Marion Clamer
No-Tiller, Alpha, Ill.

Symptoms and Solutions for Vertical Nutrient Stratification

Stratification in soils is an often-discussed topic by farmers and agronomists, each with varying perspectives. But Marion Calmer (1996 No-Till Innovator) has data from a 15-year study on surface-applied dry phosphorus and potassium showing that this practice leads to significant vertical stratification, and that annual plant growth removes nutrients from the lower profile of the root zone and deposits them on the surface. These problems create a vertical stratification of nutrients that is far more devastating to yields than any horizontal variability of ‘P&K’ that is identified by grid sampling, says the Alpha, Ill., no-tiller. Calmer will use the data he’s collected to provide solutions to this yield-robbing problem and explain why vertical placement of nutrients is more important than the rate.