Nutrient balance is the difference between the nutrient inputs entering a farming system and the nutrient outputs leaving the system.
Nutrient inputs typically include livestock manure and fertilisers, and nutrient outputs are the uptake of the nutrients for crop and pasture production.
A nutrient deficit (negative value) indicates declining soil fertility. A nutrient surplus (positive data) indicates a risk of polluting soil, water and air.
Nutrient balances provide information about environmental pressures. Inputs of nutrients are necessary in farming systems as they are critical in maintaining and raising crop and forage productivity. However, a build-up of surplus nutrients in excess of immediate crop and forage needs can lead to nutrient losses. Not only a possible cause of economic inefficiency in nutrient use by farmers, but surplus nutrients are also a source of potential harm to the environment, through water or air pollution, notably as ammonia or greenhouse gas emissions.
This indicator is measured in kilograms of nutrient per hectare of agricultural land for the two main nutrients, nitrogen and phosphorus.
