Water from dams used to irrigate potato crops is not pure water. As well as common salt, irrigation water contains nutrients essential to plant growth such as calcium, magnesium, nitrogen, potassium, and sometimes phosphorus. If the concentration of these nutrients and the amount of water applied are high, significant quantities of a nutrient can be applied to the crop when irrigating. This fact sheet details information on nutrients that are applied to potato crops from irrigation water. It includes content on how much nutrient can be applied from irrigation water and determining the amount of water applied and water sampling.