In years of low income, nitrogen sales rise relative to phosphorus, potassium, and sulphur inputs on the basis that nitrogen produces the cheapest supplementary feed.
There’s an attitude that soil nutrients can be mined for a period of time and replenished at a later date, but it’s a theory that ignores a number of facts.
At best 50% of applied nitrogen is taken up by the pasture plants, the remaining being lost to the atmosphere or groundwater. That lost to groundwater takes with it calcium, magnesium, and potassium.
The steady ongoing loss of calcium reduces the activity of earthworms and fewer earthworms allow soils to steadily compact.
Hard soils contain less moisture limiting pasture performance over summer and early autumn.
Less available calcium also limits the amount of clover able to be grown and it is clover that is best suited to growth over summer.
On most dairy farms there is an ongoing requirement for magnesium, and dolomite containing both magnesium and calcium provides a range of benefits.
As a proven soil conditioner, dolomite allows pasture roots to access moisture and nutrient from a greater depth and encourages clover growth, providing the basis for strong summer production.