Nutrient management

Question 1

Nutrients are essential for plant and plant root growth. However supplying too much nutrients can cause nutrient leaching or runoff from the land, resulting in adverse environmental effects, such as excess plant and/or algae growth in waterways.

The two most common nutrients are nitrogen and phosphorus. These can be dissolved (soluble), solid (insoluble), or found in organic matter.

Read more about this in the Nutrients Inputs Fact Sheet (60KB, pdf). Although this fact sheet refers to the Rotorua lakes, the principles can be applied to any other waterway such as streams and rivers.

Question 2

The nitrogen cycle

Nitrogen is highly soluble when not taken up by plants and can leach through groundwater into waterways.

Question 3

The phosphorus cycle

Phosphorus is attached to soil particles and therefore can move into a waterway through erosion.

Question 4

Nitrogen management

• Prevent direct application of fertiliser to waterways
• Fence off waterways from stock
• Follow best practice to apply farm effluent

Question 5

Phosphorus management:

• Prevent direct application of phosphorus fertiliser to waterways
• Manage soil erosion (slips, slumps) to prevent soil entering waterways
• Control runoff from tracks, feed pads, races to prevent it entering waterways
• Avoid overgrazing and pugging especially close to waterways
• Fence off waterways and establish riparian vegetation or grass strips to filter nutrients from water entering the waterway.