Adding more nutrient than needed is unwise. It will increase costs and will not increase yield or returns. It can even reduce yield. Any unused nutrients add to the risk of leaching with negative environmental effects. The key is to keep the right balance. So you need to know if there is enough in the soil already, or if adding more is justified. A nutrient budget helps determine this.

This lesson presents a method for creating a vegetable crop nutrient budget. It is based on gathering information from soil tests and from the industry good practice book, “Nutrient Management for Vegetable Crops in New Zealand” by Jeff Reid and Jeff Morton, published by Horticulture New Zealand. A free electronic copy can be downloaded from Process Vegetables NZ website.

Before completing this course, it is worth reviewing material from Course 1: Nutrient management for vegetable crops, including the introductory video by Alex Dickson.

The yield of a plant will be limited by a deficiency of any one essential element, even though all others are present in adequate amounts. But it may not always be an essential nutrient(s) that is limiting crop growth and yield. There are other factors such as pH, soil compaction and drainage that must be kept in mind.

We created two simple template sheets to help draw the information together, one for nitrogen and one for phosphorous. Download the interactive Nitrogen Budget and the printable Phosphorous Budget.

The budget template has two stages: determining nutrient status and determining fertiliser requirements before planting a crop; and checking how the balance went after harvesting the crop.

We made a video showing how to complete a budget. You can view it here now, or work through the next few lessons and watch it as a refresher.