Soil physical conditions of winter and the growth of ryegrass plants: I. effects of compaction and puddling

Abstract

Abstract Six pot trials with seedling plants of perennial ryegrass (Latium perenne L.) have been carried out to investigate the effects, on growth, of compaction and saturation of the topsoil. In each trial identical soil was packed, in 1 em layers, into a number of 17 em-diameter pots, treatments comprising different degrees of compaction or puddling in the surface 5 em of the soil. Seedling plants at the two-leaf stage were planted in holes 1 em in diameter and 1.2 em deep, their root systems being previously cut down to one root 1.2 em long. The pot soils were kept at high and constant moisture contents by sub-irrigation from shallow water tables, rain being excluded, and the trials were run at winter temperatures. Growth was related to measurements of physical properties of the surface 5 em of the soil. These comprised dry density, moisture content, volume of air pores, the diffusivity of oxygen gas through an extracted core of soil, and the current flowing to a platinum micro-electrode at a depth of ...