, 0.407 2-0.496 0 g·kg^-1 and 28.96-29.50 g·kg^-1. Fertilization could significantly increase biomass of the crop, and application of special formulated slow-release fertilizer could not only improve fertilizer utilization rate, but also have less impacts on nutrient contents in the rhizosphere soil. Taking into account sustainable development of the agriculture, it is advisable to use the special slow-release fertilizer in practical production.