Nutrient Management Research Database

This source comprehensively covers all aspects related to managing nutrients in a potato cropping system.

Nutrient Uptake Patterns

Nutrient rates often start off slow and increase through the season until plants are mature. However, these rate uptake patterns differ between nutrients. This section includes a table with total plant uptake of nutrients in lbs/ac along with a graph showing the rates of nitrogen, potassium, phosphorous, and sulfur uptake through the growing season.

Factors Affective Nutrient Requirements

Potato cultivars differ in the length of their growing season. Varieties that mature earlier require a larger percentage of nutrients --especially with nitrogen-- earlier in the season.

Soil and Environmental Factors

Hardpans, shallow soil, or dry conditions reduce the ability of roots to explore a large volume of soil.

Sandy soil does not hold on strongly to nutrients, which means that nutrients need to applied in smaller amounts over a higher number of application events.

Soil pH dictates the availability of many nutrients, especially phosphorus, zinc, manganese, iron, and copper. Neutral pH, around 6.5-7, will ensure the maximum availability of these nutrients.

Pests and weeds can prevent crops from properly accessing nutrient supplied by fertilizers.

Essential Nutrients

Plants require 17 essential nutrients. Carbon, hydrogen, and oxygen are obtained from the air and water. The remaining nutrients are mostly taken up through the soil. Nitrogen, phosphorus, and potassium are known as macronutrients since they are required in largest amounts by plants. The remaining nutrients (visit the source for the full list) are required in relatively lesser quantities.

Determining Nutrients Requirements

Soil testing and plant tissue analysis are two important tools in monitoring potato nutrient requirements and supplying the correct amounts of fertilizer. This source details how soil and samples should be collected and interpreted.

Fertilizer Application Methods

Five fertilizer application techniques are covered:

1. Preplant broadcasting followed by incorporation
2. Banding at markout or planting
3. Side-dressing after planting.
4. Foliar nutrient sprays
5. Fertigation through the irrigation system

Nutrient Management

This source includes section on nitrogen, potassium, and phosphorus nutrient management. Included are subsections discussing fertilizer rate recommendations, and in-season applications. Brief sections on macronutrients are also included.

This guide was developed for potatoes grown in Idaho, so the specific rates included may differe from those that work best in California.