1. Topsoil Thickness Influence on Phosphorus and Potassium Availability and Crop Response

Soil testing to estimate nutrient availability and fertilizer needs is a widespread management practice for cropping systems in the United States. as well as in other countries. The purpose of soil testing is to simulate the ability of the plant roots lo uptake these various nutrients critical for normal growth. Crops generally uptake a s~nall amount of phosphorus (P) compared to potassium (K). The portion of soil P that is readily available for plant growth maybe limiting due to the small quantities...