What Is Nutrient Use Efficiency (NUE)?

Simply put, nutrient use efficiency is getting more from the inputs you use.

On many farms, the symptoms are familiar: soil tests show plenty of phosphorus, yet crops still test deficient. Fields receive full-rate nitrogen, but plants look pale and hungry. Heavy rains wash away expensive fertilizer. Parts of a field thrive while neighbouring areas struggle, even though everything was applied uniformly.

These patterns point to more than bad luck or less than ideal inputs. They reveal a deeper issue: a breakdown in nutrient cycling between soil, microbes, and plants. Fixing that cycle is at the heart of improving nutrient use efficiency (NUE) and, with it, both profitability and environmental performance.

Why Nutrient Use Efficiency Matters

Nutrient use efficiency describes how well nutrients — both those already in the soil and those you apply — are converted into plant growth and yield. High NUE is a cornerstone of regenerative agriculture, because it shifts the system away from dependence on soluble, salt-based fertilizers and toward a biologically driven, self-sustaining nutrient cycle.

Economically, better efficiency can mean a substantial reduction in fertilizer and chemical inputs, especially in the early years of transition. Money no longer locked into high, recurring input costs can instead support investments that build long-term resilience: diverse cover crops, compost, improved grazing management, and better infrastructure.

Ecologically, high NUE keeps nutrients where they belong — on the farm — rather than in waterways. Nitrogen and phosphorus lost through leaching and runoff are major contributors to water pollution and algal blooms. When soil structure and biological activity improve, these losses decline, and the farm becomes a more responsible part of the local landscape.

The management mindset changes from “feeding the plant” with soluble products to “feeding the soil” so that a healthy soil ecosystem can supply nutrients as crops need them.

How Low NUE Hurts Yield, Health, and Profit

Inefficient nutrient use shows up in several connected ways:

Yield and quality losses: When key nutrients are unavailable at critical stages, crops cannot reach their genetic potential. The result is stunted growth, poor grain fill, lower bushel weights, and lower nutrient density in both feed and food crops.

Higher pest and disease pressure: Nutrient imbalances create plants that are more attractive to insects and pathogens. Poor mineral nutrition can lead to an accumulation of simple sugars and incomplete proteins in plant sap—an ideal food source for many pests and fungi. This often triggers more pesticide use, adding cost and further disrupting the agroecosystem.

Wasted fertilizer and financial loss: Any nutrient not taken up by the crop is money lost. Fertilizers can leach below the root zone, run off the surface, become chemically fixed in unavailable forms, or volatilize into the atmosphere. Over time, these losses erode margins.

Degraded soil structure: Heavy use of high-salt fertilizers can damage soil biology, particularly fungi that are critical for aggregation. As soil structure collapses, compaction and crusting increase, water infiltration declines, and nutrient availability problems worsen — a downward spiral.

“Locked-Up” Nutrients and the Role of Biology

Many nutrient problems arise not from absolute shortage, but from inaccessibility:

• Phosphorus often binds tightly with iron, aluminum, or calcium, leaving only a small fraction of applied fertilizer available to plants.

• Nitrogen efficiency depends on the balance between ammonium and nitrate, the plant’s energy costs, sufficient sulfur for complete protein synthesis, and avoidance of denitrification in compacted, waterlogged soils.

• Nutrient interactions mean that excess of one element can block uptake of another, making balance as important as total supply.

A living, biologically active soil unlocks these reserves. Microbes store nutrients in their biomass and release them through the soil food web right in the root zone. Mycorrhizal fungi extend root access to a much larger soil volume and specialize in acquiring immobile nutrients like phosphorus. As microbial activity builds aggregates and pore space, water and air movement improve, further supporting nutrient cycling.