Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the EnvironmentNitrogen, Phosphorus, Potassium and Sulfur Use Efficiencies  (P and K Fertilizer Calculations)
World Nitrogen Use Efficiency for Cereal Production is 33%

Agronomy Journal 91: 357-363

NItrogen Cycle
World Phosphorus Use Efficiency for Cereal Production is 16%

Agronomy Journal 109:1-8

Phosphorus Cycle
Phosphorus Cycle
World Potassium Use Efficiency for Cereal Crops is 19%

Agronomy Journal 111: 889-896.

Potassium Cycle
Potassium Cycle
World Sulfur Use Efficiency for Cereal Crops is 18%

Agronomy Journal: 111: 2485-2492

Sulfur Cycle
Sulfur Cycle

Cereal nitrogen use efficiency in Sub Saharan Africa. J. Plant Nutr. 32:2107-2122.
P and K Fertilizers


Salt Rate  (N + K2O)

If you apply 50 lbs of N fertilizer as (NH4)2SO4 with the seed, what is the "Salt" rate?  50
If you apply 50 lbs of NH4NO3 with the seed (33%N), what is the "Salt" rate?    16.5

If you apply 20 lbs of P (18-46-0) with the seed, what is the "Salt" rate? 7.8  ((20/0.46)*0.18)
If you apply 10 lbs of K (0-0-60) with the seed, what is the "Salt" rate? 10 



Nitrogen Use Efficiency, Nitrogen Fertilizers,nitrogen algorithms, NUE, Nitrogen and the Environment

Nitrogen Cycle Page

Combined Feekes growth stages, and corresponding GDD's, Oklahoma

Combined Feekes and GDD scales, Oklahoma  Feekes Growth Stages, and GDD

Large, E.C. 1954. Growth stages in cereals. Plant Pathol. 3:128-129.