How to read NPK, micronutrients and the guaranteed analysis, and why the percentage is not the field rate.
The NPK on a label is the guaranteed percentage of nitrogen, phosphorus and potassium; micronutrients are listed separately. The percentage is the share in the bag, not the dose the crop needs. The same NPK does not mean the same nitrogen form or the same chelate statement.
The comparison uses the guaranteed analysis and the form, not the brand line.
Why calcareous soil and high pH are not the same measurement, and how high pH changes iron, zinc and phosphorus availability.
How urea, ammonium and nitrate behave differently in soil, and why one large dose is not the same as splitting it.
What a leaf analysis shows that a soil analysis does not, and why sampling time and leaf choice change the reading.
How to judge compost maturity before field use: temperature, smell, salinity and the analysis, not color alone.
Why phosphorus becomes bound in soil and why raising the rate without a soil analysis is not the management.
