Soil

A field is never one thing: the case for mapping your soil

Why a single composite soil sample hides the variation that decides yield, and how NPK, pH and EC maps change fertiliser decisions.

· 5 min read

Most farms treat a field as one thing: one soil sample, one fertiliser blend, one rate. It never is. Old homestead and boma sites are rich; eroded slopes are starved; low corners hold water and salt.

What averaging hides

A composite sample mixes soil from across the field into one bag. The lab reports the average — which may describe no actual part of the field. The rich corner and the starved slope average out to “fine”, and both are fertilised the same.

You pay for that twice: once at the agrovet for fertiliser the rich ground did not need, and again at harvest for the yield the starved ground never made.

Three maps, one farm profile

  • NPK map — which blocks are short of which nutrient
  • pH map — where acidity is locking nutrients up, and where lime pays
  • EC map — where salts and fertiliser have built up or washed away

Read together, they give a farm profile: an honest account of the ground you own. From there, fertiliser and lime go where they change the yield.

From map to management blocks

A map is only useful if you can act on it. We draw management blocks sized to what you can actually treat differently — by hand, by tractor, or through fertigation zones.

Start with a walk around your farm.

The first conversation is a site visit: we walk the farm with you and understand what you grow or keep and what is going wrong. No cost, no commitment. Buy outright, lease, or pay as you go by M-Pesa.