Albert Lea Seed House Oat Production Guide - Page 9

general through the plant unlike N and K which are seen first in older vegetation. Excess – High levels of P are not directly harmful to plants. High levels of P can create a zinc deficiency. Plant Requirements Grain requirements of phosphorus are expressed in the form lbs. of P2O5 per acre. The minimum a 100bu crop will take from the soil is 27lbs/A. It is important to consult a soil test before adding P2O5 to the soil. If soil levels are above the 50 lbs/A it may not be necessary to add phosphorus fertilizer. “Phosphorus Fertilizer Application in Crop Production.” Alberta Agriculture and Forestry. Web. Potassium Potassium requirements for grain are low. A 100bu. crop will remove a minimum of 18lbs/A of K2O. However, the plant removes much more than that from the soil and sequesters much of it in the straw. If the straw is left on the field, much of that will be returned to soil. If the straw is removed from the field, the same crop will remove about 100lbs/A of K2O. Deficiency – Potassium deficiencies will be fairly evident in oat plants. They will be seen first in the older and lower leaves with symptoms of chlorosis on leaf tips or edges. Deficiencies may also cause reduced stress tolerance, reduced disease resistance or increased lodging. Excess – The main concerns that high potassium uptake would bring are magnesium and calcium deficiencies. Plant Requirements Potassium requirements for grain are low. A 100bu. crop will take out a minimum of 18lbs/A of K2O. Straw removal requires much larger amounts of K2O. If the straw is removed from the field the same crop will use about 100lbs/A of K2O. Potassium ammendments may not be needed if soil test levels are above the 250 lbs/A. “Potassium Fertilization in Crop Production.” Soils, Fertility and Nutrients. Government of Saskatchewan, Dec. 2012. Web. Sulfur (Sulphur) Sulfur (S) is the first of the secondary macronutrients that are needed in an elevated amount. S is primarily used in the essential amino acids of the plant. When producing oats in rotation with crops of high sulfur utilization, such as canola, take extra care to ensure proper levels. Deficiency – Symptoms wi \