From fertiliser applied and nutrients removed by the harvest, compute apparent N, P and K use efficiency by the difference method to quantify uptake efficiency and losses.
| Item | Formula / Note | Source / Standard |
|---|---|---|
| N recovery efficiency | REN = (U_N − U_0)/F | Dobermann 2007 |
| P recovery efficiency | REP 10-25% first season | IPNI |
| K recovery efficiency | REK 30-50% | NY/T 496-2010 |
化肥利用率估算工具,采用差减法计算氮、磷、钾养分的表观利用率,通过施肥量、作物吸收量与土壤基础供肥量评估肥料被作物吸收的比例,辅助测土配方施肥与肥料效果评价。
肥料利用率 = (施肥区养分吸收量 − 不施肥区养分吸收量) / 施肥量 × 100%。