|Nitrogen, 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
Phosphorus Use Efficiency for Cereal
Production is 16%
Agronomy Journal 109:1-8
World Potassium Use Efficiency for Cereal Crops
Agronomy Journal 111: 889-896.
World Sulfur Use Efficiency for Cereal Crops
Agronomy Journal: 111: 2485-2492
Cereal nitrogen use efficiency in Sub Saharan Africa. J. Plant Nutr. 32:2107-2122.
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
Nitrogen Cycle Page
Combined Feekes growth stages, and corresponding GDD's, Oklahoma
Large, E.C. 1954. Growth stages in cereals. Plant Pathol. 3:128-129.