Sub-Saharan Africa (SSA) needs to increase food productivity to alleviate food insecurity exacerbated by climate variability and increasing food demand. Balancing macronutrient inputs is essential for sustaining yields, increasing farmer’s income and minimizing environmental costs deriving from fertilizer misuse. The present study calculates the nitrogen (N), phosphorus (P) and potassium (K) mass balances and estimates macronutrient inputs and outputs of a quinoa field cultivated under full and deficit irrigation conditions (100 and 50% crop evapotranspiration - ETc), in either the presence or absence of N fertilizer (100 and 0 kg ha^–1 of N). The emerging findings show that to produce one ton of quinoa biomass (including seeds, stems and leaves) 12.7, 1.6 and 35.5 kg ha^–1 of N, P and K, respectively, need to be added into the soil. While N and K are required at medium to fairly high amounts, P is needed in lower amounts. Hence, fertilizers in the form of potassium nitrate (KNO₃) are more suitable than those with higher phosphorus concentrations, for example phosphate (PO_4^3–). Overall, evidences from field experimentations are necessary for integrating farming input recommendations on crop agronomic guidelines, driven by national agricultural research institutions, and for promoting sustainable agriculture in SSA.

Highlights
- 12.7, 1.6 and 35.5 kg ha^–1 of N, P and K, respectively, are required to produce 1 ton of quinoa biomass.
- Seed yields of 1380 kg ha^–1 can be attainded under full irrigation and 100 kg ha^–1 of N. 
- MAPE values of –7.5, +4.3 and +3.3 between N, P, K mass balance calculations and observed values in the field.

撒哈拉以南非洲 (SSA) 需要提高粮食生产力，以缓解因气候变异和粮食需求增加而加剧的粮食不安全状况。平衡大量营养素的投入对于维持产量、增加农民收入和最大限度地减少因滥用肥料而造成的环境成本至关重要。本研究计算了氮 (N)、磷 (P) 和钾 (K) 质量平衡，并估计了在充分灌溉和亏缺灌溉条件下（100% 和 50% 作物蒸散量 - ETc）栽培的藜麦田的常量营养素输入和输出，在是否存在氮肥（100 和 0 kg ha ^–1 N）。新发现表明，生产一吨藜麦生物量（包括种子、茎和叶）需要 12.7、1.6 和 35.5 kg ha ^–1需要分别向土壤中添加 N、P 和 K。虽然 N 和 K 的需求量中等至相当高，但 P 的需求量较低。因此，硝酸钾 (KNO ₃ )形式的肥料比磷浓度较高的肥料更合适，例如磷酸盐 (PO _{4 ^3–} )。总体而言，在国家农业研究机构的推动下，田间试验的证据对于将农业投入建议整合到作物农艺指南中以及促进 SSA 的可持续农业是必要的。

亮点
-生产 1 吨藜麦生物量分别需要12.7、1.6 和 35.5 kg ha ^–1的 N、P 和 K。
-在充分灌溉的情况下可以获得 1380 kg ha ^{–1 的}种子产量和 100 kg ha ^–1的 N。 
- N、P、K 质量平衡计算和观测值之间的 MAPE 值为 –7.5、+4.3 和 +3.3场地。