Albert Lea Seed House Oat Production Guide | Page 8

Fertility and Fertilization

Soil Fertility
The nutrient requirements for oats are generally lower than many other crops. The oats plant is known to be a
scavenger of nutrients because of its deep and fibrous root system. However, a balanced fertility program is imperative for optimal yields and grain quality. Soil testing is recommended to help determine needs to produce the best
possible crop.
As shown in the table below, a 100 bushel per acre grain crop will take about 73lbs of nitrogen per acre. It is recommended for the soil nitrate test to have at least 120lbs/A in the top 2 feet of soil. Phosphorous (P2O5), potassium
(K2O), sulfur (S), and magnesium (Mg) are used in smaller amounts within oat production but are just as important.
The levels in the table are the bare minimum, to promote higher yields be sure to increase nutrient levels within the
soil in a balanced formulation.
Application of fertilizer can be done in the fall or spring. If applying fertilizer in the fall be sure to do so after soil temperature has decreased below 50oF or 100C as this will help limit nitrogen loss.

Crop
Alfalfa
Barley
Canola
Corn
Oats
Wheat

Yield (A)
8 ton
120 bu.
60 bu.
150 bu.
100 bu.
80-bu.

N
408
166
180
135
73
120

P2O5
96
67
90
57
27
48

Nutrient levels reflect minimum plant requirement for grain production

K2O
392
182
150
41
18
27

Mg
43
17
37
14
4
12

S
43
23
30
12
7
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Nitrogen
Nitrogen (N) is one of the five macronutrients that are imperative for a successful oat crop. Nitrogen is a crucial part
of all plants chlorophyll structure and a base element of plant DNA and RNA. The level of N in the soil is important as
problems can occur with both excess and deficient levels.
Deficiency- Plants that are deficient in N will exhibit a pale green/yellow color. They may also have a stunted appearance. The color is due to nitrogen’s role in chlorophyll development and stunting is caused by the reduction in light
uptake which is a vital part of photosynthesis. Deficiencies will typically be noticed first in the lower leaves of the
plant starting at the midrib extending to the leaf edge. N is mobile within the plant which means it will scavenge N
from older tissue to promote new tissue growth.
Excess – Extra N uptake by the plant will stimulate vegetative growth through elevated rates of photosynthesis. This
can lead to lodging, increased disease susceptibility, and delays in maturity.
Plant Requirements
When looking to produce an oat crop of 100 bushels per acre nitrogen requirements are at least 73lbs of N per acre.
This means that the oat crop will remove 73lbs of N from the soil during the production of this crop. A higher yield
will require addition N per acre. It is recommended to add enough N for available levels in the top 2 feet of the soil to
greater than 120 lbs.
Phosphorus
Phosphorus (P or applied as P2O5) is the macronutrient with the second highest rate of consumption in oat production. Phosphorus is important for plant metabolism; it is a part of ATP and ADP used in energy conversions. It is also
important in the structural pieces of cell membranes. Adequate levels are important; deficiencies will affect crop
production more than an excess of nutrients.

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Deficiency – Plants that are P deficient will show multiple symptoms. These include stunted growth, poor
root development, delays in maturity, dark green color, or purple discoloration. Symptoms can be more