Crops - 8.3 Nutrient Use

Last updated on June 12, 2015

Incorrect application of nutrients can contaminate crops.

8.3  Nutrient Use


This good agricultural practice applies to all farms that apply nutrients to crops.

What Needs to Be Done

Apply all nutrients in a way that will not pose a hazard to food.

How to Do It

For all Nutrients

  • Generally speaking, the risk of applying commercial fertilizer (except nitrates) to crops is low. Use only fertilizers and soil additives that comply with the legal limits for heavy metals and bacteria.
  • Use an application method or growing practice that minimizes the chance of the nutrient source contaminating the crop by coming into direct contact with the edible part of the crop. An example of this safe practice would be growing crops on plastic.
  • Where possible, check purchased nutrients for documentation from the supplier that identifies the origin, treatment used, tests performed and the results thereof.
  • Schedule applications in relation to both weather forecasts (for example, rain) and current soil moisture levels to avoid run-off to other sensitive areas (for example, adjacent harvestable crops, water sources).
  • Determine soil fertility levels by regular soil sampling and analysis, and estimate crop needs. Follow recommended rates to avoid excess nutrient application.
  • Calibrate spreading equipment to ensure proper application rates.
  • For optimum application of nutrients refer to the British Columbia Environmental Farm Planning Nutrient Management Guide.

Applying Compost

  • Become informed about proper treatment procedures (for example, composting) that are designed to reduce or eliminate pathogens.
  • When purchasing compost, ask for a certificate of analysis or documentation of treatment method to ensure the composting process is complete.
  • When treating manure on-farm, record the treatment procedures (for example, composting, anaerobic digestion), detailing the date treated and the method used.
  • When treating manure on-farm, clean any equipment that is used to handle raw manure before handling finished compost so as not to re-introduce pathogens.

Applying Manure

  • Incorporate manure into the soil within 24 hours to minimize contamination to adjacent crops from wind drift or run-off. Follow guidelines in the B.C. Environmental Farm Plan Reference Guide.
  • Take precautions when using untreated or partially treated manure (for example, aged) on fruits and vegetables that can be consumed raw or with minimal processing. For example:
    • For crops that are not eaten raw or where the manure does not come into contact with the edible part: apply manure when the time between application and harvest is greater than three months.
    • For crops that can be eaten raw and where the manure can come into contact with the edible part: apply manure when the time between application and harvest is greater than four months.
    • In non-fruiting years for perennial crops: apply manure when the application is not in the year of harvest.

When Using Non-Agricultural Source Organic Material

  • Apply organic material at recommended application rates and according to provincial regulations.
  • Before organic material can be applied to agricultural land, various approvals for the handling, storage and land application of the material may also be required.

Terms Used in this Good Production Practice

Fertilizer: Any material containing nitrogen, phosphorus, potassium or other plant food, manufactured, sold or represented for use as a plant nutrient.

Nutrient: Any material applied to the land for the purpose of improving the growing of agricultural crops.

Non-Agricultural Source Organic Material: Any material set out in Schedule 12 of Organic Matter Recycling Regulation that is suitable for composting. It includes sewage biosolids, yard waste and food waste.

Records to Keep

Nutrient Application Record or your own record that includes:

  • The application date,
  • Type of nutrient,
  • Amount applied,
  • Weather conditions,
  • Time to incorporation,
  • Field identification, location and size, and
  • Initials of applicator.

Note: The record requirements above can also be listed in a completed and approved nutrient management plan.

Organic Material Treatment Record or your own record that includes

  • Date,
  • Temperature,
  • Turning frequency, and
  • Initials.

If You Need an Audit

Be prepared for an auditor to review:

  • Nutrient application records,
  • Organic material treatment records, where necessary,
  • A letter of analysis from the supplier, when a compost was purchased, and

  • A land application plan, when non-agricultural source organic material was used.

Laws & Regulations that Apply

Producers should use only fertilizers and supplements that have been registered, packaged and labelled to prescribed standards in the Fertilizers Act, R.S. 1985, c. F-10 and Fertilizers Regulations, C.R.C., c. 666.

Legislation to Be Aware of