CORN ROOT PENETRATION IN MUSCATINE, ELLIOTT, AND CISNE SOILS

Abstract

Corn root penetration and development on 3 different soils was found to depend largely on soil structure and fertility level. Soil tray samples 4- by 12- by 72 in. were removed from each plot under two adjacent hills of 3 stalks each and halfway between the 2 hills and the soil washed away. The roots were photographed, cut by soil horizons, and weighed. The Muscatine, a very productive, thick loess Brunizem soil with good structure had root penetration to a depth of 6 ft. (a few roots were observed at 7 ft.) and produced 81 bu. of corn and 2008 lb. of roots per acre on a treated plot under average weather conditions in 1950. On the other hand, the Elliott, a productive, thin loess Brunizem had a rather effective root barrier of calcareous silty clay loam glacial till of high volume wt. and poor structure beginning at depths of 24-28 in. The Elliott had very little root penetration below 35 in. and produced 75 bu. of corn and 2224 lb. of roots per acre on a treated plot under average weather condition in 1950. On Cisne, a claypan Planosol developed from thin loess on leached Illinoian till, where sufficient amounts of plant nutrient elements were added and legumes turned under, the corn roots were highly developed in the compact, slowly permeable claypan which had well-developed prismatic structure. The treated Cisne had root penetration to about 5 ft. and produced 75 bu. of corn and 2647 lb. of roots per acre under dry weather conditions in 1952. The untreated Cisne had weak root development to a depth of only 3 to 3 1/2 ft. It produced 20 bu. of corn and 743 lb. of roots per acre under dry weather conditions in 1952. The much greater use of moisture because of better root development on the treated plot as compared to the untreated plot on Cisne was one factor in increasing corn yields on this soil.