Soil Index System

Index 3 is the target Index for Soil test P, K and Mg

Soil Index System for P, K and Mg for Grassland and Tillage Crops (Morgan’s soil test)

Index Phosphorus (P) Potassium (K) Magnesium (Mg)
Grassland Tillage All Crops All Crops
1 0-3.0 0-3.0 0-50 0-25
2 3.1-5.0 3.1-6.0 51-100 26-50
3 5.1-8.0 6.1-10.0 101-150 50-100
4 >8.0 >10.0 >150 >100

This P and K calculator tool provides general guidelines for crop offtake and/or general agronomic advice for P and K application to grassland and arable crops in Ireland.

For more detailed information, see Teagasc Nutrient Advice.

The guidelines included for crop requirement and organic fertilizer value may result in recommendations that exceed the maximum N and P allowances on the farm.

Fertilizer usage must be in compliance with Nitrates Regulations and other nutrient management legislation. This may constrain the rates of N and P fertilizer that are permissible relative to the guidelines shown by this tool.

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P & K Calculator

The P & K calculator is an online calculator for estimating P and K fertilizer requirements for grassland and crops. It is available online, or via the iOS and Android Smart Phone Apps.P & K Calculator