大量营养素是植物健康生长需要大量摄取的矿质元素。有六种主要的大量营养素：氮 (N)、磷 (P)、钾 (K)、钙 (Ca)、镁 (Mg) 和硫 (S)。在土壤栽培中，这些元素可以通过有机物的分解得到部分补充。在水培中，必须通过营养液以精确校准的浓度提供所有这些元素。
关键事实
- Primary macros: N, P, K — needed in the highest quantities
- Secondary macros: Ca, Mg, S — needed in significant but smaller amounts
- Calcium strengthens cell walls; deficiency causes tip burn and blossom end rot
- Magnesium is the central atom in chlorophyll; deficiency causes interveinal yellowing
- Sulphur is needed for amino acid synthesis; deficiency causes pale new growth
- All six must be present in balanced ratios — excess of one can block uptake of another