NP 18-16 — Phosphorus-Weighted Starter for Deficient Soils
On phosphorus-depleted soils where Olsen P tests below 10 mg/kg, NP 18-16 provides a slightly phosphorus-heavy ratio to rebuild soil P reserves while supplying adequate early nitrogen. The 34% total nutrient content suits lighter application rates on smallholder plots and precision farming systems. Used in potato, sugar beet and legume rotation programmes. From 1,000 MT.
Quality Parameters
- FOB
- CFR
- CIF
- Agriculture
- Blending
- Fertigation
Application Notes
Band NP 18-16 at 80–150 kg/ha at planting on P-deficient soils; reduce rate as soil P builds over successive seasons. The moderate nitrogen content avoids excess vegetative growth in root crops where tuber quality depends on controlled N input during bulking.
FAQ
How long does it take to rebuild soil P with NP 18-16?
On severely P-depleted sandy soils, 3–5 seasons of NP 18-16 at 150 kg/ha typically raise Olsen P from critical to adequate levels. Soil test annually and transition to lower-P starter once levels exceed 15 mg/kg.
Is NP 18-16 suitable for organic transition fields?
Conventional NP 18-16 is not organic-certified. Farms in organic transition may use it during the conversion period where permitted by certifying body, then switch to approved rock phosphate and compost sources.
Can NP 18-16 be applied to established perennial crops?
Yes. Orchard and vineyard replant programmes use NP 18-16 incorporated in the planting hole to supply P for root establishment in the critical first two years after replanting.