Fertiliser & Nutrient Planning: Soil Tests, NPK Rates, Manure Value & Spreader Checks

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn target yields into the phosphate and potash each field removes per hectare, add them up for the whole farm and find the area-weighted average.
• Look up each field's soil index in a factor table, turn offtake into phosphate and potash recommendations, count the fields that can be cut back and name the field that needs the most potash.
• Work out the crop-available nitrogen, phosphate and potash from slurry, farmyard manure and poultry litter, put a fertiliser value on them and total the manure nitrogen for the farm.
• Work out how much fertiliser nitrogen each field really needs after soil supply and manure, compare it with a draft plan and price the nitrogen the draft would waste.
• Turn Long Acre's nutrient need into kilograms of product per hectare, compare the cost of nitrogen from two products and combine a PK compound with a straight phosphate top-up.
• Calculate the analysis and cost of a home-made three-component blend, set the rate for the phosphate need and check how far the potash it brings misses the target.
• Turn a tray test into an applied rate and a spread-evenness figure, check the rate from the spreader's output, speed and bout width, and work out how much product to load for a field.
• Build phosphate and potash balances for every field, total the farm balance by area, count the fields running down their potash and chart the phosphate balance by field.