Abstract Besides nitrogen (N), phosphorus (P) is the most limiting nutrient for potato growth and P acquisition and utilization is affected by the N supply. Estimating accurately the P nutrition status is critical from economic and environmental standpoints. Our objectives were to (i) compare a critical P (Pc) curve based on the biomass (DM) of the whole plant (vines + tubers) with those recently developed in Argentina (Zamuner et al., 2016, Pc = 3.92 × DM−0.30) and Colombia (Gomez et al., 2016, Pc = 5.23 × DM-0.19); (ii) analyze P dilution in vines and tubers, and to develop Pc curves for vines and tubers; and (iii) analyze the relationship between N and P concentrations in vine, tuber, and total biomass along with the changes in the N:P ratio with increasing biomass. Five P rates up to 240 kg P2O5 ha-1 were applied to potatoes on soils located in four Canadian provinces from 2016 to 2018 for a total of 11 site-years. Vine, tuber, and total biomass, and N and P concentrations were measured weekly on five dates starting 50 days after planting, and tuber yield was measured at harvest. The Pc curve in total biomass (Pc = 3.57 × DM-0·38) was below that developed in Argentina and Colombia. The P and N concentrations of vine, tuber, and total biomass as well as the N:P ratio declined with increasing biomass. and Pc curves were developed for vines (Pc = 2.58 × DM-0.20) and tubers (Pc = 2.06 × DM-0.14). The P nutrition index (PNI) measured in vines or tubers with their respective Pc curves was significantly related to the PNI in total biomass, implying that P sufficiency before tuber initiation can be estimated by analyzing vines only. Indices to assess P sufficiency along with N and P imbalances in potato vine, tuber, or total biomass represent a promising alternative or a complement to the soil P tests traditionally used for fertilizer recommendations.

中文翻译：

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马铃薯临界磷稀释曲线与磷氮关系

摘要 除氮（N）外，磷（P）是马铃薯生长最受限制的养分，磷的获取和利用受氮供应的影响。从经济和环境的角度来看，准确估计磷营养状况至关重要。我们的目标是 (i) 比较基于整个植物（葡萄树 + 块茎）生物量（DM）的临界 P (Pc) 曲线与最近在阿根廷开发的那些（Zamuner 等人，2016 年，Pc = 3.92 × DM −0.30) 和哥伦比亚 (Gomez et al., 2016, Pc = 5.23 × DM-0.19)；(ii) 分析葡萄藤和块茎中磷的稀释度，并制定葡萄藤和块茎的 Pc 曲线；(iii) 分析葡萄藤、块茎和总生物量中 N 和 P 浓度之间的关系以及 N:P 比率随生物量增加的变化。从 2016 年到 2018 年，对位于加拿大四个省的土壤中的马铃薯施以高达 240 kg P2O5 ha-1 的五种磷，总共 11 个地点年。在种植后 50 天开始的五个日期每周测量葡萄、块茎和总生物量以及 N 和 P 浓度，并在收获时测量块茎产量。总生物量的 Pc 曲线（Pc = 3.57 × DM-0·38）低于阿根廷和哥伦比亚的曲线。藤本植物、块茎和总生物量的 P 和 N 浓度以及 N:P 比随着生物量的增加而下降。和 Pc 曲线是针对葡萄藤 (Pc = 2.58 × DM-0.20) 和块茎 (Pc = 2.06 × DM-0.14) 开发的。在葡萄藤或块茎中测量的 P 营养指数 (PNI) 及其各自的 Pc 曲线与总生物量的 PNI 显着相关，这意味着可以仅通过分析葡萄藤来估计块茎萌发前的 P 充足性。评估 P 充足性以及马铃薯藤、块茎或总生物量中 N 和 P 不平衡的指数代表了传统上用于肥料推荐的土壤 P 测试的有希望的替代方案或补充。