Fall-applied N is also susceptible to leaching. Consequently, no more than 50 percent of the required N should be applied in fall. In areas receiving less than 18 inches of precipitation, including traditionally summer-fallowed areas, all N may be applied in fall. Phosphorus can either be banded below the seed or applied before planting and incorporated. Banding below the seed appears to be the most efficient method.
Potassium can be surface broadcast, broadcast incorporated or banded below the seed.
Banding below the seed appears to be the most efficient method. Sulfur can either be incorporated or surface applied in fall. Sulfur may also be applied with N in spring. Contact the Extension agricultural agent in your county if you need more information. Robert L. Mahler is research soil scientist and Glen A. Murray is research agronomist and crop physiologist, both in the University of Idaho Department of Plant, Soil and Entomological Sciences, Moscow.