Author: Terry J. Logan

Publisher:

Published: 1981

Total Pages: 36

ISBN-13:

This report examines and summarizes published and some unpublished data on the relative effects of conservation tillage (primarily no till) versus conventional tillage on surface runoff, soil loss and phosphorus loss. The data show that conservation tillage increased runoff relative to conventional tillage on soils with poor internal drainage and reduced runoff on more permeable soils. Conservation tillage greatly reduced soil loss and total particulate P (TPP) loss, but the percent reduction of TPP was only 89% of the percent reduction in soil loss. Conservation tillage increased soluble P (OP) losses in all cases. Conservation tillage was less effective in reducing plant-available (Bray P1) phosphate than in reducing TPP. P fertilization in excess of crop needs increased soluble P losses in runoff, and the effect of P fertilization on soluble P losses was greatest with no till because of P accumulation at the surface. (Author).