Fertiliser Application Calculator

To calculate the amount of fertiliser needed for a paddock, multiply the application rate in kilograms per hectare (kg/ha) by the paddock area in hectares. For example, an application rate of 200 kg/ha of urea on a 50 ha paddock requires 200 x 50 = 10,000 kg, or 10 tonnes of urea. Most fertiliser is sold by the tonne, so converting to tonnes (divide kg by 1,000) simplifies ordering. When calculating costs, multiply total tonnes by the price per tonne. Note that fertiliser spreaders have a spread width and travel distance that affect the area covered per load, so work with your spreading contractor or merchant to confirm order quantities. Many NZ fertiliser companies, including Ballance Agri-Nutrients and Ravensdown, provide free online calculators and agronomist advice to help with application planning. Source: Ballance Agri-Nutrients (ballance.co.nz); Ravensdown (ravensdown.co.nz).

Fertiliser prices in New Zealand fluctuate with international commodity markets and local supply and distribution costs. As a general guide, approximate 2024 to 2025 prices are: urea approximately $700 to $900 per tonne; diammonium phosphate (DAP) approximately $900 to $1,100 per tonne; single superphosphate approximately $500 to $650 per tonne; agricultural lime approximately $90 to $150 per tonne. Prices vary by region, order volume, and season. The two main fertiliser cooperatives, Ballance Agri-Nutrients and Ravensdown, supply the majority of the NZ market and publish current price lists for shareholders. Forward buying and volume discounts are available. Always get current quotes from your supplier as prices change frequently. Freight costs to farm gate can add $20 to $80 per tonne depending on distance. Source: Ballance Agri-Nutrients (ballance.co.nz); Ravensdown (ravensdown.co.nz).

A typical New Zealand pastoral fertiliser programme aims to maintain soil fertility and replace nutrients removed by stock and crops. For sheep and beef pastoral farms, an annual application of single superphosphate at 150 to 250 kg/ha is common, providing phosphorus and sulphur. Urea is often applied in autumn and spring to boost nitrogen response and pasture growth, particularly on dairy farms where nitrogen rates of 100 to 200 kg N/ha per year may be used. Dairy farms typically have higher overall fertiliser budgets due to the intensity of production. Lime is applied every 3 to 5 years to maintain soil pH between 5.8 and 6.2. The National Policy Statement for Freshwater Management (NPS-FM) limits nitrogen losses from farms in many catchments, affecting how much nitrogen fertiliser can be applied. Always base applications on soil test results. Source: Ballance Agri-Nutrients (ballance.co.nz); MfE (mfe.govt.nz).

New Zealand has a growing framework of environmental rules governing fertiliser use, primarily aimed at reducing nutrient losses to waterways. The National Policy Statement for Freshwater Management 2020 (NPS-FM) requires regional councils to set nitrogen and phosphorus limits in their regional plans, and many catchments now have nitrogen leaching caps. Farmers in regulated catchments must operate within a nutrient loss limit, often managed through a Farm Environment Plan (FEP) prepared with an accredited farm advisor. The Overseer nutrient budgeting model is widely used in NZ to estimate farm nutrient losses and assess compliance. Additional rules may apply under regional plan rules for application near waterways, set-back distances, and application timing. Urea and nitrogen fertilisers have the greatest potential for environmental impact. Farmers are encouraged to apply only what soil tests indicate is needed. Source: MfE (mfe.govt.nz); Ravensdown (ravensdown.co.nz).